KIR+CD8+ T cells suppress pathogenic T cells and are active in autoimmune diseases and COVID-19

Science. 2022 Apr 15;376(6590):eabi9591. doi: 10.1126/science.abi9591. Epub 2022 Apr 15.

Abstract

In this work, we find that CD8+ T cells expressing inhibitory killer cell immunoglobulin-like receptors (KIRs) are the human equivalent of Ly49+CD8+ regulatory T cells in mice and are increased in the blood and inflamed tissues of patients with a variety of autoimmune diseases. Moreover, these CD8+ T cells efficiently eliminated pathogenic gliadin-specific CD4+ T cells from the leukocytes of celiac disease patients in vitro. We also find elevated levels of KIR+CD8+ T cells, but not CD4+ regulatory T cells, in COVID-19 patients, correlating with disease severity and vasculitis. Selective ablation of Ly49+CD8+ T cells in virus-infected mice led to autoimmunity after infection. Our results indicate that in both species, these regulatory CD8+ T cells act specifically to suppress pathogenic T cells in autoimmune and infectious diseases.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoimmune Diseases*
  • CD8-Positive T-Lymphocytes
  • COVID-19*
  • Humans
  • Mice
  • Receptors, KIR
  • T-Lymphocytes, Regulatory

Substances

  • Receptors, KIR