COMPARISON OF THE J-BETA GENE USAGE AMONG DIFFERENT T-CELL RECEPTOR V-BETA FAMILIES IN SPLEENS OF C57BL/6 MICE

To clarify whether there is a bias in the V-D-J combination of T cell receptor (TcR) genes, J beta gene usage has been investigated in a total of 743 TcR beta genes of V beta 2, V beta 8.2, and V beta 14 families expressed in C57BL/6 mouse spleens. Genes of TcR beta chains, amplified by a reverse transcriptase-polymerase chain reaction, were individually cloned into plasmids. Cloned genes (61 to 106), randomly selected in each respective Vp family from three different mice, were tested by means of hybridization with 12 oligo DNA probes which were designed to differentiate 12 murine functional J beta gene segments. The results are enumerated below (1) The J beta 2.6 gene segment was found to be most frequently used (V beta 2, 19.8 %; V beta 8.2, 21.2%; and V beta 14, 19.2 %). In contrast, usage of the J beta 1.6 gene segment was most infrequent (V beta 2, 1.9%; V beta 8.2, 2.9%; and V beta 14, 0.5%); (2) High frequency of the J beta 2.1 gene segment and low frequency of the J beta 1.3 and J beta 1.5 gene segments were also observed; (3) The J beta 2 cluster was used in preference to the Jpl cluster (usages of the J beta 2 cluster: V beta 2, 67.8 %; V beta 8.2, 65.9 %; and V beta 14, 70.4%); and (4) These biases were generally common to all three VP families examined and differences among individual mice were mostly small. Considering these findings, we conclude that the TcR JP gene segments in C57BL/6 mice splenocytes are selected with a bias, but are selected independently of the V beta families.