Porcine Myeloid Dendritic Cells Can Be Differentially Activated By Vesicular Stomatitis Virus And Its Matrix Protein Mutants

Vesicular stomatitis virus（VSV）is a member of the genus Rhabdoviridae,which is a benign infectious disease that causes pigs to be acute,feverish and highly contagious.VSV genome encodes five structural proteins,of which matrix protein M is an important virulence factor.Our laboratory has successfully prepared recombinant VSV with M protein carrying triple mutations（ΔM51,V221F and S226R）(VSV_MT).The results of the previous experiments showed that VSV_MTT had significant attenuation characteristics in the host pigs,but still can stimulate the body to produce an efficient immune response.Animal dendritic cells（DC）are the bridge between innate and adaptive immunities.In order to clarify the result that VSV_MT activates immune response and explore the role of M protein in the regulation and activation of DC,this dissertation has carried out following researches.1.Cell surface molecules（CD80/86,MHCⅡ）were detected by flow cytometry,indicating that MoDC possess more potentials in antigen presentation than Monocyte do.2.The multi-step growth curve of VSV and its M protein mutant in Monocytes and MoDC,which showed that3.The effects of VSV and its M protein mutant on the apoptosis of DC were detected by Western Blot and flow cytometry.The results showed that both VSV and its M protein mutant could induce apoptosis via caspase-dependent pathway,and VSV_MTT delayed the time of apoptosis and reduced the number of apoptosis cells obviously.4.Detection and analysis of DC-specific surface markers（CD80/86,MHCⅡ）after infection with VSV and its M protein by flow cytometry.The results showed that VSV_MT can induce DC maturation efficiently,However,VSV inhibits the maturation of DC by down-regulating the expression of CD80/86.5.The expression of proinflammatory cytokines induced by VSV and its M protein mutant were detected by ELISA,the results showed that VSV_MT can induce proinflmmatory cytokines efficiently.The results finally show that VSV_MT induces the maturation of MoDCs most potently,which through delayed apoptosis,efficient induction of cytokines as well as upregulation of CD80/86 and MHCⅡ.However,wild-type VSV may evade the immune response by downregulating the expression of CD80/86 to inhibit DC maturation.