BACKGROUNDConstructing replication defective recombinant adenovirus vector expressing the group specific antigen VP6 of human rotavirus and studying the immune responses induced in vivo.

METHODSThe cDNA of full length VP6 was inserted into the adenovirus vector pShuttle-CMV, and recombinant adenovirus genome DNA was obtained through homological recombination in E.coli,then the recombinant adenovirus was gained after transfecting 293 cell line with the genome DNA. Gene integration of VP6 in resultant adenovirus was confirmed by PCR and Southern blot, respectively gene expression was confirmed in 293 cells by Western blot. BALB/c mice were immunized intranasally(inl)and orally(ora), respectively, to test the immunization effects of the adenovirus.

RESULTSRecombinant adenovirus named rvAd-VP6 was obtained. The cDNA of VP6 was integrated in the adenovirus and was able to be expressed in 293 cells stably. The systemic immune responses to rotavirus VP6 could be induced effectively in both oral and intranasal group, the titer of serum IgG antibody in the two group of mice were 1?1 000 and 1?10 000-1?100 000, respectively. In addition to IgG, the serum IgA specific to VP6 could also be detected at a titer of 1?10-1?100. Secretory IgA(sIgA) was detected in both lung lavage fluid and intestinal homogenate when administered intranasally to BALB/c mice, whereas only found in intestinal homogenate in the oral group. The results indicated that the immunization efficacy of intranasal inoculation was superior to that of oral inoculation.

CONCLUSIONSThe recombinant adenovirus vector expressing human rotavirus VP6 was successfully constructed, its ability to induce immune responses has laid a solid foundation for the development of rotavirus genetically engineering vaccine against rotavirus infection.