CD8 T cells and antibodies drive SARS-CoV-2 evolution in chronic infection

Abstract ​​Since its recent zoonotic spill-over severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is constantly adapting to the human host as illustrated by the emergence of variants of concern with increased transmissibility and immune evasion. Prolonged replication in immunosuppressed individuals and evasion from spike-specific antibodies is known to drive intra-host SARS-CoV-2 evolution. Here we show for the first time the major role of CD8 T cells in SARS-CoV-2 evolution. In a patient with chronic, ultimately fatal infection, we observed three spike mutations that prevented neutralisation by convalescent plasma therapy. Moreover, at least four mutations in non-spike proteins emerged that hampered CD8 T-cell recognition of mutant epitopes, two of these occurred before spike mutations. A comparison with worldwide sequencing data showed that several of these T-cell escape mutations had emerged independently as homoplasies in multiple circulating lineages. We propose that human leukocyte antigen class I contributes to shaping the evolutionary landscape of SARS-CoV-2.