Yoshida N, Araya J E, da Silveira J F, Giorgio S
Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina, São Paulo, Brazil.
Exp Parasitol. 1993 Dec;77(4):405-13. doi: 10.1006/expr.1993.1100.
The main surface glycoproteins of metacyclic trypomastigotes of Trypanosoma cruzi, gp90, gp82, and gp35/50, were purified and the immune response elicited by these antigens was analyzed. Balb/c mice immunized with antibody-affinity-purified gp82, plus alum as adjuvant, produced antibodies that recognized both the gp82 and the heterologous gp90 and gp35/50. On the other hand, antisera to gp90 reacted only with the homologous antigen, either by immunoprecipitation or by immunoblotting. Neither sera reacted with unrelated proteins in ELISA. Both antisera lysed 90-100% metacyclic forms in a complement-mediated reaction, a property associated with protection. However, in contrast to gp90, previously shown to induce protective immunity against acute T. cruzi infection, gp82 was not immunoprotective. Lymph node (LN) cells of mice primed with gp82 or gp90, which display 40% amino acid sequence identity at the carboxy terminal domain, were strongly stimulated in vitro by either one of these antigens. Proliferation, inhibitable by anti-CD4 but not by anti-CD8 antibodies, was T. cruzi-specific, no activation being observed with irrelevant antigens. LN cells of mice immunized with unrelated proteins did not proliferate in vitro in the presence of gp82 or gp90. The 35/50-kDa glycoconjugate, which was phenol-extracted, did not elicit any detectable antibody or T cell response.
克氏锥虫循环后期锥鞭毛体的主要表面糖蛋白gp90、gp82和gp35/50被纯化，并分析了这些抗原引发的免疫反应。用抗体亲和纯化的gp82加明矾作为佐剂免疫的Balb/c小鼠产生了能识别gp82以及异源gp90和gp35/50的抗体。另一方面，gp90的抗血清仅通过免疫沉淀或免疫印迹与同源抗原发生反应。两种血清在ELISA中均不与无关蛋白质发生反应。两种抗血清在补体介导的反应中均能裂解90%-100%的循环后期形式，这一特性与保护作用相关。然而，与先前显示能诱导针对急性克氏锥虫感染的保护性免疫的gp90不同，gp82没有免疫保护作用。用gp82或gp90免疫的小鼠的淋巴结（LN）细胞，在羧基末端结构域显示40%的氨基酸序列同一性，在体外被这两种抗原中的任何一种强烈刺激。增殖可被抗CD4抗体抑制，但不能被抗CD8抗体抑制，是克氏锥虫特异性的，用无关抗原未观察到激活。用无关蛋白质免疫的小鼠的LN细胞在存在gp82或gp90的情况下在体外不增殖。通过酚提取的35/50-kDa糖缀合物未引发任何可检测到的抗体或T细胞反应。
