Modulation of γδ T cells in mouse buccal epithelium following antigen priming

Abstract

T cells using the γδ T cell receptor (TCR) are abundant in mucosal and epidermal tissues in mice. Most studies of mucosal γδ T cells, however, have examined cells from the intestinal mucosa, whereas little is known about the presence or function of γδ T cells in the oral cavity. To better understand the involvement of oral γδ T cells in immunity, we have characterized TCR variable γ-gene usage in the buccal epithelium from normal mice, and from mice challenged locally with a non-replicating antigen (bovine serum albumin [BSA]) or by influenza-virus infection as a replicating antigen. Our findings demonstrate a restricted use of Vγ genes by buccal γδ T cells, consisting primarily of Vγ1.2, Vγ3, and Vγ5, with minimal use of Vγ2 and Vγ4 genes. Of particular interest, 3–4 days post-antigen challenge with BSA, there was a precipitous drop in the level of expression of Vγ1.2, Vγ3, and Vγ5 genes, and to a lesser extent for the Vγ2 gene, whereas Vγ4 gene expression increased between days 1 and 2 post-priming. In influenza-infected mice, a similar pattern was observed for the Vγ2 and Vγ5 genes, but not other Vγ genes. The immune-modulating effects of oral antigen exposure on buccal γδ T cells suggest that these cells are functionally involved in the local immune response to both replicating and non-replicating antigens in oral mucosal surfaces.