The immunological properties of haptens coupled to thymus‐independent carrier molecules. I. The characteristics of the immune response to dinitrophenyllysinesubstituted pneumococcal polysaccharide (SIII) and levan

摘要

AbstractThe antibody response to the hapten 2,4dinitrophenyl (DNP)lysine coupled to two thymus‐independent carrier molecules (pneumococcal polysaccharide SIII and levan) has been studied in mice. The characteristics of the anti‐hapten response are essentially similar to the response to the carrier itself: both conjugates elicit a strongly dose‐dependent IgM response (with little or no IgG antibody), and supraoptimal doses paralyze both anti‐hapten and anti‐carrier antibody responses. The anti‐hapten response to DNPlyslevan is thymus‐independent; it is also carrier‐independent, since levan‐paralyzed mice give a normal antihapten response to the conjugate and, conversely, paralysis of the antihapten reactive lymphocyte population fails to affect the response to the carrier. The results do not support the concept of B cell‐B cell cooperation that has been proposed to explain the immunogenicity of haptenpolysaccharide conjugates. Instead, they indicate that these conjugates immunize separate and noninteracting B cell populations, the one hapten‐specific and the other carrier‐reactive. Both the numbers and the size of anti‐DNP hemolytic plaques were related to the immunizing dose of DNPlyslevan. Preliminary experiments suggest that the reduction in plaque size in partially tolerant mice may be caused by persisting antigen on