Tweet
Viruses
. 2022 Mar 2;14(3):511.
doi: 10.3390/v14030511.
Enhanced SARS-CoV-2-Specific CD4 + T Cell Activation and Multifunctionality in Late Convalescent COVID-19 Individuals
Nathella Pavan Kumar 1 , Kadar Moideen 2 , Arul Nancy 2 , Nandhini Selvaraj 2 , Rachel Mariam Renji 2 , Saravanan Munisankar 2 , Jeromie Wesley Vivian Thangaraj 3 , Santhosh Kumar Muthusamy 3 , C P Girish Kumar 3 , Tarun Bhatnagar 3 , Manickam Ponnaiah 3 , Sabarinathan Ramasamy 3 , Saravanakumar Velusamy 3 , Manoj Vasant Murhekar 3 , Subash Babu 2
Affiliations
- PMID: 35336918
- DOI: 10.3390/v14030511
Abstract
Background: Examination of CD4+ T cell responses during the natural course of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection offers useful information for the improvement of vaccination strategies against this virus and the protective effect of these T cells.
Methods: We characterized the SARS-CoV-2-specific CD4+ T cell activation marker, multifunctional cytokine and cytotoxic marker expression in recovered coronavirus disease 2019 (COVID-19) individuals.
Results: CD4+ T-cell responses in late convalescent (>6 months of diagnosis) individuals are characterized by elevated frequencies of activated as well as mono, dual- and multi-functional Th1 and Th17 CD4+ T cells in comparison to early convalescent (<1 month of diagnosis) individuals following stimulation with SARS-CoV-2-specific antigens. Similarly, the frequencies of cytotoxic marker expressing CD4+ T cells were also enhanced in late convalescent compared to early convalescent individuals.
Conclusion: Our findings from a low-to middle-income country suggest protective adaptive immune responses following natural infection of SARS-CoV-2 are elevated even at six months following initial symptoms, indicating the CD4+ T cell mediated immune protection lasts for six months or more in natural infection.
Keywords: CD4+ T cells; COVID-19; SARS-CoV-2; cytokines.