Project description:To investigate the function of Neuropilin-1 (NRP-1) in Foxp3+ regulatory T (Treg) cell stability and function, we cultured naïve CD4+ T cells under induced Treg cell (iTreg)-differentiating condition. We then flow sorted NRP-1+ and NRP-1- iTreg cells and performed gene expression profiling analysis.
Project description:By killing tumor cells, cytotoxic CD8+ T cells are the major effectors in antitumor immunity. A subset of CD4+ T cells also possesses cytotoxic activity by expressing perforin and granzymes and is associated with immunotherapy efficacy. Despite the progress made in characterizing cytotoxic CD4+ T cells in various diseases, the status of cytotoxic CD4+ T cells in non-small cell lung cancer (NSCLC) and the driving mechanisms and forces involved in reviving intratumoral cytotoxic CD4+ T cells remain unclear. Here, we showed that CD4+GzmB+ T cells obtained from patients with NSCLC expressed increased levels of SLC7A5 compared with their counterparts. Upregulation of SLC7A5 was essential for the differentiation of CD4+GzmB+ T cells from naïve CD4+ T cells stimulated with TCR and IL-2. Both T-bet and Eomes are required for the differentiation of CD4+GzmB+ T cells. Interestingly, IL-15 can further increase SLC7A5 expression in differentiated CD4+GzmB+ T cells. Moreover, through activation of the AKT-FOXO1-T-bet axis, IL-15 increased the effector function of intratumoral CD4+GzmB+ T cells. In addition to IL-15, owing to the unique expression profile of PD-1 and CD85j in tumor-infiltrating CD4+GzmB+ T cells, using patient-derived lung cancer explants, we showed that simultaneous blockade of PD-1 and CD85j promoted the effector function of CD4+GzmB+ T cells by activating the AKT pathway. Importantly, using a mouse model of lung cancer, we demonstrated that intrinsic MHC II expression in cancer cells determines the significance of CD4+GzmB+ T-cell-mediated antitumor immunity in response to immunotherapy.
Project description:To prevent autoimmunity, thymocytes expressing self-reactive T cell receptors (TCRs) are negatively selected, however, divergence into tolerogenic, agonist-selected lineages represent an alternative fate. As thymocyte development, selection, and lineage choices are dependent on spatial context and cell-to-cell interactions, we have performed Cellular Indexing of Transcriptomes and Epitopes by sequencing (CITE-seq) and spatial transcriptomics on paediatric human thymus. Thymocytes expressing markers of strong TCR signalling diverged from the conventional developmental trajectory prior to CD4+ lineage commitment, while markers of different agonist cell populations (CD8αα(I), CD8αα(II), T(agonist), Treg(diff) and Treg) exhibited variable timing of induction. Expression profiles of chemokines and co-stimulatory molecules, together with spatial localization, supported that dendritic cells, B cells, and stromal cells contribute to agonist selection, with different subsets influencing thymocytes at specific developmental stages within distinct spatial niches. Understanding factors influencing agonist T cells is needed to benefit from their immunoregulatory effects in clinical use.