Caprine T-cell receptor variable beta-chain (TCRV beta) repertoire analysis and potential applications in cowdriosis immune response studies

Abstract

Anchor polymerase chain reaction has been applied to the study of caprine TCR V beta-chain repertoire at the mRNA level in peripheral blood of a Saanen goat. Single stranded, g-tailed cDNA synthesized from total RNA was PCR-amplified using a sheep V beta constant region primer (3') and a poly(dC) anchor primer (5') at the variable region end of the TCR V beta-chain. The obtained amplicon was subsequently cloned into Bluescript plasmid vector. A total of 72 recombinant clones whereof 61 contained an insert of appropriate size were harvested. Up to now, the full length sequences of a total of 55 clones have been obtained. Nine clones were rearranged but not functional due to stop codons. Forty-five sequences were functionally rearranged and further analyzed. They were classified into 15 different V beta families on the basis of V-region sequence homology with their human counterpart. V beta families corresponding to the 9 published bovine families were represented in our library. This complexity enables us to develop V beta family-specific primers in order to study the TCR V beta repertoire of other goat breeds of interest, i.e., the Creole goat. There the TCR V beta repertoire analysis and kinetic study of the cowdriosis model will provide insight into the type of the immune response and the status of protection during the immunization process and challenge.