Immunologic “Amnesia” of Antibody-Forming Cells after RES Blockade ∗

Abstract

Summary

Cellular and humoral antibody formation was markedly inhibited in mice treated with colloidal carbon particles to blockade the reticuloendothelial system. Appearance of 19S IgM and 7S IgG hemolysin-forming cells was prevented when adult mice were treated with carbon prior to a single inoculation of sheep erythrocytes. Carbon treatment also reduced markedly the expected secondary immune response in mice primed several weeks previously with sheep red blood cells. Few antibody-forming cells, either IgG or IgM, and only low levels of serum hemolysins appeared in primed mice injected with carbon 1 to 4 days before a secondary immunization. Mice injected with carbon before the primary inoculation of antigen had normal 19S IgM antibody-plaque responses after a second injection of red blood cells 1 month later. However, there was a marked absence of 7S IgG antibody-forming cells. Also, there was little, if any, 2-mercaptoethenol-resistant antibody in the sera of these mice after booster immunization. The immune response of these animals was similar to that of a primary-type response of normal control mice injected only once with erythrocytes. Specific immunologic “amnesia,” as distinct from immunological tolerance, had developed as a consequence of RES blockade by carbon injection prior to initial immunization.