Identification of resident memory CD8+ T cells with functional specificity for SARS-CoV-2 in unexposed oropharyngeal lymphoid tissue.

Niessl J, Sekine T, Lange J, Konya V, Forkel M, Maric J, Rao A, Mazzurana L, Kokkinou E, Weigel W, Llewellyn-Lacey S, Hodcroft EB, Karlsson AC, Fehrm J, Sundman J, Price DA, Mjösberg J, Friberg D, Buggert M

Sci Immunol 6 (64) eabk0894 [2021-10-22; online 2021-10-22]

Cross-reactive CD4+ T cells that recognize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are more commonly detected in the peripheral blood of unexposed individuals compared with SARS-CoV-2–reactive CD8+ T cells. However, large numbers of memory CD8+ T cells reside in tissues, feasibly harboring localized SARS-CoV-2–specific immune responses. To test this idea, we performed a comprehensive functional and phenotypic analysis of virus-specific T cells in tonsils, a major lymphoid tissue site in the upper respiratory tract, and matched peripheral blood samples obtained from children and adults before the emergence of COVID-19 (coronavirus disease 2019). We found that SARS-CoV-2–specific memory CD4+ T cells could be found at similar frequencies in the tonsils and peripheral blood in unexposed individuals, whereas functional SARS-CoV-2–specific memory CD8+ T cells were almost only detectable in the tonsils. Tonsillar SARS-CoV-2–specific memory CD8+ T cells displayed a follicular homing and tissue-resident memory phenotype, similar to tonsillar Epstein-Barr virus–specific memory CD8+ T cells, but were functionally less potent than other virus-specific memory CD8+ T cell responses. The presence of preexisting tissue-resident memory CD8+ T cells in unexposed individuals could potentially enable rapid sentinel immune responses against SARS-CoV-2.

Category: Biochemistry

Category: Health

Funder: VR

Type: Journal article

PubMed 34519539

DOI 10.1126/sciimmunol.abk0894

Crossref 10.1126/sciimmunol.abk0894

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