Phenotypical and functional alteration of unconventional T cells in severe COVID-19 patients
Youenn Jouan, Antoine Guillon, Loïc Gonzalez, Yonatan Perez, Chloé Boisseau, Stéphan Ehrmann, Marion Ferreira, Thomas Daix, Robin Jeannet, Bruno François, Pierre‐François Dequin, Mustapha Si‐Tahar, Thomas Baranek, Christophe Paget
Abstract
COVID-19 includes lung infection ranging from mild pneumonia to life-threatening acute respiratory distress syndrome (ARDS). Dysregulated host immune response in the lung is a key feature in ARDS pathophysiology. However, cellular actors involved in COVID-19-driven ARDS are poorly understood. Here, in blood and airways of severe COVID-19 patients, we serially analyzed unconventional T cells, a heterogeneous class of T lymphocytes (MAIT, γδT, and iNKT cells) with potent antimicrobial and regulatory functions. Circulating unconventional T cells of COVID-19 patients presented with a profound and persistent phenotypic alteration. In the airways, highly activated unconventional T cells were detected, suggesting a potential contribution in the regulation of local inflammation. Finally, expression of the CD69 activation marker on blood iNKT and MAIT cells of COVID-19 patients on admission was predictive of clinical course and disease severity. Thus, COVID-19 patients present with an altered unconventional T cell biology, and further investigations will be required to precisely assess their functions during SARS-CoV-2-driven ARDS.