Increasing a Robust Antigen-Specific Cytotoxic T Lymphocyte Response by FMDV DNA Vaccination with IL-9 Expressing Construct

Abstract EN

Various chemokines and cytokines as adjuvants can be used to improve efficacy of DNA vaccination.

In this study, we sought to investigate if a DNA construct expressing IL-9 (designed as proV-IL9) as a molecular adjuvant enhance antigen specific immune responses elicited by the pcD-VP1 DNA vaccination.

Mice immunized with pcD-VP1 combined with proV-IL9 developed a strong humoral response.

In addition, the coinoculation induced significant higher level of antigen-specific cell proliferation and cytotoxic response.

This agreed well with higher expression level of IFN-γ and perforin in CD8+ T cells, but not with IL-17 in these T cells.

The results indicate that IL-9 induces the development of IFN-γ-producing CD8+ T cells (Tc1), but not the IL-17-producing CD8+ T cells (Tc17).

Up-regulated expressions of BCL-2 and BCL-XL were exhibited in these Tc1 cells, suggesting that IL-9 may trigger antiapoptosis mechanism in these cells.

Together, these results demonstrated that IL-9 used as molecular adjuvant could enhance the immunogenicity of DNA vaccination, in augmenting humoral and cellular responses and particularly promoting Tc1 activations.

Thus, the IL-9 may be utilized as a potent Tc1 adjuvant for DNA vaccines.