Anti-severe acute respiratory syndrome coronavirus immune responses:: The role played by Vγ9Vδ2 T cells

Severe acute respiratory syndrome (SARS) is caused by a novel coronavirus (SARS-CoV) strain. Analyses of T cell repertoires in health care workers who survived SARS-CoV infection during the 2003 outbreak revealed that their effector memory V gamma 9V delta 2 T cell populations were selectively expanded similar to 3 months after the onset of disease. No such expansion of their ab T cell pools was detected. The expansion of the Vg9Vd2 T cell population was associated with higher anti-SARS-CoV immunoglobulin G titers. In addition, in vitro experiments demonstrated that stimulated Vg9Vd2 T cells display an interferon-gamma-dependent anti-SARS-CoV activity and are able to directly kill SARS-CoV-infected target cells. These findings are compatible with the possibility that Vg9Vd2 T cells play a protective role during SARS.