Mucosal lymphatic-derived γδ T cells respond early to experimental Salmonella enterocolitis by increasing expression of IL-2Rα

To better understand the roles of γδ T cells in mucosal infection, we utilized Salmonella enterica serovar Typhimurium (Salmonella serovar Typhimurium) infection in cattle as it closely approximates Salmonella serovar Typhimurium-induced enterocolitis in humans. Protein and gene expression in αβ and γδ T cells derived from lymphatic ducts draining the gut mucosa in Salmonella serovar Typhimurium-infected calves were analyzed. In calves with enterocolitis, general gene expression trends in γδ T cells suggested subtle activation and innate response, whereas αβ T cells were relatively quiescent following Salmonella serovar Typhimurium infection. An increase in IL-2Rα expression on γδ T cells from infected calves and results from in vitro assays suggested that γδ T cells were primed by Salmonella serovar Typhimurium LPS to better respond to IL-2 and IL-15. Together with gene expression trends in vivo, these data support early priming activation of target tissue γδ T cells during Salmonella serovar Typhimurium infection.