The effects of Staphylococcal enterotoxin B on equine T cells

Abstract

Staphylococcus aureus enterotoxins and their impact on T cells in humans and mice are well described. S. aureus prevalence has not only increased in veterinary clinics, but is a relatively common isolate in horses, more so than in other animal species. Yet the role of superantigens in infection is unknown. With this in mind, the effects of staphylococcal enterotoxin B (SEB) on equine T cells were examined. Using an in vitro assay, dose responses and the kinetics of equine T cell proliferation were determined. Equine MHC class II was found to be important for SEB-mediated equine T cell stimulation. Using RT-PCR, the presence of SEB induced cytokine production (i.e. IFN-γ and IL-10) in equine T cells, but additional studies are needed. Taken together, these data suggest that virulence factors such as SEB when expressed may alter the clinical disease associated with S. aureus infection in horses.