Potential Target For Immunotherapy Research Articles

Highly expressed of BID indicates poor prognosis and mediates different tumor microenvironment characteristics in clear cell renal cell carcinoma

BackgroundStudies have found that BH3 interacting domain death agonist (BID) is closely related to the occurrence and development of many kinds of tumors. However, little attention has been paid to the situation of BID in clear cell renal cell carcinoma (ccRCC). So, our aim was to explore the effect of BID in ccRCC.MethodsSurvival analysis, ROC curve, correlation analysis and Cox regression analysis were executed to analyze the prognostic value and clinical correlation of BID in ccRCC. The risk prognosis model was constructed in the training cohort and further validated in the internal testing cohort, ICGC cohort, and GEO cohort. Transcriptome sequencing and immunohistochemical staining of clinical specimens were used to validate the results of bioinformatics analysis. The GSEA, ESTIMATE algorithm, CIBERSORT algorithm, ssGSEA, TIDE score, correlation and difference analysis were used to analyze the effects of BID on immune infiltration in tumor microenvironment (TME).ResultsBID was highly expressed in ccRCC tissues, which was verified by transcriptome sequencing and immunohistochemical staining of clinical specimens. Patients with high expression of BID had a worse prognosis. BID is an independent prognostic factor for ccRCC. The prognostic model based on BID can accurately predict the prognosis of patients in different cohorts. In addition, the expression levels of BID was closely related to immunomodulatory molecules such as PD-1, LAG3, and CTLA4. Enrichment analysis indicated that BID was significantly enriched in immune-related responses and cancer-related pathways. The change of BID expression mediates different characteristics of immune infiltration in TME.ConclusionsBID is highly expressed in ccRCC, which is a reliable biomarker of ccRCC prognosis. It is closely related to TME, and may be a potential target for immunotherapy in patients with ccRCC.

Epigenetic silencing of LDHB promotes hepatocellular carcinoma by remodeling the tumor microenvironment

Lactate dehydrogenase B (LDHB) reversibly catalyzes the conversion of pyruvate to lactate or lactate to pyruvate and expressed in various malignancies. However, the role of LDHB in modulating immune responses against hepatocellular carcinoma (HCC) remains largely unknown. Here, we found that down-regulation of lactate dehydrogenase B (LDHB) was coupled with the promoter hypermethylation and knocking down the DNA methyltransferase 3A (DNMT 3A) restored LDHB expression levels in HCC cell lines. Bioinformatics analysis of the HCC cohort from The Cancer Genome Atlas revealed a significant positive correlation between LDHB expression and immune regulatory signaling pathways and immune cell infiltrations. Moreover, immune checkpoint inhibitors (ICIs) have shown considerable promise for HCC treatment and patients with higher LDHB expression responded better to ICIs. Finally, we found that overexpression of LDHB suppressed HCC growth in immunocompetent but not in immunodeficient mice, suggesting that the host immune system was involved in the LDHB-medicated tumor suppression. Our findings indicate that DNMT3A-mediated epigenetic silencing of LDHB may contribute to HCC progression through remodeling the tumor immune microenvironment, and LDHB may become a potential prognostic biomarker and therapeutic target for HCC immunotherapy.

Fluorescence imaging sheds light on the immune evasion mechanisms of hepatic stellate cells mediated by superoxide anion

Whether and how the reactive oxygen species generated by hepatic stellate cells (HSCs) promote immune evasion of hepatocellular carcinoma (HCC) remains mysterious. Therefore, investigating the function of superoxide anion (O2•−), the firstly generated reactive oxygen species, during the immune evasion become necessary. In this work, we establish a novel in situ imaging method for visualization of O2•− changes in HSCs based on a new two-photon fluorescence probe TPH. TPH comprises recognition group for O2•− and HSCs targeting peptides. We observe that O2•− in HSCs gradually rose, impairing the infiltration of CD8+ T cells in HCC mice. Further studies reveal that the cyclin-dependent kinase 4 is deactivated by O2•−, and then cause the up-regulation of PD-L1. Our work provides molecular insights into HSC-mediated immune evasion of HCC, which may represent potential targets for HCC immunotherapy.

Dysregulation of peripheral and intratumoral KLRG1+ CD8+T cells is associated with immune evasion in patients with non-small-cell lung cancer

ObjectivesKiller cell lectin like receptor G1 (KLRG1) is identified as a co-inhibitory receptor for NK cells and antigen-experienced T cells. The role of KLRG1 in immune regulation in patients with non-small cell lung cancer (NSCLC) remains poorly understood. Materials and MethodsWe measured the proportion and immune function of KLRG1+CD8+T cells derived from peripheral blood in patients with NSCLC by flow cytometry. Besides, using data from the gene expression profiles and single-cell sequencing, we explored the expression and immune role of KLRG1 in tumor tissues of patients with NSCLC. We further determined the prognostic value of KLRG1 in terms of overall survival (OS) in NSCLC patients. ResultsWe found that the proportion of KLRG1+CD8+T cells in peripheral blood significantly increased in patients with NSCLC as compared to those with benign pulmonary nodules and healthy donors. Peripheral KLRG1+CD8+T cell proportion was increased in elder subjects compared to that in younger ones, implying an immunosenescence phenotype. Moreover, the KLRG1+CD8+T cell levels were positively correlated with tumor size and TNM stage in the NSCLC cohort. In vitro stimulation experiments demonstrated that the KLRG1+CD8+T cells from peripheral blood expressed higher levels of Granzyme B and perforin than the KLRG1−CD8+ T cells. However, single-cell RNA sequencing data revealed that the KLRG1+CD8+ T cells were less infiltrated in tumor microenvironment and exhibited impaired cytotoxicity. The KLRG1 gene expression levels were significantly lower in tumor tissues than that in normal lung tissues, and were inversely correlated with CDH1 expression levels. Moreover, higher expression of CDH1 in tumor tissues predicted worse overall survival only in patients with KLRG1-high expression, but not in the KLRG1-low subset. ConclusionThis study demonstrates that KLRG1+CD8+T cells were associated with tumor immune evasion in NSCLC and suggests KLRG1 as a potential immunotherapy target.

Abstract PO4-16-04: Decoding the immune landscape of breast cancer (BC) during pregnancy (PrBC): Impact of hormone receptors (HR) and tumor-infiltrating lymphocytes (TILs) phenotype on gene expression signatures

Abstract Introduction: PrBC is an uncommon malignancy with aggressive behavior. Its pathogenesis involves distinct immune mechanisms associated with maternal-fetal tolerance and tumor-host immunoediting. PrBC displays specific patterns of TILs with increased CD8+ cells. Gaining a comprehensive understanding of the molecular processes underlying this immune synergy is crucial for enhancing PrBC patients’ clinical management. Here, we sought to identify dysregulated immune-related genes in PrBC and explore their association with HR status and TILs. Methods: A total of n=75 PrBC (age range 26-43 years) and n=67 age-matched early-onset breast cancer (EOBC) in non-pregnant women (controls; age range 28-43 years) were selected from our Institutional registry. For all cases TILs were quantified according to the International TILs Working Group recommendations and profiled by IHC for CD4 and CD8. RNA was extracted from representative FFPE tissue blocks to perform the expression analysis of 395 genes involved in tumor-immune interactions using a targeted NGS panel (Oncomine™ Immune Response Research Assay, Thermofisher). Samples with >1,000,000 mapped reads and >800,000 valid reads were considered adequate. R package DESeq2 software 1.38.3 was used for sequencing depth differences normalization and differential gene expression analysis. Differentially expressed genes (DEGs) were identified based on a significant p-value (p< 0.05). Results: The comparison between PrBC and EOBC revealed a total of n=7 DEGs. All of these genes were upregulated and belonged to distinct superfamilies, including Cancer/Testis (CT) Antigen (MAGEA1/3, XAGE1B), Interferons/Cytokines (IFNA17, IFNB1), Chemokines (CXCL13), and Immunoglobulin (PECAM1/CD31). Notably, the upregulation of Chemokines in respect to EOBC was observed exclusively in HR+ PrBC, whereas triple-negative (TN) PrBC did not exhibit this pattern compared to the control group. Hence, the upregulation of ALOX15B, an enzyme involved in fatty acid peroxidation, was specific to TN PrBC. The immune signatures showed significant variations between PrBC and EOBC also based on TILs density and subpopulations. Indeed, the upregulation of CT genes (MAGEA1, XAGE1B) was exclusively observed in PrBC cases characterized by low TILs levels and prevalence of CD8+ or CD4+ cells. Finally, CD4+ TILs were absent or low in PrBC with upregulated Interferons, Cytokines, Chemokines, and Immunoglobulin genes, but present in cases with increased expression of CT and KLRF1 (NK cells). Conclusion: These findings highlight the heterogeneity and distinct molecular characteristics of PrBC and EOBC. The upregulation of specific immune-related gene families, such as CT and Chemokines, in different PrBC subtypes may suggest their potential role as actionable biomarkers (e.g. MAGEA, a well-known oncogene and potential immunotherapy target). The differences in immune signatures and TILs subpopulations further emphasize the importance of the immune microenvironment in PrBC biology and behavior. Future studies could delve deeper into the clinical implications of these gene expression patterns and explore their relevance in personalized treatment strategies for PrBC. Citation Format: Konstantinos Venetis, Elham Sajjadi, Chiara Frascarelli, Mariia Ivanova, Marianna D'Ercole, Concetta Blundo, Massimo Giroda, Eugenia Di Loreto, Giovanna Scarfone, Stefano Ferrero, Paolo Veronesi, Viviana Galimberti, Fedro Alessandro Peccatori, Nicola Fusco, Elena Guerini-Rocco. Decoding the immune landscape of breast cancer (BC) during pregnancy (PrBC): Impact of hormone receptors (HR) and tumor-infiltrating lymphocytes (TILs) phenotype on gene expression signatures [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-16-04.

Caspase-3/Gasdermin E-mediated pyroptosis contributes to Ricin toxin-induced inflammation

Ricin toxin (RT) is highly cytotoxic and can release a considerable amount of pro-inflammatory factors due to depurination, causing excessive inflammation that may aggravate the harm to the body. Pyroptosis, a type of gasdermin-mediated cell death, is a contributor to the exacerbation of inflammation. Accumulating evidence indicate that pyroptosis plays a significant role in the pathogen infection and tissue injury, suggesting a potential correlation between pyroptosis and RT-induced inflammation. Here, we aim to demonstrate this correlation and explore its molecular mechanisms. Results showed that RT triggers mouse alveolar macrophage MH-S cells pyroptosis by activating caspase-3 and cleaving Gasgermin E (GSDME). In contrast, inhibition of caspase-3 with Z-DEVD-FMK (inhibitor of caspase-3) or knockdown of GSDME attenuates this process, suggesting the essential role of caspase-3/GSDME-mediated pyroptosis in contributing to RT-induced inflammation. Collectively, our study enhances our understanding of a novel mechanism of ricin cytotoxicity, which may emerge as a potential target in immunotherapy to control the RT-induced inflammation.

Multi-omics pan-cancer study of SPTBN2 and its value as a potential therapeutic target in pancreatic cancer

SPTBN2 is a protein-coding gene that is closely related to the development of malignant tumors. However, its prognostic value and biological function in pan-cancer, especially pancreatic cancer (PAAD), have not been reported. In the present study, a novel exploration of the value and potential mechanism of SPTBN2 in PAAD was conducted using multi-omics in the background of pan-cancer. Via various database analysis, up-regulated expression of SPTBN2 was detected in most of the tumor tissues examined. Overexpression of SPTBN2 in PAAD and kidney renal clear cell cancer patients potentially affected overall survival, disease-specific survival, and progression-free interval. In PAAD, SPTBN2 can be used as an independent factor affecting prognosis. Mutations and amplification of SPTBN2 were detected, with abnormal methylation of SPTBN2 affecting its expression and the survival outcome of PAAD patients. Immunoassay results demonstrate that SPTBN2 was a potential biomarker for predicting therapeutic response in PAAD, and may influence the immunotherapy efficacy of PAAD by regulating levels of CD8 + T cells and neutrophil infiltration. Results from an enrichment analysis indicated that SPTBN2 may regulate the development of PAAD via immune pathways. Thus, SPTBN2 is a potential prognostic biomarker and immunotherapy target based on its crucial role in the development of PAAD.

MAL, a potential immunotherapy target, is associated with poor prognosis in cancer patients.

The MAL gene encodes Myelin and Lymphocyte Protein, mainly expressed in T cells with immunomodulatory effects, showing the potential as a target for immunotherapy. However, the mechanism of MAL in the regulation of immune infiltration and its association with the prognosis in pan-cancer patients remain elusive. We used the TCGA, TIMER2.0, GTEx, UCSC, and TISCH databases and the R programming tool to explore the role of MAL in cancers. MAL was differently expressed in the majority of malignancies relative to the matched healthy controls. Patients with low MAL levels had adverse survival outcomes in the BRCA and LUAD cohorts. In all cancer types, MAL showed a significant correlation to specific immune-subpopulation abundance in particular T cells as well as B cells. MAL was also implicated in immunological pathways in BRCA and LUAD, suggesting the important role of MAL in cancer immune regulation. In conclusion, the pan-cancer study indicates that MAL with excellent prognostic value is a potential immunotherapy target in multiple cancers.

Up-regulated PLA2G10 in cancer impairs T cell infiltration to dampen immunity.

T cells are often absent from human cancer tissues during both spontaneously induced immunity and therapeutic immunotherapy, even in the presence of a functional T cell-recruiting chemokine system, suggesting the existence of T cell exclusion mechanisms that impair infiltration. Using a genome-wide in vitro screening platform, we identified a role for phospholipase A2 group 10 (PLA2G10) protein in T cell exclusion. PLA2G10 up-regulation is widespread in human cancers and is associated with poor T cell infiltration in tumor tissues. PLA2G10 overexpression in immunogenic mouse tumors excluded T cells from infiltration, resulting in resistance to anti-PD-1 immunotherapy. PLA2G10 can hydrolyze phospholipids into small lipid metabolites, thus inhibiting chemokine-mediated T cell mobility. Ablation of PLA2G10's enzymatic activity enhanced T cell infiltration and sensitized PLA2G10-overexpressing tumors to immunotherapies. Our study implicates a role for PLA2G10 in T cell exclusion from tumors and suggests a potential target for cancer immunotherapy.

Research on the potential mechanism of Deapioplatycodin D against pulmonary fibrosis based on bioinformatics and experimental verification

BackgroundPulmonary fibrosis (PF) is a group of respiratory diseases that are extremely complex and challenging to treat. Due to its high mortality rate and short survival, it's often referred to as a “tumor-like disease” that poses a serious threat to human health. ObjectiveWe aimed validate the potential of Deapioplatycodin D (DPD) to against PF and clarify the underlying mechanism of action of DPD for the treatment of PF based on bioinformatics and experimental verification. This finding provides a basis for the development of safe and effective therapeutic PF drugs based on DPD. MethodsWe used LPS-induced early PF rats as a PF model to test the overall efficacy of DPD in vivo. Then, A variety of bioinformatics methods, such as WGCNA, LASSO algorithm and immune cell infiltration (ICI), were applied to analyze the gene microarray related to PF obtained from Gene Expression Omnibus (GEO) to obtained key targets of PF. Finally, an in vitro PF model was constructed based on BEAS-2B cells while incorporating rat lung tissues to validate the regulatory effects of DPD on critical genes. ResultsDPD can effectively alleviate inflammatory and fibrotic markers in rat lungs. WGCNA analysis resulted in a total of six expression modules, with the brown module having the highest correlation with PF. Subsequently, seven genes were acquired by intersecting the genes in the brown module with DEGs. Five key genes were identified as potential biomarkers of PF by LASSO algorithm and validation dataset verification analysis. In the ICI analysis, infiltration of activated B cell, immature B cell and natural killer cells were found to be more crucial in PF. Ultimately, it was observed that DPD could modulate key genes to achieve anti-PF effects. ConclusionIn short, these comprehensive analysis methods were employed to identify critical biomarkers closely related to PF, which helps to elucidate the pathogenesis and potential immunotherapy targets of PF. It also provides essential support for the potential of DPD against PF.

Pan-cancer analysis implicates novel insights of lactate metabolism into immunotherapy response prediction and survival prognostication

BackgroundImmunotherapy has emerged as a potent clinical approach for cancer treatment, but only subsets of cancer patients can benefit from it. Targeting lactate metabolism (LM) in tumor cells as a method to potentiate anti-tumor immune responses represents a promising therapeutic strategy.MethodsPublic single-cell RNA-Seq (scRNA-seq) cohorts collected from patients who received immunotherapy were systematically gathered and scrutinized to delineate the association between LM and the immunotherapy response. A novel LM-related signature (LM.SIG) was formulated through an extensive examination of 40 pan-cancer scRNA-seq cohorts. Then, multiple machine learning (ML) algorithms were employed to validate the capacity of LM.SIG for immunotherapy response prediction and survival prognostication based on 8 immunotherapy transcriptomic cohorts and 30 The Cancer Genome Atlas (TCGA) pan-cancer datasets. Moreover, potential targets for immunotherapy were identified based on 17 CRISPR datasets and validated via in vivo and in vitro experiments.ResultsThe assessment of LM was confirmed to possess a substantial relationship with immunotherapy resistance in 2 immunotherapy scRNA-seq cohorts. Based on large-scale pan-cancer data, there exists a notably adverse correlation between LM.SIG and anti-tumor immunity as well as imbalance infiltration of immune cells, whereas a positive association was observed between LM.SIG and pro-tumorigenic signaling. Utilizing this signature, the ML model predicted immunotherapy response and prognosis with an AUC of 0.73/0.80 in validation sets and 0.70/0.87 in testing sets respectively. Notably, LM.SIG exhibited superior predictive performance across various cancers compared to published signatures. Subsequently, CRISPR screening identified LDHA as a pan-cancer biomarker for estimating immunotherapy response and survival probability which was further validated using immunohistochemistry (IHC) and spatial transcriptomics (ST) datasets. Furthermore, experiments demonstrated that LDHA deficiency in pancreatic cancer elevated the CD8+ T cell antitumor immunity and improved macrophage antitumoral polarization, which in turn enhanced the efficacy of immunotherapy.ConclusionsWe unveiled the tight correlation between LM and resistance to immunotherapy and further established the pan-cancer LM.SIG, holds the potential to emerge as a competitive instrument for the selection of patients suitable for immunotherapy.

Comprehensive bioinformatics analysis of NOX4 as a biomarker for pan-cancer prognosis and immune infiltration.

NADPH oxidase 4 (NOX4) has been proven to be associated with the prognosis of tumors in multiple cancers and can serve as a potential immunotherapy target to provide new treatment options for various tumors. In this study, our aim is to conduct an in-depth investigation of NOX4 across a range of cancer types to determine the relationship between NOX4 and tumors. Utilizing large-scale transcriptomic and clinical data from public databases, a systematic examination of NOX4 expression patterns was performed in pan-cancer cohorts. Survival analysis, methylation analysis, and correlation studies were employed to assess the diagnostic and prognostic significance of NOX4 in diverse cancer types. Additionally, an exploration of the relationship between NOX4 expression and immune infiltration across various tumors was conducted. The analyses unveiled a consistent upregulation of NOX4 expression in multiple cancer types relative to normal tissues, indicating its potential as a universal cancer biomarker. Elevated NOX4 expression significantly correlated with poor overall survival in several cancers. Furthermore, the study demonstrated a robust correlation between NOX4 expression and immune cell infiltration, signifying its involvement in the modulation of the tumor microenvironment. This study imparts valuable insights into the potential applications of NOX4 in cancer research, highlighting its significance as a multifaceted biomarker with diagnostic, prognostic, and immunomodulatory implications across diverse malignancies.

Identification of Key lncRNAs Associated with Immune Infiltration and Prognosis in Gastric Cancer.

Long non-coding RNAs (lncRNAs), as promising novel biomarkers for cancer treatment and prognosis, can function as tumor suppressors and oncogenes in the occurrence and development of many types of cancer, including gastric cancer (GC). However, little is known about the complex regulatory system of lncRNAs in GC. In this study, we systematically analyzed lncRNA and miRNA transcriptomic profiles of GC based on bioinformatics methods and experimental validation. An lncRNA-miRNA interaction network related to GC was constructed, and the nine crucial lncRNAs were identified. These 9 lncRNAs were found to be associated with the prognosis of GC patients by Cox proportional hazards regression analysis. Among them, the expression of lncRNA SNHG14 can affect the survival of GC patients as a potential prognostic marker. Moreover, it was shown that SNHG14 was involved in immune-related pathways and significantly correlated with immune cell infiltration in GC. Meanwhile, we found that SNHG14 affected immune function in many cancers, such as breast cancer and esophageal carcinoma. Such information revealed that SNHG14 may serve as a potential target for cancer immunotherapy. As well, our study could provide practical and theoretical guiding significance for clinical application of non-coding RNAs.

Role of COX-2/PGE2/EP4 Axis-induced Macrophage Functional Activation in NSCLC Development

Tumor microenvironment (TME) is one of the important factors in tumorigenesis and progression, in which tumor-associated macrophages (TAMs) play an important role in non-small cell lung cancer (NSCLC) progression. However, the mechanism of TAMs in NSCLC progression remains unclear, so this study aimed to investigate the role of TAMs in NSCLC progression and to find potential therapeutic targets. Gene Expression Profiling Interactive Analysis (GEPIA) database was used to analyze the expression of prostaglandin E2 receptor 4 (EP4) mRNA in NSCLC and normal lung tissues; the protein expression levels of cyclooxygenase-2 (COX-2), EP4, cluster of differentiation 86 (CD86), CD163 and CD31 were detected by immunohistochemistry (IHC) in 120 NSCLC tissues and 24 paracancerous tissues specimens. The nude mouse lung adenocarcinoma cell A549 and macrophage RAW264.7 co-transplanted tumor model was established. And the samples were collected by gavage with EP4 inhibitor E7046, and then stained with hematoxylin-eosin (HE), IHC, and immunofluorescence (IF), and then detected by Western blot for the epithelial mesenchymal transformation (EMT) of the tumor tissues of the nude mice in each group. Western blot was used to detect the expressions of EMT related protiens in each group of nude mice; full-length transcriptome sequencing was used to screen the key genes causing liver metastasis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed. EP4 mRNA expression level in NSCLC tissues was generally lower than that in normal lung tissues (P<0.05); COX-2, EP4, CD163, CD31 proteins were differentially expressed in NSCLC tissues and adjacent tissues, and differences were observed in many clinicopathological parameters of NSCLC patients; RAW264.7 shortened the latency period of tumorigenesis of A549 and promoted the proliferation of tumors and liver metastasis of tumors, and E7046 could reduce tumor cell proliferation activity, tumor tissue vascular density and M2-type macrophage infiltration in nude mice; IF staining showed that macrophages were mainly distributed around the metastatic foci of tumors; Western blot results showed that compared with A549 alone transplantation group, the relative expression of E-cadherin protein in tumor tissues of mice in A549 and RAW264.7 co-transplantation group was significantly decreased, and the difference was statistically significant (P<0.05), while the relative expression of N-cadherin protein was up-regulated, but the difference was not statistically significant (P>0.05); the main pathways enriched in the differential genes of the full-length transcriptome were the PI3K-AKT and MAPK signaling pathways. During NSCLC development, the COX-2/PGE2/EP4 axis may promote tumor progression by inducing macrophage functional activation, and EP4 may be a potential new target for tumor immunotherapy. This study provides new perspectives and ideas for in-depth exploration of the mechanisms of NSCLC development, as well as a theoretical basis for the development of new therapeutic strategies for NSCLC.

Coagulation Protease-Driven Cancer Immune Evasion: Potential Targets for Cancer Immunotherapy.

Blood coagulation and cancer are intrinsically connected, hypercoagulation-associated thrombotic complications are commonly observed in certain types of cancer, often leading to decreased survival in cancer patients. Apart from the common role in coagulation, coagulation proteases often trigger intracellular signaling in various cancers via the activation of a G protein-coupled receptor superfamily protease: protease-activated receptors (PARs). Although the role of PARs is well-established in the development and progression of certain types of cancer, their impact on cancer immune response is only just emerging. The present review highlights how coagulation protease-driven PAR signaling plays a key role in modulating innate and adaptive immune responses. This is followed by a detailed discussion on the contribution of coagulation protease-induced signaling in cancer immune evasion, thereby supporting the growth and development of certain tumors. A special section of the review demonstrates the role of coagulation proteases, thrombin, factor VIIa, and factor Xa in cancer immune evasion. Targeting coagulation protease-induced signaling might be a potential therapeutic strategy to boost the immune surveillance mechanism of a host fighting against cancer, thereby augmenting the clinical consequences of targeted immunotherapeutic regimens.

TIM-3+ CD8 T cells with a terminally exhausted phenotype retain functional capacity in hematological malignancies.

Chronic antigen stimulation is thought to generate dysfunctional CD8 T cells. Here, we identify a CD8 T cell subset in the bone marrow tumor microenvironment that, despite an apparent terminally exhausted phenotype (TPHEX), expressed granzymes, perforin, and IFN-γ. Concurrent gene expression and DNA accessibility revealed that genes encoding these functional proteins correlated with BATF expression and motif accessibility. IFN-γ+ TPHEX effectively killed myeloma with comparable efficacy to transitory effectors, and disease progression correlated with numerical deficits in IFN-γ+ TPHEX. We also observed IFN-γ+ TPHEX within CD19-targeted chimeric antigen receptor T cells, which killed CD19+ leukemia cells. An IFN-γ+ TPHEX gene signature was recapitulated in TEX cells from human cancers, including myeloma and lymphoma. Here, we characterize a TEX subset in hematological malignancies that paradoxically retains function and is distinct from dysfunctional TEX found in chronic viral infections. Thus, IFN-γ+ TPHEX represent a potential target for immunotherapy of blood cancers.

Single-cell multiomic dissection of response and resistance to chimeric antigen receptor T cells against BCMA in relapsed multiple myeloma.

Markers that predict response and resistance to chimeric antigen receptor (CAR) T cells in relapsed/refractory multiple myeloma are currently missing. We subjected mononuclear cells isolated from peripheral blood and bone marrow before and after the application of approved B cell maturation antigen-directed CAR T cells to single-cell multiomic analyses to identify markers associated with resistance and early relapse. Differences between responders and nonresponders were identified at the time of leukapheresis. Nonresponders showed an immunosuppressive microenvironment characterized by increased numbers of monocytes expressing the immune checkpoint molecule CD39 and suppressed CD8+ T cell and natural killer cell function. Analysis of CAR T cells showed cytotoxic and exhausted phenotypes in hyperexpanded clones compared to low/intermediate expanded clones. We identified potential immunotherapy targets on CAR T cells, like PD1, to improve their functionality and durability. Our work provides evidence that an immunosuppressive microenvironment causes resistance to CAR T cell therapies in multiple myeloma.

CD106 in tumor-specific exhausted CD8+ T cells mediates immunosuppression by inhibiting TCR signaling.

T cell exhaustion is a major contributor to immunosuppression in the tumor microenvironment (TME). Blockade of key regulators of T cell exhaustion, such as PD-1, can reinvigorate tumor-specific T cells and activate anti-tumor immunity in various types of cancer. Here, we identified that CD106 was specifically expressed in exhausted CD8+ T cells in the TME using single-cell RNA-sequencing. High CD106 expression in the TME in clinical samples corresponded to improved response to cancer immunotherapy. CD106 in tumor-specific T cells suppressed anti-tumor immunity both in vitro and in vivo, and loss of CD106 in CD8+ T cells suppressed tumor growth and improved response to PD-1 blockade. Mechanistically, CD106 inhibited T-cell receptor (TCR) signaling by interacting with the TCR/CD3 complex and reducing its surface expression. Together, these findings provide insights into the immunosuppressive role of CD106 expressed in tumor-specific exhausted CD8+ T cells, identifying it as a potential biomarker and therapeutic target for cancer immunotherapy.

The Proteostasis of Thymic Stromal Cells in Health and Diseases.

The thymus is the key immune organ for the development of T cells. Different populations of thymic stromal cells interact with T cells, thereby controlling the dynamic development of T cells through their differentiation and function. Proteostasis represents a balance between protein expression, folding, and modification and protein clearance, and its fluctuation usually depends at least partially on related protein regulatory systems for further survival and effects. However, in terms of the substantial requirement for self-antigens and their processing burden, increasing evidence highlights that protein regulation contributes to the physiological effects of thymic stromal cells. Impaired proteostasis may expedite the progression of thymic involution and dysfunction, accompanied by the development of autoimmune diseases or thymoma. Hence, in this review, we summarize the regulation of proteostasis within different types of thymic stromal cells under physiological and pathological conditions to identify potential targets for thymic regeneration and immunotherapy.

THEMIS2 Impairs Antitumor Activity of NK Cells by Suppressing Activating NK Receptor Signaling.

NK cells are cytotoxic innate lymphocytes that play a critical role in antitumor immunity. NK cells recognize target cells by using a repertoire of activating NK receptors and exert the effector functions. Although the magnitude of activation signals through activating NK receptors controls NK cell function, it has not been fully understood how these activating signals are modulated in NK cells. In this study, we found that a scaffold protein, THEMIS2, inhibits activating NK receptor signaling. Overexpression of THEMIS2 attenuated the effector function of human NK cells, whereas knockdown of THEMIS2 enhanced it. Mechanistically, THEMIS2 binds to GRB2 and phosphorylated SHP-1 and SHP-2 at the proximity of activating NK receptors DNAM-1 and NKG2D. Knockdown of THEMIS2 in primary human NK cells promoted the effector functions. Furthermore, Themis2-deficient mice showed low metastatic burden in an NK cell-dependent manner. These findings demonstrate that THEMIS2 has an inhibitory role in the antitumor activity of NK cells, suggesting that THEMIS2 might be a potential therapeutic target for NK cell-mediated cancer immunotherapy.