Search

NLR genes are crucial components of the effector-triggered immunity (ETI) system, responsible for recognizing pathogens and initiating immune responses. Although NLR genes in many plant species have been extensively studied, the diversity of NLR genes in citrus remains largely unknown. Our analysis revealed significant variations in the copy numbers of NLR genes among these species. Gene duplication and recombination were identified as the major driving forces behind this diversity. Additionally, horizontal gene transfer (HGT) emerged as the principal mechanism responsible for the increase in NLR gene copy number in A. buxifolia. The citrus NLR genes were classified into four categories: TIR-NBS-LRR (TNL), CC-NBS-LRR (CNL), RPW8-NBS-LRR (RNL), and NL. Our findings indicate that TNL, RNL, and CNL genes originated from NL genes through the acquisition of TIR and RPW8 domains, along with CC motifs, followed by the random loss of corresponding domains. Phylogenetic analysis suggested that citrus NLR genes originated alongside the species and underwent adaptive evolution, potentially playing crucial roles in the global colonization of citrus. This study provides important insights into the diversity of citrus NLR genes and serves as a foundational dataset for future research aimed at breeding disease-resistant citrus varieties.

Abstract The response rate of pancreatic cancer to chemotherapy or immunotherapy pancreatic cancer is low. Although minimally invasive irreversible electroporation (IRE) ablation is a promising option for irresectable pancreatic cancers, the immunosuppressive tumour microenvironment that characterizes this tumour type enables tumour recurrence. Thus, strengthening endogenous adaptive antitumour immunity is critical for improving the outcome of ablation therapy and post-ablation immune therapy. Here we present a hydrogel microsphere vaccine that amplifies post-ablation anti-cancer immune response via releasing its cargo of FLT3L and CD40L at the relatively lower pH of the tumour bed. The vaccine facilitates migration of the tumour-resident type 1 conventional dendritic cells (cDC1) to the tumour-draining lymph nodes (TdLN), thus initiating the cDC1-mediated antigen cross-presentation cascade, resulting in enhanced endogenous CD8+ T cell response. We show in an orthotopic pancreatic cancer model in male mice that the hydrogel microsphere vaccine transforms the immunologically cold tumour microenvironment into hot in a safe and efficient manner, thus significantly increasing survival and inhibiting the growth of distant metastases.

BackgroundThe main objective of this study was to analyze the effects of KRAS/TP53 mutation status and tumor sideness on the immune microenvironment of colorectal cancer using integrated scRNA-seq data.MethodsA total of 78 scRNA-seq datasets, comprising 42 treatment-naive colorectal tumors, 13 tumor adjacent tissues and 23 normal mucosa tissues were included. Standardized Seurat procedures were applied to identify cellular components with canonical cell marks. The batch-effect was assessed and corrected using harmony algorithm. The scMetabolism algorithm was used for single-cell metabolic analysis. The results and clinical significance were further validated using immunofluorescent-staining and TCGA-COAD datasets. Immune-infiltration scores of bulk-RNA-seq data were estimated using ssGSEA. The presto-wilcoxauc algorithm was used to identify differentially enriched genes or pathways across different subgroups. Two-sided p-value less than 0.05 was considered statistically significant.ResultsWe refined the landscape of functional immune cell subtypes, especially T cells and myeloid cells, across normal mucosa, tumor adjacent and tumor tissue. The existence and function of two states of exhausted CD8+ T (Tex) subtypes in colorectal cancer, and FOLR2+ LYVE1+ macrophages indicating unfavorable prognosis in colorectal cancer were identified and validated. The diverse tumor mutation status reshaped the immune cell function and immune checkpoint ligands/receptors (ICLs/ICRs) expression pattern. Importantly, the KRAS/TP53 dual mutations significantly reduced the major energy metabolic functions in immune cells, and promoted the cell-to-cell communications towards immunosuppression in colorectal cancers. The results revealed LAG3, CD24-SIGLEC10 and HBEGF-CD9 pathways as potential therapeutic targets for dual mutant colorectal cancers.ConclusionsWe revealed that the immune microenvironment underwent a gradual remodeling with an enrichment of immunosuppressive myeloid cells from normal mucosa to tumor regions in colorectal cancers. Moreover, we revealed the metabolic heterogeneity of tumor-infiltrating immune cells and suggested that the KRAS/TP53 dual mutation may impair antitumor immunity by reducing T and myeloid cell energy metabolism and reshaping cellular interactions toward immunosuppression.