A Virus-Specific Immune Rheostat in the Immunome of Patients Recovering From Mild COVID-19

Front Immunol. 2021 May 25;12:674279. doi: 10.3389/fimmu.2021.674279. eCollection 2021.


An accurate depiction of the convalescent COVID-19 immunome will help delineate the immunological milieu crucial for disease resolution and protection. Using mass cytometry, we characterized the immune architecture in patients recovering from mild COVID-19. We identified a virus-specific immune rheostat composed of an effector T (Teff) cell recall response that is balanced by the enrichment of a highly specialized regulatory T (Treg) cell subset. Both components were reactive against a peptide pool covering the receptor binding domain (RBD) of the SARS-CoV-2 spike glycoprotein. We also observed expansion of IFNγ+ memory CD4+ T cells and virus-specific follicular helper T (TFH) cells. Overall, these findings pinpoint critical immune effector and regulatory mechanisms essential for a potent, yet harmless resolution of COVID-19 infection.

Keywords: COVID-19; SARS-CoV-2; follicular helper T cells; mass cytometry; regulatory T cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • CD4-Positive T-Lymphocytes / immunology
  • COVID-19 / immunology*
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Male
  • SARS-CoV-2 / immunology*
  • Spike Glycoprotein, Coronavirus / immunology
  • T Follicular Helper Cells / immunology
  • T-Lymphocytes, Regulatory / immunology
  • Young Adult


  • Spike Glycoprotein, Coronavirus
  • spike glycoprotein, SARS-CoV