Comparative analysis of CD8 T cell response to cytomegalovirus or influenza virus in healthy human adults (P3002)

Abstract

Abstract The competency of antigen specific (Ag+) lymphocytes plays a critical role in the adaptive immune response. However, little is known about the differences in the competency of Ag+ T cells against different viruses. Here, we compared the CD8 T cell responses of 23 healthy adults to CMV (pp65) or Flu (M1) peptides using an in vitro artificial antigen presenting system. We found that CD8 T cell responses to CMV or Flu varied in both proliferation and Granzyme B production and were independent of the frequency of initial CMV+ or Flu+ CD8 T cells. In the comparison of the responses of Naïve (Tn) and central memory (Tcm) CD8 T cells, Tcm exhibited a greater expansion than did Tn for both CMV and Flu antigen. Intriguingly, the variations of the expansion between CMV+ and Flu+ CD8 T cells were observed only in Tcm but not Tn cells, indicating the importance of antigen experience. Furthermore, the expansion ability was correlated with the telomere length in the initial CD8 T cells positively and expanded Ag+ CD8 T cells negatively, suggesting a role for telomere length in cell proliferation. Taken together, this study showed that incompetency of Ag+ CD8 T cells is associated with antigen experience and short telomere length in healthy adults. Currently, we are analyzing the usage of the TCR variable genes (alpha and beta) of CMV+ or Flu+ CD8 T cells by a single cell RT-PCR-Sequencing method to gain additional information about the structure of these TCR against CMV and Flu antigens.