Search Results (163)

Background/Objectives: Whilst adoptive cell therapy (ACT) using chimeric antigen receptor-engineered T (CAR-T) cells represents an efficient approach for the treatment of patients suffering from several hematological malignancies, solid tumors have been shown to be far more challenging to tackle, mainly due to the hostile tumor microenvironment that inhibits optimal T cell functionality. As proven by the broad clinical success of immune checkpoint inhibitors, blocking the interaction of programmed cell death ligand 1 (PD-L1) expressed on tumor cells and the checkpoint receptor programmed cell death 1 (PD-1) expressed on activated T cells allows an intrinsic T cell-mediated anti-tumor response to be unleashed. We developed a cellular product (MDG1015) consisting of New York esophageal squamous cell carcinoma-1 (NY-ESO-1)/L antigen family member 1a (LAGE-1a)-specific CD8+ T cell receptor-transduced (TCR-)T cells co-expressing the costimulatory switch protein (CSP) PD1-41BB, which turns an inhibitory signal mediated by the PD-1:PD-L1 axis into positive T cell costimulation. Methods: In vitro co-cultures of MDG1015 and PD-L1-positive or -negative target cells were used to analyze TCR-T cell functionality, such as TCR-T (poly-)cytokine release, the killing of target cells, and TCR-T proliferation. The safety of MDG1015 was evaluated via different panels of antigen-negative cell lines or primary cells expressing or lacking PD-L1. Results: Preclinical analyses demonstrated TCR-gated activation of the CSP, leading to enhanced functionality of MDG1015 against antigen-expressing, PD-L1-positive tumor cells without any impact on antigen-negative target cells. Conclusions: The favorable, preclinical functionality and safety profile qualifies MDG1015 as a promising cellular therapy for explorative clinical testing in hard-to-treat solid tumor indications. Full article

Social anxiety disorder (SAD) is characterized by fear and avoidance of social situations. Considering the reduced availability of conventional therapies, we aimed to improve our understanding of the biological mechanisms in SAD by evaluating gamma-aminobutyric acid (GABA) and other neurometabolites (including glutamate + glutamine/glutamix (Glx), N-acetyl aspartate (NAA), myo-inositol (mI), total choline (tCho), and total creatine (tCr) in the dorsomedial prefrontal cortex/anterior cingulate cortex (dmPFC/ACC), dorsolateral prefrontal cortex (dlPFC), and the insula). In this pilot study, we recruited 26 (age: 25.3 ± 5.0 years; 61.5% female) individuals with SAD and 26 (age: 25.1 ± 4.4 years; 61.5% female) sex-age-matched controls. Using proton magnetic resonance spectroscopy, we found that compared to the controls, GABA+ macromolecular signal (GABA+) in dlPFC (t = 2.63; p = 0.012) and Glx in the insula (Mann–Whitney U = 178.3; p = 0.024) were higher in the participants with SAD. However, no between-group differences were observed in dmPFC/ACC (t = 0.39; p = 0.699). Increased GABA+ in dlPFC could be explained by aberrant GABA transporters. In the insula, increased Glx may be associated with the dysfunction of glutamate transporters or decreased activity of glutamic acid decarboxylase in the GABAergic inhibitory neurons. However, these proposed mechanisms need to be further investigated in SAD. Full article

It is well recognized that patients with type 2 diabetes mellitus (T2DM) exhibit significant impairment of immune function resulting in a higher frequency of infections. We hypothesize in this study that a likely contributor to immune dysfunction in T2DM is alteration of T lymphocyte signaling functions induced by chronic hyperglycemia. In this study we have utilized the established UC Davis Type 2 Diabetes Mellitus (UCD-T2DM) rat model of human T2DM to investigate whether progressive hyperglycemia diminishes T cell receptor (TCR)-releasable endoplasmic reticulum (ER) Ca²⁺ stores, an essential early antigen-stimulated signal driving T cell activation. Furthermore, results from this study demonstrate that chronic hyperglycemia markedly alters the expression profile of the sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA) Ca²⁺ ion pumps, which are the major enzymatic ion transporters maintaining replenished TCR-sensitive Ca²⁺ pools. We conducted companion experiments using Jurkat T lymphocytes exposed to high glucose which allowed finer resolution of early disruptions to ER Ca²⁺ store integrity and greater clarity on SERCA isoform-specific roles in diabetes-induced Ca²⁺ signal dysregulation. In summary, these experiments suggest that hyperglycemia in T2DM drives an ER stress state manifesting in reduced expression of the SERCA pumps, erosion of ER Ca²⁺ stores and culminating in T cell and immune dysfunction. Full article

Currently, there are two major theories regarding the pathogenesis of sepsis: hyperimmune and hypoimmune. The hyperimmune theory suggests that a cytokine storm causes the symptoms of sepsis. On the contrary, the hypoimmune theory suggests that immunosuppression causes the manifestations of sepsis. By conducting a microarray analysis on peripheral leukocytes from patients with sepsis, this study found that hyperactivity of TH17 immunity was noted in sepsis patients. Innate immunity-related genes are significantly upregulated, including CD14, TLR1,2,4,5,8, HSP70, CEBP proteins, AP1 (JUNB and FOSL2), TGFB1, IL6, TGFA, CSF2 receptor, TNFRSF1A, S100A binding proteins, CCR2, FPR2, amyloid proteins, pentraxin, defensins, CLEC5A, whole complement machinery, CPD, NCF, MMP, neutrophil elastase, caspases, IgG and IgA Fc receptors (CD64, CD32), ALOX5, PTGS, LTB4R, LTA4H, and ICAM1. The majority of adaptive immunity genes were downregulated, including MHC-related genes, TCR genes, granzymes/perforin, CD40, CD8, CD3, TCR signaling, BCR signaling, T and B cell-specific transcription factors, NK killer receptors, and TH17 helper-specific transcription factors (STAT3, RORA, and REL), as well as Treg-related genes, including TGFB1, IL15, STAT5B, SMAD2/4, CD36, and thrombospondin. The findings of this study show that Th17 with Treg over-presentation play an important role in the pathophysiology of sepsis. Full article

We explored the effects of altering expression levels of the sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA) ion-transporting enzymes on key T lymphocyte signaling functions. In these studies, we have taken advantage of the Jurkat T cell line which provides a T lymphocyte model cell phenotype with a well-characterized T cell receptor (TCR)-activated signaling pathway, as well as offering a cellular system with a good understanding of the SERCA expression profile. These studies have been prompted by a strong imperative to gain a better understanding of the complex roles SERCA Ca²⁺ pumps play in the integrated TCR-activated signaling network, particularly given the central role of SERCA functions in regulating essential endoplasmic reticulum (ER) integrity. We find in this study that altering SERCA expression can significantly reconfigure ER Ca²⁺ stores, increasing or decreasing Ca²⁺ storage capacity depending on upregulation or downregulation of SERCA expression, and these effects are also associated with substantial changes in agonist-induced Ca²⁺ release and influx patterns. Not surprisingly, these fundamental changes in TCR-regulated Ca²⁺ signaling properties are associated with major alterations in T lymphocyte functions including regulation of growth patterns, cytokine secretion and energy utilization. Our study also describes additional evidence revealing intriguing functional distinctions between the major SERCA isoform-regulated Ca²⁺ stores in T lymphocytes. Our work thus serves to reinforce increasing efforts to target the SERCA pumps as a potential profitable strategy to produce novel engineered T lymphocytes in the rapidly growing field of T-cell immunotherapy Full article

Linker for activation of T cells (LAT) is an essential adaptor protein in early T cell receptor (TCR) signaling that propagates multiple signaling pathways. However, how LAT spatial organization facilitates signal initiation and propagation after TCR triggering is not clear. To differentiate de novo assembly in the plasma membrane from pre-existing LAT vesicles and clusters, we developed imaging protocols and analyses to capture the organization and dynamics of single LAT molecules immediately after TCR engagement. We could observe individual LAT molecules in the plasma membrane that assembled into immobile signaling entities requiring LAT phosphorylation. This step-wise assembly process was temporally highly coordinated via the zeta-chain-associated protein kinase 70 (Zap70)-LAT-growth factor receptor-bound protein 2 (Grb2) pathway. While multiple spatial organization co-existed even within the plasma membrane, our data suggest that de novo plasma membrane assemblies facilitated signal propagation. Full article

Extensive studies have shown that gut microbiota-derived metabolites can enhance the antitumor efficacy of immunotherapy by modulating host immune responses. However, the more comprehensive spectrum of such metabolites and their mechanisms remain unclear. In this study, we demonstrated that L-selenomethionine (L-SeMet), a gut microbial metabolite, acts as a positive regulator of immunotherapy. Through screening of a repository of gut microbial metabolites, we identified that L-SeMet can effectively enhance the effector function of CD8⁺ T cells. Furthermore, intragastric administration of L-SeMet in mice significantly suppressed the growth of subcutaneous MC38 tumors. Mechanistically, L-SeMet enhances T cell receptor (TCR) signaling by promoting LCK phosphorylation. Collectively, our findings reveal that the gut microbial metabolite L-SeMet inhibits colorectal tumor growth by potentiating CD8⁺ T cell functions, providing a potential therapeutic strategy for colorectal cancer treatment. Full article

Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus associated with adult T-cell leukemia (ATL), a hematological malignancy, and HTLV-1-associated myelopathy (HAM), a progressive neurological disorder. HTLV-1 predominantly infects CD4+ T cells in vivo. The T-cell receptor (TCR)/CD3 complex on CD4+ helper T cells plays a pivotal role in immune responses by recognizing antigens and facilitating coordination with other immune cells. Dysfunction of the TCR/CD3 complex may impair immune function. Although CD3 downregulation has been identified as a characteristic of ATL cells, it remains uncertain whether a similar downregulation occurs in HTLV-1-infected cells from HAM patients. We hypothesized that HTLV-1 infection leads to TCR and CD3 downregulation, contributing to immune dysfunction in HAM patients. To test this hypothesis, we analyzed TCR/CD3 expression, TCR signaling, and immune responses in HTLV-1-infected cells from HAM patients. Intracellular HTLV-1 Tax detection revealed that HTLV-1 preferentially targets CD4+ over CD8+ T cells. CD3 and TCR expression levels were significantly lower in CD4+ T cells from HAM patients compared to healthy controls. Furthermore, HTLV-1-infected cells exhibited markedly reduced CD3 and TCR expression compared to uninfected cells. Impairments in TCR signaling, assessed through Lck and ZAP70 phosphorylation upon CD3 stimulation, were observed in CD4+ T cells from HAM patients compared to those from healthy controls. Notably, this reduction in TCR signaling was more pronounced in HTLV-1-infected CD4+ T cells than in uninfected CD4+ T cells in HAM patients. Additionally, cytomegalovirus (CMV)-specific CD4+ T cells detected by an addition of CMV antigens demonstrated reduced interferon-γ production in HTLV-1-infected cells compared to their uninfected counterparts. These findings suggest that TCR/CD3 downregulation and impaired TCR signaling contribute to immune dysfunction in HTLV-1-infected CD4+ T cells. As CD4+ T cells play a central role in immune responses, this mechanism may partially explain the cellular immune dysfunction to other pathogens observed in HAM patients. Full article

With the success of chimeric antigen receptor (CAR) T-cell therapy in B-cell malignancies, efforts are being made to extend this therapy to other malignancies and broader patient populations. However, limitations associated with the time-consuming and highly personalized manufacturing of autologous CAR T-cells remain. Allogeneic CAR T-cell approaches may overcome these challenges but require further engineering to reduce their alloreactivity. As a means to prevent graft-versus-host disease (GvHD) of allogeneic CAR T-cells, we have selected a micro RNA (miRNA)-based short hairpin RNA (shRNA) targeting CD3ζ which efficiently downregulates the expression of the T-cell receptor (TCR) below detection level. We generated allogeneic anti-B-cell maturation antigen CAR T-cells (CYAD-211) that co-express an anti-CD3ζ miRNA-based shRNA within the CAR construct which efficiently inhibited TCR-mediated signaling in vitro and GvHD in vivo. CYAD-211 was subsequently evaluated in a Phase-I clinical trial (NCT04613557), in patients with relapsed or refractory multiple myeloma. No signs of GvHD were observed despite evidence of engraftment, demonstrating efficient downregulation of the TCR. Our data provide proof of concept that a non-gene-edited technology can generate fully functional allogeneic CAR T-cells, without any signs of GvHD. However, further engineering of the CAR T-cells is needed to improve their persistence and long-term activity. Full article

The intestinal tract is constantly exposed to a diverse mixture of luminal antigens, such as those derived from commensals, dietary substances, and potential pathogens. It also serves as a primary route of entry for pathogens. At the forefront of this intestinal defense is a single layer of epithelial cells that forms a critical barrier between the gastrointestinal (GI) lumen and the underlying host tissue. The intestinal intraepithelial T lymphocytes (T-IELs), one of the most abundant lymphocyte populations in the body, play a crucial role in actively surveilling and maintaining the integrity of this barrier by tolerating non-harmful factors such as commensal microbiota and dietary components, promoting epithelial turnover and renewal while also defending against pathogens. This immune balance is maintained through interactions between ligands in the GI microenvironment and receptors on T-IELs. This review provides a detailed examination of the ligands present in the intestinal epithelia and the corresponding receptors expressed on T-IELs, including T cell receptors (TCRs) and non-TCRs, as well as how these ligand-receptor interactions influence T-IEL functions under both steady-state and pathological conditions. By understanding these engagements, we aim to shed light on the mechanisms that govern T-IEL activities within the GI microenvironment. This knowledge may help in developing strategies to target GI ligands and modulate T-IEL receptor expression, offering precise approaches for treating intestinal disorders. Full article

Background/Objectives: MDG1011 is an autologous TCR-T therapy developed as a treatment option for patients with myeloid malignancies, including acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), and multiple myeloma (MM). It is specific for the target antigen PReferentially expressed Antigen in MElanoma (PRAME). The recombinant TCR used in MDG1011 recognizes PRAME_100–108 VLD-peptide presented by HLA-A*02:01-encoded surface molecules. Methods: Two preclinical batches of MDG1011, produced from enriched CD8+ T cells of healthy donors, underwent rigorous evaluation of on-target and off-target recognition of tumor cells and test cells representing healthy tissues. MDG1011 investigational medicinal products (IMPs) were produced for 13 patients. VLD-TCR surface expression was assessed using dual-marker flow cytometry using TCR V-beta-specific antibody and VLD/HLA-A2-specific multimer. Functionality was assessed by interferon-gamma (IFN-γ) secretion and cell-mediated cytotoxicity of target cells. Results: Preclinical MDG1011 batches displayed strong VLD-TCR expression, cytokine secretion, and cytotoxicity after antigen-specific activation, while showing no signals of on-target/off-tumor or off-target recognition. All IMPs had good VLD-TCR expression as well as functionality after activation by multiple target cells. Conclusions: Preclinical studies demonstrated that MDG1011 displayed key 3S attributes of high specificity, sensitivity, and safety required for regulatory approval of a first-in-human (FIH) clinical study of patients with myeloid malignancies (CD-TCR-001: ClinicalTrials.gov Identifier: NCT03503968). MDG1011 IMP manufacturing was successful at 92%, even including heavily pretreated elderly patients with very advanced disease. The IMPs applied in nine patients all displayed antigen-specific functionality. Elsewhere, clinical study results for MDG1011 showed no dose-limiting toxicity and signs of biological and/or clinical activity in several patients. Full article

Class IA PI3K p110δ and p110α subunits participate in TCR and costimulatory receptor signals involved in T cell-mediated immunity, but the role of p110α is not completely understood. Here, we analyzed a mouse model of the Cre-dependent functional inactivation of p110α (kinase dead) in T lymphocytes (p110αKD-T, KD). KD mice showed increased cellularity in thymus and spleen and altered T cell differentiation with increased number of CD4⁺CD8⁺ DP thymocytes, enhanced proportion of CD4⁺ SP lymphocytes linked to altered apoptosis, lower Treg cells, and increased AKT and ERK phosphorylation in activated thymocytes. In the spleen, the percentages of CD4⁺ Treg cells and CD8⁺ naive lymphocytes were reduced. In vitro, the differentiation of CD4⁺ cells from p110αKD-T mice showed lower induced Treg (iTreg) cell yield or IL-10 secretion. Moreover, Tfh cell yield, IL-21 secretion, and PI3-K-dependent elongation were hampered, as was Erk and Akt activation. Th1 or Th17 differentiation in vitro was not altered. The immunization of p110α-KD-T mice with KLH protein antigen induced an enhanced proportion of CXCR5⁺ CD4⁺ cells and germinal center B cells, increased ICOS expression in CD4⁺ cells, or IFN-γ secretion upon antigen re-activation in vitro. However, anti-KLH antibody responses in serum was similar in WT or p110α KD mice. These data show that T cell-specific p110α inactivation alters T cell differentiation and function. Full article

Ulcerative colitis (UC) is a chronic immune disease that is difficult to cure. We recently found that chick early amniotic fluid (ceAF) has notable anti-inflammatory and antioxidative properties, through its active components. This study demonstrates the potential of ceAF as a protective agent against UC. UPLC-MS mass spectrometry identified key components of ceAF, including various fatty acids and nucleosides. In vitro, ceAF improved viability in DSS-induced Caco-2 cells, reduced pro-inflammatory cytokines IL-1β and TNF-α, and increased the anti-inflammatory cytokine IL-10. It also upregulated the tight junction proteins ZO-1 and occludin. In DSS-induced UC mice, ceAF treatment alleviated weight loss, colon shortening, and disease activity, while improving histopathology, crypt depth, and colonic fibrosis. Mechanistically, ceAF’s anti-inflammatory effects are mediated by inhibiting the overactivation of TCR signaling through the LCK/ZAP70/LAT pathway. Our findings suggest that ceAF could be a valuable nutritional intervention for UC, potentially enhancing existing functional foods aimed at managing this condition. Full article

Thoracic malignancies (lung cancers and malignant pleural mesothelioma) are prevalent worldwide and are associated with high morbidity and mortality. Effective treatments are needed for patients with advanced disease. Cell therapies are a promising approach to the treatment of advanced cancers that make use of immune effector cells that have the ability to mediate antitumor immune responses. In this review, we discuss the prospect of chimeric antigen receptor-T (CAR-T) cells, natural killer (NK) cells, T cell receptor-engineered (TCR-T) cells, and tumor-infiltrating lymphocytes (TILs) as treatments for thoracic malignancies. CAR-T cells and TILs have proven successful in several hematologic cancers and advanced melanoma, respectively, but outside of melanoma, results have thus far been unsuccessful in most other solid tumors. NK cells and TCR-T cells are additional cell therapy platforms with their own unique advantages and challenges. Obstacles that must be overcome to develop effective cell therapy for these malignancies include selecting an appropriate target antigen, combating immunosuppressive cells and signaling molecules present in the tumor microenvironment, persistence, and delivering a sufficient quantity of antitumor immune cells to the tumor. Induced pluripotent stem cells (iPSCs) offer great promise as a source for both NK and T cell-based therapies due to their unlimited expansion potential. Here, we review clinical trial data, as well as recent basic scientific advances that offer insight into how we may overcome these obstacles, and provide an overview of ongoing trials testing novel strategies to overcome these obstacles. Full article

Recombinant antibodies and, more recently, T cell receptor (TCR)-engineered T cell therapies represent two immunological strategies that have come to the forefront of clinical interest for targeting intracellular neoantigens in benign and malignant diseases. T cell-based therapies targeting neoantigens use T cells expressing a recombinant complete TCR (TCR-T cell), a chimeric antigen receptor (CAR) with the variable domains of a neoepitope-reactive TCR as a binding domain (TCR-CAR-T cell) or a TCR-like antibody as a binding domain (TCR-like CAR-T cell). Furthermore, the synthetic T cell receptor and antigen receptor (STAR) and heterodimeric TCR-like CAR (T-CAR) are designed as a double-chain TCRαβ-based receptor with variable regions of immunoglobulin heavy and light chains (VH and VL) fused to TCR-Cα and TCR-Cβ, respectively, resulting in TCR signaling. In contrast to the use of recombinant T cells, anti-neopeptide MHC (pMHC) antibodies and intrabodies neutralizing intracellular neoantigens can be more easily applied to cancer patients. However, different limitations should be considered, such as the loss of neoantigens, the modification of antigen peptide presentation, tumor heterogenicity, and the immunosuppressive activity of the tumor environment. The simultaneous application of immune checkpoint blocking antibodies and of CRISPR/Cas9-based genome editing tools to engineer different recombinant T cells with enhanced therapeutic functions could make T cell therapies more efficient and could pave the way for its routine clinical application. Full article