DNA Vaccine Containing Epitope C From HSP90 Of Candida Albicans And Adjuvant Effect Of CpG In This DNA Vaccine

The mortality rate of systemic candida albicans infection is still up to 70% after treatment.So,it's vital important to develop effective vaccine against candida albicans infection.Now,there are still some problems on development of canida albicans vaccine,such as low immunogenicity,poor safety et al.We have constructed a DNA vaccine(pD-HSP90C)used pcDNA3.1 as a vector in previous work of our lab.However,it cannot be used in human because it has resistance gene against ampicillin on it.In order to solve these problems,we chose eukaryotic expression vector pVAX1 to construct pV-HSP90 C which is a new DNA vaccine.pVAX1 has higher ability of duplication and expression.More importantly,it can be used in human.We investigated the immunocompetence of pV-HSP90 C.In addition,we used CpG ODN,a oligodeoxynucleotides which can enhance immune response as adjuvant,and investigated the role of CpG ODN in immunological enhancement when it works with DNA vaccine.In this study,we selected the sequence which encoding the epitope C of Candida albicans HSP90 as the target gene,and took pVAX1 as the vector,then we constructed a DNA vaccine named pV-HSP90 C.We also constructed pV-HSP90C-CpG which has the CpG ODN.We also constructed pV-HSP90C-CpG which has the CpG ODN,subsequently,we explored their immunogenicity.C57BL/6J mice were divided into groups,and immuned intramuscularly with electroporation two times every two weeks.Two weeks after the second immunization,we took blood by removalling eyeball,then the antiserum was collected.We detected if there are specific antibody in the serum of immuned mice by western blot,and the specific antibody titer of IgG,IgG1 and IgG2 b by ELISA.The content of IL-4 and IL-12 in mouse serum was also measured by ELISA Kit.Compared with PBS group,we detected specific antibody by western blot and higher specific antibody titer of IgG,IgG1 and IgG2 b in the serum of the group of pV-HSP90 C by ELISA.The content of IL-4 and IL-12 in the serum of pV-HSP90 C group was significantly higher than that in the group of PBS.The results indicated that pV-HSP90 C can significantly enhance both Th1 and Th2 responses and it has a certain immunogenicity.The titer of IgG,IgG2b and the content of IL-12 in the serum from pV-HSP90C-CpG group were significantly higher than that from the pV-HSP90 C group.However,the titer of IgG1 and the content of IL-4 did not be increased.This study showed that CpG ODN as an adjuvant elicited Th1 response to enhance the efficacy of DNA vaccines.This study laid the foundation for the further development and utilization of the DNA vaccine of Candida albicans and the application of CpG ODN in the field of adjuvant.