Rubio M, Tato P, Govezensky T, Molinari J L
Department of Immunology, UNAM, DF, Mexico.
Vet Parasitol. 1998 Jan 31;74(2-4):179-89. doi: 10.1016/s0304-4017(97)00173-8.
To assess the immunological status of mice parasitized with Taenia crassiceps metacestodes, 6-month old female BALB/c mice experimentally parasitized with T. crassiceps and immunized with Salmonella typhimurium antigens were infected with S. typhimurium virulent bacilli (1.6 x LD50). Both T. crassiceps-parasitized and immunized and parasitized mice showed a very high susceptibility to infection (*P < 0.01) with higher bacteremia than control and immunized-control animals and produced a reduced IgG response to S. typhimurium, antigens ( P < 0.05). This indicates that T. crassiceps is able to preclude development of immunity to S. typhimurium, because appropriate antibody production to a heterologous antigenic stimulus did not take place, and the bacteremia results suggest the parasitosis altered the mononuclear phagocyte system. It has been demonstrated that Taenia solium metacestodes produce a small RNA molecule in culture which suppresses humoral and cellular responses against homologous antigens in mice. We propose that T. crassiceps may be actively synthesizing such a factor, apart from other simultaneously acting immunomodulatory mechanisms, to induce an immunosuppressed state favorable to its development in the host.
为评估感染克氏假裸头绦虫中绦期幼虫的小鼠的免疫状态，将6月龄经克氏假裸头绦虫实验性感染并经鼠伤寒沙门氏菌抗原免疫的雌性BALB/c小鼠，用鼠伤寒沙门氏菌强毒株（1.6×半数致死量）进行感染。感染克氏假裸头绦虫且已免疫和仅感染克氏假裸头绦虫的小鼠均表现出对感染的极高易感性（**P < 0.01），菌血症水平高于对照和免疫对照动物，并且对鼠伤寒沙门氏菌抗原产生的IgG反应降低（*P < 0.05）。这表明克氏假裸头绦虫能够阻止对鼠伤寒沙门氏菌的免疫发育，因为未发生针对异源抗原刺激的适当抗体产生，且菌血症结果表明寄生虫病改变了单核吞噬细胞系统。已证明猪带绦虫中绦期幼虫在培养中产生一种小RNA分子，可抑制小鼠针对同源抗原的体液和细胞反应。我们提出，除了其他同时起作用的免疫调节机制外，克氏假裸头绦虫可能正在积极合成这样一种因子，以诱导有利于其在宿主体内发育的免疫抑制状态。
