TCR gamma delta(+) cells are prominent in normal bovine skin and express a diverse repertoire of antigen receptors

More than 80% of T cells in bovine skin localized in the superficial 0.5 mm Or the dermis. Only 3% occurred within the epidermis or made contact with the stratum basale while the remainder occupied deeper dermal sites, The gamma delta T-cell receptor (TCR) was expressed by 44% of T cells in skin and 39% and 35% expressed, respectively, the CD4 and CDS markers, Same cells co-expressed CD8 and the gamma delta TCR, A highly diverse repertoire of gamma delta TCR was expressed in skin due mainly to the usage of multiple V delta segments and to extensive sequence variation at the junctions of both TCR gamma and TCR delta chains. However, a single receptor isotype was used. Transcripts encoding several new components of the bovine gamma delta TCR were identified, including three new V gamma segments, the C gamma 5 region and 13 new functional V delta segments. Taken together with earlier findings, these results emphasize that ruminant gamma delta T cells express exceptionally diverse antigen receptors and suggest they may have a more elaborate recognitive capacity than do their counterparts in other species.