Aberrant recombination events in B cell lines derived from ax-deficient human

Open Access
Publisher Website
Google Scholar
Abstract
We have analyzed the structure of Ig κ chain genes in B cell lines derived from a hiinan individual who cannot synthesize any κ chains, and whose Igs all contain λ chains (1). We have characterized secondary DNA recombination events at two κ alleles which have undergone misaligned V-J recombinations. One such secondary recombination has joined the flanking sequences of a Vκ and a Jκ2 gene segment as if it were the reciprocal product of a V-Jκ2 recombination, and resulted in the displacement of the recombined VJκ1 gene segments from the Cκ locus. The non-rearranged form of the Vκ fragment which had recombined with the Jκ2 flank was cloned. Nucleotide sequencing of this fragment identified a Vκ gene that differed by at least 38% from all previously sequenced human Vκ genes. The other V-Jκ segment analyzed has undergone a secondary recombination at a different site from that described above, at a site within the intervening sequence between the Jκ and Cκ gene segments, similar to the location of secondary recombinations which have occurred in λ + B cell lines from mice and humans (2, 3). These results prove that multiple recoiiibinations can occur at one Jκ-Cκ locus.