NK cell receptor and ligand composion influences the clearance of SARS-CoV-2

 The diversity of receptor repertoires on NK cells in the peripheral blood of COVID-19 convalescent patients were found to be negatively correlated with the rapid clearance of SARS-CoV-2. The patients showing low-diversity NK receptors had exhibited higher clearance efficiency. NK subsets expressing the receptor DNAM1 were remarkable in patients who had shown rapid clearance. The NK expressing DNAM1 was demonstrated to exhibit strong cytotoxic activity against SARS-CoV-2 infected cells by an ex vivo experiment. In contrast, SARS-CoV-2 infection induces the expression of CD155 that is a ligand of TIGIT, which is the DNAM1 paired receptor, leading to the blockage of cytotoxicity.