Purified bovine WC1+ γδ T lymphocytes are activated by staphylococcal enterotoxins and toxic shock syndrome toxin-1 superantigens: Proliferation response, TCR Vγ profile and cytokines expression

In this study, the ability of purified bovine γδ T cells in vitro to be activated by superantigens (SAg) was investigated. Freshly isolated WC1+ γδ T cells, in the presence of autologous glutaraldehyde-fixed or γ-irradiated antigen presenting cells (APC) and IL-2, were incubated with staphylococcal enterotoxins A and B (SEA and SEB), and toxic shock syndrome toxin-1 (TSST-1). Both a proliferative response and the expression of particular T cell receptor genes of the γ variable (TCR Vγ) repertoire family were induced. Genes encoding TCR Vγ1 and TCR Vγ2 family, but not TCR Vγ5 were detected. The cells also expressed cytokine transcripts, namely, those of IL-12, IFN-γ and TNF-α, but not IL-2, IL-4, IL-6, IL-7 and IL-10. The activation and proliferation of freshly isolated γδ T cells by non-processed antigens required two signals, one originating from the APC and a second dependent on exogenous IL-2. Our results show that purified bovine WC1+ γδ T cells could be driven to proliferate and to express a particular TCRVγ profile in response to superantigen activation. The possible implication of cytokines expressed by bovine γδ T cells in immunopathogenesis is discussed. © 2001 Elsevier Science B.V.