Microbiology & Immunology Gruduate Students
Caroline L. Bonnel
BS, University of Hawaii at Hilo
The ability to mount effective immune responses declines with age, which correlates clinically with decreased vaccine efficacy and increased susceptibility to infection and cancer. As a result, new vaccines should be tested for efficacy in older individuals, however are often excluded from such studies. Towards this end, young (5-6 years of age) and old (17-22 years) baboons were immunized with the LcrV candidate vaccine antigen from Yersinia pestis. Surprisingly, older baboons had a strong humoral response [JI 181:109] suggesting either that the baboon immune system is less affected by aging or that LcrV acts like a recall antigen. Thus, a second Y. pestis vaccine antigen, the F1 protein, was tested; F1 is unique to this bacterial species and would be seen as a "new" antigen. The antibody response to F1 did decline with age, but the T cell response did not. Thus, an analysis of the effects of aging on T cell fine specificity was undertaken. T cell proliferation and IFN-y ELISpots were used to map which of 32 overlapping synthetic F1 peptides stimulated T cells from the immunized baboons. A Th1 response was observed for a few individual animals in response to whole both F1 antigen and specific peptides. ELISpots specific for IL-4 and IL-5 cytokines are currently being used to follow Th2 cells specific for F1. Future efforts will focus on generating F1-specific T cell clones using herpesvirus papio transformed B cell lines as antigen presenting cells.
Annual American Association of Immunologists Meeting, "Effects of age on the immune response in baboons to the Y. pestis F1 vaccine antigen", Presented 5/2012, Poster (Also presented this same poster at the annual Terry Mikiten Graduate Research Forum earlier this month)