Elderly humans respond less robustly to vaccination than do younger people; however, there are discrepancies in the literature on the characteristics of the elderly B cell repertoire. In the Journal of Immunology, Wang et al. examine the repertoire of genes encoding the immunoglobulin heavy chain (IGH) in young and elderly adults to determine what effects aging or chronic viral infection have on B cell populations. Age does not affect the use of variable, diversity or joining segments; however, older people lose the selection against longer complementarity-determining region 3 segments, which suggests a difference in tolerance mechanisms. People who are positive for Epstein-Barr virus have large, persistent expanded B cell clones, whereas those positive for cytomegalovirus have a higher frequency of highly mutated IGH in their IgM+ and IgG+ B cell repertoire. These findings suggest that earlier reports may have missed the influence of chronic infection and may have instead attributed such effects to the aging process.

J. Immunol. (11 December 2013) doi:10.4049/jimmunol.1301384