title: The frequency and fine specificity of B cells responsive to (4-hydroxy-3-nitrophenyl)acetyl in aged mice.
abstract: The B-cell response to NP-Hy of two murine strains has been analyzed in order to evaluate the affects of aging on B-cell repertoire expression. The results indicate that for both BALB/c mice (Igha) and B10.D2 mice (Ighb) the frequency of (4-hydroxy-3-nitrophenyl)acetyl (NP)-responsive splenic B cells is approximately twofold lower, on a per B cell basis, in aged mice as compared to young adults. However, as with previous assessments of the response to DNP-Hy in aged mice, the frequency of newly generated surface immunoglobulin negative bone marrow precursor cells specific for NP in aged BALB/c mice is the same as in young mice. The decrease in frequency of responsive splenic B cells is not accompanied by a measurable decrease in repertoire diversity or changes in clonotype distribution as assessed by representation of kappa vs lambda light chain-bearing antibodies, binding of monoclonal antibodies to a panel of analogues of NP, and the proportionate representation of B10.D2 monoclonal antibodies that bear NPb idiotypic determinants. By these criteria it appears that down-regulation of B cells as they mature and emerge from the bone marrow of aged mice is pan-specific and does not disproportionately affect B cells of a predominant clonotype family. Consistent with other investigations which have demonstrated differences in secreted antibodies of immunized aged vs young mice, we have observed that 4 weeks after immunization of B10.D2 mice with NP-BSA, the frequency of newly generated secondary B cells is lower in aged than in young mice and the generation of lambda-bearing secondary precursor cells is particularly low. Thus, clonotype-specific down-regulation may play a role in shaping the B-cell repertoire subsequent to immunization of aged mice.
mesh_terms: D000375:Aging; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology / Q000502:physiology*; D000939:Epitopes / Q000276:immunology; D007114:Immunization; D007130:Immunoglobulin Idiotypes / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009596:Nitrophenols / Q000276:immunology*; D010648:Phenylacetates; D013154:Spleen / Q000166:cytology; D013234:Stem Cells / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D007130:Immunoglobulin Idiotypes; D009596:Nitrophenols; D010648:Phenylacetates; C026242:4-hydroxy-5-nitrophenyl acetic acid