Role of T-cell induced sialomucins for the final expulsion step of the gastrointestinal nematode infection

粘液与肠道寄生虫密切接触，被认为是表达保护性免疫反应的平台。将一种啮齿动物胃肠道线虫的成虫经十二指肠内感染小鼠，10天前给小鼠皮下感染该寄生虫的幼虫，并终止肠道感染。该实验系统适合于研究T细胞诱导的粘蛋白在免疫介导的驱虫中的作用。虽然几乎所有的蠕虫在攻击后24小时被驱除，但在攻击后6小时，从小肠中恢复了大量的被攻击的蠕虫。在第一次激发后18小时进行第二次十二指肠内激发，此时准备好的粘蛋白被有效地排出。再次，第二次挑战的蠕虫恢复到与第一次挑战相同的水平。这些结果表明，预置的粘蛋白…更多的是暂时允许受到挑战的成虫获得和附着，但最终从肠道阻止了建立(Ishiwata和Watanabe，2006)。这表明，预置的粘蛋白对寄居在粘膜中的成虫有一定的生理作用，并能抵抗蠕动收缩所推动的肠道内容物的自然流动。成虫体内可用能量的任何减少都会削弱这种固定能力，并促进肠道排泄。因此，成虫的能量代谢是通过使用CellTiter-Glo^&lt；[0！R]&gt；[0！R]&gt；发光细胞活力分析来测量的，该方法通过检测细胞中ATP的定量来确定培养中的活细胞数量(Ishiwata和Watanabe，出版社中)。这项研究表明成虫的能量代谢受到成虫周围环境的影响，尽管宿主免疫与能量代谢的相关性并未直接得到证明。成体线虫无疑是被寄主免疫从肠道中驱逐出去的，但这种攻击对寄生虫不是致命的。因此，上述结果表明，蠕虫的生理活动受到宿主因素的影响，这在逻辑上是可以接受的，尽管有令人信服的证据表明粘蛋白对成虫的直接影响正在研究中。较少

Mucus is closely contact with gastrointestinal parasites reside in the gut and has been recognized as a platform where protective immune responses are expressed against the parasites. Adult worms of a rodent gastrointestinal nematode, Nippostrongylus brasiliensis, were intraduodenally challenged into mice that were given subcutaneous infection with infective larvae of the parasite 10 days before and terminated the intestinal infection. This experimental system is suitable to investigate the role of T-cell induced mucins for immune-mediated worm expulsion. Although almost the all worms were expelled by 24 hr after challenge, substantial number of challenged worms was recovered from the small intestine up to 6 hr after challenge. Second intraduodenal challenge was performed 18 hr after the first challenge when primed mucins were actively discharged. Again secondary challenged worms were recovered in the same level to that of the first challenge. These results suggested that primed mucins … More allowed temporally the attainment and adhesion of the challenged adult worms, but finally prevented the establishment from the gut (Ishiwata and Watanabe, 2006). This indicates that primed mucins have some physiological effects on the adult worms dwelling in the mucosa and resisting the natural flow of intestinal contents propelled by peristaltic contractions. Any reduction in the available energy in adult worms would impair this anchoring ability and promote expulsion from the gut. Therefore, energy metabolism of adult worms was measured by employing the CellTiter-Glo^<【○!R】> Luminescent Cell Viability Assay which determines the number of alive cells in culture via detecting fluorescence based on quantitation of ATP in cells (Ishiwata and Watanabe, in press). The study suggested that energy metabolism of adult worms was affected by the environment around the worms, although relevance of host immunity to the energy metabolism was not directly demonstrated. Adult nematodes are undoubtedly expelled by host immunity from the gut, but the attack is not lethal to the parasites. Thus, above results, which suggest that physiological activities of the worms are affected by host factors, are logically acceptable, although convincing evidences demonstrating direct implications of mucins on adult N. brasiliensis are under study. Less