Next Article in Journal
Pathophysiology of Disseminated Intravascular Coagulation in Sepsis: A Clinically Focused Overview
Next Article in Special Issue
Comparison of the Single Cell Immune Landscape between Subjects with High Mycobacterium tuberculosis Bacillary Loads during Active Pulmonary Tuberculosis and Household Members with Latent Tuberculosis Infection
Previous Article in Journal
The Radiobiological Characterization of Human and Porcine Lens Cells Suggests the Importance of the ATM Kinase in Radiation-Induced Cataractogenesis
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Cells
Volume 12
Issue 16
10.3390/cells12162119
cells-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

Antisense Therapy for Infectious Diseases

by
Lwanda Abonga Buthelezi
1,2,
Shandre Pillay
1,2,
Noxolo Nokukhanya Ntuli
1,2,
Lorna Gcanga
1,2 and
Reto Guler
1,2,3,*
1
International Centre for Genetic Engineering and Biotechnology, Cape Town Component, Cape Town 7925, South Africa
2
Department of Pathology, Division of Immunology, Institute of Infectious Diseases and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
3
Faculty of Health Sciences, Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa
*
Author to whom correspondence should be addressed.
Cells 2023, 12(16), 2119; https://doi.org/10.3390/cells12162119
Submission received: 29 June 2023 / Revised: 15 August 2023 / Accepted: 17 August 2023 / Published: 21 August 2023
(This article belongs to the Special Issue Tuberculosis: From Pathogenesis to Targeted Therapies)
Browse Figures
Review Reports Versions Notes

Abstract

:
Infectious diseases, particularly Tuberculosis (TB) caused by Mycobacterium tuberculosis, pose a significant global health challenge, with 1.6 million reported deaths in 2021, making it the most fatal disease caused by a single infectious agent. The rise of drug-resistant infectious diseases adds to the urgency of finding effective and safe intervention therapies. Antisense therapy uses antisense oligonucleotides (ASOs) that are short, chemically modified, single-stranded deoxyribonucleotide molecules complementary to their mRNA target. Due to their designed target specificity and inhibition of a disease-causing gene at the mRNA level, antisense therapy has gained interest as a potential therapeutic approach. This type of therapy is currently utilized in numerous diseases, such as cancer and genetic disorders. Currently, there are limited but steadily increasing studies available that report on the use of ASOs as treatment for infectious diseases. This review explores the sustainability of FDA-approved and preclinically tested ASOs as a treatment for infectious diseases and the adaptability of ASOs for chemical modifications resulting in reduced side effects with improved drug delivery; thus, highlighting the potential therapeutic uses of ASOs for treating infectious diseases.

1. Introduction

Antisense therapy involves administering antisense oligonucleotides (ASOs) to targets and inhibiting the translation of disease-associated messenger RNA (mRNA) [1]. ASOs are short, single-stranded, synthetic polymer nucleotides that regulate gene expression by gene silencing or modulating splicing [2]. While they hinder protein expression, they can also promote the expression of desired proteins through splice modulation of targeted pre-mRNA [3,4]. These genetically engineered oligonucleotides specifically bind to complementary target pre-mRNA or mRNA [5].
ASOs can be categorized into two broad modes of action based on their design: RNA cleavage and RNA blockage. ASO-mediated RNA cleavage involves molecular RNA degradation using ribonuclease RNAse-1-H [6] or gene silencing through RNA interference (RNAi) [7]. ASO-mediated RNA blockage relies on steric hindrance achieved by advanced binding affinity or splice modulation, resulting in exon exclusion [8] or inclusion [9], depending on the desired outcome [10,11]. Compared to conventional therapies, antisense therapies have shown promising success due to their engineered target specificity, leading to fewer side effects like cytotoxicity. Chemical modifications have led to improved generations of ASOs, enhancing resistance to degradation, binding affinity, delivery, cellular uptake, and intracellular trafficking [12,13,14,15]. The efficacy of ASOs was improved by introducing chemical modifications to the ribose sugar or phosphorothioate (PS) backbone of the molecule [16]. These chemical modifications further provide the ability to customize the ASOs for different clinical applications.
The major challenge with current antimicrobial therapies for infectious diseases is the emergence of multi-drug-resistant pathogens, as seen in tuberculosis, the leading cause of global death due to drug-resistant strains [17]. Therefore, the search for highly effective, safe, and precise therapies is crucial for global health development [18]. Antisense therapies have demonstrated their potential in inhibiting viral replication and silencing disease-associated genes [19,20], making them a viable option for emerging and re-emerging infectious diseases. ASOs can be employed as host-directed therapy adjuncts to existing treatments, targeting host factors contributing to pathogenesis [21,22]. This not only enhances the host’s immune response but also reduces drug resistance. ASO-based therapies hold promise for personalized therapy and may revolutionize disease treatment [23].

2. ASO Modifications and Delivery

Previously, chemically unmodified ASOs were ineffective as RNA therapeutics due to their larger size, charge, and the presence of the phosphodiester bond. These characteristics hindered the passive diffusion of ASOs into the target cell [24], rendering them susceptible to degradation by nucleases [25]. However, newer generations of ASOs have been developed to address these limitations, offering enhanced efficiency, accuracy, reduced toxicity, and enzymatic stability. The first significant chemical modification involved the introduction of phosphorothioate (PS) linkages, wherein a phosphate group replaced the non-bridging oxygen with a sulfur group [26]. PS-ASOs exhibit improved enzymatic stability, effectively resisting nuclease degradation [27] and enhancing efficiency through targeted mRNA degradation by RNase H [28]. Despite these improvements, the first-generation ASOs were associated with some adverse effects, such as low binding affinity and immune stimulation [29].
The second generation of ASOs includes 2′-modified phosphorothioates, such as 2′-O-methyl (2′-O-Me) and 2′-O-methoxyethyl (2′-O-MOE) oligonucleotides, which have alkyl modifications at the 2′-position of the ribose [30]. These ASOs are highly resistant to nuclease degradation and have higher target binding affinity [31,32]. For instance, IONIS-HBV, a 2′-O-Me ASO, is currently undergoing clinical trials for chronic hepatitis B (HBV) infection. Phase 2 findings revealed a dose-dependent reduction in HBV DNA and the HBV surface antigens [33].
The third generation comprises Phosphorodiamidate Morpholino Oligomers (PMOs) with morpholine rings as a backbone connected with Phosphorodiamidate linkages [34], Peptide Nucleic Acids (PNAs) replacing the ribose phosphate backbone with N-aminoethylglycine polyamide [35], and Locked Nucleic Acids (LNAs) containing a methylene bridge between 2′-O and 4′-C [36]. These recent chemical modifications have produced improved ASOs with overall higher enzymatic stability, increased binding affinity, reduced immune stimulation, and better pharmacokinetics [37]. Notably, one of the third-generation ASOs currently undergoing clinical trials is Miravirsen, a LNA-ASO targeting miR-122 in the context of hepatitis C (HCV) [38]. Efficient cellular uptake of ASOs can be achieved by conjugating them to charged molecules like N-acetylgalactosamine (GalNAc) [39,40] or using cell-penetrating peptides (CPP) designed for selective drug delivery [41]. Another approach involves using unmethylated cytosine-guanine dinucleotide (CpG) oligodeoxynucleotides (CpG-ODN), which trigger an innate immune response by binding to Toll-like receptor 9 (TLR9) [42].
Drug delivery to the target site poses a significant challenge in ASO therapies, primarily because ASOs must surmount biological barriers, escape lysosomal degradation, and avoid becoming trapped in secretory vesicles [16]. To address this issue, various strategies are currently being developed to enhance ASO stability and trafficking. As discussed, chemical modifications have proven effective in improving ASOs’ resistance to nucleases, binding affinity, cell penetration, and reducing off-target effects, thus enhancing the delivery of therapeutic oligonucleotides. One promising approach to advancing drug delivery involves conjugating ASOs with peptides, aptamers, antibodies, and N-acetylgalatosamine (GalNAc). Peptide conjugates, for instance, can traverse cell membranes and induce endosome disruption for efficient drug release [43]. Antibody conjugates, on the other hand, facilitate the internalization of ASO drugs, increasing their bioavailability in target organs [40]. Aptamers, by binding to cell surface proteins and mimicking antibody function [44], offer another avenue to improve ASO delivery. Moreover, GalNAc conjugation enhances ASO potency and provides a reliable entry route to hepatocytes [45]. In clinical trials targeting chronic HBV infection, Bepirovirsen was conjugated to GSK3389404, a GalNAc conjugate, with the aim of enhancing drug delivery to hepatocytes [46].
In addition to GalNAc conjugation, researchers are also exploring nano-drug vehicles, such as liposomes, for ASO delivery [47]. Liposomes consist of a lipid bilayer encapsulating an aqueous compartment and have shown great promise for drug delivery due to their ability to accumulate in diseased cell populations [48]. Liposomes have been extensively researched and tested in clinical trials due to their stability, selective delivery capacity, low toxicity, biocompatibility, and potential for conjugation with targeting moieties like peptides for cell-specific drug delivery [16,49]. These advancements in drug delivery technologies hold significant potential for improving the efficacy and safety of ASO therapies in various diseases.

3. Mode of Action

The use of ASOs as a treatment for diseases offers significant advantages in therapeutics. ASOs can be specifically modified and applied for different diseases or unique genetic disorders, such as Milasen, which is tailored to individual patients [50]. ASOs function through the Watson–Crick base pairing method, specifically binding to their cognate target pre-mRNA or mRNA [51]. ASOs are classified based on their mode of action and their dependence on the RNA-degrading enzyme RNase H. They are categorized as either RNA-cleaving/degrading ASOs or RNA-blocking/steric-hindrance ASOs, also known as RNase H-dependent and RNase H-independent ASOs, respectively [52].

3.1. RNA Degrading ASOs

The RNA-degrading ASOs rely on RNase H-mediated RNA degradation, involving the binding of the target mRNA’s RNA-DNA heteroduplex to the complementary ASO [53]. This recruits the RNase H1 enzyme, which degrades the RNA in the heteroduplex. Consequently, the translation of the target mRNA is inhibited, leading to the downregulation of the corresponding protein [54,55]. FDA-approved ASOs that utilize this method include fomivirsen, mipomersen, and inotersen [56].

3.2. RNA Blocking ASOs

RNA-blocking ASOs have been primarily used as a treatment for genetic disorders like Duchenne Muscular Dystrophy (DMD). In this approach, ASOs repair the reading frame, resulting in the production of a functional protein [57]. ASOs’ advanced binding affinity is crucial in this process, as they directly bind to the specific targeted pre-mRNA or mRNA. Recently, FDA-approved ASOs have been combined with alternative splicing mechanisms, such as exon skipping and exon inclusion, for disease treatment. Exon skipping involves the ASO binding to the targeted exon in the pre-mRNA, leading to its exclusion during translation and inducing the expression of a shorter yet functional protein. This method has been applied in eteplirsen [58], golodirsen [59], and casimersen for DMD treatment [60]. On the other hand, exon inclusion restores the full length of the mRNA, resulting in the upregulation of the desired functional protein [61]. Nusinersen employs this method for the treatment of SMA [56].

4. FDA-Approved ASOs

Vitravene, also known as fomivirsen, was the pioneering ASO-approved drug, authorized in 1998 for the treatment of human cytomegalovirus (HCMV) retinitis [62]. HCMV infection can lead to vision loss, particularly in immunocompromised AIDS patients [63]. Vitravene, a 21-mer phosphorothioate oligo-2′-deoxynucleotide, was designed to be complementary to its target HCMV mRNA, where it binds to the major immediate early region. By doing so, Vitravene reduces HCMV viral replication and decreases viral load [64,65]. Vitravene treatment showed no extreme adverse effects, although some patients reported intraocular inflammation and increased pressure. However, these symptoms were not directly linked to Vitravene but rather to HCMV infection [66,67].

5. Therapeutic Applications

Antimicrobial oligonucleotides target the pathogens’ essential genes responsible for replication, antibiotic resistance, and virulence. By targeting these genes, it is possible to augment the host’s immune response, resulting in reduced pathogen replication and proliferation.

5.1. Antibacterial Oligonucleotides

As of now, there are no FDA-approved antibacterial oligonucleotides available. However, preclinical studies have shown promising results in exploring ASOs as potential antibacterial agents [68]. Notably, back in 1981, it was demonstrated that oligonucleosides methylphosphonates could effectively inhibit the growth of Escherichia coli [69]. Additionally, lipid oligonucleotides have been utilized to efficiently deliver the oligonucleotide sequence, thereby decreasing the Minimum Inhibitory Concentration (MIC) and effectively combating antibiotic resistance [70].
Pathogens have acquired resistance to the currently available antibacterial therapies, rendering them ineffective. The possibility of using antisense therapy as an adjunct therapy has been demonstrated in culture, where methicillin-resistant Staphylococcus aureus was sensitized using PNAs and PS-ODNs. These strains were then found to be susceptible to oxacillin, decreasing bacterial growth [71]. Another challenge with bacterial infections is the formation of biofilms, which can enhance bacterial virulence due to the overexpression of non-essential genes coding for bacterial virulence, necessitating a larger dose of treatment. Targeting the genes involved in biofilm formation and inhibition was previously discussed as advances in bacterial antisense therapy [72] and has shown effectiveness against Haemophilus influenzae [73] and Pseudomonas aeruginosa [74]. Table 1 outlines chemically modified ASOs and their bacterial target genes as antisense therapy for bacterial infections.
The peptide-conjugated PNAs’ 1 and 2 (PPNA1 and PPNA2) ASOs are complementary to different sites of the target filamentous temperature-sensitive protein Z (ftsZ) gene, which is critical for the replication of methicillin-resistant Staphylococcus aureus (MRSA) [75]. Both PPNA1 ASO and PPNA2 ASO displayed bactericidal effects and inhibited the growth of MRSA in cell culture [75] (Figure 1A1). The peptide-conjugated LNA, PLNA787 ASO, targets the ftsZ mRNA of Staphylococcus aureus [76]. Treatment with PLNA787 ASO treatment inhibited the growth of methicillin-resistant Staphylococcus aureus in cell cultures. Moreover, its therapeutic impact extended to in vivo studies, as evidenced by an increased survival rate among mice infected with the Mu50 strain of S. aureus [76] (Figure 1A2). Furthermore, in a Staphylococcus aureus-infected cutaneous mouse wound, the use of PMO conjugates in conjunction with a novel thermoresponsive gel delivery system targeted the essential gyrA mRNA, resulting in decreased bacterial growth and enhanced cutaneous wound healing in the mice [77] (Figure 1A3). The rpoA-PNA ASO, a CPP-PNA, effectively targeted the RNA polymerase α subunit (rpoA) involved in transcription in Listeria monocytogenes [78]. By inhibiting bacterial DNA transcription, this rpoA-PNA ASO significantly reduced bacterial growth of L. monocytogenes in broth culture. In vivo treatment of L. monocytogenes-infected Caenorhabditis elegans worms with rpoA-PNA resulted in a remarkable 72% growth reduction [78]. (Figure 1B). Similarly, the polA-PNA ASO, a CPP-PNA, effectively targeted the DNA polymerase I (polA) gene responsible for DNA replication in Brucella suis [79]. Treatment with 12–30 μM of polA-PNA ASO inhibited the growth of Brucella suis in both broth culture and infected macrophages [79] (Figure 1C). Additionally, the acpP-PPMO ASO targeted the acyl carrier protein (acpP) gene involved in the fatty acid biosynthesis of Acinetobacter baumannii. Intranasal treatment with acpP-PPMO ASO demonstrated its bactericidal effect, significantly increasing the survival rate of A. baumannii-infected mice while reducing inflammation and bacterial burden in the lungs [80] (Figure 1D).

5.2. Antiviral Oligonucleotides

Antiviral oligonucleotides have been extensively studied in preclinical research as a therapeutic approach to target specific virus-specific mRNAs. Notably, previous studies have explored the potential applications of antiviral oligonucleotides in combating viral infections, including Dengue fever. For instance, the peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO) ASO effectively inhibited Dengue virus replication by blocking RNA translation and RNA synthesis [81]. Various ASOs have been employed to treat different viral infections, leading to a notable overall decrease in viral titers, as summarized in Table 2.
A 3′-SLT PPMO ASO was designed to target the 3′ stem-loop (3′SLT) in the Dengue viral genome imperative for the translation and synthesis of viral RNA [88,89]. The 3′SLT PPMO effectively reduced viral RNA levels by over 450-fold, thereby inhibiting viral translation and RNA synthesis in Baby Hamster Kidney fibroblasts (BHK) cells [81] (Figure 2A1). Another ASO, Vivo-MO-1, effectively targeted the 3′ stem-loop (3′ SLT) on the 3′ UTR of the Dengue viral genome, resulting in the inhibition of Dengue infection by decreasing viral RNA levels by over 1000-fold in dendritic cells treated with ASO Vivo-MO-1 [82] (Figure 2A2). In the context of Hepatitis B virus (HBV) infection, an LNA-single-stranded oligonucleotide (LNA-SSO) conjugated to N-acetylgalactosamine (GalNAc) ASO was utilized to target HBV transcripts in human hepatoma cell lines. The conjugation to GalNAc aids in the specific binding to asialoglycoprotein receptor (ASGPR), which is expressed on hepatocytes preventing the accumulation of ASO in the kidney. This led to a long-lasting reduced expression of viral antigens (HBsAg and HBeAg) and mRNA [86] (Figure 2B). Furthermore, promising results were achieved in treating Ebola infection in mice using a PMO ASO conjugated with an arginine-rich peptide (PPMO). This PPMO ASO effectively targeted the VP24 mRNA and inhibited viral replication [85]. Notably, treatment with 50 μg and 5 μg of VP24-AUG PPMO resulted in 100% and 90% protection against lethal Ebola infection in mice, respectively [85]. (Figure 2C). Another successful example involves the P7-PMO ASO, which targeted the 3′-terminal region of nucleoprotein viral genome RNA (NP-v3′), displaying enhanced antiviral activity with a >85% reduction in viral Influenza titers in infected Madin–Darby canine kidney (MDCK) cells [84] (Figure 2D). Another successful example involved the AUG-2 PPMO ASO, designed to target the translational start site of the RSV-L mRNA. This ASO showed significant efficacy with a >2.0 log10 decrease in RSV viral titers in infected mouse and human cell lines [83] (Figure 2E). Lastly, the 2′-deoxy-2′-fluoroarabinonucleotide (FANA) ASO effectively targeted the conserved regions of the HIV-1 genome, resulting in the inhibition of viral p24 replication in human PBMCs. They further investigated the duration of the ASOs’ anti-HIV effects and noted that treatment with FANA ASO had a prolonged viral p24 inhibition period of 13 days [87] (Figure 2F). Finally, the 2′-deoxy-2′-fluoroarabinonucleotide (FANA) ASO effectively targeted the conserved regions of the HIV-1 genome, resulting in the inhibition of viral p24 replication in human PBMCs. Investigations into the longevity of the ASO’s anti-HIV effects revealed an impressive duration, with treatment using FANA ASO resulting in the prolonged inhibition of viral p24 for a period of 13 days [87] (Figure 2F).

5.3. Antiparasitic Oligonucleotides

Parasitic infections represent one of the most neglected types of infectious diseases due to the lack of improved and updated therapies. Currently, there are no FDA-approved antisense therapies specifically targeting parasitic infections, nor are there any ASOs in clinical trials for such purposes. However, preclinical studies have shown promising results using oligonucleotides to target parasitic infections, as summarized in Table 3. An excellent example of the potential of antiparasitic applications in preclinical studies is demonstrated by PPMOs and VMOs that target essential genes of Plasmodium falciparum, leading to reduced RNA expression and inhibition of parasite growth [90]. Additionally, oligonucleotide therapy can be utilized to target genes responsible for drug resistance in the parasite. This approach was successful in treating chloroquine-resistant Plasmodium falciparum, where a MO conjugate was used, resulting in restored chloroquine susceptibility [90]. Table 3 outlines the various oligonucleotides and their target genes for different parasitic infections.
For instance, GRA10-PPMO ASO targets the GRA10 mRNA, resulting in the downregulation of the GRA10 granular protein and disrupting the intracellular replication of Toxoplasma gondii in human fibroblasts [91] (Figure 3A). Furthermore, PfCRT-VMO ASO (1) and PfDXR-PPMO ASO (2) are designed to target essential genes, PfCRT is responsible for chloroquine resistance, and PfDXR is involved in apicoplast formation, which is crucial for metabolic functions in Plasmodium falciparum [90]. Inhibiting the expression of the PfCRT gene resulted in restored drug susceptibility, and treatment with 1.25 µM and 1.75 µM of PfPMT-VMO and PfCRT-VMO, respectively, inhibited 53% of parasitic growth in the presence of chloroquine [90] (Figure 3B1,2). Another approach involves the PNA ASO, which targets PfSec13, a gene involved in Plasmodium falciparum proliferation. The downregulation of PfSec13 leads to decreased parasitic proliferation in human erythrocytes [93] (Figure 3B3). Similarly, the antisense 5995 ASO targets the inositol 1,4,5-trisphosphate receptor (TcIP3R) of Trypanosoma cruzi, a gene that plays a role in the parasite’s replication and virulence [92]. By treating trypomastigotes, the infective stage of T. cruzi, reduced TcIP3R expression hampers the parasite’s ability to invade cells and replicate [92] (Figure 3C).

6. Anti-Mycobacterial and Host Factor Targeted ASOs for Mycobacterium Species

Several ASOs have demonstrated successful inhibition of disease-causing genes during Mycobacterium infections through knockdown experiments. For instance, the knockdown of an immunoregulatory long intergenic noncoding RNA, lincRNA-MIR99AHG, using an LNA GapmeR-ASO, significantly reduced the intracellular growth of Mycobacterium tuberculosis in murine and human macrophages [94]. In mice, intranasal administration of LNA GapmeR-ASO led to a substantial reduction in bacterial burden within the lungs (Figure 4A) [94]. Moreover, a phosphorothioate-modified antisense oligodeoxyribonucleotide (PS-ODN) was found to inhibit the expression of inositol-1-phosphate synthase, a key enzyme encoded by the inositol-1 (INO1) gene, in inositol synthesis [95]. This suppression resulted in a notable decrease in mycothiol levels following exposure to 20 and 40 μM of the PS-ODN over a span of 6 weeks, consequently reducing the proliferation of M. tuberculosis. The ASO PS-ODN’s impact was remarkable, rendering the bacteria 7–9 times more susceptible to antibiotics at the 40 μM concentration (Figure 4B) [96]. Additionally, phosphoryl guanidine oligo-2′-O-methylribonucleotides (2′-OMe PGOs) have demonstrated successful penetration of Mycobacterium smegmatis and inhibited the expression of alanine dehydrogenase, encoded by the mycobacterial ald gene. Consequently, treatment with 20 μM of these PGOs resulted in a substantial reduction in M. smegmatis growth by 54% and 62% at 24 and 40 h, respectively, in murine macrophages (Figure 4C) [97]. These findings showcase the versatility of ASOs as potent therapeutic agents, offering multiple mycobacterial and host-directed targeting for combatting TB.

7. ASOs Targeting Host Factors for Viral Infections

Investigating potential ASO therapy targets for infectious diseases has led to a focus on host factors that viral pathogens manipulate for their survival. The ability of ASOs to disrupt viral pathogenesis by silencing essential host factors has shown great potential in inhibiting viral replication and propagation, providing new possibilities for the treatment of infectious diseases.
ASOs can silence viral targets using steric hindrance, thereby disrupting viral pathogenesis and rendering the virus susceptible to the host’s immune response. Figure 5 illustrates ASOs labelled A–F, which target different host factors responsible for viral replication and propagation. In the case of SARS-CoV-2 infection, the viral spike protein attaches to the angiotensin-converting enzyme 2 (ACE2) receptor on the host cell, enabling cellular entry [98]. The ACE2 ASO targets the ACE2 gene, resulting in reduced expression and preventing SARS-CoV-2 cellular entry and release of the viral genome [99] (Figure 5A). MicroRNA-122 (miR-122) plays a role in the replication of the Hepatitis C virus (HCV) in infected human Huh7 cells. The 2′-O-methylated RNA oligonucleotide (122-2′OMe) targets miR-122, preventing the stabilization of the viral genome and hindering viral replication [100] (Figure 5B). For Ebola virus, binding to Niemann–Pick C1 (NPC1) mRNA prompts the release of the ribonucleoprotein (RNP) complex responsible for viral transcription and replication [101]. An LNA ASO that directly binds to the NPC1 mRNA inhibits membrane fusion, prevents RNP release, and reduces viral replication in Ebola-infected murine and human cell lines [102] (Figure 5C). In the case of H1N1 influenza, binding to the programmed cell death protein 5 (PDCD5) induces apoptosis and viral replication [103]. PROP5 ASO binds to the PDCD5 mRNA and impedes viral propagation of H1N1 influenza [103] (Figure 5D). Hepatitis B virus (HBV) replication has been associated with the virus binding to asialoglycoprotein receptor 1 (ASGPR1). ASODN2 ASO binds to ASGPR1 mRNA, resulting in the inhibition of HBV replication [104] (Figure 5E). The host factor Mammalian relative of DnaJ (MRJ/DNAJB6) is involved in both HIV-1 and respiratory syncytial virus (RSV) infection. For HIV-1, MRJ promotes viral entry into the host nucleus [100], and for RSV, it is involved in the production of viral subgenomic RNA [105]. The binding of MoMRJ ASO to the MRJ-L isoform suppresses HIV-1′s nuclear entry and viral genome integration and inhibits RSV’s viral RNA and mRNA expression [105,106] (Figure 5F).

8. Advantages and Disadvantages

8.1. Advantages

Antisense therapy has revolutionized the outlook for future treatments in patients with various diseases, offering the potential for personalized and accessible treatment options [103]. One major advantage of this therapy lies in its simplicity and accuracy, as it is complementary-based and requires the target mRNA sequence. This allows for the synthesis of specific ASOs targeting known sequences of viral or bacterial mRNAs involved in pathogenesis [107]. This approach has been particularly valuable in cases where protein-based therapies were ineffective due to the inaccessibility of the disease target. Chemical modifications to oligonucleotide structures have significantly improved therapy efficacy and safety by enhancing binding affinity and reducing toxicities. Moreover, the production time and cost-effectiveness of ASO therapy are advantageous, especially for large-scale production, while its increased efficacy reduces the need for frequent drug administration.

8.2. Disadvantages and Improvements

Despite its promising potential, the clinical use of oligonucleotides has faced challenges. The delivery of first-generation oligonucleotides to specific organs and tissues has been problematic due to their weight, negative charge, and instability, resulting in poor absorption and susceptibility to nuclease degradation [108]. However, second- and third-generation ASOs with chemical modifications, including cell-penetrating peptides, have addressed these issues and facilitated delivery to target organs. Concerns about off-target toxicity observed in first-generation oligonucleotides [109] have been minimized in later generations due to improved chemical modifications, leading to reduced toxicity. Moreover, specific oligonucleotide therapies, like small interfering RNA, have been linked to heightened immune responses, leading to inflammatory syndromes. This phenomenon was primarily observed in therapies using small interfering RNA that acted as TLR agonists, resulting in clinical adverse effects [110].

9. Conclusions and Future Perspectives

Antisense therapy has undergone significant evolution over the years, with numerous advancements aimed at enhancing its efficacy and applications in the field of health sciences. The ability to modify protein expression, either by reducing or restoring it without toxicity, has presented remarkable therapeutic possibilities for numerous diseases and genetic disorders. Improved chemical modifications of ASOs have effectively addressed many concerns associated with earlier first-generation oligonucleotide therapies. From the introduction of the phosphorothioate linkage, which improved enzymatic stability, to the conjugation of cell-penetrating peptides for enhanced cellular uptake, ASOs have become more versatile and potent in their therapeutic potential.
The applications of ASOs in infectious diseases have been extensively explored and discussed in this review. Most of the antimicrobials discussed have been rigorously tested in cell cultures, mouse models, and human cell lines. Notably, one significant finding in ASO applications is their potential as host-directed therapy. By targeting multiple host factors involved in viral entry and replication, complementary ASOs can effectively inhibit viral replication and growth.
ASOs offer promising prospects for actively combating emerging, re-emerging, and multi-drug-resistant infectious diseases. However, there is still ample room for improvement in most antisense therapeutics. Optimizing ASO delivery to specific target organs can prevent undesirable accumulation in the kidney and liver, thus enhancing overall efficacy. Novel delivery modalities for oligonucleotide therapies can further improve their effectiveness while reducing the required drug dosage. Leveraging approved delivery strategies used in other diseases should be thoroughly explored as they may prove advantageous.
In conclusion, ASO therapies hold tremendous potential for treating various diseases, including those caused by bacteria, viruses, and parasites. To fully harness this potential, addressing drug delivery challenges remains a key focus. Through ongoing research, preclinical studies, and clinical trials, the optimization of ASO design, delivery, and personalized medicine can revolutionize the treatment landscape, benefiting patients worldwide and offering new hope in the fight against infectious diseases.

Author Contributions

Conceptualization, L.A.B. and R.G.; writing, original draft preparation, L.A.B.; writing, review and editing, R.G., L.A.B., S.P., N.N.N. and L.G.; Figures-created using bioRender, S.P., L.A.B., R.G. and N.N.N. All authors have read and agreed to the published version of the manuscript.

Funding

This research was supported by The National Health Laboratory Service (NHLS) Research Trust and the NHLS (GRANT004–94836) awarded to R.G. Research reported in this publication was supported by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health under Award No. R01AI160501 awarded to R.G. L.A.B is supported by the National Research Foundation (Innovation Masters Partial Cost Award). S.P is supported by the National Research Foundation (Postdoctoral Innovation Fellowship). N.N.N is supported by a PhD fellowship from the National Institute of Health Award No. R01AI160501 awarded to R.G. This research was funded in whole, or in part, by the Wellcome Trust [Grant number 203135/Z/16/Z]. For the purpose of open access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Acknowledgments

We thank Camilla Davids, who was supported by the Erasmus+ International Credit Mobility (ICM) program (STT-3927), for the critical reading of the manuscript.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Dhuri, K.; Bechtold, C.; Quijano, E.; Pham, H.; Gupta, A.; Vikram, A.; Bahal, R. Antisense Oligonucleotides: An Emerging Area in Drug Discovery and Development. J. Clin. Med. 2020, 9, 2004. [Google Scholar] [CrossRef] [PubMed]
  2. Roberts, T.C.; Langer, R.; Wood, M.J.A. Advances in oligonucleotide drug delivery. Nat. Rev. Drug Discov. 2020, 19, 673–694. [Google Scholar] [CrossRef] [PubMed]
  3. Singh, N.N.; Luo, D.; Singh, R.N. Pre-mRNA Splicing Modulation by Antisense Oligonucleotides. Methods Mol. Biol. 2018, 1828, 415–437. [Google Scholar]
  4. Liang, X.H.; Sun, H.; Shen, W.; Wang, S.; Yao, J.; Migawa, M.T.; Bui, H.-H.; Damle, S.S.; Riney, S.; Graham, M.J.; et al. Antisense oligonucleotides targeting translation inhibitory elements in 5’ UTRs can selectively increase protein levels. Nucleic Acids Res. 2017, 45, 9528–9546. [Google Scholar] [CrossRef] [PubMed]
  5. Arechavala-Gomeza, V.; Garanto, A. Antisense RNA Therapeutics: A Brief Overview. Methods Mol. Biol. 2022, 2434, 33–49. [Google Scholar] [PubMed]
  6. Vickers, T.A.; Crooke, S.T. The rates of the major steps in the molecular mechanism of RNase H1-dependent antisense oligonucleotide induced degradation of RNA. Nucleic Acids Res. 2015, 43, 8955–8963. [Google Scholar] [CrossRef] [PubMed]
  7. Chery, J. RNA therapeutics: RNAi and antisense mechanisms and clinical applications. Postdoc. J. 2016, 4, 35–50. [Google Scholar] [CrossRef]
  8. McNally, E.M.; Wyatt, E.J. Welcome to the splice age: Antisense oligonucleotide-mediated exon skipping gains wider applicability. J. Clin. Investig. 2016, 126, 1236–1238. [Google Scholar] [CrossRef]
  9. Hua, Y.; Krainer, A.R. Antisense-mediated exon inclusion. Methods Mol. Biol. 2012, 867, 307–323. [Google Scholar]
  10. Chan, J.H.; Lim, S.; Wong, W.S. Antisense oligonucleotides: From design to therapeutic application. Clin. Exp. Pharmacol. Physiol. 2006, 33, 533–540. [Google Scholar] [CrossRef]
  11. Watts, J.K.; Corey, D.R. Silencing disease genes in the laboratory and the clinic. J. Pathol. 2012, 226, 365–379. [Google Scholar] [CrossRef] [PubMed]
  12. McClorey, G.; Wood, M.J. An overview of the clinical application of antisense oligonucleotides for RNA-targeting therapies. Curr. Opin. Pharmacol. 2015, 24, 52–58. [Google Scholar] [CrossRef] [PubMed]
  13. Tarn, W.Y.; Cheng, Y.; Ko, S.H.; Huang, L.M. Antisense Oligonucleotide-Based Therapy of Viral Infections. Pharmaceutics 2021, 13, 2015. [Google Scholar] [CrossRef] [PubMed]
  14. Crooke, S.T.; Baker, B.F.; Crooke, R.M.; Liang, X.H. Antisense technology: An overview and prospectus. Nat. Rev. Drug Discov. 2021, 20, 427–453. [Google Scholar] [CrossRef] [PubMed]
  15. Crooke, S.T.; Vickers, T.A.; Liang, X.H. Phosphorothioate modified oligonucleotide-protein interactions. Nucleic Acids Res. 2020, 48, 5235–5253. [Google Scholar] [CrossRef] [PubMed]
  16. Gagliardi, M.; Ashizawa, A.T. The Challenges and Strategies of Antisense Oligonucleotide Drug Delivery. Biomedicines 2021, 9, 433. [Google Scholar] [CrossRef] [PubMed]
  17. World Health Organization. Global Tuberculosis Report 2022; World Health Organization: Geneva, Switzerland, 2022. [Google Scholar]
  18. Streicher, L.M. Exploring the future of infectious disease treatment in a post-antibiotic era: A comparative review of alternative therapeutics. J. Glob. Antimicrob. Resist. 2021, 24, 285–295. [Google Scholar] [CrossRef]
  19. Stephenson, M.L.; Zamecnik, P.C. Inhibition of Rous sarcoma viral RNA translation by a specific oligodeoxyribonucleotide. Proc. Natl. Acad. Sci. USA 1978, 75, 285–288. [Google Scholar] [CrossRef]
  20. Spurgers, K.B.; Sharkey, C.M.; Warfield, K.L.; Bavari, S. Oligonucleotide antiviral therapeutics: Antisense and RNA interference for highly pathogenic RNA viruses. Antivir. Res. 2008, 78, 26–36. [Google Scholar] [CrossRef]
  21. Guler, R.; Brombacher, F. Host-directed drug therapy for tuberculosis. Nat. Chem. Biol. 2015, 11, 748–751. [Google Scholar] [CrossRef]
  22. Guler, R.; Ozturk, M.; Sabeel, S.; Motaung, B.; Parihar, S.P.; Thienemann, F.; Brombacher, F. Targeting Molecular Inflammatory Pathways in Granuloma as Host-Directed Therapies for Tuberculosis. Front. Immunol. 2021, 12, 733853. [Google Scholar] [CrossRef] [PubMed]
  23. Damase, T.R.; Sukhovershin, R.; Boada, C.; Taraballi, F.; Pettigrew, R.I.; Cooke, J.P. The Limitless Future of RNA Therapeutics. Front. Bioeng. Biotechnol. 2021, 9, 628137. [Google Scholar] [CrossRef] [PubMed]
  24. Dowdy, S.F. Overcoming cellular barriers for RNA therapeutics. Nat. Biotechnol. 2017, 35, 222–229. [Google Scholar] [CrossRef] [PubMed]
  25. Bennett, C.F.; Baker, B.F.; Pham, N.; Swayze, E.; Geary, R.S. Pharmacology of Antisense Drugs. Annu. Rev. Pharmacol. Toxicol. 2017, 57, 81–105. [Google Scholar] [CrossRef] [PubMed]
  26. Eckstein, F. Phosphorothioates, essential components of therapeutic oligonucleotides. Nucleic Acid Ther. 2014, 24, 374–387. [Google Scholar] [CrossRef] [PubMed]
  27. Furdon, P.J.; Dominski, Z.; Kole, R. RNase H cleavage of RNA hybridized to oligonucleotides containing methylphosphonate, phosphorothioate and phosphodiester bonds. Nucleic Acids Res. 1989, 17, 9193–9204. [Google Scholar] [CrossRef] [PubMed]
  28. Shen, W.; De Hoyos, C.L.; Migawa, M.T.; Vickers, T.A.; Sun, H.; Low, A.; Bell, T.A.; Rahdar, M.; Mukhopadhyay, S.; Hart, C.E.; et al. Chemical modification of PS-ASO therapeutics reduces cellular protein-binding and improves the therapeutic index. Nat. Biotechnol. 2019, 37, 640–650. [Google Scholar] [CrossRef] [PubMed]
  29. Miroshnichenko, S.K.; Patutina, O.A.; Burakova, E.A.; Chelobanov, B.P.; Fokina, A.A.; Vlassov, V.V.; Altman, S.; Zenkova, M.A.; Stetsenko, D.A. Mesyl phosphoramidate antisense oligonucleotides as an alternative to phosphorothioates with improved biochemical and biological properties. Proc. Natl. Acad. Sci. USA 2019, 116, 1229–1234. [Google Scholar] [CrossRef]
  30. Scoles, D.R.; Minikel, E.V.; Pulst, S.M. Antisense oligonucleotides: A primer. Neurol Genet. 2019, 5, e323. [Google Scholar] [CrossRef]
  31. Sproat, B.S.; Lamond, A.I.; Beijer, B.; Neuner, P.; Ryder, U. Highly efficient chemical synthesis of 2’-O-methyloligoribonucleotides and tetrabiotinylated derivatives; novel probes that are resistant to degradation by RNA or DNA specific nucleases. Nucleic Acids Res. 1989, 17, 3373–3386. [Google Scholar] [CrossRef]
  32. Agrawal, S.; Jiang, Z.; Zhao, Q.; Shaw, D.; Cai, Q.; Roskey, A.; Channavajjala, L.; Saxinger, C.; Zhang, R. Mixed-backbone oligonucleotides as second generation antisense oligonucleotides: In vitro and in vivo studies. Proc. Natl. Acad. Sci. USA 1997, 94, 2620–2625. [Google Scholar] [CrossRef] [PubMed]
  33. Yuen, M.F.; Heo, J.; Jang, J.W.; Yoon, J.H.; Kweon, Y.O.; Park, S.J.; Bennett, C.F.; Kwoh, T.J. Phase 2a, Randomized, double-blind, placebo controlled study of an antisense inhibitor (ISIS 505358) in treatment-naive Chronic Hepatitis B (CHB) patients: Safety and Antiviral efficacy. Hepatology 2019, 70, 437a–438a. [Google Scholar]
  34. Nan, Y.; Zhang, Y.J. Antisense Phosphorodiamidate Morpholino Oligomers as Novel Antiviral Compounds. Front. Microbiol. 2018, 9, 750. [Google Scholar] [CrossRef] [PubMed]
  35. Oh, S.Y.; Ju, Y.; Park, H. A highly effective and long-lasting inhibition of miRNAs with PNA-based antisense oligonucleotides. Mol. Cells 2009, 28, 341–345. [Google Scholar] [CrossRef] [PubMed]
  36. Hagedorn, P.H.; Persson, R.; Funder, E.D.; Albaek, N.; Diemer, S.L.; Hansen, D.J.; Møller, M.R.; Papargyri, N.; Christiansen, H.; Hansen, B.R.; et al. Locked nucleic acid: Modality, diversity, and drug discovery. Drug Discov. Today 2018, 23, 101–114. [Google Scholar] [CrossRef] [PubMed]
  37. Lundin, K.E.; Gissberg, O.; Smith, C.I.E.; Zain, R. Chemical Development of Therapeutic Oligonucleotides. Methods Mol. Biol. 2019, 2036, 3–16. [Google Scholar] [PubMed]
  38. Ottosen, S.; Parsley, T.B.; Yang, L.; Zeh, K.; van Doorn, L.J.; van der Veer, E.; Raney, A.K.; Hodges, M.R.; Patick, A.K. In vitro antiviral activity and preclinical and clinical resistance profile of miravirsen, a novel anti-hepatitis C virus therapeutic targeting the human factor miR-122. Antimicrob. Agents Chemother. 2015, 59, 599–608. [Google Scholar] [CrossRef] [PubMed]
  39. Springer, A.D.; Dowdy, S.F. GalNAc-siRNA Conjugates: Leading the Way for Delivery of RNAi Therapeutics. Nucleic Acid Ther. 2018, 28, 109–118. [Google Scholar] [CrossRef]
  40. Hammond, S.M.; Aartsma-Rus, A.; Alves, S.; Borgos, S.E.; Buijsen, R.A.M.; Collin, R.W.J.; Covello, G.; Denti, M.A.; Desviat, L.R.; Echevarría, L.; et al. Delivery of oligonucleotide-based therapeutics: Challenges and opportunities. EMBO Mol. Med. 2021, 13, e13243. [Google Scholar] [CrossRef]
  41. Xie, J.; Bi, Y.; Zhang, H.; Dong, S.; Teng, L.; Lee, R.J.; Yang, Z. Cell-Penetrating Peptides in Diagnosis and Treatment of Human Diseases: From Preclinical Research to Clinical Application. Front. Pharmacol. 2020, 11, 697. [Google Scholar] [CrossRef]
  42. Kayraklioglu, N.; Horuluoglu, B.; Klinman, D.M. CpG Oligonucleotides as Vaccine Adjuvants. Methods Mol. Biol. 2021, 2197, 51–85. [Google Scholar]
  43. Copolovici, D.M.; Langel, K.; Eriste, E.; Langel, U. Cell-penetrating peptides: Design, synthesis, and applications. ACS Nano 2014, 8, 1972–1994. [Google Scholar] [CrossRef]
  44. Ni, S.; Zhuo, Z.; Pan, Y.; Yu, Y.; Li, F.; Liu, J.; Wang, L.; Wu, X.; Li, D.; Wan, Y.; et al. Recent Progress in Aptamer Discoveries and Modifications for Therapeutic Applications. ACS Appl. Mater. Interfaces 2021, 13, 9500–9519. [Google Scholar] [CrossRef] [PubMed]
  45. Prakash, T.P.; Graham, M.J.; Yu, J.; Carty, R.; Low, A.; Chappell, A.; Schmidt, K.; Zhao, C.; Aghajan, M.; Murray, H.F.; et al. Targeted delivery of antisense oligonucleotides to hepatocytes using triantennary N-acetyl galactosamine improves potency 10-fold in mice. Nucleic Acids Res. 2014, 42, 8796–8807. [Google Scholar] [CrossRef]
  46. Yuen, M.F.; Heo, J.; Kumada, H.; Suzuki, F.; Suzuki, Y.; Xie, Q.; Jia, J.; Karino, Y.; Hou, J.; Chayama, K.; et al. Phase IIa, randomised, double-blind study of GSK3389404 in patients with chronic hepatitis B on stable nucleos(t)ide therapy. J. Hepatol. 2022, 77, 967–977. [Google Scholar] [CrossRef] [PubMed]
  47. Daraee, H.; Etemadi, A.; Kouhi, M.; Alimirzalu, S.; Akbarzadeh, A. Application of liposomes in medicine and drug delivery. Artif. Cells Nanomed. Biotechnol. 2016, 44, 381–391. [Google Scholar] [CrossRef]
  48. New, R.R.; Chance, M.L.; Thomas, S.C.; Peters, W. Antileishmanial activity of antimonials entrapped in liposomes. Nature 1978, 272, 55–56. [Google Scholar] [CrossRef] [PubMed]
  49. Tagami, T.; Ozeki, T. Recent Trends in Clinical Trials Related to Carrier-Based Drugs. J. Pharm. Sci. 2017, 106, 2219–2226. [Google Scholar] [CrossRef]
  50. Kim, J.; Hu, C.; Moufawad El Achkar, C.; Black, L.E.; Douville, J.; Larson, A.; Pendergast, M.K.; Goldkind, S.F.; Lee, E.A.; Kuniholm, A.; et al. Patient-Customized Oligonucleotide Therapy for a Rare Genetic Disease. N. Engl. J. Med. 2019, 381, 1644–1652. [Google Scholar] [CrossRef]
  51. Gheibi-Hayat, S.M.; Jamialahmadi, K. Antisense Oligonucleotide (AS-ODN) Technology: Principle, Mechanism and Challenges. Biotechnol. Appl. Biochem. 2021, 68, 1086–1094. [Google Scholar] [CrossRef]
  52. Vickers, T.A.; Crooke, S.T. Antisense oligonucleotides capable of promoting specific target mRNA reduction via competing RNase H1-dependent and independent mechanisms. PLoS ONE 2014, 9, e108625. [Google Scholar] [CrossRef] [PubMed]
  53. Nishina, K.; Piao, W.; Yoshida-Tanaka, K.; Sujino, Y.; Nishina, T.; Yamamoto, T.; Nitta, K.; Yoshioka, K.; Kuwahara, H.; Yasuhara, H.; et al. DNA/RNA heteroduplex oligonucleotide for highly efficient gene silencing. Nat. Commun. 2015, 6, 7969. [Google Scholar] [CrossRef] [PubMed]
  54. Wu, H.; Lima, W.F.; Zhang, H.; Fan, A.; Sun, H.; Crooke, S.T. Determination of the role of the human RNase H1 in the pharmacology of DNA-like antisense drugs. J. Biol. Chem. 2004, 279, 17181–17189. [Google Scholar] [CrossRef] [PubMed]
  55. Cerritelli, S.M.; Crouch, R.J. Ribonuclease H: The enzymes in eukaryotes. FEBS J. 2009, 276, 1494–1505. [Google Scholar] [CrossRef] [PubMed]
  56. Kim, Y. Drug Discovery Perspectives of Antisense Oligonucleotides. Biomol. Ther. 2023, 31, 241–252. [Google Scholar] [CrossRef] [PubMed]
  57. Echevarria, L.; Aupy, P.; Goyenvalle, A. Exon-skipping advances for Duchenne muscular dystrophy. Hum. Mol. Genet. 2018, 27, R163–R172. [Google Scholar] [CrossRef] [PubMed]
  58. McDonald, C.M.; Shieh, P.B.; Abdel-Hamid, H.Z.; Connolly, A.M.; Ciafaloni, E.; Wagner, K.R.; Goemans, N.; Mercuri, E.; Khan, N.; Koenig, E.; et al. Open-Label Evaluation of Eteplirsen in Patients with Duchenne Muscular Dystrophy Amenable to Exon 51 Skipping: PROMOVI Trial. J. Neuromuscul. Dis. 2021, 8, 989–1001. [Google Scholar] [CrossRef] [PubMed]
  59. Servais, L.; Mercuri, E.; Straub, V.; Guglieri, M.; Seferian, A.M.; Scoto, M.; Leone, D.; Koenig, E.; Khan, N.; Dugar, A.; et al. Long-Term Safety and Efficacy Data of Golodirsen in Ambulatory Patients with Duchenne Muscular Dystrophy Amenable to Exon 53 Skipping: A First-in-human, Multicenter, Two-Part, Open-Label, Phase 1/2 Trial. Nucleic Acid Ther. 2022, 32, 29–39. [Google Scholar] [CrossRef]
  60. Wagner, K.R.; Kuntz, N.L.; Koenig, E.; East, L.; Upadhyay, S.; Han, B.; Shieh, P.B. Safety, tolerability, and pharmacokinetics of casimersen in patients with Duchenne muscular dystrophy amenable to exon 45 skipping: A randomized, double-blind, placebo-controlled, dose-titration trial. Muscle Nerve 2021, 64, 285–292. [Google Scholar] [CrossRef]
  61. Hua, Y.; Vickers, T.A.; Baker, B.F.; Bennett, C.F.; Krainer, A.R. Enhancement of SMN2 exon 7 inclusion by antisense oligonucleotides targeting the exon. PLoS Biol. 2007, 5, e73. [Google Scholar] [CrossRef]
  62. Roehr, B. Fomivirsen approved for CMV retinitis. J. Int. Assoc. Physicians AIDS Care 1998, 4, 14–16. [Google Scholar] [PubMed]
  63. Schottstedt, V.; Blumel, J.; Burger, R.; Drosten, C.; Groner, A.; Gurtler, L.; Heiden, M.; Hildebrandt, M.; Jansen, B.; Montag-Lessing, T.; et al. Human Cytomegalovirus (HCMV)—Revised. Transfus. Med. Hemother. 2010, 37, 365–375. [Google Scholar] [PubMed]
  64. De Smet, M.D.; Meenken, C.J.; van den Horn, G.J. Fomivirsen—A phosphorothioate oligonucleotide for the treatment of CMV retinitis. Ocul. Immunol. Inflamm. 1999, 7, 189–198. [Google Scholar] [CrossRef] [PubMed]
  65. Geary, R.S.; Henry, S.P.; Grillone, L.R. Fomivirsen: Clinical pharmacology and potential drug interactions. Clin. Pharmacokinet. 2002, 41, 255–260. [Google Scholar] [CrossRef]
  66. Perry, C.M.; Balfour, J.A. Fomivirsen. Drugs 1999, 57, 375–380; discussion 381. [Google Scholar] [CrossRef] [PubMed]
  67. Vitravene Study Group. A randomized controlled clinical trial of intravitreous fomivirsen for treatment of newly diagnosed peripheral cytomegalovirus retinitis in patients with AIDS. Am. J. Ophthalmol. 2002, 133, 467–474. [Google Scholar]
  68. Tan, X.X.; Actor, J.K.; Chen, Y. Peptide nucleic acid antisense oligomer as a therapeutic strategy against bacterial infection: Proof of principle using mouse intraperitoneal infection. Antimicrob. Agents Chemother. 2005, 49, 3203–3207. [Google Scholar] [CrossRef]
  69. Jayaraman, K.; McParland, K.; Miller, P.; Ts’o, P.O. Selective inhibition of Escherichia coli protein synthesis and growth by nonionic oligonucleotides complementary to the 3’ end of 16S rRNA. Proc. Natl. Acad. Sci. USA 1981, 78, 1537–1541. [Google Scholar] [CrossRef]
  70. Kauss, T.; Arpin, C.; Bientz, L.; Vinh Nguyen, P.; Vialet, B.; Benizri, S.; Barthélémy, P. Lipid oligonucleotides as a new strategy for tackling the antibiotic resistance. Sci. Rep. 2020, 10, 1054. [Google Scholar] [CrossRef]
  71. Goh, S.; Loeffler, A.; Lloyd, D.H.; Nair, S.P.; Good, L. Oxacillin sensitization of methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus pseudintermedius by antisense peptide nucleic acids in vitro. BMC Microbiol. 2015, 15, 262. [Google Scholar] [CrossRef]
  72. Hegarty, J.P.; Stewart Sr, D.B. Advances in therapeutic bacterial antisense biotechnology. Appl. Microbiol. Biotechnol. 2018, 102, 1055–1065. [Google Scholar] [CrossRef] [PubMed]
  73. Otsuka, T.; Brauer, A.L.; Kirkham, C.; Sully, E.K.; Pettigrew, M.M.; Kong, Y.; Geller, B.L.; Murphy, T.F. Antimicrobial activity of antisense peptide-peptide nucleic acid conjugates against non-typeable Haemophilus influenzae in planktonic and biofilm forms. J. Antimicrob. Chemother. 2017, 72, 137–144. [Google Scholar] [CrossRef] [PubMed]
  74. Howard, J.J.; Sturge, C.R.; Moustafa, D.A.; Daly, S.M.; Marshall-Batty, K.R.; Felder, C.F.; Zamora, D.; Yabe-Gill, M.; Labandeira-Rey, M.; Bailey, S.M.; et al. Inhibition of Pseudomonas aeruginosa by Peptide-Conjugated Phosphorodiamidate Morpholino Oligomers. Antimicrob. Agents Chemother. 2017, 61, e01938-16. [Google Scholar] [CrossRef] [PubMed]
  75. Liang, S.; He, Y.; Xia, Y.; Wang, H.; Wang, L.; Gao, R.; Zhang, M. Inhibiting the growth of methicillin-resistant Staphylococcus aureus in vitro with antisense peptide nucleic acid conjugates targeting the ftsZ gene. Int. J. Infect. Dis. 2015, 30, 1–6. [Google Scholar] [CrossRef]
  76. Meng, J.; Da, F.; Ma, X.; Wang, N.; Wang, Y.; Zhang, H.; Li, M.; Zhou, Y.; Xue, X.; Hou, Z.; et al. Antisense growth inhibition of methicillin-resistant Staphylococcus aureus by locked nucleic acid conjugated with cell-penetrating peptide as a novel FtsZ inhibitor. Antimicrob. Agents Chemother. 2015, 59, 914–922. [Google Scholar] [CrossRef] [PubMed]
  77. Sawyer, A.J.; Wesolowski, D.; Gandotra, N.; Stojadinovic, A.; Izadjoo, M.; Altman, S.; Kyriakides, T.R. A peptide-morpholino oligomer conjugate targeting Staphylococcus aureus gyrA mRNA improves healing in an infected mouse cutaneous wound model. Int. J. Pharm. 2013, 453, 651–655. [Google Scholar] [CrossRef]
  78. Alajlouni, R.A.; Seleem, M.N. Targeting Listeria monocytogenes rpoA and rpoD genes using peptide nucleic acids. Nucleic Acid Ther. 2013, 23, 363–367. [Google Scholar] [CrossRef] [PubMed]
  79. Rajasekaran, P.; Alexander, J.C.; Seleem, M.N.; Jain, N.; Sriranganathan, N.; Wattam, A.R.; Setubal, J.C.; Boyle, S.M. Peptide nucleic acids inhibit growth of Brucella suis in pure culture and in infected murine macrophages. Int. J. Antimicrob. Agents. 2013, 41, 358–362. [Google Scholar] [CrossRef]
  80. Geller, B.L.; Marshall-Batty, K.; Schnell, F.J.; McKnight, M.M.; Iversen, P.L.; Greenberg, D.E. Gene-silencing antisense oligomers inhibit acinetobacter growth in vitro and in vivo. J. Infect. Dis. 2013, 208, 1553–1560. [Google Scholar] [CrossRef]
  81. Holden, K.L.; Stein, D.A.; Pierson, T.C.; Ahmed, A.A.; Clyde, K.; Iversen, P.L.; Harris, E. Inhibition of dengue virus translation and RNA synthesis by a morpholino oligomer targeted to the top of the terminal 3’ stem-loop structure. Virology 2006, 344, 439–452. [Google Scholar] [CrossRef]
  82. Phumesin, P.; Junking, M.; Panya, A.; Yongpitakwattana, P.; Noisakran, S.; Limjindaporn, T.; Yenchitsomanus, P.-T. Inhibition of dengue virus replication in monocyte-derived dendritic cells by vivo-morpholino oligomers. Virus Res. 2019, 260, 123–128. [Google Scholar] [CrossRef] [PubMed]
  83. Lai, S.H.; Stein, D.A.; Guerrero-Plata, A.; Liao, S.L.; Ivanciuc, T.; Hong, C.; Iversen, P.L.; Casola, A.; Garofalo, R.P. Inhibition of respiratory syncytial virus infections with morpholino oligomers in cell cultures and in mice. Mol. Ther. 2008, 16, 1120–1128. [Google Scholar] [CrossRef] [PubMed]
  84. Ge, Q.; Pastey, M.; Kobasa, D.; Puthavathana, P.; Lupfer, C.; Bestwick, R.K.; Iversen, P.L.; Chen, J.; Stein, D.A. Inhibition of multiple subtypes of influenza A virus in cell cultures with morpholino oligomers. Antimicrob. Agents Chemother. 2006, 50, 3724–3733. [Google Scholar] [CrossRef] [PubMed]
  85. Swenson, D.L.; Warfield, K.L.; Warren, T.K.; Lovejoy, C.; Hassinger, J.N.; Ruthel, G.; Blouch, R.E.; Moulton, H.M.; Weller, D.D.; Iversen, P.L.; et al. Chemical modifications of antisense morpholino oligomers enhance their efficacy against Ebola virus infection. Antimicrob. Agents Chemother. 2009, 53, 2089–2099. [Google Scholar] [CrossRef] [PubMed]
  86. Javanbakht, H.; Mueller, H.; Walther, J.; Zhou, X.; Lopez, A.; Pattupara, T.; Blaising, J.; Pedersen, L.; Albæk, N.; Jackerott, M.; et al. Liver-Targeted Anti-HBV Single-Stranded Oligonucleotides with Locked Nucleic Acid Potently Reduce HBV Gene Expression In Vivo. Mol. Ther. Nucleic Acids 2018, 11, 441–454. [Google Scholar] [CrossRef] [PubMed]
  87. Takahashi, M.; Li, H.; Zhou, J.; Chomchan, P.; Aishwarya, V.; Damha, M.J.; Rossi, J.J. Dual Mechanisms of Action of Self-Delivering, Anti-HIV-1 FANA Oligonucleotides as a Potential New Approach to HIV Therapy. Mol. Ther. Nucleic Acids 2019, 17, 615–625. [Google Scholar] [CrossRef] [PubMed]
  88. Holden, K.L.; Harris, E. Enhancement of dengue virus translation: Role of the 3’ untranslated region and the terminal 3’ stem-loop domain. Virology 2004, 329, 119–133. [Google Scholar] [CrossRef]
  89. You, S.; Padmanabhan, R. A novel in vitro replication system for Dengue virus. Initiation of RNA synthesis at the 3’-end of exogenous viral RNA templates requires 5’- and 3’-terminal complementary sequence motifs of the viral RNA. J. Biol. Chem. 1999, 274, 33714–33722. [Google Scholar] [CrossRef]
  90. Garg, A.; Wesolowski, D.; Alonso, D.; Deitsch, K.W.; Ben Mamoun, C.; Altman, S. Targeting protein translation, RNA splicing, and degradation by morpholino-based conjugates in Plasmodium falciparum. Proc. Natl. Acad. Sci. USA 2015, 112, 11935–11940. [Google Scholar] [CrossRef]
  91. Witola, W.H.; Bauman, B.; McHugh, M.; Matthews, K. Silencing of GRA10 protein expression inhibits Toxoplasma gondii intracellular growth and development. Parasitol. Int. 2014, 63, 651–658. [Google Scholar] [CrossRef]
  92. Hashimoto, M.; Nara, T.; Hirawake, H.; Morales, J.; Enomoto, M.; Mikoshiba, K. Antisense oligonucleotides targeting parasite inositol 1,4,5-trisphosphate receptor inhibits mammalian host cell invasion by Trypanosoma cruzi. Sci. Rep. 2014, 4, 4231. [Google Scholar] [CrossRef] [PubMed]
  93. Dahan-Pasternak, N.; Nasereddin, A.; Kolevzon, N.; Pe’er, M.; Wong, W.; Shinder, V.; Turnbull, L.; Whitchurch, C.B.; Elbaum, M.; Gilberger, T.W.; et al. PfSec13 is an unusual chromatin-associated nucleoporin of Plasmodium falciparum that is essential for parasite proliferation in human erythrocytes. J. Cell Sci. 2013, 126 Pt 14, 3055–3069. [Google Scholar] [CrossRef] [PubMed]
  94. Gcanga, L.; Tamgue, O.; Ozturk, M.; Pillay, S.; Jacobs, R.; Chia, J.E.; Mbandi, S.K.; Davids, M.; Dheda, K.; Schmeier, S.; et al. Host-Directed Targeting of LincRNA-MIR99AHG Suppresses Intracellular Growth of Mycobacterium tuberculosis. Nucleic Acid Ther. 2022, 32, 421–437. [Google Scholar] [CrossRef] [PubMed]
  95. Bachhawat, N.; Mande, S.C. Identification of the INO1 gene of Mycobacterium tuberculosis H37Rv reveals a novel class of inositol-1-phosphate synthase enzyme. J. Mol. Biol. 1999, 291, 531–536. [Google Scholar] [CrossRef] [PubMed]
  96. Li, Y.; Chen, Z.; Li, X.; Zhang, H.; Huang, Q.; Zhang, Y.; Xu, S. Inositol-1-phosphate synthetase mRNA as a new target for antisense inhibition of Mycobacterium tuberculosis. J. Biotechnol. 2007, 128, 726–734. [Google Scholar] [CrossRef] [PubMed]
  97. Skvortsova, Y.V.; Salina, E.G.; Burakova, E.A.; Bychenko, O.S.; Stetsenko, D.A.; Azhikina, T.L. A New Antisense Phosphoryl Guanidine Oligo-2’-O-Methylribonucleotide Penetrates Into Intracellular Mycobacteria and Suppresses Target Gene Expression. Front. Pharmacol. 2019, 10, 1049. [Google Scholar] [CrossRef] [PubMed]
  98. Shang, J.; Ye, G.; Shi, K.; Wan, Y.; Luo, C.; Aihara, H.; Geng, Q.; Auerbach, A.; Li, F. Structural basis of receptor recognition by SARS-CoV-2. Nature 2020, 581, 221–224. [Google Scholar] [CrossRef]
  99. Qiao, Y.; Wotring, J.W.; Zhang, C.J.; Jiang, X.; Xiao, L.; Watt, A.; Gattis, D.; Scandalis, E.; Freier, S.; Zheng, Y.; et al. Antisense oligonucleotides to therapeutically target SARS-CoV-2 infection. PLoS ONE 2023, 18, e0281281. [Google Scholar] [CrossRef]
  100. Fabani, M.M.; Gait, M.J. miR-122 targeting with LNA/2’-O-methyl oligonucleotide mixmers, peptide nucleic acids (PNA), and PNA-peptide conjugates. RNA 2008, 14, 336–346. [Google Scholar] [CrossRef]
  101. Groseth, A.; Charton, J.E.; Sauerborn, M.; Feldmann, F.; Jones, S.M.; Hoenen, T.; Feldmann, H. The Ebola virus ribonucleoprotein complex: A novel VP30-L interaction identified. Virus Res. 2009, 140, 8–14. [Google Scholar] [CrossRef]
  102. Chery, J.; Petri, A.; Wagschal, A.; Lim, S.Y.; Cunningham, J.; Vasudevan, S.; Kauppinen, S.; Näär, A.M. Development of Locked Nucleic Acid Antisense Oligonucleotides Targeting Ebola Viral Proteins and Host Factor Niemann-Pick C1. Nucleic Acid Ther. 2018, 28, 273–284. [Google Scholar] [CrossRef] [PubMed]
  103. Li, K.; Zhou, Z.; Wang, Y.O.; Liu, J.; Zhao, H.B.; Yang, J.; Wang, S.Q. Pretreatment of mice with oligonucleotide prop5 protects them from influenza virus infections. Viruses 2014, 6, 573–581. [Google Scholar] [CrossRef] [PubMed]
  104. Yang, J.; Bo, X.C.; Ding, X.R.; Dai, J.M.; Zhang, M.L.; Wang, X.H.; Wang, S.Q. Antisense oligonucleotides targeted against asialoglycoprotein receptor 1 block human hepatitis B virus replication. J. Viral Hepat. 2006, 13, 158–165. [Google Scholar] [CrossRef] [PubMed]
  105. Ko, S.H.; Huang, L.M.; Tarn, W.Y. The Host Heat Shock Protein MRJ/DNAJB6 Modulates Virus Infection. Front. Microbiol. 2019, 10, 2885. [Google Scholar] [CrossRef]
  106. Ko, S.H.; Liau, Y.J.; Chi, Y.H.; Lai, M.J.; Chiang, Y.P.; Lu, C.Y.; Chang, L.Y.; Tarn, W.Y.; Huang, L.M. Interference of DNAJB6/MRJ Isoform Switch by Morpholino Inhibits Replication of HIV-1 and RSV. Mol. Ther. Nucleic Acids 2019, 14, 251–261. [Google Scholar] [CrossRef] [PubMed]
  107. Gredell, J.A.; Berger, A.K.; Walton, S.P. Impact of target mRNA structure on siRNA silencing efficiency: A large-scale study. Biotechnol. Bioeng. 2008, 100, 744–755. [Google Scholar] [CrossRef] [PubMed]
  108. Wadhwa, A.; Aljabbari, A.; Lokras, A.; Foged, C.; Thakur, A. Opportunities and Challenges in the Delivery of mRNA-based Vaccines. Pharmaceutics 2020, 12, 102. [Google Scholar] [CrossRef] [PubMed]
  109. Yoshida, T.; Naito, Y.; Yasuhara, H.; Sasaki, K.; Kawaji, H.; Kawai, J.; Naito, M.; Okuda, H.; Obika, S.; Inoue, T. Evaluation of off-target effects of gapmer antisense oligonucleotides using human cells. Genes. Cells 2019, 24, 827–835. [Google Scholar] [CrossRef]
  110. Judge, A.; MacLachlan, I. Overcoming the innate immune response to small interfering RNA. Hum. Gene Ther. 2008, 19, 111–124. [Google Scholar] [CrossRef]
Cells 12 02119 g001
Figure 1. Antibacterial oligonucleotides targeting essential bacterial genes. (A1) PPNA1/2 ASOs target ftsZ mRNA and inhibit the growth of methicillin-resistant Staphylococcus aureus. (A2) PLNA787 ASO binds to ftsZ mRNA of Staphylococcus aureus to inhibit its growth. (A3) PMO ASO attaches to gyrA mRNA, causing a growth reduction in Staphylococcus aureus. (B) rpoA-PNA ASO binds to rpoA mRNA resulting in a reduction in L. monocytogenes growth. (C) polA-PNA ASO attaches to the polA mRNA, inhibiting the growth of Brucella suis. (D) The binding of acpP-PPMO ASO with the acpP mRNA results in the reduction in Acinetobacter baumannii growth. Abbreviations: ftsZ, filamentous temperature-sensitive protein Z; gyrA, gyrase A; rpoA, RNA polymerase α subunit; polA, DNA polymerase I; acpP, acyl carrier protein. Created in BioRender.com.
Figure 1. Antibacterial oligonucleotides targeting essential bacterial genes. (A1) PPNA1/2 ASOs target ftsZ mRNA and inhibit the growth of methicillin-resistant Staphylococcus aureus. (A2) PLNA787 ASO binds to ftsZ mRNA of Staphylococcus aureus to inhibit its growth. (A3) PMO ASO attaches to gyrA mRNA, causing a growth reduction in Staphylococcus aureus. (B) rpoA-PNA ASO binds to rpoA mRNA resulting in a reduction in L. monocytogenes growth. (C) polA-PNA ASO attaches to the polA mRNA, inhibiting the growth of Brucella suis. (D) The binding of acpP-PPMO ASO with the acpP mRNA results in the reduction in Acinetobacter baumannii growth. Abbreviations: ftsZ, filamentous temperature-sensitive protein Z; gyrA, gyrase A; rpoA, RNA polymerase α subunit; polA, DNA polymerase I; acpP, acyl carrier protein. Created in BioRender.com.
Cells 12 02119 g001
Cells 12 02119 g002
Figure 2. Antiviral oligonucleotides targeting essential viral genes. (A1) 3′SLT PPMO ASO targets the 3′ terminal stem-loop of the Dengue viral genome, inhibiting viral translation and RNA synthesis. (A2) Vivo-MO-1 ASO binds to the 3′ terminal stem-loop of the Dengue viral genome and inhibits the production of viral proteins. (B) Ga1Nac-LNA (SSO) ASO binds to the hepatitis B virus (HBV) transcript preventing the expression of viral antigens. (C) PMO ASO conjugated to an arginine-rich peptide (PPMO) successfully inhibited the viral replication of Ebola by attaching to the VP24 mRNA. (D) P7-PMO ASO targets the NP-v3′ site on the viral mRNA, obstructing the replication of Ebola. (E) AUG-2 PPMO ASO binds to respiratory syncytial virus (RSV)-L mRNA leading to reduced viral titers. (F) FANA ASO binds to the conserved regions of the HIV-1 genome, inhibiting HIV-1 replication. Abbreviations: 3′SLT, 3′ stem loop; Ga1NAc, N-acetylgalactosamine; NP-v3′, nucleoprotein viral genome; FANA, 2′-deoxy-2′-fluoroarabinonucleotide; HBV, Hepatitis B virus; RSV, Respiratory syncytial virus; HIV, Human immunodeficiency virus. Created in BioRender.com.
Figure 2. Antiviral oligonucleotides targeting essential viral genes. (A1) 3′SLT PPMO ASO targets the 3′ terminal stem-loop of the Dengue viral genome, inhibiting viral translation and RNA synthesis. (A2) Vivo-MO-1 ASO binds to the 3′ terminal stem-loop of the Dengue viral genome and inhibits the production of viral proteins. (B) Ga1Nac-LNA (SSO) ASO binds to the hepatitis B virus (HBV) transcript preventing the expression of viral antigens. (C) PMO ASO conjugated to an arginine-rich peptide (PPMO) successfully inhibited the viral replication of Ebola by attaching to the VP24 mRNA. (D) P7-PMO ASO targets the NP-v3′ site on the viral mRNA, obstructing the replication of Ebola. (E) AUG-2 PPMO ASO binds to respiratory syncytial virus (RSV)-L mRNA leading to reduced viral titers. (F) FANA ASO binds to the conserved regions of the HIV-1 genome, inhibiting HIV-1 replication. Abbreviations: 3′SLT, 3′ stem loop; Ga1NAc, N-acetylgalactosamine; NP-v3′, nucleoprotein viral genome; FANA, 2′-deoxy-2′-fluoroarabinonucleotide; HBV, Hepatitis B virus; RSV, Respiratory syncytial virus; HIV, Human immunodeficiency virus. Created in BioRender.com.
Cells 12 02119 g002
Cells 12 02119 g003
Figure 3. Antiparasitic oligonucleotides targeting essential parasitic genes. (A) GRA10-PPMO ASO downregulates GRA10 expression, resulting in growth inhibition Toxoplasma gondii. (B1) PfCRT-VMO ASO and (B2) PfDXR-PPMO ASO target the essential genes, PfCRT and PfDXR, respectively, leading to growth inhibition of Plasmodium falciparum. (B3) The binding of PNA ASO and PfSec13 results in decreased P. falciparum proliferation. (C) Antisense 5995 ASO binds to the TcIP3R mRNA of T. cruzi, inhibiting cell entry and replication. Abbreviations: GRA10, dense granule protein 10; PfCRT, P. falciparum chloroquine resistance transporter; PfDXR, P. falciparum deoxyxylulose 5-phosphate reductoisomerase; TcIP3R, T. cruzi inositol 1,4,5-trisphosphate receptor. Created in BioRender.com.
Figure 3. Antiparasitic oligonucleotides targeting essential parasitic genes. (A) GRA10-PPMO ASO downregulates GRA10 expression, resulting in growth inhibition Toxoplasma gondii. (B1) PfCRT-VMO ASO and (B2) PfDXR-PPMO ASO target the essential genes, PfCRT and PfDXR, respectively, leading to growth inhibition of Plasmodium falciparum. (B3) The binding of PNA ASO and PfSec13 results in decreased P. falciparum proliferation. (C) Antisense 5995 ASO binds to the TcIP3R mRNA of T. cruzi, inhibiting cell entry and replication. Abbreviations: GRA10, dense granule protein 10; PfCRT, P. falciparum chloroquine resistance transporter; PfDXR, P. falciparum deoxyxylulose 5-phosphate reductoisomerase; TcIP3R, T. cruzi inositol 1,4,5-trisphosphate receptor. Created in BioRender.com.
Cells 12 02119 g003
Cells 12 02119 g004
Figure 4. ASOs targeting host factors and essential bacterial genes. (A) The LNA GapmeR-ASO binds to the host lincRNA-MIR99AHG, resulting in the reduction in Mycobacterium tuberculosis in both murine and human macrophages. (B) PS-ODN ASO effectively targets the INO1 gene, resulting in reduced mycothiol levels and suppressed proliferation of M. tuberculosis. This, in turn, enhances the bacteria’s susceptibility to antibiotics (C) The 2′-OMe PGOs target the mycobacterial ald gene, leading to a significant inhibition of M. smegmatis growth within murine macrophages: LNA, locked nucleic acid; lincRNA-MIR99AHG, long intergenic noncoding RNA-MIR99AHG; PS-ODN, phosphorothioate-modified antisense oligodeoxyribonucleotide; INO1, inositol-1; M. tuberculosis, Mycobacterium tuberculosis; 2′-OMe PGOs, phosphoryl guanidine oligo-2′-O-methylribonucleotides; M. smegmatis, Mycobacterium smegmatis. Created in BioRender.com.
Figure 4. ASOs targeting host factors and essential bacterial genes. (A) The LNA GapmeR-ASO binds to the host lincRNA-MIR99AHG, resulting in the reduction in Mycobacterium tuberculosis in both murine and human macrophages. (B) PS-ODN ASO effectively targets the INO1 gene, resulting in reduced mycothiol levels and suppressed proliferation of M. tuberculosis. This, in turn, enhances the bacteria’s susceptibility to antibiotics (C) The 2′-OMe PGOs target the mycobacterial ald gene, leading to a significant inhibition of M. smegmatis growth within murine macrophages: LNA, locked nucleic acid; lincRNA-MIR99AHG, long intergenic noncoding RNA-MIR99AHG; PS-ODN, phosphorothioate-modified antisense oligodeoxyribonucleotide; INO1, inositol-1; M. tuberculosis, Mycobacterium tuberculosis; 2′-OMe PGOs, phosphoryl guanidine oligo-2′-O-methylribonucleotides; M. smegmatis, Mycobacterium smegmatis. Created in BioRender.com.
Cells 12 02119 g004
Cells 12 02119 g005
Figure 5. ASOs targeting host factors during various viral infections in the host cell. (A) ACE2 ASO binds to the ACE2 receptor, inhibiting the entry of SARS-CoV-2. (B) PNA ASO attaches to miR-122, preventing HCV viral genome stabilization and replication. (C) LNA-PS ASO inhibits Ebola membrane fusion and prevents ribonucleoprotein (RNP) release by binding to NPC1 mRNA. (D) PROP5 ASO binds to PDCD5 mRNA, resulting in the inhibition of programmed cell death and H1N1 influenza viral replication. (E) ASODN2 ASO hinders HBV replication by binding to the ASGPR1 receptor. (F) The binding of VIVO-PMO ASO to MRJ-L isoform results in the inhibition of HIV-1’s nuclear entry and genome integration, as well as the RSV’s viral RNA and mRNA expression. Abbreviations: ACE2, angiotensin-converting enzyme 2; miR-122, microRNA-122; NPC1, Niemann–Pick C1; PDCD5, programmed cell death protein 5; ASGPR1, asialoglycoprotein receptor 1; MRJ-L, Mammalian relative of DnaJ; HCV, Hepatitis C virus. Created in BioRender.com.
Figure 5. ASOs targeting host factors during various viral infections in the host cell. (A) ACE2 ASO binds to the ACE2 receptor, inhibiting the entry of SARS-CoV-2. (B) PNA ASO attaches to miR-122, preventing HCV viral genome stabilization and replication. (C) LNA-PS ASO inhibits Ebola membrane fusion and prevents ribonucleoprotein (RNP) release by binding to NPC1 mRNA. (D) PROP5 ASO binds to PDCD5 mRNA, resulting in the inhibition of programmed cell death and H1N1 influenza viral replication. (E) ASODN2 ASO hinders HBV replication by binding to the ASGPR1 receptor. (F) The binding of VIVO-PMO ASO to MRJ-L isoform results in the inhibition of HIV-1’s nuclear entry and genome integration, as well as the RSV’s viral RNA and mRNA expression. Abbreviations: ACE2, angiotensin-converting enzyme 2; miR-122, microRNA-122; NPC1, Niemann–Pick C1; PDCD5, programmed cell death protein 5; ASGPR1, asialoglycoprotein receptor 1; MRJ-L, Mammalian relative of DnaJ; HCV, Hepatitis C virus. Created in BioRender.com.
Cells 12 02119 g005
Table 1. Antibacterial oligonucleotides.
Table 1. Antibacterial oligonucleotides.
BacteriaASOTargetRef.
Staphylococcus aureusPPNA1/2ftsZ[75]
Staphylococcus aureusPLNA787ftsZ[76]
Staphylococcus aureusPMOgyrA[77]
Listeria monocytogenesrpoA-PNArpoA[78]
Brucella suispolA-PNApolA[79]
Acinetobacter baumanniiAcpP-PPMOacpP[80]
Table 2. Antiviral oligonucleotides.
Table 2. Antiviral oligonucleotides.
VirusASOTargetRef.
Dengue virus3′SLT PPMO3′-SLT[81]
Dengue virus Vivo-MO-13′-SLT on 3′ UTR of genome[82]
Respiratory Syncytial virusAUG-2 PPMORSV-L mRNA[83]
InfluenzaP7-PMONP-v3′[84]
EbolaArginine rich PPMOVP24 mRNA[85]
Hepatitis B virusGa1Nac-LNA(SSO)HBV transcript[86]
Human Immunodeficiency virusFANA-ASOHIV-1 genome[87]
Table 3. Antiparasitic oligonucleotides.
Table 3. Antiparasitic oligonucleotides.
ParasiteASOTargetRef.
Toxoplasma gondiiGRA10-PPMOGRA10[91]
Trypanosoma cruziAntisense 5995TcIP3R[92]
Plasmodium falciparumPfCRT-VMO PfDXR-PPMOPfCRT
PfDXR		[90]
Plasmodium falciparumPNAPfSec13[93]
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Buthelezi, L.A.; Pillay, S.; Ntuli, N.N.; Gcanga, L.; Guler, R. Antisense Therapy for Infectious Diseases. Cells 2023, 12, 2119. https://doi.org/10.3390/cells12162119

AMA Style

Buthelezi LA, Pillay S, Ntuli NN, Gcanga L, Guler R. Antisense Therapy for Infectious Diseases. Cells. 2023; 12(16):2119. https://doi.org/10.3390/cells12162119

Chicago/Turabian Style

Buthelezi, Lwanda Abonga, Shandre Pillay, Noxolo Nokukhanya Ntuli, Lorna Gcanga, and Reto Guler. 2023. "Antisense Therapy for Infectious Diseases" Cells 12, no. 16: 2119. https://doi.org/10.3390/cells12162119

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop