Vγ2Vδ2 T cells are found only in primates and have diverse functions, mediating host defences during bacterial and parasitic infections. In November 1 Journal of Clinical Investigation, Lisheng Wang and colleagues from Harvard Medical School, show that Vγ2Vδ2 T cells are sufficient to control bacterial infections in mice that lack B or T cells and therefore are important in innate immune responses that do not involve immunological memory.

Wang et al. used chimeric severe combined immunodeficiency mice (hu-SCID) engrafted with human Vγ2Vδ2 T cells and found that these animals showed bacterial resistance 1 day after infection with gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli and Morganella morganii) bacteria. Bacteria were cleared well before γδT cell expansion was detected, 6 days after infection. In addition, intravenous treatment with pamidronate (a human Vγ2Vδ2 T cell–specific antigen), increased significantly the antibacterial effect of Vγ2Vδ2 T cells...