Abstract
Abstract We have previously shown that elderly humans have fewer percentages of CD19+ total B cells, switch memory B cells, and increased percentages of naïve B cells. Activated CD19+ B cells have less E47, AID and Igγ1 circle transcripts (CTs) with age. AID is critical for class switch recombination (CSR) and somatic hypermutation, both necessary for optimal function of immunoglobulin (Ig). More recently we have initiated a series of experiments to measure the antibody response to influenza vaccination by hemagglutination inhibition assay (HI) and associated this with the isolated/intrinsic B cell response to these antigens (containing adjuvants) in vitro. Our results show that the specific in vitro AID response of B cells to vaccination and the in vivo serum HI response to vaccination are both decreased with age. We are currently pursuing these studies with more subjects and with both seasonal as well as H1N1 vaccine response. These results indicate that these biomarkers (decreased E47, AID, CSR, IgG) could more accurately track optimal immune responses and activity, and would be better predictors of vaccine and therapeutic agent effectiveness in humans.