| First Author | Matheson LS | Year | 2009 |
| Journal | Int Immunol | Volume | 21 |
| Issue | 8 | Pages | 957-66 |
| PubMed ID | 19561045 | Mgi Jnum | J:151668 |
| Mgi Id | MGI:4354708 | Doi | 10.1093/intimm/dxp062 |
| Citation | Matheson LS, et al. (2009) Light chain-deficient mice produce novel multimeric heavy-chain-only IgA by faulty class switching. Int Immunol 21(8):957-66 |
| abstractText | Recently, we identified that diverse heavy chain (H-chain)-only IgG is spontaneously produced in light chain (L-chain)-deficient mice (L(-/-) with silenced kappa and lambda loci) despite a block in B cell development. In murine H-chain IgG, the first Cgamma exon, C(H)1, is removed after DNA rearrangement and secreted polypeptides are comparable with camelid-type H-chain IgG. Here we show that L(-/-) mice generate a novel class of H-chain Ig with covalently linked alpha chains, not identified in any other healthy mammal. Surprisingly, diverse H-chain-only IgA can be released from B cells at levels similar to conventional IgA and is found in serum and sometimes in milk and saliva. Surface IgA without L-chain is expressed in B220(+) spleen cells, which exhibited a novel B cell receptor, suggesting that associated conventional differentiation events occur. To facilitate the cellular transport and release of H-chain-only IgA, chaperoning via BiP association seems to be prevented as only alpha chains lacking C(H)1 are released from the cell. This appears to be accomplished by imprecise class-switch recombination (CSR) from Smu into the alpha constant region, which removes all or part of the Calpha1 exon at the genomic level. |
