SECONDARY IGG RESPONSES TO TYPE-3 PNEUMOCOCCAL POLYSACCHARIDE .2. DIFFERENT CELLULAR REQUIREMENTS FOR INDUCTION AND ELICITATION

  • 1 January 1976
    • journal article
    • research article
    • Vol. 116  (4) , 904-910
Abstract
Mice primed with a thymus- (T) dependent form of Type III pneumococcal polysaccharide (S3), i.e., S3 coupled to [horse] erythrocytes (S3-RBC) produce S3-specific Ig[immunoglobulin]G antibody after secondary challenge with S3 or S3-RBC. The production of IgG antibody by mice challenged with S3 was T independent since secondary responses were enhanced when mice were treated with [rabbit] anti-lymphocyte serum (ALS) at the time of secondary challenge with S3, and T-depleted spleen cells responded as well as unfractionated spleen cells to S3 in an adoptive transfer system. Secondary S3-specific IgG responses in mice challenged with S3-RBC were T dependent by the same criteria. The results obtained by using S3 as antigen indicate that IgG-producing B [bone marrow-derived] cells (B .gamma. cells) can recognize and respond to antigen in the absence of helper T cells. T cells were required for the induction of S3-specific memory B .gamma. cells since mice depleted of T cells, by treatment with ALS at the time of priming with S3-RBC, failed to produce S3-specific IgG antibody after secondary challenge with S3 or S3-RBC. Since RBC-specific memory cells were induced in T-deprived mice, T cell regulation of IgG antibody production may vary for different antigens.