Research on the induction of T cell subset response via oral vaccination with liposome-mediated recombinant pCDNA3.1~+/Ag85A plasmid
- VernacularTitle:口服免疫Ag85A脂质体DNA诱导T细胞亚群应答效应研究
- Author:
Yan JIANG
;
Changlong LV
- Publication Type:Journal Article
- Keywords:
DNA vaccine;
Cationic liposome;
T cell subsets;
Adjuvant;
Down-regulation effect
- From:
Chinese Journal of Immunology
2001;0(10):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To prepare recombinant pCDNA3.1+/Ag85A DNA vaccine encoding tuberculosis Ag85A gene mediated with LipofectamineTM 2000 and to study the effect on T cell subpopulation via oral vaccination.Methods:Recombinant plasmid containing Ag85A using liposome as a vector was constructed and administered to C57BL/6 mice via oral route.Determination of the contents of IFN-r,IL-4 in serum of C57BL/6 mice was performed by double antibody sandwich ELISA.Furthermore,the ability of splenocytes to secret IFN-? and IL-4 was tested by ELISPOT method.When the mice were vaccinated with recombinant eukaryotic expressing vector 5 weeks later,titers of serum antibody against Ag85A were detected by ELISA.The percentage of the CD4+ and CD8+ T cell subsets in the splenocytes was determined by flow cytometry.Results:Lymphocytes obtained from the spleen of liposomal pcDNA3.1+/Ag85A vaccine-immunized mice exhibited lower IFN-? production and higher IL-4 production than those of pcDNA3.1+ vector immunized mice.The number of spleen MNC secreting IFN-? stimulated by Ag85A protein in vitro was significantly lower than that of plasmid vector group.Liposomal pcDNA3.1+/Ag85A vaccine immunized mice elicited higher Ag85A-specific antibodcy titres.The percentage of the CD4+ and CD8+ T cell subsets in the splenocytes was decreased.The subset both were shown the profile of Th2 responses.Conclusion:The oral recombinant plasmid pCDNA3.1+/Ag85A mediated with LipofectamineTM 2000 It shows down-regulation effect on the subsets of CD4+ T cells and CD8+ T cells.The regimen has good immunogenecity and could induce Th2 type humoral response in C57BL/6 mice.The immunization suppresses secretion of IFN-?.It can greatly enhance the titres of Ag85A-specific antibodies.LipofectamineTM 2000 can act as an adjuvant through comparation with negative control group.
