Improved Function and Maturation of Dendritic Cells Stimulated by Recombinant pp65 Protein: In vitro Design

BACKGROUND: Stimulated dendritic cells (DCs) have been shown to be effective in the induction of specific immune cells. Also, the CMV pp65 plays an important role in CMV life cycle and immune recognition. OBJECTIVE: To assess the effect of CMV pp65 on the maturity and function of dendritic cells. METHODS: Splenic DCs were treated with non-cytotoxic concentrations of the pp65 and analyzed for MHC II, CD86, and CD40 expression by flow cytometry. Then, ROR-γ, GATA3, T-bet, and FOXP3 gene expression levels were evaluated in T cells co-cultured with DCs using Real time-PCR. Finally, the effects of pp65 on allogenic T-cell responses in mixed lymphocyte culture (MLR), and the release of cytokines were investigated by ELISA and flow cytometry. RESULTS: The phagocytosis rate was significantly lower in the pp65-treated DCs than the non-stimulated DCs. There were significant differences in the raised level of CD40, CD86, and CCR7 in DCs as maturation markers. Furthermore, ROR-γ, and T-bet overexpression in T cells of the pp65-treated group compared with the non-stimulated group was observed. Significant differences were observed in the levels of IL-2, IL-6, IL-17, IL-22, TNF-α, and IFN-γ in pp65-stimulated groups compared with the non-stimulated DCs. CONCLUSIONS: The pp65-treated DCs can induce differentiation and functional activity of the cellular immune system, including Th17, and Th1, but not other major T-cell subsets such as Tregs, and Th2 population.