Regulation of antibody synthesis against Escherichia coli endotoxin. I. Suppressive effect of endogenously produced and passively transferred antibodies.

Abstract

Summary Cyclical fluctuations of cellular and humoral 19 S antibody synthesis were evoked by one single injection of heat-killed E. coli 055:B5 bacteria into CBA mice. The phenomenon was interpreted as involving feedback suppression of active antibody synthesis by 19 S antibodies. The biologically stable antigen would be prevented from stimulating antibody synthesis by reacting with the initially produced 19 S antibodies. In the absence of further stimulation 19 S-producing cells and serum antibodies would decay, leaving antigen free to initiate a second cycle of antibody synthesis. This hypothesis was supported by the finding that antiserum taken from the time of the first peak could suppress the appearance of a second peak. Antigen and 19 S antibodies injected simultaneously delayed active antibody synthesis which eventually appeared spontaneously. Presumably this represents a more rapid catabolism of the blocking antibodies than of the antigen. 7 S antibodies were not detected against this antigen during the primary response but appeared after intense hyperimmunization. The most sensitive method for detection of 7 S antibodies was inhibition of antibody synthesis by passive transfer of purified 7 S fractions. 7 S antibodies were more potent in inhibiting active antibody synthesis than 19 S antibodies when equal quantities of hemagglutinins were injected.