Identification, purification, and characterization of antigen-activated and antigen-specific human B lymphocytes.

Following immunization with PPS, there is a transient but considerable enrichment in the peripheral blood of activated PPS-specific B cells. The activated cells are large, 4F2 positive, surface IgG positive and IgD negative, responsive to BCGF but refractory to anti-mu or SAC. The analysis of B lymphocyte physiology in terms of activation states which have precise signal requirements for the transition between these states should contribute to our further understanding of both normal and abnormal B cell function.