Search Results (206)

BAP31, a transmembrane protein in the endoplasmic reticulum, is known for its oncogenic properties, but its role in immunotherapy is not well understood. While BAP31’s involvement in liver, gastric, and cervical cancers has been documented, its role in pan-cancer immune regulation, particularly in breast cancer, remains unexplored. Using TCGA data, analysis via the Xiantao academic and GEPIA2 database showed that BAP31 upregulation correlates with advanced clinical stages and a poor prognosis. ROC analysis demonstrated BAP31’s high accuracy in distinguishing cancerous tissue from normal tissues. Additionally, BAP31 expression is associated with CNV, methylation, TMB, and MSI. In breast cancer, TIMER database analysis revealed that BAP31 expression is inversely correlated with the infiltration levels of myeloid-derived suppressor cells (MDSCs), macrophages, T lymphocytes, B lymphocytes, and neutrophils. Additionally, we investigated the relationship between BAP31 and the expression of major histocompatibility complex (MHC) molecules and chemokine receptors utilizing the TISIDB database. LinkedOmics analysis demonstrated associations between BAP31 and various immune-inflammatory pathways, while also indicating a negative correlation between BAP31 expression and four critical pathways: extracellular matrix receptor interaction, focal adhesion, JAK-STAT signaling, and TGF-β signaling. Furthermore, loss-of-function experiments employing shRNA-mediated knockdown of BAP31 resulted in a marked reduction in cell proliferation and an increase in apoptosis in breast cancer cells, thereby confirming its role in tumor promotion. These findings suggest that BAP31 may serve as a promising prognostic biomarker and a potential target for immunotherapy in breast cancer. Full article

Malignant tumors of the digestive system are widespread and pose a serious threat to humans. Immune escape is an important factor promoting the deterioration of malignant tumors in the digestive system. Natural killer cells (NK cells) are key members of the anti-tumor and immune surveillance system, mainly exerting cytotoxic effects by binding to the activating receptor natural killer cell group 2D (NKG2D) on their cell surface with the corresponding ligands (major histocompatibility complex class I chain-related protein A/B, MICA/B) on the surface of tumor cells. Malignant tumors of epithelial origin usually highly express NKG2D ligands such as MICA, which can attract NK cells to kill tumor cells and also serve as an important basis for NK cell-based immunotherapy. Tumor cells highly express hypoxia-inducible factor-1α (HIF-1α), which promotes the expression of matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinases (ADAMs). These metalloproteinases hydrolyze MICA and other ligands on the surface of tumor cells to generate soluble molecules. These soluble ligands, when binding to NKG2D, cannot activate NK cells and also block the binding of NKG2D to MICA on the surface of tumor cells, enabling tumor cells to evade the killing effect of NK cells. Almost all organs in the digestive system originate from epithelial tissue, so the soluble ligands generated by the HIF-1α/MMPs or HIF-1α/ADAMs signaling pathways play a crucial role in evading NK cell killing. A comprehensive understanding of this immune escape process is helpful for a deeper understanding of the molecular mechanism of NK cell anti-tumor activity. This article reviews the molecular mechanisms of common digestive system malignancies evading NK cell killing, providing new insights into the mechanism of tumor immune escape. Full article

The DNA-damage response (DDR) network and the immune system are significant mechanisms linked to the normal functioning of living organisms. Extensive observations suggest that agents that damage the DNA can boost immunity in various ways, some of which may be useful for immunotherapeutic applications. Indeed, the immune system can be activated by the DDR network through a number of different mechanisms, such as via (a) an increase in the tumor neoantigen burden, (b) the induction of the stimulator of interferon genes pathway, (c) the triggering of immunogenic cell death, (d) an increase in antigen presentation as a result of the augmented expression of the major histocompatibility complex type I molecule, (e) modification of the cytokine milieu in the tumor microenvironment, and (f) altered expression of the programmed cell death ligand-1. Together, the DDR network may improve the effect of immunostimulatory anticancer agents and provide a basis for devising more efficient treatment strategies, such as combinatorial therapies of DDR targeting drugs and immunomodulators. Here, the molecular mechanisms underlying the immune system’s activation by DDR are summarized, along with some of their possible uses in cancer treatment. Full article

Alternative splicing (AS) is a pivotal post-transcriptional mechanism that expands the functional diversity of the proteome by enabling a single gene to generate multiple mRNA and protein isoforms. This process, which involves the differential inclusion or exclusion of exons and introns, is tightly regulated by splicing factors (SFs), such as serine/arginine-rich proteins (SRs), heterogeneous nuclear ribonucleoproteins (hnRNPs), and RNA-binding motif (RBM) proteins. These factors recognize specific sequences, including 5′ and 3′ splice sites and branch points, to ensure precise splicing. While AS is essential for normal cellular function, its dysregulation is increasingly implicated in cancer pathogenesis. Aberrant splicing can lead to the production of oncogenic isoforms that promote tumorigenesis, metastasis, and resistance to therapy. Furthermore, such abnormalities can cause the loss of tumor-suppressing activity, thereby contributing to cancer development. Importantly, abnormal AS events can generate neoantigens, which are presented on tumor cell surfaces via major histocompatibility complex (MHC) molecules, suggesting novel targets for cancer immunotherapy. Additionally, splice-switching oligonucleotides (SSOs) have shown promise as therapeutic agents because they modulate splicing patterns to restore normal gene function or induce tumor-suppressive isoforms. This review explores the mechanisms of AS dysregulation in cancer, its role in tumor progression, and its potential as a therapeutic target. We also discuss innovative technologies, such as high-throughput sequencing and computational approaches, that are revolutionizing the study of AS in cancer. Finally, we address the challenges and future prospects of targeting AS for personalized cancer therapies, emphasizing its potential in precision medicine. Full article

Hypersensitivity reactions are dysregulated and potentially devastating immune responses, characterized by a tendency to become chronic. They target either self-proteins or harmless foreign proteins and are driven by both T and B cells. Although numerous symptomatic treatment options for hypersensitivity reactions have been established over recent decades, only a few antigen-specific, causal approaches capable of specifically targeting the pathogenic autoreactive T and/or B cells have been developed. Among these are cell-based treatment modalities involving chimeric antigen receptor (CAR)- or chimeric autoantibody-receptor (CAAR)-expressing cells. These therapies utilize B- or T-cell antigens, presented as B-cell epitopes or peptide-major histocompatibility complexes (pMHCs) to serve as bait. The latter are coupled to potent activation domains derived from the TCR/CD3 complex itself, such as the zeta or CD3 chains, as well as domains from bona fide co-stimulatory molecules (e.g., CD28, 4-1BB). Recent in vitro and in vivo studies have demonstrated the therapeutic potential of these ATMP-based strategies in eliminating autoreactive lymphocytes and alleviating hypersensitivity reactions. This systematic review provides a comprehensive overview of the current status of antigen-specific CAR and CAAR T-cell therapies, highlighting novel directions as well as the ongoing challenges within this promising research field. Full article

This review explores the mechanisms by which Human Immunodeficiency Virus type 1 (HIV-1) regulatory proteins manipulate host cellular pathways to promote viral replication and immune evasion. Key viral proteins, such as Nef, Vpu, Vif, Vpr, and Env, disrupt immune defenses by downregulating surface molecules such as CD4 (Cluster of Differentiation 4) and Major Histocompatibility Complex (MHC) class I, degrading antiviral enzymes like APOBEC3G (Apolipoprotein B mRNA editing catalytic polypeptide-3G) and SAMHD1 (Sterile Alpha Motif and Histidine Aspartate domain-containing protein 1), and counteracting restriction factors including BST-2 (Bone Marrow Stromal Antigen 2)/Tetherin and SERINC5 (Serin Incorporator 5). These interactions support viral persistence and contribute to the establishment of chronic infection. Emerging therapeutic strategies aim to disrupt these HIV-host interactions to restore innate antiviral responses and enhance immune clearance. Approaches such as stabilizing host restriction factors or blocking viral antagonists offer a promising alternative to conventional antiretroviral therapy. By targeting host-dependent pathways, these interventions may reduce drug resistance, tackle latent reservoirs, and provide a pathway toward sustained viral remission or functional cure. Full article

Various inhibitors targeting T-cell immunoglobulin and mucin-containing molecule 3 (TIM3) aimed at reversing T-cell exhaustion for better immunotherapy outcomes have demonstrated limited clinical efficacy as monotherapy, with the underlying mechanisms remaining ambiguous. TIM3 is markedly expressed in dendritic cells (DCs), and the inconsistent research findings on its role in myeloid cells underscore its vital function within DCs. Through the establishment of an in vitro differentiation model generating mature dendritic cells (mDCs) under TIM3-targeted interventions, combined with an RNA sequencing analysis, this investigation systematically examined TIM3-mediated regulation and ligand interactions in human primary DCs. The findings indicate that TIM3 inhibition hinders DC maturation, which subsequently diminishes the antigen-presenting capacity of DCs, ultimately leading to immune suppression in T cells. These findings collectively establish TIM3 as a regulator of DC differentiation that promotes DC maturation while optimizing the antigen-processing and presentation capacity. This study elucidates the rationale behind the suboptimal efficacy of TIM3 inhibitors and advocates for retaining TIM3 signaling pathways in DCs. Full article

Antigen presentation on major histocompatibility complex (MHC) molecules is central to the initiation of immune responses, and a lot of our understanding about the antigen processing and presentation pathway has been gained through studies in mice. MHC molecules are the most genetically diverse genes; consequently, mouse strains differ substantially in their MHC make up and resulting antigen presentation. Swiss mice are commonly used in pharmacological research, yet our understanding of antigen presentation in this strain is surprisingly limited. Here, we have tested a range of anti-MHC antibodies and present a range of clones suitable to analyse MHC class I and class II molecules in Swiss mice who have the H2-q MHC haplotype. Moreover, we demonstrate using immunopeptidomics that clones 28-12-8, 34-1-2, MKD6, and N22 are also suited to isolate MHC class I and class II ligands in this mouse strain. Thus, this work also establishes a first experimental account of the H2-q-derived thymus and spleen immunopeptidome in Swiss mice which bears strong resemblance with ligands isolated from the H2-d MHC haplotype of Balb/C mice. The analysis of source proteins shows common but also organ- and function-specific antigen presentation in line with the involvement of the thymus in tolerance induction and the function of the spleen as a site of immune responses. Full article

There are about 5000 species of Passeriformes birds, which are half of the extant ones. Their class I MHC molecules are found to be different from all other studied vertebrates, including other bird species; i.e., amino acid residues 10 and 96 are not the seven canonic residues extant in all other vertebrate molecules. Thus, the canonic residues in MHC class I vertebrate molecules are reduced to five. These differences have physical effects in MHC (Major Histocompatibility Complex) class I alpha chain interaction with beta-2-microglobulin but have yet unknown functional effects. Also, introns show specific Passeriformes distinction both in size and invariance. The studies reviewed in this paper on MHC structure have been done in wild birds that cover most of the world’s passerine habitats. In this context, we are going to expose the most commonly occurring bird diseases with the caveat that MHC and disease linkage pathogenesis is not resolved. In addition, this field is poorly studied in birds; however, common bird diseases like malaria and Marek’s disease are linked to MHC. On the other hand, the main established function of MHC molecules is presenting microbial and other antigens to T cells in order to start immune responses, and they also may modulate the immune system through NK receptors and other receptors (non-classical class I MHC molecules). Also, structural and polymorphic differences between classical class I molecules and non-classical class I molecules are at present not clear, and their definition is blurred. These passerine exceptional MHC class I molecules may influence linkage to diseases, transplantation, and other MHC presentation and self-protection functions. Further studies in more Passeriformes species are ongoing and needed. Full article

Background: The cyclic GMP-AMP synthase (cGAS)–type I interferon (IFN-I) pathway detects cytoplasmic DNA and triggers immune responses. Cancer cells often suppress this pathway to evade immune surveillance; however, its therapeutic potential remains unclear. Methods: Mouse oral squamous cell carcinoma models, representing a prominent subtype of head and neck squamous cell carcinoma (HNSCC), were employed in this study. Flow cytometry, Western blot, ELISA, and PCR were used for analysis. Results: We found that immune-unresponsive MOC2 tumors exhibited a deficiency of antigen-presenting cells and cytotoxic T lymphocytes, along with a significant suppression of the cGAS-IFN-I pathway, compared to immune-responsive MOC1 tumors. An MOC2-conditioned medium impaired the differentiation of bone marrow-derived cells into dendritic cells (DCs), reducing the expression of DC markers as well as class I and II major histocompatibility complex (MHC) molecules. The activation of the cGAS-IFN-I pathway in MOC2 cells, either through exogenous DNA or direct IFN-I expression, enhanced class I MHC expression and antigen presentation on MOC2 cells. Furthermore, IFNB1 expression in MOC2 cells induced apoptosis and upregulated chemokines, such as CXCL9 and CXCL10, which recruit immune cells. In immunocompetent mice, IFNB1 expression suppressed MOC2 tumor growth by attracting DCs and T cells, an effect amplified by co-expressing the granulocyte–macrophage colony-stimulating factor. Conclusions: These findings highlight the potential of enhancing cancer cell-intrinsic cGAS-IFN-I signaling to improve tumor immune surveillance and control the progression of immune-cold HNSCC tumors. Full article

Background: T-cell-engaging bispecific (TCB) antibodies represent a promising therapy that utilizes T-cells to eliminate cancer cells independently of the major histocompatibility complex. Despite their success in hematologic cancers, challenges such as cytokine release syndrome (CRS), off-tumor toxicity, and resistance limit their efficacy in solid tumors. Optimizing biodistribution is key to overcoming these challenges. Methods: A physiologically based pharmacokinetic (PBPK) model was developed that incorporates T-cell transmigration, retention, receptor binding, receptor turnover, and cellular engagement. Preclinical biodistribution data were modeled using two TCB formats: one lacking tumor target binding and another with target arm binding, each with varying CD3 affinities in a transgenic tumor-bearing mouse model. Results: The PBPK model successfully described the distribution of activated T-cells and various TCB formats. It accurately predicted preclinical biodistribution patterns, demonstrating that higher CD3 affinity leads to faster clearance from the blood and increased accumulation in T-cell-rich organs, often reducing tumor exposure. Simulations of HER2-CD3 TCB doses (0.1 µg to 100 mg) revealed monotonic increases in synapse AUC within the tumor. A bell-shaped dose-Cmax relationship for synapse formation was observed, and Tmax was delayed at higher doses. Blood PK was a reasonable surrogate for tumor synapse at low doses but less predictive at higher doses. Conclusions: We developed a whole-body PBPK model to simulate the biodistribution of T-cells and TCB molecules. The insights from this model provide a comprehensive understanding of the factors affecting PK, synapse formation, and TCB activity, aiding in dose optimization and the design of effective therapeutic strategies. Full article

Background/Objectives: Neuroinflammation, a hallmark of Alzheimer’s disease (AD), is characterized by elevated levels of inflammatory signaling molecules, including cytokines and eicosanoids, as well as increased microglial reactivity, and is augmented by gut microbiota dysbiosis via the gut–brain axis. We conducted a pilot experiment to elucidate the anti-inflammatory effects of dietary omega-3 polyunsaturated fatty acid (ω-3 PUFA) eicosapentaenoic acid (EPA) on the gut microbiota and neuroinflammation. Methods: Female APP/PS1 mice (TG) and non-transgenic littermates (WT), 13–14 months old, were fed a diet supplemented with 0.3% EPA or control chow for 3 weeks. The gut microbiota composition, hippocampal and plasma eicosanoids levels, platelet activation, and microglial phagocytosis, as well as the brain and retinal genes and protein expression, were analyzed. Results: EPA supplementation decreased the percentage of Bacteroidetes and increased bacteria of the phylum Firmicutes in APP/PS1 and WT mice. Inflammatory lipid mediators were elevated in the hippocampus of the TG mice, accompanied by a reduction in the endocannabinoid docosahexaenoyl ethanolamide (DHEA). Dietary EPA did not affect hippocampal lipid mediators, but reduced the levels of arachidonic-derived 5-HETE and N-arachidonoylethanolamine (AEA) in WT plasma. Moreover, EPA supplementation decreased major histocompatibility complex class II (MHCII) gene expression in the retina in both genotypes, and MHCII+ cells in the hippocampus of TG mice. Conclusions: This pilot study showed that short-term EPA supplementation shaped the gut microbiota by increasing butyrate-producing bacteria of the Firmicutes phylum and decreasing Gram-negative LPS-producing bacteria of the Bacteroidetes phylum, and downregulated the inflammatory microglial marker MHCII in two distinct regions of the central nervous system (CNS). Further investigation is needed to determine whether EPA-mediated effects on the microbiome and microglial MHCII have beneficial long-term effects on AD pathology and cognition. Full article

The immune system is alerted for virally infected cells in the body by the antigen presentation pathway, which is in turn mediated by the major histocompatibility complex (MHC) class I and II molecules. Cancer cells overcome immune evasion as a major hallmark by downregulation of the antigen presentation pathway. Therefore, the present study aimed to explore the effect of genetic variants in genes involved in MHC class I and II pathways in patients treated with first-line chemotherapy in combination with targeted antibodies in metastatic colorectal cancer (mCRC) patients. Genomic DNA from the blood samples of 775 patients enrolled in three independent, randomized, first-line trials, namely TRIBE (FOLFIRI-bevacizumab, N = 215), FIRE-3 (FOLFIRI-bevacizumab, N = 107; FOLFIRI-cetuximab, N = 129), and MAVERICC (FOLFIRI-bevacizumab, N = 163; FOLFOX6-bevacizumab, N = 161), was genotyped through OncoArray, a custom array manufactured by Illumina including approximately 530K SNP markers. The impact on the outcome of 40 selected SNPs in 22 genes of MHC class I and II pathways was analyzed. We identified several SNPs in multiple genes associated with targeted treatment benefits across different treatment arms in our study population (p < 0.05). Treatment–SNP interaction analyses confirmed a significant treatment interaction with the targeted agents (bevacizumab vs. cetuximab) and the chemotherapy backbone (FOLFIRI vs. FOLFOX) in certain selected SNPs. Our results highlight a potential role for MHC SNPs as prognostic and predictive biomarkers for first-line treatment in mCRC, with differential effects based on the biologic agent and chemotherapy backbone. These biomarkers, when further validated, may contribute to personalized treatment strategies for mCRC patients. Full article

After four decades of intensive research, traditional vaccination strategies for HIV-1 remain ineffective due to HIV-1′s extraordinary genetic diversity and complex immune evasion mechanisms. Cytomegaloviruses (CMV) have emerged as a novel type of vaccine vector with unique advantages due to CMV persistence and immunogenicity. Rhesus macaques vaccinated with molecular clone 68-1 of RhCMV (RhCMV68-1) engineered to express simian immunodeficiency virus (SIV) immunogens elicited an unconventional major histocompatibility complex class Ib allele E (MHC-E)-restricted CD8⁺ T-cell response, which consistently protected over half of the animals against a highly pathogenic SIV challenge. The RhCMV68-1.SIV-induced responses mediated a post-infection replication arrest of the challenge virus and eventually cleared it from the body. These observations in rhesus macaques opened a possibility that MHC-E-restricted CD8⁺ T-cells could achieve similar control of HIV-1 in humans. The potentially game-changing advantage of the human CMV (HCMV)-based vaccines is that they would induce protective CD8⁺ T-cells persisting at the sites of entry that would be insensitive to HIV-1 evasion. In the RhCMV68-1-protected rhesus macaques, MHC-E molecules and their peptide cargo utilise complex regulatory mechanisms and unique transport patterns, and researchers study these to guide human vaccine development. However, CMVs are highly species-adapted viruses and it is yet to be shown whether the success of RhCMV68-1 can be translated into an HCMV ortholog for humans. Despite some safety concerns regarding using HCMV as a vaccine vector in humans, there is a vision of immune programming of HCMV to induce pathogen-tailored CD8⁺ T-cells effective against HIV-1 and other life-threatening diseases. Full article

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by self-antibody production and widespread inflammation affecting various body tissues. This disease is driven by the breakdown of immune tolerance, which promotes the activation of autoreactive B and T cells. A key feature of SLE is dysregulation in antigen presentation, where antigen-presenting cells (APCs) play a central role in perpetuating immune responses. Dendritic cells (DCs) are highly specialized for antigen presentation among APCs. At the same time, myeloid-derived suppressor cells (MDSCs) can also express MHC-II molecules, although their role in SLE is less understood. Utilizing the SLE model, MRL/MpJ-Fas^lpr/J, we determined the presence of different phenotypes of DCs and MDSCs expressing MHC-II in secondary lymphoid organs, along with the gene expression of ICOSL, CD80 and CD86 in the spleen. Our study determined that the most abundant population of APCs in secondary lymphoid organs corresponds to cDC CD103⁻CD11b⁺ MHC-II⁺ throughout SLE development. Additionally, ICOSL expression increased over time, becoming more preponderant in week 16 in the SLE model, which could indicate that it is a crucial pathway for the development and progression of the pathology. In week 16, we observed a positive correlation between M-MDSC MHC-II and IFN-γ-producing CD4⁺ T cells. Full article