Genetic diversity and immunogenicity analysis of 6-cysteine protein family members in Plasmodium ovale curtisi importess from Africa to China: P12, P38 and P41

Abstract Background The s48/45 six-cysteine proteins exist throughout the Plasmodium life cycle and play important roles in the interaction between Plasmodium parasites and their hosts. P12, P38, and P41, which containing specific s48/45 domains, have recently attracted widespread attention due to their unique molecular structure. In this study, we aimed to characterize the genetic diversity and immunogenicity of P12, P38, and P41 in order to evaluate their potential protective efficacy against malaria in mice. Methods Blood samples were collected from 37 patients infected with P. ovale curtisi and genomic DNA was extracted for sequencing and protein expression. After expression and purification of the recombinant PocP12, PocP38, and PocP41 proteins, they were used for the assessment of immune responses and antigen-specific T-cell responses in BALB/c mice. Results The sequences of pocp12, pocp38 , and pocp41 were found to be highly conserved. The recombinant PocP12, PocP38, and PocP41 proteins were expressed successfully with high purity. When immunized with recombinant PocP38, the mice had higher levels of IFN-γ in CD4+ and CD8+ T cells, and even showed effective lymphoproliferation. Conclusions Low genetic polymorphism of pocp12, pocp38 , and pocp41 , and appropriate immunoreactivity in mice support their efficient immune defence against malaria.