Vγ9Vδ2 T-cells are potent inhibitors of SARS-CoV-2 replication and represent effector phenotypes in COVID-19 patients.

Vγ9Vδ2 T-cells play a key role in the innate immune response to viral infections through butyrophilin (BTN)-3A. Here, we reported that blood Vγ9Vδ2 T-cells decreased in clinically mild COVID-19 compared to healthy volunteers (HV), and was maintained up to 28-days and in the recovery period. Terminally differentiated Vγ9Vδ2 T-cells tend to be enriched on the day of diagnosis, 28-days after and during the recovery period. These cells showed cytotoxic and inflammatory activities following anti-BTN3A activation. BTN3A upregulation and Vγ9Vδ2 T-cell infiltration were observed in a lung biopsy from a fatal SARS-CoV-2 infection. In vitro, SARS-CoV-2 infection increased BTN3A expression in macrophages and lung cells that enhanced the anti-SARS-CoV-2 Vγ9Vδ2 T-cells cytotoxicity and IFNγ and TNFα. Increasing concentrations of anti-BTN3A lead to viral replication inhibition. Altogether, we report that Vγ9Vδ2 T-cells are important in the immune response against SARS-CoV-2 infection and that activation by an anti-BTN3A antibody may enhance their response.