Different competency of CMV-pp65 or Flu-M1 specific CD8+ T cells in naïve and central memory population in healthy human adults (TRAN3P.885)

Abstract

Abstract The competency of antigen specific (Ag+) lymphocytes plays a critical role in the outcome of an adaptive immune response during an infection. Although the precursor frequency of Ag+ T cells often serves as an indicator, the evaluation of the proliferative capacity of Ag+ T cells of healthy humans to known viral antigens is limited. Here, we compared CD8 T cell responses to the antigen from cytomegalovirus (CMV-pp65) or influenza virus (Flu-M1) using an artificial antigen presenting system in vitro. We found that CD8 T cell responses (proliferation and Granzyme B production) to these two antigens varied in 23 healthy adults analyzed. The antigen specific CD8 T cell expansion did not correlate with the precursor frequency of total Ag+ CD8 T cells. Further comparing the response of isolated naïve (Tn) and central memory (Tcm) CD8 T cells showed that Tcm expanded more than Tn did to both antigens. Finally, we found that longer telomere lengths in CD8 T cells were positively correlated with the better expansion of these Ag+ CD8 T cells. Together, our study shows that antigen specific CD8 T cell response to CMV-pp65 and Flu-M1 is varied in healthy adults and the capacity of proliferation of these Ag+ CD8 T cells depends partly on the telomere length in these cells.