The Average IFN-γSecreting Capacity of Specific CD8+T Cells Is Compromised While Increasing Copies of a Single T Cell Epitope Encoded by DNA Vaccine

Abstract

Previous studies suggested that both the frequency and the mean fluorescence intensity (MFI) of cytokine secreting T cells could be of great value for immunogenicity evaluation of a vaccine. In this study, by constructing epitope-based DNA vaccines encoding a previously identified CD8+T cell epitope, we investigated the influence of multiplying epitope copies on both the frequency and the MFI of specific IFN-γsecreting CD8+T cells. We found that frequencies of specific CD8+T cell could be improved by multiplying epitope copies, while the MFI of IFN-γsecreted by epitope-specific CD8+T cells decreased synchronously. And further analysis showed that the decrease of MFI was not caused by the functional avidity variation of CD8+T cell receptor.