V gamma 2 TCR repertoire overlap in different anatomical compartments of healthy, unrelated rhesus macaques

gamma delta T cells show preferential homing that is characterized by biase d TCR repertoire at different anatomical locations. The processes that regu late this compartmentalization are largely unknown, A model that allows rep eated multiple sample procurement under different conditions and enables wi th relatively straightforward extrapolation to a human situation will facil itate our understanding. The peripheral blood V gamma2 T cell population is the best-characterized human gamma delta T cell subset. To determine its d iversity at multiple immunocompartments matching blood, colon, and vagina s amples from rhesus macaques were investigated. Four joining segments used i n V gamma2-J gamma transcripts were identified, including one segment with no human counterpart. Like in humans, the rhesus peripheral blood V gamma2 TCR repertoire was limited and contained common sequences that were shared by genetically heterogeneous animals, Furthermore, this subset comprised se veral phylogenetically conserved V gamma2 complementarity-determining regio n 3 (CDR3) motifs between rhesus and humans. Common sequences were also fou nd within the colon and vagina of the same animal, and,within the periphera l blood and intestine of different unrelated animals. These results validat e rhesus macaques as a useful model for gamma delta TCR repertoire and homi ng studies, Moreover, they provide evidence that the concept of limited but overlapping V gamma TCR repertoire between unrelated individuals can be ex tended including the mucosa of the digestive and reproductive tract.