C57BL/6 x BALB/c hybridomas produce IgA which assembles into molecules with covalent bonds between heavy chains (H) and light chains (L), and into molecules lacking covalent bonds between H and L.
Examination of the gel electrophoresis patterns of 14C-biosynthetically labeled immunoglobulin from C57BL/6 X BALB/c IgA hybridomas reveals that each of the monoclonal cell populations produces two different forms of IgA: molecules with heavy chains (H) and light chains (L) joined by disulfide bonds, as well as molecules with H and L being noncovalently associated. The possible origin of this was explored: Southern blot analysis of the hybridoma DNA indicated that only one alpha gene is expressed by each cell line; hybridoma cells labeled in the presence of the N-glycosylation inhibitor tunicamycin exhibit both forms; and electrophoresis of biosynthetically labeled spleen cell IgA from C57BL/6, BALB/c and (C57BL/6 X BALB/c) F1 mice shows that BALB/c mice produce only the noncovalently associated form, while C57BL/6 and (C57BL/6 X BALB/c) F1 mice produce both. Possible mechanisms by which two types of IgA may be assembled by the same hybridoma cell are discussed.
D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004220:Disulfides / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006825:Hybridomas / Q000276:immunology*; D007070:Immunoglobulin A / Q000096:biosynthesis*; D007143:Immunoglobulin Heavy Chains / Q000096:biosynthesis*; D007147:Immunoglobulin Light Chains / Q000096:biosynthesis*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000276:immunology
D004220:Disulfides; D007070:Immunoglobulin A; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains