Expansion of cytotoxic tissue-resident CD8+ T cells and CCR6+CD161+ CD4+ T cells in the nasal mucosa following mRNA COVID-19 vaccination
Aloysious Ssemaganda, Huong Mai Nguyen, Faisal Nuhu, Naima Jahan, Catherine M. Card, Sandra Kiazyk, Giulia Severini, Yoav Keynan, Ruey‐Chyi Su, Hezhao Ji, Bernard Abrenica, Paul J. McLaren, T. Blake Ball, Jared Bullard, Paul Van Caeseele, Derek R. Stein, Lyle R. McKinnon
Abstract
Abstract Vaccines against SARS-CoV-2 have shown high efficacy in clinical trials, yet a full immunologic characterization of these vaccines, particularly within the human upper respiratory tract, is less well known. Here, we enumerate and phenotype T cells in nasal mucosa and blood using flow cytometry before and after vaccination with the Pfizer-BioNTech COVID-19 vaccine ( n = 21). Tissue-resident memory (Trm) CD8 + T cells expressing CD69 + CD103 + increase in number ~12 days following the first and second doses, by 0.31 and 0.43 log 10 cells per swab respectively ( p = 0.058 and p = 0.009 in adjusted linear mixed models). CD69 + CD103 + CD8 + T cells in the blood decrease post-vaccination. Similar increases in nasal CD8 + CD69 + CD103 − T cells are observed, particularly following the second dose. CD4 + cells co-expressing CCR6 and CD161 are also increased in abundance following both doses. Stimulation of nasal CD8 + T cells with SARS-CoV-2 spike peptides elevates expression of CD107a at 2- and 6-months ( p = 0.0096) post second vaccine dose, with a subset of donors also expressing increased cytokines. These data suggest that nasal T cells may be induced and contribute to the protective immunity afforded by this vaccine.