The Effects Of Interaction Between HUVECs Infected With DENV-2 And Human CD4~+T Cells On The Expression Of The Main Adhesion Molecules And Immunosuppressive Factors

Objective:To investigate the effect of interaction between Human umbilical vein endothelial cells infected with DENV-2 and CD4+T cells on the expression of ICAM-1,VCAM-1mRNA in HUVECs,and IL-10,TGF-?1 mRNA in CD4+T cells,respectively.To further understand the related molecular immunological mechanism of dengue fever.Methods:HUVECs was treated with S1P1 selective agonists CYM5442 in 24 hours,then infected with 103 TCID50 DENV-2 before co-culturing with CD4 + T cells.The mRNA expressions changes of NS1(DENV-2 nonstructural protein),SPHK1(S1P1 synthesize),ICAM-1,VCAM-1,IL-10 and TGF-?1 were detected by Real time-PCR after collecting cell samples in 4,8,12,24,48 and 72 h respectively.Result:There is a certain timeliness in the expression of the mRNA of virus NS1 after infected with DENV-2 and a peak reaching at 24h.The expression of DENV-2 NS1 mRNA was not significantly different between CYM-5442 treated and untreated group.The expression of SPHK1 mRNA was significantly increased after HUVECs were treated with CYM-5442 and DENV-2,and the difference was statistically significant(P<0.05).There was statistically significant difference in the mRNA expression of ICAM-1 and VCAM-1 in HUVECs,relative to groups that HUVECs were only infected with DENV-2 and untreated groups,when culturing with CD4+T cells(P<0.01),In the case of co-culture of CD4+T cells and HUVECs infected with DENV-2,the expression of ICAM-1 and VCAM-1 mRNA in HUVECs was significantly higher than that in HUVECs treated with DENV-2 and untreated(P<0.01),the expression of TGF-?1 mRNA in CD4+T cells was not significantly different,IL-10 mRNA expression was up-regulated and statistically significant(P<0.05).Conclusion:In vitro,DENV-2 could reproduce and proliferate in HUVECs after infected.CD4+ T cells can inhibit the proliferation of DENV-2,and CYM-5442 has no significant effect on DENV-2 infection and replication.CD4+T cells play a significant role in promoting the expression of VCAM-1 and ICAM-1 in HUVECs infected with DENV-2.DENV-2 infection HUVECs can up-regulate the expression of ICAM-1 and VCAM-1mRNA,which can induce the adhesion of inflammatory cells and produce local inflammatory response.CD4+T cells can significantly promote the expression of ICAM-1 and VCAM-1 mRNA in HUVECs infected with DENV-2,which indicated that CD4+ T cells could further promote the activation of HUVECs and enhance the inflammatory response.And this may be one of the important molecular mechanisms of vascular endothelial permeability and vascular leakage induced by DENV-2 infection.CYM-5442 has a certain inhibitory effect on immune activation of HUVECs infected with DENY-2,which can reduce the inflammatory response.The expression of IL-10 mRNA in CD4+T cells was significantly up-regulated by HUVECs infected with DENV-2,which had no significant effects on the expression of TGF-?1 indicating that the immunosuppressive regulation was not dominant but the proinflammatory in the first DENV-1 infection.And IL-10 and TGF-?1 in CD4+T cells were not significantly regulated by DENV-2 infection in HUVECs treated with CYM-5442.