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Review
. 2021 Jun 30;44(6):401-407.
doi: 10.14348/molcells.2021.0079.

Phenotypes and Functions of SARS-CoV-2-Reactive T Cells

Min Kyung Jung  1 , Eui-Cheol Shin  1   2
Affiliations
Review

Phenotypes and Functions of SARS-CoV-2-Reactive T Cells

Min Kyung Jung et al. Mol Cells. .

Abstract

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which is an ongoing pandemic disease. SARS-CoV-2-specific CD4+ and CD8+ T-cell responses have been detected and characterized not only in COVID-19 patients and convalescents, but also unexposed individuals. Here, we review the phenotypes and functions of SARS-CoV-2-specific T cells in COVID-19 patients and the relationships between SARS-CoV-2-specific T-cell responses and COVID-19 severity. In addition, we describe the phenotypes and functions of SARS-CoV-2-specific memory T cells after recovery from COVID-19 and discuss the presence of SARS-CoV-2-reactive T cells in unexposed individuals and SARS-CoV-2-specific T-cell responses elicited by COVID-19 vaccines. A better understanding of T-cell responses is important for effective control of the current COVID-19 pandemic.

Keywords: COVID-19; SARS-CoV-2; T cell; vaccine.

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Conflict of interest statement

CONFLICT OF INTEREST

The authors have no potential conflicts of interest to disclose.

Figures

Fig. 1
Fig. 1. Phenotypes and functions of SARS-CoV-2-specific CD8+ T cells in patients with acute COVID-19.
During acute COVID-19, SARS-CoV-2-specific CD8+ T cells express not only activation markers (CD38 and HLA-DR), a proliferation marker (Ki-67), and cytotoxic molecules (perforin and granzyme B), but also immune checkpoint inhibitory receptors (PD-1 and TIM-3). However, SARS-CoV-2-specific CD8+ T cells produce IFN-γ regardless of PD-1 expression, indicating that SARS-CoV-2-specific PD-1+CD8+ T cells are functional, not exhausted.
Fig. 2
Fig. 2. Differentiation of SARS-CoV-2-specific CD8+ T cells during the convalescent period of COVID-19.
From the early convalescent to the late convalescent phases, the frequency of SARS-CoV-2-specific CD8+ T cells expressing CD38 and PD-1 decreases gradually, whereas the frequency of SARS-CoV-2-specific CD8+ T cells expressing CCR7, CD45RA, and CD127 increases. In particular, among SARS-CoV-2-specific CD8+ T cells, the frequency of CCR7+CD45RA+CD95+ stem cell-like memory T (TSCM) cells that have the capacity for self-renewal and multipotency increases in the late convalescent phase. The generation of TSCM cells is also observed among SARS-CoV-2-specific CD4+ T cells.
See this image and copyright information in PMC

References

    1. Agerer B., Koblischke M., Gudipati V., Montano-Gutierrez L.F., Smyth M., Popa A., Genger J.W., Endler L., Florian D.M., Muhlgrabner V., et al. SARS-CoV-2 mutations in MHC-I-restricted epitopes evade CD8(+) T cell responses. Sci. Immunol. 2021;6:eabg6461. doi: 10.1126/sciimmunol.abg6461. - DOI - PMC - PubMed
    1. Akondy R.S., Fitch M., Edupuganti S., Yang S., Kissick H.T., Li K.W., Youngblood B.A., Abdelsamed H.A., McGuire D.J., Cohen K.W., et al. Origin and differentiation of human memory CD8 T cells after vaccination. Nature. 2017;552:362–367. doi: 10.1038/nature24633. - DOI - PMC - PubMed
    1. Anderson E.J., Rouphael N.G., Widge A.T., Jackson L.A., Roberts P.C., Makhene M., Chappell J.D., Denison M.R., Stevens L.J., Pruijssers A.J., et al. Safety and immunogenicity of SARS-CoV-2 mRNA-1273 vaccine in older adults. N. Engl. J. Med. 2020;383:2427–2438. doi: 10.1056/NEJMoa2028436. - DOI - PMC - PubMed
    1. Bacher P., Rosati E., Esser D., Martini G.R., Saggau C., Schiminsky E., Dargvainiene J., Schroder I., Wieters I., Khodamoradi Y., et al. Low-avidity CD4(+) T cell responses to SARS-CoV-2 in unexposed individuals and humans with severe COVID-19. Immunity. 2020;53:1258–1271.e5. doi: 10.1016/j.immuni.2020.11.016. - DOI - PMC - PubMed
    1. Bodewes R., Kreijtz J.H., Rimmelzwaan G.F. Yearly influenza vaccinations: a double-edged sword? Lancet Infect. Dis. 2009;9:784–788. doi: 10.1016/S1473-3099(09)70263-4. - DOI - PubMed

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