Murine γδ T cells in infections: beneficial or deleterious?

Although the importance of γδ T cells in pathogen-induced immune responses is becoming increasingly apparent, it is not clear that their involvement is always of benefit to the host. Here we review evidence for the protective and damaging roles of γδ T cells in infection and discuss how these disparate findings might be resolved by considering the nature and properties of the pathogen, the sites of infection and conditions under which γδ T cell responses are initiated, and the involvement of different subsets of γδ T cells.