Costa F, Franchin G, Pereira-Chioccola V L, Ribeirão M, Schenkman S, Rodrigues M M
Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, Brazil.
Vaccine. 1998 May;16(8):768-74. doi: 10.1016/s0264-410x(97)00277-6.
Trypanosoma cruzi, the protozoan parasite that causes Chagas' disease, does not synthesize sialic acid, but expresses a trans-sialidase that catalyses the transfer of sialic acid from host glycoconjugates to the parasite surface. Several lines of evidence suggest that this enzyme is a virulence factor implicated in the establishment of infection. Here we studied whether immunization with a plasmid DNA containing a gene encoding for the catalytic domain of the enzyme could elicit protective immunity against T. cruzi infection in mice. We observed that immunization with this plasmid DNA generated antibody and T-cell mediated immune responses. Antibodies recognized the native enzyme and inhibited its activity in vitro. Upon challenge with bloodstream trypomastigotes, immunized animals displayed reduced parasitemia and mortality.
克氏锥虫是引发恰加斯病的原生动物寄生虫，它自身不能合成唾液酸，但能表达一种转唾液酸酶，该酶可催化唾液酸从宿主糖缀合物转移至寄生虫表面。多项证据表明，这种酶是一种与感染确立相关的毒力因子。在此，我们研究了用包含编码该酶催化结构域基因的质粒DNA进行免疫，是否能在小鼠中引发针对克氏锥虫感染的保护性免疫。我们观察到，用这种质粒DNA免疫可产生抗体和T细胞介导的免疫反应。抗体能识别天然酶并在体外抑制其活性。在用血流型锥鞭毛体攻击后，免疫动物的寄生虫血症和死亡率降低。
