title: In vitro studies of the genetically determined unresponsiveness to thymus-independent antigens in CBA/N mice.
abstract: The X-chromosome-linked B lymphocyte defect of CBA/N mice has been studied in vitro by comparing the ability of (CBA/N X DBA/2)F1 (X-/X- X X+/Y) male (X-/Y) and female (X-/X+) spleen cells to respond to the thymus-independent antigen DNP (or TNP)-AECM-Ficoll. (CBA/N X DBA/2)F1 male spleen cells failed to generate significant in vitro anti-TNP antibody responses to DNP- or TNP-AECM-Ficoll, in contrast to spleen cells from F1 female (X-/X+) mice which responded normally to these T-independent antigens. Spleen cells from male F1 mice responded almost as well as F1 female cells to the thymus-dependent antigen, TNP-sheep red blood cells (TNP-SRBC) in vitro. Adding F1 male cells to F1 female cells failed to reduce the response of the latter to DNP-AECM-Ficoll, suggesting that the inability of F1 male cells to respond was not due to active suppression. The response of F1 male spleen cells to TNP-SRBC was not impaired by adding high concentrations of TNP-AECM-Ficoll indicating that the mechanism of unresponsiveness was not tolerance induction in all TNP-specific precursors. Lymphocytes from F1 male mice were capable of forming anti-TNP antibody after stimulation with lipopolysaccharide (LPS) in high concentrations; DNP-AECM-Ficoll had no effect on this polyclonal response. B lymphocytes from mice bearing only the X-chromosome of the CBA/N strain thus display a profound defect in B cell activation. This functional defect may represent either an inability of the defective B cells to be activated by thymus-independent antigens or the absence of a sub-class of B cells which respond to thymus-independent antigens.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000941:Antigens; D000939:Epitopes; D005260:Female; D005362:Ficoll / Q000276:immunology; D007165:Immunosuppression Therapy; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D008297:Male; D008782:Methylurea Compounds / Q000276:immunology; D051379:Mice; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D009578:Nitrobenzenes / Q000276:immunology; D011135:Polysaccharides, Bacterial / Q000494:pharmacology; D012737:Sex Factors; D013154:Spleen / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology*
chemical_list: D000941:Antigens; D000939:Epitopes; D008782:Methylurea Compounds; D009578:Nitrobenzenes; D011135:Polysaccharides, Bacterial; D005362:Ficoll