T-cell receptor gamma/delta: comparison of gene configurations and function between humans and chimpanzees

The human and chimpanzee T-cell receptor gamma-delta (TCR ) bearing cells represent a minor subset (3–8%) of T lymphocytes. In the periphery, the TCR population has a restricted combinatorial repertoire. The TCRD-V1 and-V2 gene products are expressed in a mutually exclusive fashion, whereas, the TCRD-V2 and the TCRG-V9 encoded proteins show, in general, a coordinated expression. Restriction fragment length polymorphism analysis showed conservation of the restriction sites that identify the TCRG-V9 and TCRD-V2 rearrangements. The human TCRG-V9 locus has two alleles, TCRG-V9A1 and TCRG-V9A2 differing at codon position 31. The chimpanzee TCRG-V9 gene product differs from the products of the human TCRG-V9A1 and TCRG-V9A2 allele by two and three amino acid replacements, respectively. The human and the chimpanzee TCRG-V9-TCRD-V2 lymphocytes show a similar specific proliferative and cytolytic response to human Daudi Burkitt's lymphoma cells. Therefore, the amino acid replacements found in the chimpanzee TCRG-V9 gene product do not change the superantigen specificity across this species barrier.This nucleotide sequence data reported in this paper have been submitted to the EMBL data library and have been assigned the accession number: X61069 P. Troglodytes TCR VGG.