[PDF][PDF] Tissue-resident memory T cells mediate immune homeostasis in the human pancreas through the PD-1/PD-L1 pathway

SP Weisberg, DJ Carpenter, M Chait, P Dogra… - Cell reports, 2019 - cell.com
SP Weisberg, DJ Carpenter, M Chait, P Dogra, RD Gartrell-Corrado, AX Chen, S Campbell…
Cell reports, 2019cell.com
Non-recirculating tissue-resident memory T cells (TRMs) are the predominant T cell subset
in diverse tissue sites, where they mediate protective immune responses in situ. Here, we
reveal a role for TRM in maintaining immune homeostasis in the human pancreas through
interactions with resident macrophages and the PD-1/PD-L1 inhibitory pathway. Using
tissues obtained from organ donors, we identify that pancreas T cells comprise CD8+ PD-1
hi TRMs, which are phenotypically, functionally, and transcriptionally distinct compared to …
Summary
Non-recirculating tissue-resident memory T cells (TRMs) are the predominant T cell subset in diverse tissue sites, where they mediate protective immune responses in situ. Here, we reveal a role for TRM in maintaining immune homeostasis in the human pancreas through interactions with resident macrophages and the PD-1/PD-L1 inhibitory pathway. Using tissues obtained from organ donors, we identify that pancreas T cells comprise CD8+PD-1hi TRMs, which are phenotypically, functionally, and transcriptionally distinct compared to TRMs in neighboring jejunum and lymph node sites. Pancreas TRMs cluster with resident macrophages throughout the exocrine areas; TRM effector functions are enhanced by macrophage-derived co-stimulation and attenuated by the PD-1/PD-L1 pathways. Conversely, in samples from chronic pancreatitis, TRMs exhibit reduced PD-1 expression and reduced interactions with macrophages. These findings suggest important roles for PD-1 and TRM-macrophage interactions in controlling tissue homeostasis and immune dysfunctions underlying inflammatory disease, with important implications for PD-1-based immunotherapies.
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