摘要
目的探讨在毕赤酵母中表达的恶性疟原虫重组蛋白次黄嘌呤-鸟嘌呤-黄嘌呤磷酸核糖转移酶(HGX-PRT)诱导小鼠产生的免疫原性和免疫保护作用。方法35只BALB/c小鼠随机分为HGXPRT+ISA720实验组、HGXPRT+福氏佐剂试验组、ISA720对照组、福氏佐剂对照组和空白对照组等5组。HGXPRT(50μg/200μl)经小鼠后腿皮下免疫3次,间隔3周。每次免疫后2周尾静脉采血,ELISA检测血清特异性抗体水平。以间接免疫荧光试验(I-FAT)分析免疫血清对恶性疟原虫天然抗原的识别情况。于末次免疫后10d,各组小鼠经腹腔攻击感染约氏疟原虫致死株105个,继而每隔1d采尾血制薄血片,观察原虫感染的动态变化。结果重组蛋白HGXPRT经与佐剂乳化后免疫的小鼠均诱导出针对HGXPRT的体液免疫应答,3次免疫后血清中特异性抗体滴度达到1∶105以上,而两佐剂组和空白对照组小鼠均未产生特异性抗体。经HGXPRT诱导血清能识别恶性疟原虫天然HGXPRT抗原。经约氏疟原虫致死株攻击感染后4d,两佐剂对照组和空白对照组疟原虫感染高峰相比实验组提前1d。HGXPRT+ISA720实验组平均原虫率(29.3%)明显低于ISA720对照组(70.0%)和空白对照组(70.0%)(P<0.05);HGXPRT+福氏佐剂实验组平均原虫率(51.0%)亦明显低于福氏佐剂对照组(60.7%)与空白对照组(70.0%)(P<0.05)。结论恶性疟原虫重组蛋白HGXPRT对小鼠有较强的免疫原性,产生的抗体能识别恶性疟原虫HGXPRT天然蛋白,并对疟原虫攻击感染后的小鼠有一定免疫保护作用。
Objective To investigate immunogenicity and protection efficacy of the recombinant hypoxanthine- guanine-xanthine （HGXPRT） of Plasmodium falciparum expressed in Pichia pastoris. Methods 35 BALB/c mice were divided randomly into five groups： HGXPRT＋ISA720 experiment group, HGXPRT＋Freund experiment group, ISA720 adjuvant control group, Freund adjuvant control group, and blank control group. BALB/c mice were subcutaneously immunized three times with the HGXPRT protein formulated by either Freund or ISA720 adjuvants at a three weeks interval. Mice were bled via tail vein at 2 weeks after each immunization. Specific antibodies were detected by ELISA as well as IFAT using cultured parasites. The immunized mice were challenged with 10^5 P.yoelii 10 days after the third immunization and parasitemia was monitored daily by examining Giemsa-stained thin film. Results Strong immune response was induced by the HGXPRT antigen formulated with the adjuvant. Antibody titers of more than 1：105 were detected after the third immunization while no specific antibody was detected in the mice immunized with adjuvants only. The antibodies against HGXPRT recognized the cultured parasite by IFAT. Four days after mice were challenged with P.yoelii, high parasitemia appeared in the two control groups, which were 24 h earlier than experiment groups. The mean parasitemia of HGXPRT＋ISA720 experiment group （29.3%） was significantly lower than that of control groups （70.0%） （P〈0.05）. The mean parasitemia of HGXPRT＋Freund experiment group （51.0%） was significantly lower than that of adjuvant control （60.7%） and blank control（70.0%） （P〈0.05）. Conclusion HGXPRT of P.falciparum expressed in Pichia pastoris was highly immunogenic in mice. Antibody against the recombinant protein recognizes the cultured parasites, and immunization of mice with the recombinant protein provides partial protection against the challenge of P. yoelii.
出处
《中国寄生虫学与寄生虫病杂志》
CAS
CSCD
北大核心
2006年第3期192-195,共4页
Chinese Journal of Parasitology and Parasitic Diseases
基金
国家杰出青年科学基金(No.30225041)~~
