Antibodies from the Lyb-5- B cell subset predominate in the secondary IgG response to phosphocholine

• Published in: The Journal of immunology (1950) Vol. 129; no. 3; pp. 950 - 953
• Main Authors: Wicker, LS, Guelde, G, Scher, I, Kenny, JJ
• Format: Journal Article
• Language: English
• Published: United States Am Assoc Immnol 01.09.1982
• Subjects: Animals; Antibody Formation; Antibody Specificity; Antigens, Ly; B-Lymphocytes - immunology; Choline - analogs & derivatives; Immunization, Passive; Immunoglobulin G - biosynthesis; Immunoglobulin Idiotypes; Immunoglobulin M - biosynthesis; Immunologic Memory; Mice; Mice, Inbred Strains - immunology; Phosphorylcholine - immunology
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.129.3.950

The X-linked CBA/N immune defect was used to investigate the role of the Lyb-5- B cell subset in phosphocholine- (PC) specific memory responses. Immune-defective mice, which express only the Lyb-5- B cell subset, are unable to mount a primary or secondary T15+, IgM response to PC but can produce a substantial secondary IgG response. The majority of these IgG anti-PC antibodies are T15- and can be inhibited by phenylphosphocholine, but not PC. Normal mice, which possess Lyb-5+ and Lyb-5- B cells, produce both IgM and IgG anti-PC antibodies; however, there is a striking difference in the idiotype and fine specificity of antibodies expressed by these two classes. The IgM anti-PC antibodies are T15+ and PC-inhibitable, whereas the IgG antibodies are identical to those observed in the immune-defective mice, i.e., T15- and PC-noninhibitable. This unexpected difference in both idiotype and fine specificity between IgM and IgG anti-PC antibodies results from activation of different B cell subsets. Lyb-5+ B cells produce T15+, PC-inhibitable IgM antibodies, whereas T15-, PC-noninhibitable IgG antibodies are produced by Lyb-5- B cells. These data indicate that a majority of the thymus-dependent, anti-PC IgG memory responses arises from Lyb-5- B cells.