Endogenous Mtv-8 or a closely linked sequence stimulates rearrangement of the downstream V kappa 9 gene.
Mtv-8 is an endogenous retrovirus located 4.6 kb upstream of a V kappa region gene (called V kappa 9M) within the kappa-Ig locus. The proximity of these two genes resulted in several effects. Using a newly developed RNase protection assay for measuring transcription from a single endogenous provirus, we found that Mtv-8 transcription could be detected after juxtaposition of the kappa-enhancers to the normally silent provirus. Reciprocally, using the polymerase chain reaction we observed that the frequency of V kappa 9M rearrangement was 5- to 10-fold higher in spleens from Mtv-8-positive mice (BALB/c, C58.C, A/J, and B6) compared to spleens from mice that lacked the Mtv-8 provirus (C58, C.C58, NZB, and PERA/Ei). Molecular cloning and sequencing of the V kappa 9M gene from C.C58 mice (containing the kappa-locus from C58 mice on a BALB/c background) indicated that at least some Mtv-8-negative strains have a functional V kappa 9M gene. Together these data suggest that Mtv-8 or a closely linked gene enhances V kappa 9M rearrangement. Since Mtv-8 also reportedly produces a superantigen, it appears that Mtv-8 may influence both the T cell and B cell repertoires.
Yang
J N
JN
Department of Microbiology, University of Texas, Austin 78712.
Dudley
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology*; D001483:Base Sequence; D004279:DNA, Viral / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D015870:Gene Expression; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain; D005803:Genes, Immunoglobulin; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D009052:Leukemia Virus, Murine / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D011533:Proviruses / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping
D004279:DNA, Viral; D007135:Immunoglobulin Variable Region; D007145:Immunoglobulin kappa-Chains; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger