Akram Abouie Mehrizi
Pasteur Institute of Iran, Iran
Title: Th1 immune responses to Plasmodium falciparum merozoite surface protein 1 in combination with poly I:C/alum in BALB/c mice
Biography
Biography: Akram Abouie Mehrizi
Abstract
The C-terminal region of Plasmodium falciparum Merozoite Surface protein 1 (PfMSP-142) is a leading malaria vaccine candidate antigen. Nevertheless, the results of clinical trials of MSP-1 based vaccines have not shown complete efficacy. In this regard, the main obstacle is the lack of potent adjuvants suitable for using in human. In this study, to induce high titer of total antibodies and polarized Th1 immune responses against PfMSP-142, poly I:C as a potent and human compatible adjuvant was used. For this purpose, the PfMSP-142 gene was cloned and expressed in E. coli M15-pQE30 expression system. Five test groups of BALB/c mice were immunized with affinity purified recombinant PfMSP-142 antigen alone or in combination with poly I:C, poly I:C/alum, alum or CFA/IFA adjuvants. The control groups received PBS1 or corresponding adjuvants without antigen. Immunization was carried out three times, 2 weeks intervals via subcutaneous rout. Anti-PfMSP-142 IgG and IgG subclasses were measured 10 days after last immunization. The results showed that antibody response was highest in the mice groups that received rPfMSP-142+poly I:C/alum. Interestingly, among the five test groups, the level of IgG2a antibody as the Th1 response was significantly increased in the mice groups that received rPfMSP-142 in combination with poly I:C/alum or poly I:C. In conclusion, the results showed that in compare with CFA/IFA adjuvant, the poly I:C/alum combination adjuvant could improve the immune responses to rPfMSP-142 antigen, which could imply that poly I:C is a potent adjuvant that elicits Th1 immune responses against Plasmodium antigens.