Project description:Temporal analysis of T-cell receptor (TCR) repertoire has been used to monitor treatment-induced changes in antigen-specific T cells in patients with cancer. However, lack of experimental model that allows the temporal analysis of TCR repertoire in same individual in homogeneous population limit the understanding of causal relationship between changes in TCR repertoire and antitumor responses. A bilateral tumor model, in which tumor cells were inoculated into the bilateral backs of mice, can be used for temporal analysis in TCR repertoire. In this study, we examined the prerequisite for this strategy: TCR repertoire are conserved between the bilateral tumor with same growth rate. The bilateral tumors with equivalent tumor size and draining lymph nodes (dLN) were collected 13 days after the tumor inoculation to analyze the TCR repertoire of CD4+ and CD8+ T cells. Most of the tumor-infiltrating T-cell clones were highly conserved between the bilateral tumors, and the extent of clonal expansion was equivalent. In addition, the similarity between bilateral tumors were equivalent to the heterogeneity in one side of the tumor. The similarity of TCR repertoire in the bilateral dLN was markedly lower than that of the tumor, suggesting that tumor-reactive T-cell clones induced independently in each dLN were integrated during recirculation and then infiltrated the tumor. These findings suggest that our bilateral tumor model is suitable for temporal monitoring of TCR repertoire to evaluate temporal and treatment-induced changes in tumor-reactive T-cell clones.
Project description:HLA-E molecules can present self and pathogen-derived peptides to both NK-cells and T-cells. T-cells that recognize HLA-E peptides via their T-cell receptor (TCR) are termed donor-unrestricted T-cells due to restricted allelic variation of HLA-E. The composition and repertoire of HLA-E TCRs is not known so far. We performed TCR sequencing on CD8+ T-cells from 21 individuals recognizing HLA-E tetramers (TM) folded with 2 Mtb HLA-E restricted peptides. We sorted HLA-E Mtb TM+ and TMCD8+ T-cells directly ex vivo and performed bulk RNA-sequencing and single cell TCR sequencing. The identified TCR repertoire was diverse and showed no conservation between and within individuals. TCRs selected from our single cell TCR sequencing data could be activated upon HLA-E/peptide stimulation, although not robust, reflecting potentially weak interactions between HLA-E peptide complexes and TCRs. Thus, HLA-E Mtb specific T-cells have a highly diverse TCR repertoire.
Project description:Natural killer (NK) cells contribute to immunosurveillance and first-line defense in the control of tumor growth and metastasis diffusion. NKEVs are constitutively secreted, are biologically active, reflect the protein and genetic repertoire of their originating cells and exert anti-tumor activity in vitro and in vivo. NKEVs from tumor-conditioned NK cells interact with naïve NK cells promoting their cytotoxic activity. In cancer NK cells exhibit profound defects in degranulation ability, a status probably reflected by their NKEVs. Hence, NKEVs could contribute to improve cancer therapy by interacting with tumor and/or immune cells at the same time sensing the actual NK cell status in cancer patients. Here we investigated the role of NKEVs in stimulating the immune system and developed an immune enzymatic test (NKExoELISA) to sense the systemic NK cell status by measuring plasma NK-derived exosomes through combined capture of exosomes, expressing typical EV (tsg101) and NK cell (CD56) markers. We analyzed by LC-MS/MS the protein content from NKEVs evaluating proteins differentially expressed in exosomes (NKExo), vescicles (NKMV) and total cell extract (Tot extr) from parental NK cells. Proteomic data confirmed the presence of many EV markers and detected several proteins involved in immune response, cell adhesion and complement biological processes.
Project description:To assess the impact of Arpp21 deficiency on the TCR repertoire, we generated Arpp21-deficient mice from which we isolated CD4 T cells and subjected them to NGS sequencing.
Project description:Infiltrating T-lymphocytes from the peripheral blood into the central nervous system (CNS) play a dynamic role in the development of a neurological immune-mediated diseases. HAM/TSP is a chronic progressive inflammatory neurological disorder associated with human T-cell lymphotropic virus type I (HTLV-I) infection. In this chronic myelopathy, virus-infected circulating T-cells infiltrate the CNS and an immune response is initiated against the components of CNS. As the HTLV-I proviral load (PVL) has been used as the best clinical marker for patient diagnostic with HAM/TSP, we hypothesized there might be a signature on T-cell receptor (TCR) clonal repertoire in these patients, which could distinguish HAM/TSP patients from the healthy population, as well as from patients with a more heterogeneous CNS-reactive inflammatory disease as multiple sclerosis (MS). With this in mind, we applied an innovative unbiased molecular technique – unique molecular identifier (UMI) library-strategy to investigate with high accuracy the TCR clonal repertoire by high throughput sequencing (HTS) technology. cDNA-TCR β-chain libraries were sequenced from 2 million peripheral mononuclear cells (PBMCs) in 14 HAM/TSP patients, 34 MS patients and 20 healthy controls (HC). To address whether the clonal expansion correlates with the patient’s PVL level, analysis of longitudinal TCR repertoire was performed in 2 HAM/TSP patients. Over 5.6 million TCR sequences were generated per sample on HiSeq 2500 Illumina system and analyzed through the molecular identifier groups-based error correction pipeline (MiGEC). Bioinformatic analysis showed that clones with more than 8 reads had a lower coefficient of variation (CV) and then could be used with confidence to evaluate the TCR clonal expansion. While HAM/TSP patients showed the higher clonal T-cell expansion compared to MS and HC, increase of the TCR clonal expansion was inversely correlated with the diversity of TCR repertoire in all subject’s group. In addition, correlation of the PVL with TCR clonal expansion was observed in HAM/TSP patients at longitudinal time-points. Surprisingly, MS patients showed a higher diversity of TCR repertoire along with a very slight clonal T-cell expansion in comparison to either HAM/TSP patients or HC. Despite of the higher TCR clonal expansion in HAM/TSP patients, a non-shared or “private” TCR repertoire was observed in these patients. No clones that shared the same CDR3 amino acid sequences were seen in HC and MS patients. However, a cluster of related CDR3 amino acid sequences were observed for 18 out of 34 MS patients when evaluated by phylogenetic tree analysis. It suggestes that a TCR-repertoire signature might characterize patients with MS. Our findings suggest that even though a unique TCR-b repertoire shapes the immune response in patients with neurological immune-mediated disease, a relatedness on clonal T-cell repertoire exist in MS.
Project description:To assess the impact of Rag1 3'-UTR deficiency on the TCR repertoire, we generated Rag1 3'-UTR -deficient mice from which we isolated CD4 T cells and subjected them to NGS sequencing.
Project description:As the anti-PD-1 monoclonal antibody (mAb) becomes to be used in many types of cancers, the needs for the predictive biomarker of PD-1 blockade are growing. T cell receptor (TCR) repertoire—which reflects the anti-tumor T-cell responses based on the antigen specificity—is a potential biomarker of cancer immunotherapy. Here, we analyzed the TCR repertoire of patients with advanced gastrointestinal cancer and explored its association with clinical responses.