A shared kappa reciprocal fragment and a high frequency of secondary Jk5 rearrangements among influenza hemagglutinin specific B cell hybridomas.
Ig kappa-chain gene rearrangement results in the displacement or loss of the DNA immediately 5' of Jk. This retained DNA is found on a different size fragment than in the germline (a reciprocal fragment), and contains the reciprocal joint of rearranged Vk and Jk genes, the back-to-back fusion of the heptamer/nonamer recombination signals. B cells of independent origin rarely have reciprocal fragments of the same size. However, we report that 9 of 15 B cell hybridomas of independent origin have reciprocal fragments of the same size (8-kb BamHI fragments) unrelated to their productive rearrangements. An 8-kb reciprocal fragment has also occurred on about 25% of the kappa alleles of normal splenic B cells. We find that the reciprocal fragments in two of these hybridomas contain the reciprocal joints of Jk1 genes and different Vk8 genes. In addition, we find that at least 8 of the 12 Jk4 or Jk5 expressing hybridomas have undergone double recombinations on their productive kappa alleles. The implications of these findings on the high frequency of 8-kb reciprocal rearrangements and on Vk rearrangement are discussed.
Clarke
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S
Department of Microbiology and Immunology, University of North Carolina, Chapel Hill 27599.
McCray
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S
D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain; D005803:Genes, Immunoglobulin; D006389:Hemagglutinins, Viral / Q000276:immunology*; D006825:Hybridomas; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D009980:Influenza A virus / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D013154:Spleen / Q000166:cytology
D000914:Antibodies, Viral; D006389:Hemagglutinins, Viral; D007145:Immunoglobulin kappa-Chains