Age effects on B cells and humoral immunity in humans

Both humoral and cellular immune responses are impaired in aged individuals, leading to decreased vaccine responses. Although T cell defects occur, defects in B cells play a significant role in age-related humoral immune changes. The ability to undergo class switch recombination (CSR), the enzyme for CSR, AID (activation-induced cytidine deaminase) and the transcription factor E47 are all decreased in aged stimulated B cells. We here present an overview of age-related changes in human B cell markers and functions, and also discuss some controversies in the field of B cell aging.

Research highlights▶ The ability to undergo class switch recombination (CSR) and produce IgG is decreased in aged stimulated human B cells. ▶ The transcription factor E47 and enzyme AID necessary for CSR are also decreased in these B cells. ▶ The numbers and percentages of human switch memory B cells decrease with age. ▶ Aging decreases the anti-influenza vaccine antibody response in vivo together with the in vitro AID response to the vaccine. ▶ AID in human stimulated B cells can predict an optimal influenza vaccine response.