| Plasmodium falciparum PfMAg-1 protein is expressed on the surface of Plasmodium falciparum merozoites,and this protein is not present in other types of Plasmodium that infect humans.In our laboratory,PfMAg-1 was used to immunize New Zealand rabbits with N,C,and mid-antigen proteins,and antisera against Plasmodium were used for in vitro culture experiments.All of the antibodies specific to the anti-PfMAg-1 fragment were shown to have inhibitory effects on the growth of Plasmodium falciparum.In order to further observe the function of PfMAg-1 whole protein,this study used CRISPR/dCas9 technology to construct a low expression and overexpression plasmid of PfMAg-1 of Plasmodium falciparum,and then screen MAg1-KD strain and MAg1-OE strain after transfection of Plasmodium falciparum.The expression of PfMAg-1 was detected by PCR and qRT-PCR.The growth trend of the MAgl-KD and MAgl-OE strains and the efficiency of merozoite invasion were observed under in vitro culture conditions.The results showed that:1)The growth rate of P.falciparum MAgl-KD strains was significantly lower than that of the control strains.Further experiments suggested that the reason for the proliferative rate of malaria parasites was that the merozoite invasion efficiency of MAgl-KD strains decreased.2)The proliferation rate of MAgl-OE strain overexpressing PfMAg-1 was significantly higher than that of the control strain.Further experiments suggested that the reason for the proliferation rate of Plasmodium was related to the increased rate of merozoite invasion of the MAgl-OE strain.In addition,after transcriptome sequencing of MAgl-KD strains,it was found that the differentially expressed genes in the two strains belong to the var family and the rifin family,which encode the mutated erythrocyte surface antigens.Since var and rifin gene expression products play an important role in the adhesion and invasion of Plasmodium,it is suggested that PfMAg-1 may be involved in the pathogenesis of these gene families.This study provides an important experimental basis for the further evaluation of PfMAg-1 protein as a malaria vaccine candidate antigen or antimalarial drug target. |
