PD-1hi CD8+ resident memory T cells balance immunity and fibrotic sequelae

Z Wang, S Wang, NP Goplen, C Li, IS Cheon… - Science …, 2019 - science.org
Z Wang, S Wang, NP Goplen, C Li, IS Cheon, Q Dai, S Huang, J Shan, C Ma, Z Ye, M Xiang…
Science immunology, 2019science.org
CD8+ tissue-resident memory T (TRM) cells provide frontline immunity in mucosal tissues.
The mechanisms regulating CD8+ TRM maintenance, heterogeneity, and protective and
pathological functions are largely elusive. Here, we identify a population of CD8+ TRM cells
that is maintained by major histocompatibility complex class I (MHC-I) signaling, and CD80
and CD86 costimulation after acute influenza infection. These TRM cells have both
exhausted-like phenotypes and memory features and provide heterologous immunity …
CD8+ tissue-resident memory T (TRM) cells provide frontline immunity in mucosal tissues. The mechanisms regulating CD8+ TRM maintenance, heterogeneity, and protective and pathological functions are largely elusive. Here, we identify a population of CD8+ TRM cells that is maintained by major histocompatibility complex class I (MHC-I) signaling, and CD80 and CD86 costimulation after acute influenza infection. These TRM cells have both exhausted-like phenotypes and memory features and provide heterologous immunity against secondary infection. PD-L1 blockade after the resolution of primary infection promotes the rejuvenation of these exhausted-like TRM cells, restoring protective immunity at the cost of promoting postinfection inflammatory and fibrotic sequelae. Thus, PD-1 serves to limit the pathogenic capacity of exhausted-like TRM cells at the memory phase. Our data indicate that TRM cell exhaustion is the result of a tissue-specific cellular adaptation that balances fibrotic sequelae with protective immunity.
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