Studies on roles of mucosal mast cells in protection against intestinal parasites

重复腹膜内注射IL-3诱导肥大细胞增多症，其为C57 BL/6小鼠中杆状圆线虫（Sr）感染中肥大细胞增多症峰值的30-40%。粘膜肥大细胞（MMC）的研究可以通过这一发现的进展。Sr的排出分为两个步骤，从小肠到盲肠，再从盲肠到外部。尽管Sr感染增加了盲肠中MMC的数量，但盲肠中嗜酸性粒细胞和杯状细胞的数量也显著增加，表明盲肠和小肠之间存在不同的效应机制。同时感染Sr和N.反复注射IL-3后，Sr被排出，Nb则不被排出。因此，Sr和Nb的排矿机制是不同的。C57 BL/6小鼠反复注射超过10^4 U的IL-3，然后感染Sr，显示出对小肠蠕虫的强大保护作用。有效保护的诱导 ...更多信息 IL-3注射4 ~ 5天。保护作用与小肠MMC数量增加密切相关。小鼠注射IL-3，然后口服Sr感染开始消除蠕虫在6小时内感染后。因此，由IL-3诱导的保护应该与抗原特异性免疫应答无关。IL-3注射不仅能诱导对经口感染的幼虫的保护作用，而且能诱导对经口感染的蠕虫的保护作用。然而，它是无效的，以诱导保护免受组织迁移幼虫从头部后，s.c.感染IL-3注射不能诱导肥大细胞缺陷W/W^V小鼠对Sr的保护作用。IL-3注射使未感染小鼠肠腔中MMC特异性蛋白酶MMCP-1的量增加200倍，并使肠道MMC的数量增加。因此，MMC可以在没有IgE抗体的情况下引起脱粒。这些结果表明，MMC与肠道对Sr的保护作用有关，而对Nb无保护作用。不同种类线虫的驱虫效应机制不同。少

A repetitive i.p. injection of IL-3 induces mastocytosis which is 30-40% of the peak mastocytosis in Strongyloides ratti (Sr)-infection in C57BL/6 mice. Studies on mucosal mast cells (MMC) can be progressed by this finding. Expulsion of Sr was caused by two steps, from the small intestine to the caecum and from the caecum to outside. Although number of MMC in the caecum was increased by Sr-infection, numbers of eosinophils and goblet cells were also increased markedly in the caecum, suggesting a different effector mechanism is operating between the caecum and the small intestine. When nude mice were concurrently infected with Sr and N. brasiliensis (Nb) and injected repeatedly with IL-3, Sr was expelled but Nb was not. Therefore, mechanism of expulsion is distinct between Sr and Nb-infection. C57BL/6 mice injected repeatedly with more than a total of 10^4 U IL-3 and then infected with Sr showed strong protection against the worm in the small intestine. Induction of the effective protec … More tion by IL-3 injection took 4 to 5 days. The protective effect was well correlated with number of intestinal MMC increased. Mice injected with IL-3 and then orally infected with Sr began to eliminate the worms within 6 h post-infection. Therefore, the protection induced by IL-3 should have no concern with antigen specific immune responses. IL-3 injection could induce protection against not only larvae but also adult worms infected orally. However, it was ineffective to induce protection against tissue migrating larvae recovered from the head after s.c. infection. IL-3 injection could not induce protection against Sr in the mast cell deficient W/W^V mice. IL-3 injection increased amount of MMCP-1, a protease specific to MMC, in the intestinal lumen by 200 times and number of intestinal MMC in uninfected mice. MMC, therefore, can cause degranulation without IgE antibodies. All these results indicate that MMC are concerned with intestinal protection against Sr but not against Nb. Effector mechanisms of the worm expulsion should be different among various species of nematodes. Less