Çağan, ErenTezcan, GülçinŞimşek, AbdurrahmanKızmaz, Muhammed AliDombaz, FatmaAsan, AliDemir, H. İbrahimBal, HaldunYoyen Ermiş, DiğdemGörek Dilektaşlı, AslıKazak, EsraAkalın, E. HalisOral, H. BarbarosBudak, Ferah2024-11-132024-11-132022-04-230882-8245https://doi.org/10.1089/vim.2021.0132https://www.liebertpub.com/doi/10.1089/vim.2021.0132https://hdl.handle.net/11452/47813Coronavirus disease 2019 (COVID-19) has clinical manifestations ranging from mild symptoms to respiratory failure, septic shock, and multi-organ failure. Lymphocytes are divided into different subtypes based on their cytokine production pattern. In this study, we investigated the role of cytokine expressions of CD4(+) T (T helper [Th]1, Th2, Th17, Th22) and CD8(+) T cell subtypes (T cytotoxic [Tc]1, Tc2, Tc17, Tc22) in the pathogenesis of COVID-19. Peripheral blood mononuclear cells (PBMCs) were extracted with Ficoll by density gradient centrifugation from blood samples of 180 COVID-19 patients (children and adults) and 30 healthy controls. PBMCs were stimulated with PMA and Ionomycin and treated with Brefeldin A in the fourth hour, and a 10-colored monoclonal antibody panel was evaluated at the end of the sixth hour using flow cytometry. According to our findings, the numbers of Th22 (CD3(+), CD4(+), and interleukin [IL]-22(+)) and Tc22 (CD3(+), CD8(+), IL-22(+)) cells increased in adult patients regardless of the level of pneumonia (mild, severe, or symptom-free) as compared with healthy controls (p < 0.05). In addition, the number of Tc17 (CD3(+), CD8(+), and IL-17A(+)) cells increased in low pneumonia and severe pneumonia groups compared with the healthy controls (p < 0.05). Both IL-22 and IL-17A production decreased during a follow-up within 6 weeks of discharge. Our findings suggest that the increase in only IL-22 expressed Tc22 cells in the 0-12 age group with a general symptom-free course and higher levels of Th22 and Tc22 in uncomplicated adult cases may indicate the protective effect of IL-22. On the contrary, the association between the severity of pneumonia and the elevation of Tc17 cells in adults may reveal the damaging effect of IL-22 when it is co-expressed with IL-17.eninfo:eu-repo/semantics/closedAccessA virus-infectionT-cellInterleukin-22InflammationIl-22ProtectsImmunityBiologySubsetCovid-19Sars-cov-2Th22Tc22Tc17ImmunologyVirologyArticle00077965070000131832735410.1089/vim.2021.0132