Antigen Presentation Process Research Articles

The complex role of immune cells in antigen presentation and regulation of T-cell responses in hepatocellular carcinoma: progress, challenges, and future directions.

Hepatocellular carcinoma (HCC) is a prevalent form of liver cancer that poses significant challenges regarding morbidity and mortality rates. In the context of HCC, immune cells play a vital role, especially concerning the presentation of antigens. This review explores the intricate interactions among immune cells within HCC, focusing on their functions in antigen presentation and the modulation of T-cell responses. We begin by summarizing the strategies that HCC uses to escape immune recognition, emphasizing the delicate equilibrium between immune surveillance and evasion. Next, we investigate the specific functions of various types of immune cells, including dendritic cells, natural killer (NK) cells, and CD8+ T cells, in the process of antigen presentation. We also examine the impact of immune checkpoints, such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and the pathways involving programmed cell death protein 1 (PD-1) and programmed death ligand 1 (PD-L1), on antigen presentation, while taking into account the clinical significance of checkpoint inhibitors. The review further emphasizes the importance of immune-based therapies, including cancer vaccines and CAR-T cell therapy, in improving antigen presentation. In conclusion, we encapsulate the latest advancements in research, propose future avenues for exploration, and stress the importance of innovative technologies and customized treatment strategies. By thoroughly analyzing the interactions of immune cells throughout the antigen presentation process in HCC, this review provides an up-to-date perspective on the field, setting the stage for new therapeutic approaches.

Enhancing CAR-T cell therapy against solid tumor by drug-free triboelectric immunotherapy

Chimeric antigen receptor (CAR) T cell therapy is a highly effective immunotherapy for hematological tumors, but its efficacy against most solid tumors remains challenging. Herein, a novel synergistic combination therapy of drug-free triboelectric immunotherapy and CAR-T cell therapy against solid tumor was proposed. A triboelectric nanogenerator (TENG) that can generate pulsed direct-current by coupling triboelectrification effect and electrostatic breakdown effect was fabricated. The TENG can generate up to 30 pulse direct-current peaks with peak current output ≈35 μA in a single sliding to power the triboelectric immunotherapy. The pulsed direct-current stimulation induced immunogenic cell death of tumor cells (survival rate of 35.9 %), which promoted dendritic cells maturation, accelerated the process of antigen presentation to CAR-T cells and enhanced the systemic adaptive immune response. Furthermore, triboelectric immunotherapy promoted M1-like macrophage polarization, reduced regulatory T cells differentiation and reprogrammed the tumor immunosuppressive microenvironment, which ultimately enhanced the efficacy of CAR-T cells to eradicate nearly 60 % of NALM6 solid tumor mass. Notably, considering that triboelectric immunotherapy is a safe and effective drug-free antitumor strategy, the combined therapy did not increase the burden of double-medication on patients.

Immunogenetic Landscape in Pediatric Common Variable Immunodeficiency.

Common variable immunodeficiency (CVID) is the most common symptomatic antibody deficiency, characterized by heterogeneous genetic, immunological, and clinical phenotypes. It is no longer conceived as a sole disease but as an umbrella diagnosis comprising a spectrum of clinical conditions, with defects in antibody biosynthesis as their common denominator and complex pathways determining B and T cell developmental impairments due to genetic defects of many receptors and ligands, activating and co-stimulatory molecules, and intracellular signaling molecules. Consequently, these genetic variants may affect crucial immunological processes of antigen presentation, antibody class switch recombination, antibody affinity maturation, and somatic hypermutation. While infections are the most common features of pediatric CVID, variants in genes linked to antibody production defects play a role in pathomechanisms of immune dysregulation with autoimmunity, allergy, and lymphoproliferation reflecting the diversity of the immunogenetic underpinnings of CVID. Herein, we have reviewed the aspects of genetics in CVID, including the monogenic, digenic, and polygenic models of inheritance exemplified by a spectrum of genes relevant to CVID pathophysiology. We have also briefly discussed the epigenetic mechanisms associated with micro RNA, DNA methylation, chromatin reorganization, and histone protein modification processes as background for CVID development.

HLA-Cw6 Polymorphism in Autoimmune Blistering Diseases.

Autoimmune blistering diseases of the pemphigus and pemphigoid groups are immune-mediated disorders due to circulating pathogenetic autoantibodies. Multiple human leukocyte antigen (HLA) genes have been associated with predisposition to these disorders. HLA-Cw6 is involved in antigen presentation processes and has been linked to psoriasis. The aim of our study was to investigate the association between the presence of the HLA-Cw6 allele and susceptibility to pemphigus vulgaris and bullous pemphigoid. A genetic study in vitro with a cross-sectional design was performed enrolling forty patients with pemphigus vulgaris and forty patients with bullous pemphigoid. The detection of HLA-Cw6 was performed through the EUROArray test on DNA obtained from whole blood samples. The polymorphism was detected in 3/40 genotypes in the pemphigus vulgaris group and in 4/40 genotypes of patients with bullous pemphigoid, unveiling a non-statistically significant different frequency in pemphigus (p = 0.6368) and in pemphigoid (p = 0.62) compared to the reference frequency from the literature of 0.086. Further research is needed to better investigate the role of HLA-Cw6 in immune-mediated diseases and to identify novel genetic markers associated with susceptibility to autoimmune blistering diseases and with disease severity and response to immunosuppressive therapies.

ASO-mediated knockdown of GPNMB in mutant- GRN and Grn -deficient peripheral myeloid cells disrupts lysosomal function and immune responses.

Increases in GPNMB are detectable in FTD- GRN cerebrospinal fluid (CSF) and post-mortem brain, and brains of aged Grn -deficient mice. Although no upregulation of GPNMB is observed in the brains of young Grn -deficient mice, peripheral immune cells of these mice do exhibit this increase in GPNMB. Importantly, the functional significance of GPNMB upregulation in progranulin-deficient states is currently unknown. Given that GPNMB has been discussed as a potential therapeutic target in GRN -mediated neurodegeneration, it is vital for the field to determine what the normal function of GPNMB is in the immune system, and whether targeting GPNMB will elicit beneficial or deleterious effects. The effects of GPNMB knock-down via antisense oligonucleotide (ASO) were assessed in peripheral blood mononuclear cells (PBMCs) from 25 neurologically healthy controls (NHCs) and age- and sex-matched FTD- GRN patients, as well as peritoneal macrophages (pMacs) from progranulin-deficient ( Grn -/- ) and B6 mice. Lysosomal function, antigen presentation and MHC-II processing and recycling were assessed, as well as cytokine release and transcription. We demonstrate here that ASO-mediated knockdown of GPNMB increases lysosomal burden and cytokine secretion in FTD-GRN carrier and neurologically healthy controls (NHCs) monocytes. ASO-mediated knockdown of GPNMB in Grn -deficient macrophages decreased lysosomal pan-cathepsin activity and protein degradation. In addition, ASO-mediated knockdown of GPNMB increased MHC-II surface expression, which was driven by decreased MHC-II uptake and recycling, in macrophages from Grn -deficient females. Finally, ASO-mediated knockdown of GPNMB dysregulated IFNγ-stimulated cytokine transcription and secretion by mouse macrophages due to the absence of regulatory actions of the GPNMB extracellular fragment (ECF). Our data herein reveals that GPNMB has a regulatory effect on multiple immune effector functions, including capping inflammation and immune responses in myeloid cells via secretion of its ECF. Therefore, in progranulin-deficient states, the drastic upregulation in GPNMB transcript and protein may represent a compensatory mechanism to preserve lysosomal function in myeloid cells. These novel findings indicate that targeted depletion in FTD- GRN would not be a rational therapeutic strategy because it is likely to dysregulate important immune cell effector functions.

Advanced Strategies for Strengthening the Immune Activation Effect of Traditional Antitumor Therapies.

The utilization of traditional therapies (TTS), such as chemotherapy, reactive oxygen species-based therapy, and thermotherapy, to induce immunogenic cell death (ICD) in tumor cells has emerged as a promising strategy for the activation of the antitumor immune response. However, the limited effectiveness of most TTS in inducing the ICD effect of tumors hinders their applications in combination with immunotherapy. To address this challenge, various intelligent strategies have been proposed to strengthen the immune activation effect of these TTS, and then achieve synergistic antitumor efficacy with immunotherapy. These strategies primarily focus on augmenting the tumor ICD effect or facilitating the antigen (released by the ICD tumor cells) presentation process during TTS, and they are systematically summarized in this review. Finally, the existing bottlenecks and prospects of TTS in the application of tumor immune regulation are also discussed.

Causal relationships between immune cell phenotypes and lung adenocarcinoma: A bidirectional two-sample Mendelian randomization study.

Lung adenocarcinoma (LUAD) is the most common type of lung cancer and closely associated with the immune system. Emerging evidence suggests that blood immune cell phenotypes in patients with LUAD may undergo alterations. Nevertheless, the limited amount of relevant research makes it difficult to understand the causal links between LUAD and changes in the immune cells. This study aimed to reveal the potential causal relationships between 731 immune cell phenotypes and LUAD. A bidirectional two-sample Mendelian randomization (MR) analysis was used to clarify causal relationships. Four types of immune phenotypes, absolute cell counts, relative cell counts, median fluorescence intensities (MFIs) of surface antigens, and morphological parameters, were investigated in this study. Heterogeneity tests, horizontal pleiotropy tests, and leave-one-out analyses were performed to validate the reliability of our study. A total of 26 immune cell characteristics were identified as contributing to the occurrence of LUAD. Memory B cells, IgD-CD38br cells, CD4+ regulatory T cells (Tregs), and plasmacytoid dendritic cells (DCs) may play a role in the development of LUAD. Through reverse MR, our study discovered that the presence of LUAD also induced changes in the expression levels of 16 immune cell traits involving specific surface markers and various types of immune cells, some of which pertain to antigen presentation and immune activation processes. Our study demonstrated causal links between several immune cell phenotypes and LUAD, thereby providing indications of the potentially oncogenic physiological state and early screening biomarkers for future research.

Single-cell analysis identifies PLK1 as a driver of immunosuppressive tumor microenvironment in LUAD.

PLK1 (Polo-like kinase 1) plays a critical role in the progression of lung adenocarcinoma (LUAD). Recent studies have unveiled that targeting PLK1 improves the efficacy of immunotherapy, highlighting its important role in the regulation of tumor immunity. Nevertheless, our understanding of the intricate interplay between PLK1 and the tumor microenvironment (TME) remains incomplete. Here, using genetically engineered mouse model and single-cell RNA-seq analysis, we report that PLK1 promotes an immunosuppressive TME in LUAD, characterized with enhanced M2 polarization of tumor associated macrophages (TAM) and dampened antigen presentation process. Mechanistically, elevated PLK1 coincides with increased secretion of CXCL2 cytokine, which promotes M2 polarization of TAM and diminishes expression of class II major histocompatibility complex (MHC-II) in professional antigen-presenting cells. Furthermore, PLK1 negatively regulates MHC-II expression in cancer cells, which has been shown to be associated with compromised tumor immunity and unfavorable patient outcomes. Taken together, our results reveal PLK1 as a novel modulator of TME in LUAD and provide possible therapeutic interventions.

Immune Checkpoints in Endometriosis-A New Insight in the Pathogenesis.

Endometriosis (EMS) is an oestrogen-dependent, chronic disease affecting women of a reproductive age. One of the important factors involved in the development of this disease is the complex disorders associated with the functioning of the immune system. Recent evidence has shown that EMS development is associated with changes in systemic and local immunity, including functional disturbances of effector and antigen-presenting cells. One of the reasons for immune imbalance can be the improper expression of immune checkpoints (ICPs). ICPs and their ligands are responsible for maintaining self-tolerance and the modulation of the initiation, duration, and magnitude of the immune response of effector cells in normal tissues to avoid tissue damage. Considering the complex nature of co-stimulatory or co-inhibitory ICPs and the signalling between effector cells and APCs, we hypothesise that changes in cells' activity caused by ICPs may lead to serious immune system disturbances in patients with endometriosis. Moreover, both upregulation and downregulation in the expression of ICPs may be implicated in this process, including the reduced activity of effector cells against endometrial implants and disturbances in the antigen-presenting process. In this narrative review, we discuss, for the first time, key findings from the emerging literature, describing the associations between ICPs and their possible implication in the pathogenesis of endometriosis.

The Functional Mechanism of BP9 in Promoting B Cell Differentiation and Inducing Antigen Presentation.

The Bursa of Fabricius, an avian unique humoral immune organ, is instrumental to B cell development. Bursal-derived peptide BP9 fosters B-cell development and formation. Yet, the exact mechanism wherein BP9 impacts B cell differentiation and antigenic presentation remains undefined. In this paper, B cell activation and differentiation in the spleen cells from mice immunized with the AIV vaccine and BP9 were detected following flow cytometry (FCM) analysis. Furthermore, the molecular mechanism of BP9 in B cell differentiation in vivo was investigated with RNA sequencing technology. To verify the potential functional mechanism of BP9 in the antigenic presentation process, the transcriptome molecular basis of chicken macrophages stimulated by BP9 was measured via high-throughput sequencing technology. The results proved that when given in experimental dosages, BP9 notably accelerated total B cells, and enhanced B-cell differentiation and plasma cell production. The gene expression profiles of B cells from mice immunized with 0.01 mg/mL BP9 and AIV vaccine disclosed that 0.01 mg/mL BP9 initiated the enrichment of several biological functions and significantly stimulated key B-cell pathways in immunized mice. Crucially, a total of 4093 differentially expressed genes were identified in B cells with BP9 stimulation, including 943 upregulated genes and 3150 downregulated genes. Additionally, BP9 induced various cytokine productions in the chicken macrophage HD11 cells and activated 9 upregulated and 20 downregulated differential miRNAs, which were involved in various signal and biological processes. Furthermore, BP9 stimulated the activation of multiple transcription factors in HD11 cells, which was related to antigen presentation processes. In summary, these results suggested that BP9 might promote B cell differentiation and induce antigen presentation, which might provide the valuable insights into the mechanism of B cell differentiation upon bursal-derived immunomodulating peptide stimulation and provide a solid experimental groundwork for enhancing vaccine-induced immunity.

The necessary role of an efficient tumor immunotherapy by MHC II expression on amateur APCs

AbstractAntigen presentation, as the initial step in inducing the activation of T lymphocytes, plays a crucial role in antitumor response. Studies concentrating on major histocompatibility complex class II (MHC II) molecules and the activated CD4+ helper T (Th) cells have gained popularity in light of the past limited efficacy of MHC I‐activated CD8+ T cells alone. In general, MHC II is canonically expressed by professional antigen‐presenting cells (pAPCs), yet attempts to increase antigen presentation by dendritic cell (DC) activation have mostly been unsuccessful. In recent years, a number of studies have found that a variety of cells, including cancer cells, fibroblasts, vascular endothelial cells (VECs), and lymphoid stromal cells (LSCs), are considered amateur APCs (aAPCs) and can express MHC II molecules, which have piqued the interest of researchers. These groups vastly outnumber DCs or macrophages, and it has been confirmed that they also qualify as antigen‐presenting complexes that are functionally related to conventional pAPCs. Herein, we will review current research regarding the antigen presentation process of MHC II, its advances in APC surfaces, especially for aAPCs, the special mechanisms of regulation of MHC II on aAPCs, and combination therapy targeting MHC II as a possible treatment strategy in cancer.

TFEB regulates dendritic cell antigen presentation to modulate immune balance in asthma

ObjectiveAsthma stands as one of the most prevalent chronic respiratory conditions in children, with its pathogenesis tied to the actived antigen presentation by dendritic cells (DCs) and the imbalance within T cell subgroups. This study seeks to investigate the role of the transcription factor EB (TFEB) in modulating the antigen presentation process of DCs and its impact on the differentiation of T cell subgroups.MethodsBone marrow dendritic cells (BMDCs) were activated using house dust mites (HDM) and underwent RNA sequencing (RNA-seq) to pinpoint differentially expressed genes. TFEB mRNA expression levels were assessed in the peripheral blood mononuclear cells (PBMCs) of both healthy children and those diagnosed with asthma. In an asthma mouse model induced by HDM, the TFEB expression in lung tissue DCs was evaluated. Further experiments involved LV-shTFEB BMDCs co-cultured with T cells to explore the influence of TFEB on DCs’ antigen presentation, T cell subset differentiation, and cytokine production.ResultsTranscriptomic sequencing identified TFEB as a significantly differentially expressed gene associated with immune system pathways and antigen presentation. Notably, TFEB expression showed a significant increase in the PBMCs of children diagnosed with asthma compared to healthy counterparts. Moreover, TFEB exhibited heightened expression in lung tissue DCs of HDM-induced asthmatic mice and HDM-stimulated BMDCs. Silencing TFEB resulted in the downregulation of MHC II, CD80, CD86, and CD40 on DCs. This action reinstated the equilibrium among Th1/Th2 and Th17/Treg cell subgroups, suppressed the expression of pro-inflammatory cytokines like IL-4, IL-5, IL-13, and IL-17, while augmenting the expression of the anti-inflammatory cytokine IL-10.ConclusionTFEB might have a vital role in asthma’s development by impacting the antigen presentation of DCs, regulating T cell subgroup differentiation, and influencing cytokine secretion. Its involvement could be pivotal in rebalancing the immune system in asthma. These research findings could potentially unveil novel therapeutic avenues for treating asthma.

Chaperone-mediated MHC-I peptide exchange in antigen presentation.

This work focuses on molecules that are encoded by the major histocompatibility complex (MHC) and that bind self-, foreign- or tumor-derived peptides and display these at the cell surface for recognition by receptors on T lymphocytes (T cell receptors, TCR) and natural killer (NK) cells. The past few decades have accumulated a vast knowledge base of the structures of MHC molecules and the complexes of MHC/TCR with specificity for many different peptides. In recent years, the structures of MHC-I molecules complexed with chaperones that assist in peptide loading have been revealed by X-ray crystallography and cryogenic electron microscopy. These structures have been further studied using mutagenesis, molecular dynamics and NMR approaches. This review summarizes the current structures and dynamic principles that govern peptide exchange as these relate to the process of antigen presentation.

Bacterial Biohybrids for Invasion of Tumor Cells Promote Antigen Cross-Presentation Through Gap Junction.

Due to inherent differences in cellular composition and metabolic behavior with host cells, tumor-harbored bacteria can discriminatorily affect tumor immune landscape. However, the mechanisms by which intracellular bacteria affect antigen presentation process between tumor cells and antigen-presenting cells (APCs) are largely unknown. The invasion behavior of attenuated Salmonella VNP20009 (VNP) into tumor cells is investigated and an attempt is made to modulate this behavior by modifying positively charged polymers on the surface of VNP. It is found that non-toxic chitosan oligosaccharide (COS) modified VNP (VNP@COS) bolsters the formation of gap junction between tumor cells and APCs by enhancing the ability of VNP to infect tumor cells. On this basis, a bacterial biohybrid is designed to promote in situ antigen cross-presentation through intracellular bacteria induced gap junction. This bacterial biohybrid also enhances the expression of major histocompatibility complex class I molecules on the surface of tumor cells through the incorporation of Mdivi-1 coupled with VNP@COS. This strategic integration serves to heighten the immunogenic exposure of tumor antigens; while, preserving the cytotoxic potency of T cells. A strategy is proposed to precisely controlling the function and local effects of microorganisms within tumors.

Comprehensive analysis of the interaction of antigen presentation during anti-tumour immunity and establishment of AIDPS systems in ovarian cancer.

There are hundreds of prognostic models for ovarian cancer. These genes are based on different gene classes, and there are many ways to construct the models. Therefore, this paper aims to build the most stable prognostic evaluation system known to date through 101 machine learning strategies. We combined 101 algorithm combinations with 10 machine learning algorithms to create antigen presentation-associated genetic markers (AIDPS) with outstanding precision and steady performance. The inclusive set of algorithms comprises the elastic network (Enet), Ridge, stepwise Cox, Lasso, generalized enhanced regression model (GBM), random survival forest (RSF), supervised principal component (SuperPC), Cox partial least squares regression (plsRcox), survival support vector machine (Survival-SVM). Then, in the train cohort, the prediction model was fitted using a leave-one cross-validation (LOOCV) technique, which involved 101 different possible combinations of prognostic genes. Seven validation data sets (GSE26193, GSE26712, GSE30161, GSE63885, GSE9891, GSE140082 and ICGC_OV_AU) were compared and analysed, and the C-index was calculated. Finally, we collected 32 published ovarian cancer prognostic models (including mRNA and lncRNA). All data sets and prognostic models were subjected to a univariate Cox regression analysis, and the C-index was calculated to demonstrate that the antigen presentation process should be the core criterion for evaluating ovarian cancer prognosis. In a univariate Cox regression analysis, 22 prognostic genes were identified based on the expression profiles of 283 genes involved in antigen presentation and the intersection of genes (p < 0.05). AIDPS were developed by our machine learning-based integration method, which was applied to these 22 genes. One hundred and one prediction models are fitted using the LOOCV framework, and the C-index is calculated for each model across all validation sets. Interestingly, RSF + Lasso was the best model overall since it had the greatest average C-index and the highest C-index of any combination of models tested on the validated data sets. In comparing external cohorts, we found that the C-index correlated AIDPS method using the RSF + Lasso method in 101 prediction models was in contrast to other features. Notably, AIDPS outperformed the vast majority of models across all data sets. Antigen-presenting anti-tumour immune pathways can be used as a representative gene set of ovarian cancer to track the prognosis of patients with cancer. The antigen-presenting model obtained by the RSF + Lasso method has the best C-INDEX, which plays a key role in developing antigen-presenting targeted drugs in ovarian cancer and improving the treatment outcome of patients.

The role of goblet cells in Crohn' s disease.

The prevalence of Crohn's disease (CD), a subtype of inflammatory bowel disease (IBD), is increasing worldwide. The pathogenesis of CD is hypothesized to be related to environmental, genetic, immunological, and bacterial factors. Current studies have indicated that intestinal epithelial cells, including columnar, Paneth, M, tuft, and goblet cells dysfunctions, are strongly associated with these pathogenic factors. In particular, goblet cells dysfunctions have been shown to be related to CD pathogenesis by direct or indirect ways, according to the emerging studies. The mucus barrier was established with the help of mucins secreted by goblet cells. Not only do the mucins mediate the mucus barrier permeability and bacterium selection, but also, they are closely linked with the endothelial reticulum stress during the synthesis process. Goblet cells also play a vital role in immune response. It was indicated that goblet cells take part in the antigen presentation and cytokines secretion process. Disrupted goblet cells related immune process were widely discovered in CD patients. Meanwhile, dysbiosis of commensal and pathogenic microbiota can induce myriad immune responses through mucus and goblet cell-associated antigen passage. Microbiome dysbiosis lead to inflammatory reaction against pathogenic bacteria and abnormal tolerogenic response. All these three pathways, including the loss of mucus barrier function, abnormal immune reaction, and microbiome dysbiosis, may have independent or cooperative effect on the CD pathogenesis. However, many of the specific mechanisms underlying these pathways remain unclear. Based on the current understandings of goblet cell's role in CD pathogenesis, substances including butyrate, PPARγagonist, Farnesoid X receptor agonist, nuclear factor-Kappa B, nitrate, cytokines mediators, dietary and nutrient therapies were all found to have potential therapeutic effects on CD by regulating the goblet cells mediated pathways. Several monoclonal antibodies already in use for the treatment of CD in the clinical settings were also found to have some goblet cells related therapeutic targets. In this review, we introduce the disease-related functions of goblet cells, their relationship with CD, their possible mechanisms, and current CD treatments targeting goblet cells.

Identifying MS4A6A+ macrophages as potential contributors to the pathogenesis of nonalcoholic fatty liver disease, periodontitis, and type 2 diabetes mellitus

PurposeConcrete epidemiological evidence has suggested the mutually-contributing effect respectively between nonalcoholic fatty liver disease (NAFLD), type 2 diabetes mellitus (T2DM), and periodontitis (PD); however, their shared crosstalk mechanism remains an open issue. MethodThe NAFLD, PD, and T2DM-related datasets were obtained from the NCBI GEO repository. Their common differentially expressed genes (DEGs) were identified and the functional enrichment analysis performed by the DAVID platform determined relevant biological processes and pathways. Then, the STRING database established a PPI network of such DEGs and topological analysis through Cytoscape 3.7.1 software along with the machine-learning analysis by the least absolute shrinkage and selection operator (LASSO) algorithm screened out hub characteristic genes. Their efficacy was validated by external datasets using the receiver operating characteristic (ROC) curve, and gene expression and location of the most robust one was determined using single-cell sequencing and immunohistochemical staining. Finally, the promising drugs were predicted through the CTD database, and the CB-DOCK 2 and Pymol platform mimicked molecular docking. ResultIntersection of differentially expressed genes from three datasets identified 25 shared DEGs of the three diseases, which were enriched in MHC II-mediated antigen presenting process. PPI network and LASSO machine-learning analysis determined 4 feature genes, of which the MS4A6A gene mainly expressed by macrophages was the hub gene and key immune cell type. Molecular docking simulation chosen fenretinide as the most promising medicant for MS4A6A+ macrophages. ConclusionMS4A6A+ macrophages were suggested to be important immune-related mediators in the progression of NAFLD, PD, and T2DM pathologies.

Abstract 4006: IL12-secreting CAR-T cells eliminate the requirement for lymphodepletion and promote epitope spreading via local antigen presenting cells

Abstract Introduction: EGFRvIII is a commonly studied tumor-specific antigen in glioblastoma (GBM) and poses an enticing target for immunotherapy. Its varied expression, however, complicates its effectiveness as a Chimeric Antigen Receptor (CAR) T cell target. Given the increasing prominence of Interleukin-12 (IL12) in treating solid tumors, its synergy with EGFRvIII specific CARs in treating preclinical models of GBM is explored. Methods: To simulate tumor heterogeneity, mice were implanted with equal ratios of CT2A and CT2A EGFRvIII+ cells. We developed EGFRvIII-specific third-generation CAR T cells, both with and without IL12 using a MSGV retrovirus backbone and transduced them into murine T cells. Their antitumor effectiveness was gauged by evaluating survival rates, and their capability to enhance and modify the tumor environment was determined using single-cell sequencing. Results: Standalone EGFRvIII CARs were unsuccessful in curing mice with heterogeneous tumors. However, 60% of mice treated with EGFRvIII CARs combined with IL12 were long term survivors. IL12 secreting CARs exhibited prolonged persistence in vivo, and there was no need for prior lymphodepletion before ALT introduction. Our studies reveal that EGFRvIII CARs secreting IL12 can eliminate EGFRvIII negative tumor cells by drawing on the inherent CD8 T cell compartment. Moreover, IL12 prominently impacted microglia among all Antigen Presenting Cells in the tumor environment, amplifying antigen presentation processes and broadening epitope exposure. Conclusion: By leveraging IL12, EGFRvIII CARs can counteract antigen heterogeneity in tumors by recruiting endogenous CD8 T cells and polarizing microglia. These IL12-secreting CARs outlast their traditional counterparts without requiring lymphodepletion. Harnessing CAR-T cells that secrete IL12 represents a novel strategy for overcoming tumor heterogeneity and treating GBM in a clinical context. Citation Format: Aditya Mohan, Steven Shen, Kelly Hotchkiss, Sarah Quackenbush, John Sampson, Peter Fecci, Anoop Patel. IL12-secreting CAR-T cells eliminate the requirement for lymphodepletion and promote epitope spreading via local antigen presenting cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4006.

Cold Tumour Phenotype Explained Through Whole Genome Sequencing in Clinical Nasopharyngeal Cancer: A Preliminary Study.

Nasopharyngeal cancer (NPC) is a complex cancer due to its unique genomic features and association with the Epstein-Barr virus (EBV). Despite therapeutic advancements, NPC prognosis remains poor, necessitating a deeper understanding of its genomics. Here, we present a comprehensive whole genome sequencing (WGS) view of NPC genomics and its correlation with the phenotype. This study involved WGS of a clinical NPC biopsy specimen. Sequencing was carried out using a long read sequencer from Oxford Nanopore. Analysis of the variants involved correlation with the phenotype of NPC. A loss of genes within chromosome 6 from copy number variation (CNV) was found. The lost genes included HLA-A, HLA-B, and HLA-C, which work in the antigen presentation process. This loss of the major histocompatibility complex (MHC) apparatus resulted in the tumour's ability to evade immune recognition. The tumour exhibited an immunologically "cold" phenotype, with mild tumour-infiltrating lymphocytes, supporting the possible etiology of loss of antigen presentation capability. Furthermore, the driver mutation PIK3CA gene was identified along with various other gene variants affecting numerous signaling pathways. Comprehensive WGS was able to detect various mutations and genomic losses, which could explain tumour progression and immune evasion ability. Furthermore, the study identified the loss of other genes related to cancer and immune pathways, emphasizing the complexity of NPC genomics. In conclusion, this study underscores the significance of MHC class I gene loss and its probable correlation with the cold tumour phenotype observed in NPC.

Antigen Self-Presented Personalized Nanovaccines Boost the Immunotherapy of Highly Invasive and Metastatic Tumors.

Dendritic cell (DC)-based vaccines have shown promise in adoptive cell therapy for enhancing the antigen-specific response of antitumor immunity. However, their clinical efficacy is limited by the less-presented tumor-associated antigens (TAAs) through MHC I and low lymph node homing efficiency. Herein, to address these issues, we rationally design and fabricate DC-based nanovaccines by coating Cu2-xSe nanoparticles (CS NPs) with the membrane of matured DCs (named as DCNV(CSD) nanovaccines). We reveal the important roles of CS NPs in the DCNV(CSD) nanovaccines from three aspects: (1) inducing the immunogenic cell death of tumor cells to expose abundant TAAs; (2) promoting the escape of TAAs from the lysosomes of DCs during the antigen presenting process through MHC I; (3) sustainably releasing traces of copper ions to promote the proliferation of T cells. Our DCNV(CSD) nanovaccines are characterized with high expressions of MHC I, CD80, CD86, CCR7, and ICAM-1 proteins, which not only endow them with abundantly processed specific TAAs, but also a strong capability of homing to the lymph nodes. The homing capability of our small DCNV(CSD) nanovaccines is better than that of matured DCs. More importantly, they can elicit the strong response of potent antispecific CD8+ T cells for antitumor immunotherapy, as tested in the treatment of highly invasive glioblastoma and highly metastatic melanoma. Additionally, DCNV(CSD) nanovaccines can generate memory T cells (TEM) in the spleen of mice to effectively prevent the recurrence of treated tumors. This work demonstrates a universal approach to fabricate high-performance DC-based nanovaccines for tumor immunotherapy by using versatile CS NPs.