Merozoite surface protein 1 (MSP1), a well-known target antigen for protective immune responses against asexual blood-stage malaria, yet effective vaccines constructed on MSP1 N terminal have not been developed so far compared to the well-known MSP1 C...
Merozoite surface protein 1 (MSP1), a well-known target antigen for protective immune responses against asexual blood-stage malaria, yet effective vaccines constructed on MSP1 N terminal have not been developed so far compared to the well-known MSP1 C terminal region. Using an in silico approach, we predicted the immunogenicity of the N-terminal (462 aa) region of MSP1 from Plasmodium yoelii (PyMSP1). Recombinant protein was generated using pET21b(+) and purified for further use. In an in vivo study, humoral responses were determined, and after nine weeks, immunized mice were challenged with 104 parasites. At day 9, PyMSP1 N showed significantly decreased parasitemia and a 20% weight difference in Plasmodium yoelii - infected mice and PyMSP1 N immunized mice with 100% survival. In addition, we observed IgG1 and IgG2a responses to the antigen in the serum of mice immunized with PyMSP1 N, and determined that this antigen activates CD4+ T cell. In vitro, a 40% boost in the CD86c+ population was observed in PyMSP1 N compared to the negative control, confirming antigen stimulation by FACS. Cytokine ELISA was performed by the co-culture of stimulated DCs and T cells. These results suggest that PyMSP1 N activates CD4+ T cells. Conclusively, the immunological significance of PyMSP1 N terminal region suggest that the PyMSP1 N terminal region exhibited Th1 and Th2 type immune responses and has a potential as vaccine material.