title: Late clonal selection and expansion of the TEPC-15 germ-line specificity.
abstract: The maturation of the antibody response to phosphorylcholine (PC) in neonatal BALB/c mice was studied. A T cell-independent class 1 1 PC-antigen, 3-(p-azophenyl phosphorylcholine)-N-acetyl-L-tyrosylglycylglycine lipopolysaccharide, was synthesized and used to immunize neonatal mice of different ages. The earliest anti-PC hemolytic plaque-forming response could be induced in 1-d-old neonates. Idiotype analysis on these early anti-PC antibodies showed that the response was not TEPC-15 dominant although TEPC-15-positive plaque-forming cells were detected. However, idiotype analysis of the anti-PC-LPS response in 7 d or older animals indicated that clonal dominance had been established. Similar results were obtained in splenic fragment culture with cells from neonatal livers and spleens. PC-specific precursors were detected in the liver of 1-d-old neonates, whereas the spleen of those animals contained no precursors for PC. Precursors for PC residing in the neonatal liver are not TEPC-15 dominant, whereas the splenic PC precursors of 5- to 6-day-old animals express the TEPC-15 idiotype dominatly. These findings demonstrate that during ontogeny PC-specific B cells appear before the TEPC-15 clone becomes dominant. Thus clonal dominance in the adult anti-PC response and late acquisition of the TEPC-15 specificity during ontogeny do not signify a particularly unique or direct relationship to the expression of genes encoded in the germline.
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001402:B-Lymphocytes / Q000276:immunology; D002794:Choline / Q000031:analogs & derivatives*; D002999:Clone Cells / Q000276:immunology*; D005260:Female; D007130:Immunoglobulin Idiotypes / Q000235:genetics*; D008099:Liver / Q000166:cytology; D051379:Mice; D008807:Mice, Inbred BALB C; D010767:Phosphorylcholine / Q000276:immunology*; D012641:Selection, Genetic; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D007130:Immunoglobulin Idiotypes; D010767:Phosphorylcholine; D002794:Choline