Bacterial Superantigens Induce The Proliferation of Resting γ/δ Receptor Bearing T Cells

Abstract

We observe that highly purified (≥97% pure) γ/δ T cells isolated from normal peripheral blood proliferate to bacterial toxin superantigens SEA, SEB, SED, and TSST-1. MHC class II molecules were necessary and sufficient for the recognition of superantigens by γ/δ T cells because MHC Class II deficient B cell line failed to support the proliferation of γ/δ T cells to toxins and murine L cells transfected with HLA-DR but not untransfected cells were capable of presenting toxins to γ/δ T cells. As in the case with α/β T cells, bacterial superantigens synergized with PMA in causing the proliferation of purified γ/δ T cells rigorously depleted of accessory cells. Together, our findings suggest that γ/δ T cells recognize and respond to bacterial superantigens in a manner similar to α/β T cells.