Induction of an IgM anti-(bovine)-IgG response in mice by bacterial lipopolysaccharide

Abstract

BACTERIAL endotoxin stimulates the appearance in mice of a large number of plaque forming cells (PFC) secreting an IgM globulin with specificity for bovine IgG (bovine gamma globulin; BGG). Reversed plaquing (antibody on the target erythrocyte) has enabled us to enumerate the total number of IgM secreting cells and show that the anti-BGG PFC comprise at least 10% of the total. Plaque inhibition with free antigen shows that anti-BGG PFC stimulated by LPS, as distinct from those specifically stimulated, secrete a product with low avidity. The evidence reported both here and in a previous study1, leads us to suggest that substances such as LPS stimulate the production of an M-anti-G response. The rheumatoid-factor-like molecule which is produced may possibly serve to amplify complement fixation by high avidity/specificity IgG antibodies. © 1976 Nature Publishing Group.