Project description:CD8 tissue-resident memory T cells (TRM) provide frontline immunity in mucosal tissues. The mechanisms regulating CD8 TRM maintenance, heterogeneity, protective and pathological functions are largely elusive. Here we identify an epitope-specific CD8 TRM population that is maintained by in situ MHC-I and B7 signaling following acute influenza infection. These TRM cells co-exhibit exhausted-like phenotypes and memory features, and provide heterologous immunity against secondary infection. PD-L1 blockade at the memory stage promotes exhausted-like TRM rejuvenation and secondary immunity at the cost of developing post-infection fibrotic sequelae. Increased numbers of CD8 TRM cells are observed in the lungs of pulmonary fibrosis patients compared to control patients. Thus, TRM exhaustion results from a tissue-specific cellular adaptation to balance fibrotic sequelae and secondary immunity.
Project description:Fresh human breast tumor tissue was dissociated into single cells and viably frozen. Patient samples were annotated as having an ""exhausted"" or ""non-exhausted"" immune environment based on CyTOF characterization of T cell phenotypes (Wagner et al, Cell 2019). 14 samples (7 exhausted, 7 non-exhausted) were selected for scRNA-seq (without prior cell type enrichment) with the goal to compare the two immune environment types and to comprehensively characterize exhaustion-associated features of the tumor microenvironment.
Project description:Tissue-resident memory T (TRM) cells are crucial mediators of adaptive immunity in non-lymphoid tissues. However, the functional heterogeneity and pathogenic roles of CD4+ TRM cells that reside within chronic inflammatory lesions remain unknown. We found that CD69hiCD103low CD4+ TRM cells produced effector cytokines and promoted the inflammation and fibrotic responses induced by chronic exposure to Aspergillus fumigatus. Simultaneously, immunosuppressive CD69hiCD103hiFoxp3+ CD4+ regulatory T (Treg) cells were induced and constrained the ability of pathogenic CD103low TRM cells to cause fibrosis. Thus, lung tissue-resident CD4+ T cells play crucial roles in the pathology of chronic lung inflammation, and CD103 expression defines pathogenic effector and immunosuppressive tissue-resident cell subpopulations in the inflamed lung.
Project description:CD103hi lung-resident regulatory T cells constrain the fibrotic responses induced by CD103low tissue-resident pathogenic CD4 T cells
Project description:Hepatocellular carcinoma (HCC) often develops following chronic hepatitis B virus (HBV) infection and responds poorly to immune checkpoint blockade. Here we examined the antigen specificities of HCC-infiltrating T cells and their relevance to tumor control. Using highly multiplexed peptide-MHC tetramer staining of unexpanded cells from blood, liver and tumor tissues from 46 HCC patients, we detected 91 different antigen-specific CD8+ T cell populations targeting HBV, neoantigen, tumor-associated and disease-unrelated antigens. Parallel high-dimensional analysis delineated five distinct antigen-specific tissue-resident memory T (Trm) cell populations. Intratumoral and intrahepatic HBV-specific T cells were enriched for two Trm cell subsets that were PD-1-low and TOX-low, despite being clonally expanded. High frequencies of intratumoral terminally exhausted T cells was uncommon. Patients with tumor-infiltrating HBV-specific CD8+ Trm cells exhibited longer-term relapse-free survival. Thus, non-terminally exhausted HBV-specific CD8+ Trm cells show hallmarks of active involvement and effective antitumor response, implying that these cells could be harnessed for therapeutic purposes.
Project description:CD8 T cells normally differentiate from resting naïve T cells into function effector and then memory CD8 T cells following acute infections. During chronic viral infections, however, virus-specific CD8 T cells often become exhausted. We used microarrays to examine the gene expression differences between naive, effector, memory and exhausted virus-specific CD8 T cells following lymphocytic choriomeningitis virus infection. Experiment Overall Design: Three or four independent samples were sorted by flow cytometry for each cell type (naive, effector, memory and exhausted) virus-specific CD8 T cells. RNA was extracted and hybridized to Affymetrix microarrays.
Project description:We isolated non-hematopoietic cells from fibrotic and non-fibrotic mouse bone marrow and perfomed scRNAseq on them. We identified 8 different stromal populations. Our analysis revealed two distinct mesenchymal stromal cells (MSC) subsets as pro-fibrotic cells. MSCs were functionally reprogrammed in a stagedependent manner with loss of their progenitor status and initiation of differentiation in the prefibrotic stage and acquisition of a pro-fibrotic and inflammatory phenotype in the fibrotic stage. In parallel, IL-33-expressing myelinating Schwann cell progenitors expanded, likely as a repair mechanism for the previously described neuropathy in MPN.
Project description:To further understand the pathologic microenvironment in IPF, we have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to distinguish normal and IPF lung in normal-looking, fibrotic foci and hyperplastic areas of IPF lung. Four IPF lungs were dissected into normal-looking, fibrotic foci and hyperplastic areas by Laser-Capture-Microdissection. Gene expression analysis showed that 638 significantly different genes were identified that clearly distinguished the different IPF microenvironments . Among them, MMP19 was revealed as one of the most significantly up-regulated genes that distinguished normal looking epithelial cells (N) to hyperplastic epithelial cells, MMP19 up-regulation in IPF lungs was verified by immunohistochemical (IHC), qRT-PCR and Western-blot. IPF lungs are heterogeneity complex, which comprise normal looking area, fibrotic foci and hyperplastic area. In this study we separated the normal, fibrotic foci and hyperplastic area by LCM and employed Agilent whole genome gene expression microarray profiling to identify genes with the potential to distinguish the unique microenironment of IPF