Continuing V gamma 2 to J gamma 2 rearrangements of murine T cell receptor gamma genes in a B-committed immature cell line.
In SPL2-1-2, a murine B-committed immature cell line transformed with a temperature-sensitive mutant of Abelson virus, T cell receptor (TCR) gamma gene rearrangements, together with IgH gene rearrangements, were induced during culture at a non-permissive temperature (39 degrees C). During 11-12 months of culture, TCR gamma gene rearrangements occurred in all cells. In contrast to TCR gamma genes, neither TCR beta or TCR delta were detected even after 11-12 months of culture at a non-permissive temperature. The majority of the TCR gamma gene rearrangements observed here were V gamma 2 to J gamma 2 joinings and the remaining rearrangements were J gamma 1-linked. V gamma 1 to J gamma 4 and V gamma 3 to J gamma 3 joinings were not detected. Approximately 70% of cells with TCR gamma gene rearrangements produced normal-sized transcripts from the rearranged TCR gamma genes. Cloning and sequencing analysis of a cDNA from the transcripts demonstrated that the whole structure of the cDNA was similar to that of T-lineage cells. These results showed that TCR gene rearrangements were restricted to the gamma genes and that V gamma 2 to J gamma 2 joinings occurred preferentially in this B-committed immature cell line. Furthermore, TCR gamma gene rearrangements also occurred in intracytoplasmic mu-chain producing cells. This indicated that the existence of intracytoplasmic mu-chains did not prevent TCR gamma gene rearrangements, although the existence of mu-chains is known to inhibit further productive IgH gene rearrangements, (allelic exclusion). These results should provide many implications for the mechanism of TCR gene rearrangements, especially that of cross-lineage rearrangements.
Third Department of Internal Medicine, Osaka University Medical School, Japan.
S
S
Tsukada
Y
Y
Oka
H
H
Sugiyama
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000032:analysis; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D016694:Gene Rearrangement, delta-Chain T-Cell Antigen Receptor; D015334:Gene Rearrangement, gamma-Chain T-Cell Antigen Receptor / Q000235:genetics*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D012313:RNA / Q000032:analysis; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics*; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D014170:Transformation, Genetic
D007143:Immunoglobulin Heavy Chains; D016692:Receptors, Antigen, T-Cell, gamma-delta; D012313:RNA; D004247:DNA