Demonstration of phosphorylcholine-specific IgE B cells in CBA/N mice.

CBA/N mice, which did not make anti-PC IgM or IgG antibody against PC-conjugated T-dependent or T-independent antigens, produced IgE antibody to PC-determinant when they were immunized with PC-KLH. PC-specificity of IgE antibody produced in CBA/N mice was determined by inhibition of PCA reaction with free PC-hapten or C-polysaccharide or by absorption of reaginic activity in the serum with C-polysaccharide. The presence of T15 idiotype on anti-PC IgE antibody produced in CBA/N x BALB/c F1 males also showed that anti-PC IgE antibody in defective mice was PC-specific. The results suggest that PC-specific B epsilon cells may belong to a subpopulation distinct from PC-specific precursors for IgM and IgG responses.