title: Reactions among IgM antibodies derived from normal, neonatal mice.
abstract: Attempting to obtain a representative sample of the "natural antibody" repertoire in the developing immune system, we have derived IgM-secreting hybridomas from 4 normal untreated BALB/c mice of the same litter on day 6 after birth. Partially purified IgM preparations obtained in the supernatants of 70 such clones were each screened in binding assays for reactivity with a panel of 9 IgM antibodies, randomly selected from the same collection. Five of these 9 IgM antibodies were found to react with a considerable number of other IgM in the collection, while the other 4 showed only sporadic reactivity. On the other hand, more than half of the 70 antibodies were found to bind specifically to at least one of these five. With a few exceptions, these reactions showed quantitative levels ranging from 5 to 20% of those observed between either of the two interacting IgM and monoclonal rat anti-mu antibodies. The selectivity of these reactions indicated V-region specificity, which was confirmed by analyzing in some detail the reaction between 2 IgM antibodies isolated from the same mouse.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000276:immunology; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D000915:Antibody Affinity; D003429:Cross Reactions; D007130:Immunoglobulin Idiotypes / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology*; D007135:Immunoglobulin Variable Region / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D000888:Antibodies, Anti-Idiotypic; D007130:Immunoglobulin Idiotypes; D007075:Immunoglobulin M; D007135:Immunoglobulin Variable Region