Verity C K, McManus D P, Brindley P J
Division of Infectious Diseases and Immunology and The CRC for Vaccine Technology, The Queensland Institute of Medical Research, Royal Brisbane Hospital, Queensland, Australia.
Parasite Immunol. 2001 Mar;23(3):153-62. doi: 10.1046/j.1365-3024.2001.00369.x.
Mice were vaccinated with recombinant Schistosoma japonicum cathepsin D aspartic protease, expressed in both insect cells and bacteria, in order to evaluate the vaccine efficacy of the schistosome protease. Mean total worm burdens were significantly reduced in vaccinated mice by 21-38%, and significant reductions in female worm burdens were also recorded (22-40%). Vaccination did not reduce fecundity; rather, we recorded increased egg output per female worm in vaccinated animals, suggesting a crowding effect. Vaccinated mice developed high levels of antibodies (predominantly IgG1, IgG2a and IgG2b isotypes), but there was no correlation between antibody levels and protective efficacy. Immune sera from vaccinated mice did not inhibit the in vitro degradation of human haemoglobin by the recombinant protease, and passive transfer of serum or antibodies from vaccinated animals, before and after parasite challenge, did not significantly reduce worm or egg burdens in recipient animals. These results suggest that antibodies may not play a key role in the protective effect elicited, and that protection may be due to a combination of humoral and cell-mediated responses
用在昆虫细胞和细菌中均有表达的重组日本血吸虫组织蛋白酶D天冬氨酸蛋白酶对小鼠进行免疫接种，以评估血吸虫蛋白酶的疫苗效力。接种疫苗的小鼠体内的平均总虫负荷显著降低了21%-38%，雌性虫负荷也有显著降低（22%-40%）。免疫接种并未降低繁殖力；相反，我们记录到接种疫苗的动物中每条雌虫的产卵量增加，提示存在拥挤效应。接种疫苗的小鼠产生了高水平的抗体（主要是IgG1、IgG2a和IgG2b亚型），但抗体水平与保护效力之间并无相关性。接种疫苗的小鼠的免疫血清并未抑制重组蛋白酶对人血红蛋白的体外降解，并且在寄生虫攻击前后，将接种疫苗动物的血清或抗体被动转移至受体动物体内，并未显著降低受体动物体内的虫负荷或卵负荷。这些结果表明，抗体可能在引发的保护作用中不发挥关键作用，并且保护作用可能是体液免疫和细胞介导免疫反应共同作用的结果
