Newlands G F, Miller H R, MacKellar A, Galli S J
Moredun Research Institute, Edinburgh, UK.
Blood. 1995 Sep 1;86(5):1968-76.
We assessed the effects of the c-kit ligand, stem cell factor (SCF), in the jejunal mucosal mast cell hyperplasia that occurs during infection with the intestinal nematodes, Nippostrongylus brasiliensis or Trichinella spiralis in rats. Compared with vehicle-treated rats, rats treated with SCF (25 micrograms/kg/d, intravenous [i.v.] for 14 days) during N brasiliensis infection exhibited significantly higher levels of the rat mucosal mast cell (MMC)-associated protease, rat mast cell protease II (RMCP II) in the jejunum and serum on day 8 of infection, but not on days 10 or 15 of infection. By contrast, in comparison to rats treated with normal sheep IgG, rats treated with a polyclonal sheep antirat SCF antibody exhibited markedly decreased numbers of jejunal MMCs, levels of jejunal RMCP II, and serum concentrations of RMCP II during infection with either nematode, particularly at the earlier intervals of infection (< or = day 10). Taken together, these findings indicate that SCF importantly contributes to MMC hyperplasia and/or survival during N brasiliensis or T spiralis infection in rats, but that levels of endogenous SCF are adequate to sustain near maximal MMC hyperplasia during infection with these nematodes. Notably, treatment of rats with SCF somewhat increased, and treatment with anti-SCF significantly decreased, parasite egg production during N brasiliensis infection. This finding raises the interesting possibility that certain activities of intestinal MMCs may contribute to parasite fecundity during infection with this nematode.
我们评估了c-kit配体干细胞因子（SCF）对大鼠感染巴西日圆线虫或旋毛虫等肠道线虫期间空肠黏膜肥大细胞增生的影响。与用赋形剂处理的大鼠相比，在感染巴西日圆线虫期间用SCF（25微克/千克/天，静脉注射[i.v.]，共14天）处理的大鼠，在感染第8天时，空肠和血清中大鼠黏膜肥大细胞（MMC）相关蛋白酶——大鼠肥大细胞蛋白酶II（RMCP II）的水平显著更高，但在感染第10天或第15天时并非如此。相比之下，与用正常绵羊IgG处理的大鼠相比，在用多克隆绵羊抗大鼠SCF抗体处理的大鼠中，在感染任何一种线虫期间，尤其是在感染的早期阶段（≤第10天），空肠MMC的数量、空肠RMCP II的水平以及血清中RMCP II的浓度均显著降低。综上所述，这些发现表明，SCF在大鼠感染巴西日圆线虫或旋毛虫期间对MMC增生和/或存活起着重要作用，但内源性SCF的水平足以在感染这些线虫期间维持接近最大程度的MMC增生。值得注意的是，在感染巴西日圆线虫期间，用SCF处理大鼠会使寄生虫产卵量有所增加，而用抗SCF处理则会显著降低寄生虫产卵量。这一发现提出了一个有趣的可能性，即肠道MMC的某些活性可能在感染这种线虫期间有助于寄生虫的繁殖力。
