Chronic viral infections lead to persistent CD8 T cell activation and functional exhaustion. Expression of programmed cell death-1 (PD-1) has been associated to CD8 T cell dysfunction in HIV infection. Herein we report that another negative regulator of T cell activation, CD160, was also upregulated on HIV-specific CD8 T lymphocytes mostly during the chronic phase of infection. CD8 T cells that expressed CD160 or PD-1 were still functional whereas co-expression of CD160 and PD-1 on CD8 T cells defined a novel subset with all the characteristics of functionally exhausted T cells. Blocking the interaction of CD160 with HVEM, its natural ligand, increased HIV-specific CD8 T cell proliferation and cytokine production. Transcriptional profiling showed that CD160−PD-1+CD8 T cells encompassed a subset of CD8+ T cells with activated transcriptional programs, while CD160+PD-1+ T cells encompassed primarily CD8+ T cells with an exhausted phenotype. The transcriptional profile of CD160+PD-1+ T cells showed the downregulation of the NFκB transcriptional node and the upregulation of several inhibitors of T cell survival and function. Overall, we show that CD160 and PD-1 expressing subsets allow differentiating between activated and exhausted CD8 T cells further reinforcing the notion that restoration of function will require multipronged approaches that target several negative regulators.

Metastatic microsatellite-stable (MSS) colorectal cancer rarely responds to immune checkpoint inhibitors (ICI). Metabolism heterogeneity in the tumor microenvironment (TME) presents obstacles to antitumor immune response. Combining transcriptome (The Cancer Genome Atlas MSS colorectal cancer, n ¼ 383) and digital pathology (n ¼ 96) analysis, we demonstrated a stroma metabolism-immune excluded subtype with poor prognosis in MSS colorectal cancer, which could be attributed to interaction between chondroitin-6-sulfate (C-6-S) metabolites and M2 macrophages, forming the "exclusion barrier" in the invasive margin. Furthermore, C-6-S derived from cancerassociated fibroblasts promoted co-nuclear translocation of pSTAT3 and GLI1, activating the JAK/STAT3 and Hedgehog pathways. In vivo experiments with C-6-S-targeted strategies decreased M2 macrophages and reprogrammed the immunosuppressive TME, leading to enhanced response to anti-PD-1 in MSS colorectal cancer. Therefore, C-6-S-induced immune exclusion represents an "immunometabolic checkpoint" that can be exploited for the application of combination strategies in MSS colorectal cancer ICI treatment.

Necrotizing enterocolitis (NEC) is one of the most common and destructive diseases in neonates and an unpredictable surgical emergency. However, the molecular pathological mechanism of NEC is still not well understood. This study was designed to provide a molecular basis for the pathogenesis of human NEC through bioinformatics analysis and immune infiltration. For RNA‐Seq, DEseq2 algorithm was used to identify differentially expressed genes (DEGs) and to perform functional enrichment analysis. Immune infiltration was analyzed by CIBERSORT algorithm. A total of 34,712 genes were detected and 7463 DEGs were identified in this study. Gene Ontology analysis revealed that DEGs were mainly involved in CCR1 chemokine receptor binding, transporter activity, growth factor binding, etc. KEGG pathway analysis showed that the DEGs were significantly enriched in the toll‐like receptor signaling pathway, Th17 cell differentiation, and cytokine–cytokine receptor interaction. The immune infiltration profiles varied significantly between NEC, NEC self‐control, and normal intestinal tissues. Finally, the expression levels of 21 DEGs were verified by reverse transcription quantitative real‐time PCR. Our findings may provide new insights into the development of NEC.

Tumor cells undergo metabolic reprogramming to meet their energy and anabolic demands to maintain their malignant phenotype. Activation of oncogenes and deletion of tumor suppressors promotes metabolic reprogramming in cancer by directly or indirectly regulating enzymatic activities associated with metabolic pathways. Metabolic reprogramming in tumor cells mainly involves the glycolytic pathway, pentose phosphate pathway, serine synthesis pathway, enhanced glutamine metabolism or fatty acid anabolism, and abnormal mitochondrial oxidative phosphorylation (OXPHOS). The tricarboxylic acid (TCA) cycle is the central pathway of mitochondrial OXPHOS, and glucose, amino acid and fatty acid metabolism are associated with the TCA cycle. Metabolic abnormalities and rewiring of metabolic pathways are also present in Osteosarcoma (OS). The abnormal metabolic pattern in OS is associated with cell proliferation, migration, invasion and drug resistance. This review summarizes the current studies on glycolysis, amino acid metabolism, lipid synthesis and the TCA cycle related to OS.