[Identification of recombinant aldolase of Plasmodium falciparum and its monoclonal antibody preparation].

ABSTRACT

OBJECTIVE: To identify the recombinant aldolase (ALD) of Plasmodium falciparum, and to develop monoclonal antibodies (McAbs) against the recombinant ALD. METHODS: ALD gene was amplified by PCR from genomic DNA of FCC1/HN strain, and expressed in E. coli DH5 alpha. BALB/c mice were immunized with the recombinant ALD of P. falciparum via celiac injection for 3 times with 2 weeks interval. Three days after a booster injection, spleen cells of the immunized mice were used for producing McAbs. The immune serum was tested by IFAT and Western blotting. RESULTS: BALB/c mice immunized with purified aldolase protein developed strong immune response to the antigen, and the titer of specific antibody reached 110(5) in all immune sera after the third immunization. Moreover, immune sera specifically recognized the cultured P. falciparum. Western blotting showed that the immune sera recognized specifically a Mr 41000 band of crude malaria antigen. No cross-reaction with human red cells was detected. Seven positive hybridoma cell lines were obtained after 3 rows of selection. All the McAbs' subclasses belong to IgG1. IFAT showed that only 4 McAbs could recognize the cultured P. falciparum. CONCLUSION: Plasmodial aldolase has been successfully expressed and purified, and the established hybridoma cell lines can secrete McAbs specific to the aldolase of P. falciparum.