Low-Avidity CD4⁺ T Cell Responses to SARS-CoV-2 in Unexposed Individuals and Humans with Severe COVID-19.

ABSTRACT: CD4⁺ T cells reactive against SARS-CoV-2 can be found in unexposed individuals, and these are suggested to arise in response to common cold coronavirus (CCCoV) infection. Here, we utilized SARS-CoV-2-reactive CD4⁺ T cell enrichment to examine the antigen avidity and clonality of these cells, as well as the relative contribution of CCCoV cross-reactivity. SARS-CoV-2-reactive CD4⁺ memory T cells were present in virtually all unexposed individuals examined, displaying low functional avidity and multiple, highly variable cross-reactivities that were not restricted to CCCoVs. SARS-CoV-2-reactive CD4⁺ T cells from COVID-19 patients lacked cross-reactivity to CCCoVs, irrespective of strong memory T cell responses against CCCoV in all donors analyzed. In

SUBMITTER: Bacher P 

PROVIDER: S-EPMC7689350 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature