SEQUENCE AND DIVERSITY OF THE RAT DELTA T CELL RECEPTOR

Watson D, Ando T, Knight JF

Centre For Kidney Research, Royal Alexandra Hospital for Children, P O Box 3515, Parramatta NSW 2124

Our previous work has implicated gamma-delta T cells in renal interstitial inflammation. In order to study this in a rat model it was first necessary to determine the sequence of the rat V-delta locus, as GenBank held sequences for rat V-gamma but not for V-delta.

The cDNA sequence of the delta T cell receptor (TCR) in the adult Lewis rat thymus was determined using the technique rapid amplification of cDNA ends (RACE). Sixteen variable region genes (V ), two diversity regions (D ), two joining regions (J ), and a single constant (C ) region gene were identified. The sixteen unique V genes identified represented eight different subfamilies in the rat and were highly conserved (>80% nucleotide identity) to corresponding mouse sequences. Extensive junctional diversity was observed in the rat, with both D regions (D 1 and D 2) utilised in the majority of cDNA clones identified. The two J genes were highly conserved and corresponded to J 1 and J 2 in the mouse, and the majority of clones utilised J 1. The C region in the rat was 91.1% identical to the mouse C gene and highly conserved to other species.

Although extensive sequence information about mouse TCR genes is available, current knowledge of rat T cells is limited. The sequence analysis presented in this study adds to our understanding of T cells in general, and may be useful in studying the role of T cells in immune-mediated disease and transplantation models previously established in the rat.

Presented at the Annual Scientific Meeting of the Australian and New Zealand Society of Nephrology, Melbourne, March 2000