The Role of Immune and Natural Specific Antibodies in Immunologic Paralysis and Immunity of Mice to Pneumococcal Polysaccharide Type III

Abstract
Young offspring of immunologically paralyzed mice were more susceptible to the induction of both paralysis and immunity to SIII than were normal mice of the same age. This difference decreased gradually with age. We attributed the difference in immunologic responsiveness between the two types of mice to a lesser concentration of natural antibody specific for the SIII in the offspring of paralyzed mice as compared to normal mice of the same age. Administration of either specifically purified anti-SIII or normal IgG restored the offspring of paralyzed mice to the same level of susceptibility to the induction of both paralysis and immunity as that exhibited by normal mice. The biologic activity of normal IgG was removed by a specific immunosorbent, thereby confirming that the effect of normal IgG was also due to specific anti-SIII antibody. We therefore concluded that a relative deficiency of natural anti-SIII antibodies was indeed responsible for the altered immunologic behavior of offspring of paralyzed mice, and that the results obtained are compatible with, and explained by, a role of preformed antibody in the regulation of antibody formation.