Search Results (2,877)

Acute myeloid leukemia (AML) is an aggressive and often fatal hematopoietic malignancy, diagnosed predominantly in the elderly. The five-year survival of patients with AML is as low as 30%. Differentiation therapy of a subtype of AML, named acute promyelocytic leukemia (APL), using all-trans retinoic acid (ATRA) was the most successful example of a targeted therapy against AML. Epigenetic-based differentiation therapies for other subtypes of AML are also showing improvements in response and in survival rates. Thus, in this study, we investigated a potential differentiation therapy with a combination of 1,25-dihydroxyvitamin D (1,25D) analog (named PRI5202) and low concentration of Fludarabine. We show that such a combination elicits immunostimulatory and pro-differentiation effects in AML cells, specifically in those with activating mutations in fibroblast growth factor receptor (FGFR) and Janus kinase (JAK) pathways. We show here that both PRI5202 and Fludarabine are potent activators of the transcription of many innate immunity-related genes, and that, in combination, their effects are in many aspects synergistic. We propose that such a low-intensity regimen may be suitable for older patients with AML, who are unfit for intensive chemotherapy. We also present data indicating that PRI5202 induces myeloid differentiation in blasts from patients with myelodysplastic syndrome (MDS), and we propose to further investigate PRI5202 as a differentiation therapy for patients suffering from MDS. Full article

Ochratoxin A (OTA) is a widespread mycotoxin with documented nephrotoxic, hepatotoxic, immunotoxic, and carcinogenic effects, while its role in hematological malignancies and immune cells remains insufficiently defined. This study examined the cytotoxic and pro-apoptotic OTA activity in three human leukemia cell lines (CCRF-CEM, K-562, HL-60) and in peripheral blood mononuclear cells (PBMCs) from healthy donors. Cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and trypan blue assays, mitochondrial membrane potential (ΔΨM) was assessed with JC-1 dye, caspase-3/7 activity was measured by flow cytometry, and the expression of apoptosis-related genes was analyzed by RT-qPCR. OTA did not significantly affect viability, mitochondrial function, or caspase activity in leukemia cell lines, suggesting relative resistance to OTA-induced apoptosis. In contrast, PBMCs exhibited clear dose- and time-dependent sensitivity, manifested by reduced viability, ΔΨM, caspase-3/7 activation, and transcriptional changes consistent with intrinsic apoptosis, including decreased BCL-2 (anti-apoptotic) and increased BAX (pro-apoptotic), APAF1 (apoptosome component), CASP3, and CASP9 (executioner and initiator caspases) expression. These findings demonstrate that OTA selectively targets healthy immune cells rather than leukemia cells, highlighting its pronounced immunotoxic risk and the importance of caution when considering its effect in a hematological context. Although limited to in vitro models, this study underscores the necessity of further research to clarify the molecular basis of differential OTA sensitivity and its contribution to immunosuppression and hematological disease. Full article

Megakaryocytes (MKs) are specialized hematopoietic cells long recognized for their ability to produce platelets. Increasing evidence now highlights MKs as multifunctional immune effectors that bridge hematopoiesis with host immunity. In the bone marrow (BM), MKs arise through thrombopoietin (TPO)-mediated differentiation of hematopoietic stem cells (HSCs) and show substantial heterogeneity, with discrete subsets specialized for platelet production (thrombopoiesis), HSC niche maintenance, or immune modulation. Outside the BM, MKs in the lungs and spleen perform tissue-specific immune functions, including pathogen recognition, phagocytosis, antigen presentation, and secretion of cytokines. During bacterial infections and sepsis, infectious or inflammatory cues reprogram MKs to amplify immune signaling and host responses, but can also drive coagulopathy and contribute to organ failure. Collectively, these findings redefine MKs as dynamic immunomodulatory cells positioned at the interface of thrombopoiesis and innate and adaptive immunity. In this review, we synthesize emerging literature on MK biogenesis, functional diversity, and immune modulation, with a special focus on their roles in bacterial infections and sepsis. Full article

Dengue virus (DENV) affects not only peripheral immune cells but also hematopoietic progenitors in the bone marrow, particularly megakaryocytic precursors, which contribute to the thrombocytopenia characteristic of the disease. In this study, we evaluated the relationship between the differentiation status of the megakaryocytic lineage and its permissiveness and antiviral response to DENV. Our results demonstrate that the erythroid–megakaryocytic precursor (K562 cells) was more permissive to DENV infection than megakaryoblasts, as evidenced by immunofluorescence, flow cytometry, and quantification of viral particles. The antiviral response in K562 cells peaked at three days post-infection, with maximal expression of genes associated with the type I interferon (IFN-I) pathway. In vitro-induced differentiation of K562 cells reduced the initial susceptibility to DENV and enhanced the expression of Toll-like receptor 3 (TLR3) and the type I interferon receptor (IFNAR1), accelerating and intensifying IFN-β secretion, and increasing the expression of OAS2 and IRF3. Furthermore, pretreatment of K562 cells with recombinant IFN-β significantly reduced viral replication from the first day post-infection. Collectively, these findings demonstrate for the first time that the differentiation status of erythroid–megakaryocytic progenitor critically shapes their antiviral response and underscore the central role of IFN-β in the early restriction of DENV infection. Full article

Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss, primarily driven by oxidative stress–induced degeneration of retinal pigment epithelium (RPE). Erythropoietin (EPO), a hematopoietic cytokine with neuroprotective properties, has been shown to reduce apoptosis and retinal degeneration. In this study, we examined the cytoprotective role of a non-erythropoietic EPO variant, EPO-R76E, in suppressing oxidative stress and mitochondrial dysfunction related to oxidative stress in RPE cells. Stable ARPE-19 cell lines expressing EPO-R76E were generated via lentiviral transduction and exposed to paraquat to induce oxidative stress. Oxidative stress was induced using paraquat. EPO-R76E expression conferred increased cell viability and resistance to mitochondrial damage, as assessed by cytotoxicity assays. Western blot analysis revealed reduced expression of ferritin and p62/SQSTM1, diminished activation of p-AMPK and NRF2, and restoration of GPX4 levels, indicating enhanced antioxidant defenses. Moreover, intracellular iron accumulation and reactive oxygen species were significantly reduced in EPO-R76E-expressing cells exposed to paraquat. These findings suggest that EPO-R76E promotes mitochondrial homeostasis and modulates oxidative stress pathways. Our study positions EPO-R76E as a promising therapeutic candidate for halting RPE degeneration in AMD. Full article

Cardiovascular morbidity and mortality rise precipitously during the 6th–9th decades of life, identifying aging as a critical risk factor. Simultaneously, older individuals are susceptible to severe viral infection, raising the question whether shared mechanisms exist that predispose to both cardiovascular disease (CVD) and failing anti-viral immunity. The aging process causes steady decline in immune fitness (immune aging), which undermines the ability to generate protective anti-viral immune responses. Paradoxically, the aging immune system supports unopposed inflammatory pathways (inflammaging), which exacerbates tissue inflammation in CVD, specifically atherosclerosis. Here, we review the current evidence of how innate and adaptive immune aging promotes tissue-destructive inflammation in atherosclerosis while failing to fight viral infections. Further, we consider how these two disease processes mutually influence each other. We propose that mounting an effective anti-viral response induces off-target bystander activation and exhausts immune cells, ultimately exacerbating CVD. Additionally, we explore how atherosclerotic CVD impacts innate immunity through epigenetic modification of hematopoietic precursors and metabolically conditioning immune cells, leading to a dysfunctional immune system that accelerates plaque inflammation while simultaneously impairing host defense. Full article

Sickle cell disease comprises a group of prevalent inherited disorders defined by an underlying sickle cell allele that forms sickle hemoglobin. The incidence of this disease is rising, with more than 500,000 children born with it globally. The disease carries significant morbidity and mortality. Its only curative treatment was an allogeneic hematopoietic stem cell (HSC) transplant (HSCT) until late 2023, when two one-time gene therapies were approved for treating patients aged 12 years or older with severe sickle cell disease. This work aims to inform readers about these two gene therapies: one lentiviral-based and the other nonviral. The latter is based on the Nobel Prize-winning discovery of clustered, regularly interspaced, short, palindromic repeats (CRISPR)/CRISPR-associated (Cas)9 proteins and single-guide RNA (sgRNA)-based genome editing. Both approved gene therapies require an autologous HSCT with ex vivo genetically edited autologous hematopoietic stem and progenitor cells. Therefore, access to these gene therapies is limited to specialized centers with expertise in HSCTs. This review is meant for students, researchers, and clinical practitioners. It explains the basis for both approved gene therapies, their mechanisms of action, differences, risks, and other lentiviral-based and CRISPR-Cas9-based ex vivo gene therapies for sickle cell disease in clinical development. Additionally, it discusses the current state of preclinical studies for in vivo HSC gene therapy for sickle cell disease, which utilize advanced genome editing technologies developed after CRISPR-Cas9-sgRNA-based genome editing. In vivo HSC gene therapy, after it is clinically developed, would eliminate the need for an HSCT in receiving gene therapy and vastly increase access for numerous patients worldwide, even in low-income countries with the most significant disease burden. Full article

The process of aging is fundamentally driven by genomic instability and the accumulation of DNA damage, which progressively impair cellular and tissue function. In order to counteract these challenges, cells rely on the DNA damage response (DDR), a multilayered signaling and repair network that preserves genomic integrity and sustains homeostasis. Within this framework, nucleases and helicases have pivotal and complementary roles by remodeling aberrant DNA structures, generating accessible repair intermediates, and determining whether a cell achieves faithful repair, undergoes apoptosis, or enters senescence. Defects in these enzymes are exemplified in human progeroid syndromes, where inherited mutations lead to premature aging phenotypes. This phenomenon is also replicated in genetically engineered mouse models that exhibit tissue degeneration, stem cell exhaustion, and metabolic dysfunction. Beyond their canonical repair functions, helicases and nucleases also interface with the epigenome, as DNA damage-induced chromatin remodeling alters enzyme accessibility, disrupts transcriptional regulation, and drives progressive epigenetic drift and chronic inflammatory signaling. Moreover, their dysfunction accelerates the exhaustion of adult stem cell populations, such as hematopoietic, neural, and mesenchymal stem cells. As a result, tissue regeneration is undermined, establishing a self-perpetuating cycle of senescence, impaired repair, and organismal aging. Current research is focused on developing therapeutic strategies that target the DDR–aging axis on several fronts: by directly modulating repair pathways, by regulating the downstream consequences of senescence, or by preventing DNA damage from accumulating upstream. Taken together, evidence from human disease, animal models, molecular studies, and pharmacological interventions demonstrates that nucleases and helicases are not only essential for genome maintenance but also decisive in shaping aging trajectories. This provides valuable knowledge into how molecular repair pathways influence organismal longevity and age-related diseases. Full article

Desmosomal junctions provide structural stability supporting concerted cardiomyocyte contractility. Previously, we demonstrated that a deficiency in the desmosomal transmembrane cadherin desmoglein 2 (Dsg2) reduces desmosome formation and disrupts cardiac morphogenesis, leading to excessive endothelial-to-hematopoietic cell transformation and embryonic lethality. It remained unclear whether this phenotype was specifically driven by Dsg2-deficiency or was a broader consequence of impaired desmosome adhesion. To address this question, we generated Pkp2^mt/mt mouse embryos lacking the desmosomal plaque protein Pkp2, which resulted in loss of desmosome formation. Despite the absence of cardiac wall rupture, Pkp2^mt/mt and some Pkp2^wt/mt presented accumulations of Ter-119⁺ blood cells and RUNX1⁺/CD44⁺ hematopoietic stem cells in the pericardial space. Remarkably, in Pkp2^mt/mt hearts, the epicardium was detached from the myocardium, contained rounded cells expressing the hematopoietic stem cell marker RUNX1, and showed altered intermediate filament expression. These findings suggest a potential trans-differentiation of the epicardial cells into hematopoietic cells. In conclusion, deficiencies in both Dsg2 and Pkp2 promote hematopoiesis in the developing murine heart but target different cell types, i.e., endothelial cells, which lack desmosomes, or desmosome-containing epicardial cells. Our results provide evidence for the involvement of Pkp2 in epicardial morphogenesis and remodeling. Full article

Background: Posaconazole is an antifungal medication used to treat invasive fungal infections (IFI) in pediatric onco-hematological patients. Its approval for pediatric use was recent, and limitations still apply. Despite limited data, the safety and efficacy profile appear generally favorable in children. This study describes how posaconazole is used across centers affiliated with the Associazione Italiana Ematologia e Oncologia Pediatrica (AIEOP). Methods: A national survey was conducted among physicians within the AIEOP network to evaluate current use of posaconazole in pediatric cancer patients, including those undergoing hematopoietic stem cell transplantation (HSCT). A 25-item web questionnaire was developed and distributed in June 2024. Data analysis involved descriptive statistics. Results: Twenty-one of thirty-one centers (68%) responded, reporting availability of various posaconazole formulations: oral suspension (76%), delayed-release tablets (95%), and intravenous solution (14%). Posaconazole was primarily used for prophylaxis in patients with acute lymphoblastic leukemia (ALL, 38%), acute myeloid leukemia (AML, 38%), and aplastic anemia (19%). It was also used as secondary prophylaxis against previous possible or probable IFI or as salvage therapy for probable or confirmed aspergillosis or mucormycosis, often combined with other treatments. Drug plasma level monitoring was common but varied in scheduling across centers. Most centers (74%) discontinued posaconazole if adverse events suspected drug–drug interactions, such as with vincristine. Conclusions: Posaconazole is widely used in AIEOP centers, though application varies significantly. This variability emphasizes the need for prospective studies to better define indications, dosing, and monitoring protocols for pediatric use of this antifungal. Full article

Chromodomain helicase DNA-binding protein 8 (CHD8), a frequently mutated gene in autism spectrum disorder (ASD), is an ATP-dependent chromatin remodeler with emerging roles in hematopoiesis. While CHD8 is known to maintain hematopoietic stem and progenitor cells (HSPCs) in the bone marrow, its function during developmental hematopoiesis remains undefined. Here, using a zebrafish model, we demonstrate that chd8 loss severely depletes the HSPC pool in the caudal hematopoietic tissue through a p53-dependent apoptotic mechanism. Furthermore, chd8^−/− embryos exhibit a p53-independent expansion of myelopoiesis. chd8 deficiency upregulates brd4, which promotes systemic inflammatory cytokine expression. Inhibiting brd4 alleviates cytokine expression, suppresses excessive myelopoiesis, and restores HSPC development. Our findings reveal a dual regulatory mechanism in which chd8 governs HSPC development by repressing p53-mediated apoptosis and constraining brd4-driven immune cell differentiation. Full article

A systematic literature review was conducted to evaluate the emerging evidence on newborn screening (NBS) for metachromatic leukodystrophy (MLD; MIM #250100). The review focuses on (1) screening assay performance, (2) diagnostic confirmation methods and care pathways, (3) feasibility of population-based identification, and (4) the impact of early diagnosis and treatment on health outcomes. Electronic databases were searched in February 2025, and supplementary searches were performed up to 17 June 2025, for articles referencing NBS for MLD and treatments for MLD; 52 publications were eligible for inclusion. Nationwide NBS for MLD is currently carried out in Norway and large prospective pilots are running in Germany, Austria, Italy and the US. MLD meets established Wilson and Jungner criteria, with a reliable screening algorithm, established confirmatory diagnostics, and actionable care pathways. There is ongoing work to develop tools to predict disease severity and subtype. Early intervention—via gene therapy for early-onset MLD and hematopoietic stem cell transplantation (HSCT) for late-onset forms—significantly improves outcomes when initiated before symptom onset. This review provides the first comprehensive synthesis of the evidence supporting MLD for inclusion in NBS programs, underscoring the public health value of early identification and intervention. Full article

Background/Objectives: Children who have received hematopoietic cell transplants (HCTs) often face complex clinical courses and complications that increase their risk of functional impairments. Because of this, pediatric HCT recipients may benefit from early mobilization efforts to reduce long-term functional issues. However, early ambulation can be limited by clinical complexity and concerns about infectious transmission in HCT patients. Some patients are under contact precautions due to colonization with bacteria that produce extended-spectrum beta-lactamase (ESBL) enzymes. Our goal was to significantly increase ambulation in pediatric HCT recipients at our institution within three months of the intervention. We aimed to raise the number of ambulation events per day, the number of physical therapy (PT) visits per week, and the distance patients walked with PT per session. Methods: From January to October 2022, data on mobilization, demographics, and clinical characteristics were retrospectively collected from electronic health records. Starting in June 2022, we permitted ESBL-colonized patients to leave their rooms while wearing personal protective equipment (PPE), and we trained clinical staff about this in our QI initiative. Results: In Group 1, the ambulation rate was 1.36 times higher before the intervention than after, with an effect size of 0.3042 (p = 0.004 *). The ambulation rate in Group 2, admitted before the intervention, was 1.33 times higher than in Group 3, admitted after the intervention, with an effect size of 0.2856 (p = 0.016 *). Conclusions: The initiative did not increase ambulation among the targeted group. Patients ambulated more before the intervention, though these results lack statistical power. The lack of success of the intervention may be due to various factors, including the short monitoring period, retrospective data collection, difficulties with PPE use among young patients, and uncollected confounding variables related to clinical status. Full article

Polyomaviruses (BKPyV and JCPyV) and herpesviruses (EBV, CMV) usually infect people during childhood, and may be associated, in some clinical states, with immunocompromised individuals. The aim of this study was to investigate the occurrence and coexistence of polyomavirus (BKPyV and JCPyV) and herpesvirus (CMV and EBV) DNAemia in pediatric hematology/oncology patients, including HCT recipients, and to assess the clinical relevance of polyomaviruses DNAemia. Whole blood samples of 99 children (including 71 patients undergoing HCT) were analyzed for the DNA of the herpes- and polyomaviruses. Co-existence of herpesvirus DNAemia was checked for the patients and clinically analyzed in detail, especially for those positive for BKPyV DNA. BKPyV DNAemia was detected in 15 (15.2%) patients, with viral loads ranging from 1.2 × 10³–1.7 × 10⁷ DNA IU/mL. No JCPyV DNA was detected in any of the samples. Coinfections with EBV or CMV DNAemia were observed in a subset of BKPyV-positive patients. BKPyV DNAemia was more frequent among children with leukemia and in those undergoing HCT. Our findings highlight the clinical associations between BKPyV and herpesvirus DNAemia in immunocompromised pediatric patients. Routine BKPyV DNA monitoring, alongside standard herpesvirus screening, may provide clinically valuable insights in high-risk pediatric cohorts, particularly those with hematologic malignancies and post-HCT status. Full article

Background/Objectives: Dendritic cell (DC)-based immunotherapies offer a promising strategy for cancer treatment but are limited by inefficient activation of cytotoxic T cells and, in turn, the host immune system. This report demonstrated that CD34⁺ hematopoietic stem cell (HSC)-derived allogeneic DCs engineered by an optimized lentiviral vector (LVV) expressing CD93, CD40-ligand (CD40L), and Chemokine (C-X-C motif) ligand-13 (CXCL13) significantly enhanced the host immune system, activated tumor-specific cytotoxic T cells, and led to complete regression of both primary and metastatic pancreatic tumors in humanized mouse models. This LVV shows comparable pre-clinical efficacy compared to the first-generation vector, in addition to being compliant for clinical use, which allows further pre-clinical development towards the human trials. Methods: This 2nd generation (Gen) LVV incorporates codon-optimized transgenes (CD40L, CD93, and CXCL13) with rearranged sequence to enhance expression, driven by a strong EF1α promoter. CD34⁺ HSCs were transduced with this modified 2nd Gen LVV and differentiated to Engineered DCs. Therapeutic efficacy of the DC therapy with the modified vector was tested on humanized mouse models of pancreatic tumors. This was accomplished by establishing an early-stage disease model (using MIA PaCa-2 (MP2)-tumors) and late-stage metastatic disease model of the pancreatic tumors to mimic the clinical setting using luciferase-expressing MP2-(Luc)-pancreatic tumor-bearing humanized mice. Results: The modified lentiviral construct had 6-fold greater expression of CD40L, 2% less toxicity, 4.5-fold greater CD40L, and 2.2-fold greater CXCL13 secretion than its predecessor. In vitro, Engineered DCs induced robust T cell proliferation in up to 20% of T cells, up to 4-fold greater interferon-gamma (IFN-γ) secretion than controls, and showcased antigen-specific cytotoxicity by CD8⁺ T cells. In vivo, two intradermal doses of the 2nd Gen DCs led to complete regression of primary pancreatic tumors and metastases. Treated mice exhibited prolonged survival, indicating the induction of durable anti-tumor immunity. Conclusions: Vector optimization retained the efficacy of DC-based therapy, achieving curative responses in pancreatic tumor models. These findings support the clinical development of this 2nd Gen DC immunotherapy for pancreatic and potentially other tumors. Full article