Subclass restriction of murine antibodies. II. The IgG plaque-forming cell response to thymus-independent type 1 and type 2 antigens in normal mice and mice expressing an X-linked immunodeficiency.
Antigens have been classified previously into three categories, thymus-dependent (TD), thymus-independent type (TI) 1, and TI-2, based upon thymic dependence and ability to stimulate an immunodeficient strain of mouse, CBA/N. Here we demonstrate that the different antigen classes elicit IgG antibodies of different subclasses. TD antigens stimulate predominantly IgG1 antibodies, with smaller amounts of IgG2 and IgG3 being expressed. TI-1 antigens stimulate almost no IgG1 antibodies and equal amounts of IgG2 and IgG3. TI-2 antigens elicit predominantly IgG3 antibodies. Mice expressing the CBA/N phenotype are known to be nonresponsive to TI-2 antigens. This was confirmed in this study. In addition, we demonstrate that the IgG3 component of the response to TI-1 antigens is virtually absent in mice expressing the CBA/N phenotype, which supports our previous finding that the CBA/N defect may be restricted to a B-lymphocyte subpopulation containing most of the precursors of IgG3-secreting cells.
D000818:Animals; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology*; D005260:Female; D005362:Ficoll / Q000276:immunology; D008040:Genetic Linkage; D007074:Immunoglobulin G / Q000096:biosynthesis*; D007075:Immunoglobulin M / Q000096:biosynthesis; D007153:Immunologic Deficiency Syndromes / Q000235:genetics / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology; D051379:Mice; D008808:Mice, Inbred CBA / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D014960:X Chromosome
D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; D005362:Ficoll