Complement receptor C5aR1 blockade reprograms tumor-associated macrophages and synergizes with anti-PD-1 therapy in gastric cancer.

In gastric cancer (GC), the therapeutic response of immune checkpoint blockade (ICB) remains suboptimal. Targeting myeloid cell checkpoints might be feasible as adjuvant to current ICB regimens. We sought to evaluate the crucial role of C5aR1+ TAMs in regulating antitumor immunity and the efficacy of combinatorial treatment with antiprogrammed cell death protein-1 (PD-1) and C5aR1 blockade. Here, we found that C5aR1 was predominantly expressed on macrophages and high level of C5aR1+ TAMs infiltration could predict poor prognosis and inferior chemotherapeutic response. The flow cytometry (FCM) and single-cell RNA-seq (scRNA-seq) data revealed that C5aR1+ TAMs exhibited immunosuppressive property which might contribute to CD8+ T cell dysfunction. Blockade of C5aR1 could diminish the immunosuppressive function of TAMs and led to reinvigorated CD8+ T cells mediated antitumor immunity. Moreover, using in vitro intervention experiment based on fresh GC surgical specimens, we discovered that C5aR1 blockade exert a synergistic effect when combined with PD-1 inhibitor for tumor clearance. Our study demonstrated that C5aR1 is a critical myeloid checkpoint and plays a crucial role in regulating the immunosuppressive property of TAMs and CD8+ T cell immune tolerance. C5aR1 blockade reprograms TAMs and reinvigorated the cytotoxicity of CD8+ T cells, thus improving the efficacy of anti-PD-1 therapy for tumor eradication in GC.

C-type lectin receptor Dectin-1 blockade on tumour-associated macrophages improves anti-PD-1 efficacy in gastric cancer.

BACKGROUND: This study aimed to investigate the expression and clinical significance of Dendritic cell-associated C-type lectin-1 (Dectin-1) in gastric cancer (GC), and to explore the mechanism of Dectin-1 regulating tumour-associated macrophage (TAM)-mediated immune evasion in GC. METHODS: The association of Dectin-1+ cells with clinical outcomes was inspected by immunohistochemistry on tumour microarrays. Flow cytometry and RNA sequencing were applied to detect characteristics of T cells, phenotypic and transcriptional features of Dectin-1+ TAMs. The effect of Dectin-1 blockade was evaluated using an in vitro intervention experiment based on fresh GC tissues. RESULTS: High infiltration of intratumoral Dectin-1+ cells predicted poor prognosis in GC patients. Dectin-1+ cells were mainly composed of TAMs, and the accumulation of Dectin-1+ TAMs was associated with T-cell dysfunction. Notably, Dectin-1+ TAMs exhibited an immunosuppressive phenotype. Furthermore, blockade of Dectin-1 could reprogramme Dectin-1+ TAMs and reactivate anti-tumour effects of T cells, as well as enhanced PD-1 inhibitor-mediated cytotoxicity of CD8+ T cells against tumour cells. CONCLUSIONS: Dectin-1 could affect T-cell anti-tumour immune response by regulating the immunosuppressive function of TAMs, leading to poor prognosis and immune evasion in GC patients. Blockade of Dectin-1 can be used alone or in combination with current therapeutic strategies in GC.

The Integration of Genome-Wide DNA Methylation and Transcriptomics Identifies the Potential Genes That Regulate the Development of Skeletal Muscles in Ducks.

DNA methylation is a pivotal epigenetic regulatory mechanism in the development of skeletal muscles. Nonetheless, the regulators responsible for DNA methylation in the development of embryonic duck skeletal muscles remain unknown. In the present study, whole genome bisulfite sequencing (WGBS) and transcriptome sequencing were conducted on the skeletal muscles of embryonic day 21 (E21) and day 28 (E28) ducks. The DNA methylation pattern was found to fall mainly within the cytosine-guanine (CG) context, with high methylation levels in the intron, exon, and promoter regions. Overall, 7902 differentially methylated regions (DMRs) were identified, which corresponded to 3174 differentially methylated genes (DMGs). By using integrative analysis of both WGBS with transcriptomics, we identified 1072 genes that are DMGs that are negatively associated with differentially expressed genes (DEGs). The gene ontology (GO) analysis revealed significant enrichment in phosphorylation, kinase activity, phosphotransferase activity, alcohol-based receptors, and binding to cytoskeletal proteins. The Kyoto Encyclopedia of Genes and Genomes (KEGGs) analysis showed significant enrichment in MAPK signaling, Wnt signaling, apelin signaling, insulin signaling, and FoxO signaling. The screening of enriched genes showed that hyper-methylation inhibited the expression of Idh3a, Got1, Bcl2, Mylk2, Klf2, Erbin, and Klhl38, and hypo-methylation stimulated the expression of Col22a1, Dnmt3b, Fn1, E2f1, Rprm, and Wfikkn1. Further predictions showed that the CpG islands in the promoters of Klhl38, Klf2, Erbin, Mylk2, and Got1 may play a crucial role in regulating the development of skeletal muscles. This study provides new insights into the epigenetic regulation of the development of duck skeletal muscles.

TIM3+ cells in gastric cancer: clinical correlates and association with immune context.

BACKGROUND: T cell immunoglobulin and mucin domain-containing protein 3 (TIM3) is a crucial immune checkpoint and is considered as an emerging target for cancer treatment. However, the clinical significance and immune-related role of TIM3+ cells in gastric cancer remain unknown. This study aimed to investigate the clinical significance of tumour-infiltrating TIM3+ cells and their association with immune contexture in gastric cancer. METHODS: This study enrolled three cohorts, including 436 tumour tissue microarray specimens and 58 fresh tumour tissues of gastric cancer patients from Zhongshan Hospital, and 330 transcriptional data from The Cancer Genome Atlas. TIM3+ cells and their association with CD8+ T cells were evaluated by immunohistochemistry and flow cytometry analyses. Kaplan-Meier curves, Cox model and interaction test were performed to assess clinical outcomes. RESULTS: Tumour-infiltrating TIM3+ cells' high subgroups experienced poorer overall survival and disease-free survival and predicted inferior therapeutic responsiveness to fluorouracil-based adjuvant chemotherapy. TIM3 indicated CD8+ T cell dysfunction, which impeded chemotherapeutic responsiveness. Besides, HAVCR2 messenger RNA expression was associated with specific molecular characteristics. CONCLUSIONS: The abundance of tumour-infiltrating TIM3+ cells could identify an immunoevasive subtype gastric cancer with CD8+ T cell dysfunction, suggesting that TIM3 might serve as a promising target for immunotherapy in gastric cancer.

Poor Clinical Outcomes and Immunoevasive Contexture in Intratumoral IL-10-Producing Macrophages Enriched Gastric Cancer Patients.

OBJECTIVE: To investigate the clinical significance of IL-10+ tumor-associated macrophages (TAMs) in gastric cancer. BACKGROUND: Due to the plasticity and diversity of TAMs, it is necessary to phenotypically and functionally classify subsets of TAMs to better understand the critical role of TAMs in cancer progression. TAMs expressing interleukin-10 (IL-10) have been found to facilitate immune evasion in many malignancies, but the role of IL-10+ TAMs in gastric cancer remains obscure. METHODS: Four hundred and sixty-eight tumor tissue microarray specimens, 52 fresh tumor tissue samples of gastric cancer patients from Zhongshan Hospital, and data of 298 gastric cancer patients from the Cancer Genome Atlas (TCGA) were analyzed. IL-10+ TAM level and immune contexture were examined by CIBERSORT, immunohistochemistry, and flow cytometry. Clinical outcomes were analyzed by Kaplan-Meier curves and Cox model. RESULTS: Gastric cancer patients with high IL-10+ TAM infiltration exhibited poor prognosis and inferior therapeutic responsiveness to fluorouracil-based adjuvant chemotherapy. IL-10+ TAM infiltration yielded an immunoevasive tumor microenvironment featured by regulatory T cell infiltration and CD8+ T cell dysfunction. The combinational analysis of IL-10+ TAM and CD8+ T cell infiltration stratified patients into distinct risk groups with different clinical outcomes. Moreover, IL-10+ TAM infiltration was correlated with tumor-intrinsic characteristics including EBV status, PD-L1 expression, and genome stability in gastric cancer. CONCLUSIONS: This study revealed that IL-10+ TAMs might drive an immunoevasive microenvironment and determine poor prognosis and inferior therapeutic responsiveness to fluorouracil-based adjuvant chemotherapy, indicating IL-10+ TAMs could be applied as a potential target for immunotherapeutic approach in gastric cancer.

Intratumoral Foxp3+RORγt+ T cell infiltration determines poor prognosis and immunoevasive contexture in gastric cancer patients.

BACKGROUND: Foxp3+RORγt+ T cells possess both characteristics of regulatory T cells and T helper 17 cells and show significant immunoregulatory functions in autoimmune diseases. However, the role and clinical significance of Foxp3+RORγt+ T cells in gastric cancer remains unclear. METHODS: We enrolled 452 gastric cancer tissue microarray samples and 60 fresh tumor tissue samples from Zhongshan Hospital. The infiltration of Foxp3+RORγt+ T cells and immune contexture were examined by immunohistochemistry and flow cytometry. Survival analyses of patient subgroups were conducted by Kaplan-Meier curves, log-rank test and Cox proportional model. RESULTS: High infiltration of Foxp3+RORγt+ T cells predicted poor overall survival (P = 0.0222 and 0.0110) and inferior therapeutic response (P = 0.003 for interaction) in gastric cancer. Foxp3+RORγt+ T cells were associated with impaired effective function of CD8+ T cells featured by decreased interferon-γ, granzyme B and CD107a expression. Co-evaluation of Foxp3+RORγt+ T cells and CD8+ T cells could predict survival outcomes and chemotherapeutic responsiveness more precisely. CONCLUSIONS: We found that Foxp3+RORγt+ T cells could potentially attenuate effective functions of CD8+ T cells and led to adverse survival outcomes and inferior chemotherapeutic responsiveness. Moreover, the novel co-evaluation system might be useful for prognosis prediction for appropriate treatment in gastric cancer. NOVELTY AND IMPACT STATEMENTS: Clinical significance of Foxp3+RORγts+ T cells has not been studied in gastric cancer. Herein, we investigated the prognostic value of Foxp3+RORγt+ T cells in 452 patients. We demonstrated that intratumoral Foxp3+RORγt+ T cell infiltration was a prognostic biomarker for overall survival and the identification of patients might benefit from post-gastrectomy 5-fluorouracil. These findings allow a more precise stratification upon the co-evaluation with CD8+ T cells to better clinical management for patients who would benefit from 5-fluorouracil.

Manipulation of focal Wnt activity via synthetic cells in a double-humanized zebrafish model of tumorigenesis.

The canonical Wnt signaling pathway is activated in numerous contexts, including normal and cancerous tissues. Here, we describe a synthetic cell-based therapeutic strategy that inhibits aberrant Wnt activity in specific focuses without interfering with the normal tissues in vivo. As a proof of principle, we generated a triple transgenic zebrafish liver cancer model that conditionally expressed human MET and induced ectopic Wnt signaling in hepatocytes. Then, we generated a customized synthetic Notch receptor (synNotch) cascade to express Wnt inhibitor DKK1 in Jurkat T cells and human peripheral blood mononuclear cells (PBMCs) after recognizing MET as antigen. After that, the synNotch PBMCs were sorted and microinjected into different tissues of the zebrafish model. In MET-expressing cancerous liver tissues, the injected cells expressed DKK1 and inhibited the local proliferation and Wnt activity; while in the yolk sac without MET, the injected cells remained inactive. Overall, our studies revealed the use of synthetic cells with antigen receptors to improve the spatiotemporal accuracy of anti-Wnt therapy, and proposed that the genetically humanized zebrafish model may serve as a small-scale and highly optically accessible platform for the functional evaluation of human synthetic cells.

Lymphocyte-activation gene 3 expression associates with poor prognosis and immunoevasive contexture in Epstein-Barr virus-positive and MLH1-defective gastric cancer patients.

Lymphocyte activation gene 3 (LAG-3) is a transmembrane immune checkpoint that facilitates immune escape via suppressing T-cell-mediated anti-tumor immunity. The role of LAG-3 in gastric cancer is little known. Consequently, we assessed the clinical significance of LAG-3 in gastric cancer. In our study, patients with gastric cancer from Zhongshan Hospital (n = 464) and data from the Asian Cancer Research Group (n = 300) were analyzed. LAG-3+ cell infiltration and other immune contexture in gastric cancer were detected by immunohistochemistry. Kaplan-Meier curves and log-rank test were used for survival analyses. Intratumoral LAG-3+ cells mainly accumulated in Epstein-Barr virus (EBV)-positive (EBV subtype) and MLH1-defective (dMLH1 subtype) gastric cancer. Furthermore, LAG-3+ cell infiltration was strongly associated with inferior clinical outcomes in patients with these two subtypes of gastric cancer. Moreover, we found intratumoral LAG-3+ cell high infiltration was associated with an immunoevasive contexture featured by decreased IFN-γ+ cells and perforin-1+ cells, but increased regulatory T cells and M2-like macrophages in EBV/dMLH1 subtype of gastric cancer. LAG-3 was a poor prognostic factor and might be a potential immunotherapeutic target in EBV-positive and MLH1-defective gastric cancer.

CD47 expression in gastric cancer clinical correlates and association with macrophage infiltration.

BACKGROUND: CD47 has been identified as an innate immune checkpoint and found to be associated with inferior survival in various types of cancer. However, the critical role of CD47 in gastric cancer and its association with tumor associated macrophages remain unclear. METHODS: Tumor tissues of gastric cancer from Zhongshan Hospital and data from GSE62254, GSE84437 and TCGA datasets were analyzed. Immunohistochemistry was performed to detect the expression of CD47, CD11c, CD163 and CD68 in gastric cancer tissues. Kaplan-Meier curves and Cox model were used for comparing the clinical outcomes of patients belonging to different subgroups. RESULTS: Gastric cancer patients with high CD47 expression exhibited poor prognosis and inferior therapeutic responsiveness to fluorouracil-based adjuvant chemotherapy (ACT). A positive correlation was found between M1-polarized macrophage infiltration and CD47 expression in gastric cancer; however, the prognostic value of M1-polarized macrophages was attenuated in CD47-high gastric cancer patients. Moreover, we found that CD47 mRNA level was enriched in microsatellite-instable (MSI) subtype of gastric cancer and associated with ARID1A mutation and FGFR2 signaling pathway activation. CONCLUSIONS: Aberrant CD47 expression represented an independent predictor for adverse survival outcome and ACT resistance in gastric cancer. Targeting CD47 might be a promising strategy for gastric cancer patients.

Clinical Outcomes and Immune Metrics in Intratumoral Basophil-Enriched Gastric Cancer Patients.

BACKGROUND: Accumulation of basophils has been reported in several malignancies. In gastric cancer, the relation between tumor-infiltrating basophils and patient overall survival and chemotherapeutic responsiveness still remains obscure. OBJECTIVE: We aimed to investigate the postoperative prognostic and predictive significance of basophils to survival outcomes and chemotherapeutic responsiveness in resectable gastric cancer. METHODS: The study enrolled two independent patient data sets with 448 gastric cancer patients overall. Basophils were evaluated with the use of immunohistochemistry (IHC) staining, and the correlation with clinicopathological characteristics, survival outcomes, and responsiveness to fluorouracil-based adjuvant chemotherapy (ACT) were investigated. Additionally, IHC was applied to characterize immune contexture in gastric cancer. RESULTS: In either the discovery or validation data sets, accumulated basophils indicated poorer prognosis, and tumor-infiltrating basophils were identified as an independent adverse prognostic factor by multivariate analysis. Furthermore, tumor-infiltrating basophils determined significantly inferior therapeutic responsiveness to fluorouracil-based ACT in patients with stage III tumors. In addition, the abundance of basophils was correlated with an immunoevasive contexture characterized by M2-polarized macrophage infiltration. Moreover, our findings indicated elevated interleukin-4 expression but decreased interferon-γ expression in the high-basophils subgroup. CONCLUSIONS: Tumor-infiltrating basophils in gastric cancer were identified as an independent adverse prognosticator, and also predicted inferior chemotherapeutic responsiveness, which identified those patients in need of much more individualized postoperative adjuvant therapy and more stringent follow-up. Furthermore, the infiltration of basophils was associated with immunoevasive tumor microenvironment, which might be a potential immunotherapeutic target for gastric cancer.

Identification and validation of an immunogenic subtype of gastric cancer with abundant intratumoural CD103+CD8+ T cells conferring favourable prognosis.

BACKGROUND: Intratumoural CD103+CD8+ T cells have been linked to prolonged survival in several malignancies. However, the clinical significance of CD103+CD8+ T cells in gastric cancer remains unexplored. METHODS: Gastric cancer tissues from Zhongshan Hospital and data from Gene Expression Omnibus were obtained and analysed. Immunohistochemistry and flow cytometry were performed to detect the number and phenotypical characteristics of CD103+CD8+ T cells. The effect of programmed cell death protein-1 (PD-1) blockade on CD103+CD8+ T cells was evaluated with the use of an in vitro study based on fresh tumour tissues. RESULTS: CD103+CD8+ T cells predicted superior overall survival and provided better prognostic power than total CD8+ T cells in gastric cancer. Patients with high CD103+CD8+ T cell infiltration also gained more benefit from adjuvant chemotherapy. Flow cytometry analysis showed that CD103+CD8+ T cells exerted superior anti-tumour effects with stronger retention capacity and cytotoxicity. Moreover, an in vitro study showed that CD103+CD8+ T cells were more functionally restored after PD-1 blockade than CD103-CD8+ T cells. CONCLUSIONS: CD103+CD8+ T cells might be a useful marker to predict prognosis and therapeutic efficacy for gastric cancer patients. Efforts to increase intratumoural CD103+CD8+ T cell frequency might be a novel therapeutic strategy in gastric cancer.

Identification of relevant differential genes to the divergent development of pectoral muscle in ducks by transcriptomic analysis.

OBJECTIVE: The objective of this study was to identify candidate genes that play important roles in skeletal muscle development in ducks. METHODS: In this study, we investigated the transcriptional sequencing of embryonic pectoral muscles from two specialized lines: Liancheng white ducks (female) and Cherry valley ducks (male) hybrid Line A (LCA) and Line C (LCC) ducks. In addition, prediction of target genes for the differentially expressed mRNAs was conducted and the enriched gene ontology (GO) terms and Kyoto encyclopedia of genes and genomes signaling pathways were further analyzed. Finally, a protein-to-protein interaction network was analyzed by using the target genes to gain insights into their potential functional association. RESULTS: A total of 1,428 differentially expressed genes (DEGs) with 762 being up-regulated genes and 666 being down-regulated genes in pectoral muscle of LCA and LCC ducks identified by RNA-seq (p<0.05). Meanwhile, 23 GO terms in the down-regulated genes and 75 GO terms in up-regulated genes were significantly enriched (p<0.05). Furthermore, the top 5 most enriched pathways were ECM-receptor interaction, fatty acid degradation, pyruvate degradation, PPAR signaling pathway, and glycolysis/gluconeogenesis. Finally, the candidate genes including integrin b3 (Itgb3), pyruvate kinase M1/2 (Pkm), insulinlike growth factor 1 (Igf1), glucose-6-phosphate isomerase (Gpi), GABA type A receptorassociated protein-like 1 (Gabarapl1), and thyroid hormone receptor beta (Thrb) showed the most expression difference, and then were selected to verification by quantitative realtime polymerase chain reaction (qRT-PCR). The result of qRT-PCR was consistent with that of transcriptome sequencing. CONCLUSION: This study provided information of molecular mechanisms underlying the developmental differences in skeletal muscles between specialized duck lines.

Analysis of carcass traits, meat quality, amino acid and fatty acid profiles between different duck lines.

To investigate the effect of genetic selection on meat quality in ducks, twenty of each fast growth ducks (LCA) and slow growth ducks (LCC) selected from F6 generation of Cherry Valley ducks (♂) x Liancheng white ducks (♀) were analyzed for carcass characteristics, meat quality (physicochemical and textural characteristics), amino acid and fatty acid profiles at 7 wk. Results showed that live body weight, slaughter weight, eviscerated yield and abdominal fat percentage of LCA were significantly higher than those in LCC ducks (P < 0.01). Moreover, the average area and diameter of myofiber were larger in LCA than LCC ducks (P < 0.01). The breast and thigh muscles of LCA exhibited significantly lower water holding capacity and thermal loss compared with LCC ducks (P < 0.01). In addition, the content of nonessential amino acids (Glu, Asp, and Arg) in breast muscles and Asp, Ser, Thr, and Met in thigh muscles was higher in LCC than LCA ducks (P < 0.05). The proportion of polyunsaturated fatty acids (PUFA) in breast muscles of LCC was higher than LCA ducks (P < 0.05). However, the content of saturated fatty acids (SFA) in breast and thigh muscles of LCA was higher compared with LCC ducks (P < 0.05). The proportion of monounsaturated fatty acids (MUFA) in thigh muscles was significantly higher in LCC compared with LCA ducks (P < 0.01). Finally, multiple traits were evaluated by applying principal component analysis (PCA) and the results indicated that PUFA and SFA in breast muscles of LCA played important roles in meat quality, followed by Warner-Bratzler shear force (WBSF) and MUFA. However, water holding capacity (WHC) had a dominant effect in meat quality of thigh muscles in both LCA and LCC ducks.

Targeting myeloid checkpoint Siglec-10 reactivates antitumor immunity and improves anti-programmed cell death 1 efficacy in gastric cancer.

OBJECTIVE: Immunotherapy has not yielded satisfactory therapeutic responses in gastric cancer (GC). However, targeting myeloid checkpoints holds promise for expanding the potential of immunotherapy. This study aims to evaluate the critical role of Siglec-10+ tumor-associated macrophages (TAMs) in regulating antitumor immunity and to explore the potential of the myeloid checkpoint Siglec-10 as an interventional target. DESIGN: Siglec-10+ TAMs were assessed based on immunohistochemistry on tumor microarrays and RNA-sequencing data. Flow cytometry, RNA sequencing, and single-cell RNA-sequencing analysis were employed to characterize the phenotypic and transcriptional features of Siglec-10+ TAMs and their impact on CD8+ T cell-mediated antitumor immunity. The effectiveness of Siglec-10 blockade, either alone or in combination with anti-programmed cell death 1 (PD-1), was evaluated using an ex vivo GC tumor fragment platform based on fresh tumor tissues. RESULTS: Siglec-10 was predominantly expressed on TAMs in GC, and associated with tumor progression. In Zhongshan Hospital cohort, Siglec-10+ TAMs predicted unfavorable prognosis (n=446, p<0.001) and resistance to adjuvant chemotherapy (n=331, p<0.001), which were further validated in exogenous cohorts. In the Samsung Medical Center cohort, Siglec-10+ TAMs demonstrated inferior response to pembrolizumab in GC (n=45, p=0.008). Furthermore, Siglec-10+ TAMs exhibited an immunosuppressive phenotype and hindered T cell-mediated antitumor immune response. Finally, blocking Siglec-10 reinvigorated the antitumor immune response and synergistically enhances anti-PD-1 immunotherapy in an ex vivo GC tumor fragment platform. CONCLUSIONS: In GC, the myeloid checkpoint Siglec-10 contributes to the regulation of immunosuppressive property of TAMs and promotes the depletion of CD8+ T cells, ultimately facilitating immune evasion. Targeting Siglec-10 represents a potential strategy for immunotherapy in GC.

Poor clinical outcomes and immunoevasive contexture in CXCL13+CD8+ T cells enriched gastric cancer patients.

As an adverse survival prognosticator, chemokine (C-X-C motif) ligand 13 (CXCL13) has been studied in several types of malignancies. The secretion and physiological roles of CXCL13 in follicular helper T cells (TFH) cells have been well described, while the clinical significance of CD8+ tumor-infiltrating lymphocytes (TILs)-associated CXCL13 remains unknown. This study aims to investigate the clinical significance of CXCL13+CD8+ T cells in survival and chemotherapeutic responsiveness prediction in gastric cancer. In this study, 440 patients enrolled from Zhongshan Hospital with tumor microarray (TMA) specimens were randomly divided into testing set (n = 220) and validation set (n = 220) for analysis. CXCL13+CD8+ T cells were detected by multicolor immunohistochemistry. Fresh tumor tissue samples from another 60 gastric cancer patients were collected to detect CXCL13+CD8+ T cells functional status by flow cytometry (FCM). We found that high intratumoral CXCL13+CD8+ T cells infiltration predicted poor overall survival and inferior chemotherapeutic responsiveness in gastric cancer. CXCL13+CD8+T cells were associated with immunoevasive contexture with increased regulatory T (Treg) cells and dysfunctional cytotoxic T lymphocytes (CTLs). Moreover, the combinational analysis of CXCL13+CD8+ T cells and CD8+ T cells infiltration stratified patients into distinct risk groups with different clinical outcomes and chemotherapeutic responsiveness. Conclusively, intratumoral CXCL13+CD8+ T cells infiltration could be an independent prognostic and predictive marker for gastric cancer patients. CXCL13+CD8+ T cells represented an exhausted CD8+ T cell subset, and might be a potential immunotherapeutic target in gastric cancer.

Intratumoral CXCR5+CD8+T associates with favorable clinical outcomes and immunogenic contexture in gastric cancer.

Studies that examined an association between CD8+T and prognosis in gastric cancer are inconsistent, and a distinct population of CXCR5+CD8+T associated with better overall survival has been reported among various malignancies. Here, we show that the abundance of intratumoral CXCR5+CD8+T cells is associated with better overall survival in patients with gastric cancer. Patients with TNM II + III gastric cancer with higher intratumoral CXCR5+CD8+T cell infiltration are more likely to benefit from adjuvant chemotherapy. Microsatellite-unstable and Epstein-Barr virus positive tumors are enriched with CXCR5+CD8+T cells. Gastric cancer infiltrating CXCR5+CD8+T cells represent a specific subtype of stem-like CD8+T with effector memory feature. Identification of the clinical significance and phenotype of gastric cancer infiltrating CXCR5+CD8+T provides a roadmap for patient stratification and trials of targeted therapies.

Impact of intratumoural CD73 expression on prognosis and therapeutic response in patients with gastric cancer.

AIM: CD73 overexpression has been reported in several malignancies and is considered to be a novel immune checkpoint. However, the role and significance of CD73 in gastric cancer (GC) still remain obscure. We aim to investigate the role of CD73 expression in predicting prognosis, shaping immune contexture and guiding therapeutic strategy in GC. METHODS: The study enrolled four independent cohorts with a total of 902 patients with GC. CD73 expression and immune contexture were examined by immunohistochemistry, single-sample gene set enrichment analysis and flow cytometry. Clinical outcomes of patient subgroups were evaluated using the Kaplan-Meier curves and Cox proportional hazard analysis. All statistical tests were two-sided. RESULTS: CD73 was identified as an independent adverse prognostic factor for survival in GC. CD73high tumours showed a specific microenvironment with more CD8+ T cell infiltration, but these CD8+ T cells displayed a dysfunctional phenotype. Furthermore, the CD73 (NT5E) mRNA level was associated with the Cancer Genome Atlas molecular subtypes, and NT5E high tumours showed significant fibroblast growth factor receptor 2 activation and vascular endothelial growth factor and receptor enrichment. In addition, CD73high tumours indicated better chemotherapeutic responsiveness to fluorouracil yet a worse objective response rate to pembrolizumab in GC. CONCLUSIONS: High CD73 expression indicated an immunoevasive contexture with CD8+ T cell dysfunction and represented an independent predictor for adverse clinical outcomes. As a potential immunotherapeutic target, CD73 could potentially be a novel biomarker for adjuvant chemotherapy, targeted therapies and immunotherapy. The crucial role of CD73 in the therapeutic landscape of GC needs further validation retrospectively and prospectively.

Tumor-infiltrating podoplanin+ cells in gastric cancer: clinical outcomes and association with immune contexture.

Podoplanin (PDPN) has been proved to have significant immunoregulatory effects in several types of malignancies and is considered to be a novel immune checkpoint molecule. However, the clinical significance of PDPN and its potential influence on immune contexture in gastric cancer remain obscure. Here, we aimed to investigate the clinical outcomes and immunoregulatory role of tumor-infiltrating PDPN+ cells (tPDPNs) in gastric cancer. A total of 454 tumor tissue microarray specimens and 68 fresh tumor tissues of gastric cancer patients from Zhongshan Hospital, and transcriptional data of 293 gastric cancer patients from The Cancer Genome Atlas were included. We demonstrated that tPDPNs high subgroup experienced worse overall survival and disease-free survival, and indicated inferior therapeutic responsiveness to fluorouracil-based adjuvant chemotherapy (ACT) in gastric cancer. The abundance of tPDPNs was correlated with an immunoevasive contexture characterized by pro-tumor macrophage and dysfunctional CD8+ T cell infiltration. Moreover, dysfunctional CD8+ T cells in tPDPNs high subgroup exhibited decreased interferon-γ, granzyme B and perforin-1 expression yet elevated programmed cell death-1 (PD-1) and T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) expression. Stratification of gastric cancer patients into different risk groups based on tPDPNs and CD8+ T cells showed distinct prognosis, responsiveness to ACT and molecular characteristics. This study revealed that the abundance of tPDPNs could identify an immunoevasive contexture and might be applied as an independent predictor for poor prognosis and suboptimal ACT responsiveness. Thus, we recommended tPDPNs as a promising therapeutic target in gastric cancer.

Intratumoral CD103+CD4+ T cell infiltration defines immunoevasive contexture and poor clinical outcomes in gastric cancer patients.

Our previous study has identified intratumoral CD103+CD8+ T cells as a favorable prognostic factor in gastric cancer. However, the significance of CD103+CD4+ T cells in gastric cancer hasn't yet been elucidated. Here, we aimed to investigate the clinical significance and phenotype characteristics of intratumoral CD103+CD4+ T cells in gastric cancer. In our study, 469 formalin-fixed and paraffin-embedded samples and 24 fresh tissue specimens of patients with gastric cancer from Zhongshan Hospital were included. We manifested that intratumoral CD103+CD4+ T cells in gastric cancer predicted poor overall survival and inferior responsiveness to fluorouracil-based ACT. The density and phenotypic characteristics of CD103+CD4+ T cells in gastric cancer were detected by immunohistochemistry and flow cytometry, which showed that CD103+CD4+ T cells exhibited an immunosuppressive phenotype and higher retention capacity in tumor tissues. Furthermore, increased CD103+CD4+ T cells contributed to CD8+T cell dysfunction with decreased granzyme B (GZMB), interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α) and perforin (PRF-1) expression in gastric cancer. Overall, this study revealed that intratumoral CD103+CD4+T cell infiltration defined immunoevasive contexture and predicted poor prognosis and inferior responsiveness to fluorouracil-based ACT. Therefore, we recommended that CD103+CD4+ T cells might be a potential immunotherapeutic target for gastric cancer.