gamma delta T Cells Exhibit Multifunctional and Protective Memory in Intestinal Tissues

The study of T cell memory and the target of vaccine design have focused on memory subsumed by T cells bearing the alpha beta T cell receptor. Alternatively, gamma delta T cells are thought to provide rapid immunity, particularly at mucosal borders. Here, we have shown that a distinct subset of mucosal gamma delta T cells mounts an immune response to oral Listeria monocytogenes (Lm) infection and leads to the development of multifunctional memory T cells capable of simultaneously producing interferon- gamma and interleukin-17A in the murine intestinal mucosa. Challenge infection with oral Lm, but not oral Salmonella or intravenous Lm, induced rapid expansion of memory gamma delta T cells, suggesting contextual specificity to the priming pathogen. Importantly, memory gamma delta T cells were able to provide enhanced protection against infection. These findings illustrate that gamma delta T cells play a role with hallmarks of adaptive immunity in the intestinal mucosa.