恶性疟原虫融合抗原PfCP-2.9在不同品系小鼠中的免疫特性

目的:探讨恶性疟原虫融合抗原PfCP-2.9在不同品系小鼠(BALB/ca、C57BL/6J、C3H/He、DBA/2J及昆明种)中的免疫原性和免疫反应特性.方法:以ISA720为佐剂,PfCP-2.9抗原皮下免疫5种品系小鼠3次,间隔3周.以ELISA检测免疫血清中特异性抗体的动态变化、IgG抗体亚型及对融合抗原各组分的抗体水平,以间接荧光抗体实验分析免疫血清对恶性疟原虫天然抗原的识别情况.结果:5种品系小鼠均能产生针对PfCP-2.9的免疫应答,3次免疫后血清中特异性抗体滴度达105以上.PfCP-2.9所诱生的免疫血清不但能识别MSP1-19和AMA-1(Ⅲ)两个主要片段,而且能识别恶性疟原虫天然抗原.所诱导的4种IgG抗体亚型中,IgG1和IgG2a是免疫血清中主要的抗体类型.但特异性抗体水平及抗体亚型分布因遗传背景不同而异.结论:融合蛋白PfCP-2.9在5种不同品系小鼠中具有强的免疫原性,其抗体能识别疟原虫天然蛋白.

Immunogenicity of Plasmodium falciparum chimeric protein PfCP-2.9 in various strains of mice

Objective:To investigate the immunogenicity and characteristics of immune response of the chimeric antigen PfCP-2.9 in various strains of mice.Methods:Five strains of mice were immunized with the chimeric antigen formulated with ISA720 adjuvant subcutaneously 3 times at three-week intervals.After immunization,kinetics of antibody responses,isotype of IgG antibody,and antibody responses to the individual components of the chimeric antigen were detected by ELISA.Interactions of the antibodies with native antigens located on surface of merozoite of Plasmodium falciparum were analyzed by indirect immunofluorescent assay (IFA).Results:Significant immune responses were induced in all strains of mice (detected with ELISA titer ＞105) after the third immunization.Moreover,the specific antibodies recognized individual proteins of the chimeric antigen,MSP1-19 and AMA-1 (Ⅲ),as well as native antigens of the cultured Plasmodium falciparum.The prevailing isotypes of IgG associated with the immunization were IgG1 and IgG2a.However,there were clear differences in antibody levels and isotypes of IgG among 5 strains of mice.Conclusion:The chimeric antigen PfCP-2.9 is highly immunogenic in all strains of mice detected and the anti-PfCP-2.9 antibodies recognize native proteins of the malaria parasite.