In vitro experimental studies on immune responses to human dendritic cells infected with enterovirus 71

Abstract

Objective To study the mechanism of immune responses in enterovirus 71 (EV71)-infected human dendritic cells (DCs) in vitro and provide theoretical basis for EV71 infection and host immune response.Methods Peripheral blood mononuclear cells were purified from the healthy adult peripheral blood and immature DCs were generated from monocytes by culturing in medium containing cytokines.DCs surface markers wereanalyzed by flow cytometry before and after EV71 infection.PCR array was employed to detect the gene expressions of CD molecules and cytokines from EV71-infected DCs at 2 and 8 h postinfection,respectively.The cytokines of EV71-infected DCs in culture supernatants were measured by Luminex liquichip.In addition,the activity of navie T-cell by EV71-infected DCs was examined by mixed-lymphocyte reaction.Results EV71 infection increased the expressing percentages of CD80 and CD83 on DCs by 8.2％ and 35.4％,respectively.PCR array revealed that the expressions of CD80,CD83,IL-1α,IL-6,and ICAM-1 genes were significantly upregulated 2.08 to 5.49-fold at 2 h and 8 h postinfection,while IL-18 gene was downregulated 5.12-fold.Compared with control,the levels of IL-6 and IL-12 were distinctly elevated in EV71-infected DCs (P ＜0.05).However,the proliferation of navie T-cell stimulated by EV71-infected DCs weren't observed by MLR.Conclusion It indicates that EV71 infection not only can increase the viability,the survival time and activation of DCs,but also can significantly increase releases of IL-6 and IL-12 in DCs,which initiate immune response in host cells. Key words: Enterovirus ; Dendritic cells ; Polomerase chain reaction ; Cytokines