Hill D R, Pohl R
Department of Medicine, University of Connecticut School of Medicine, Farmington 06030.
Infect Immun. 1990 Oct;58(10):3202-7. doi: 10.1128/iai.58.10.3202-3207.1990.
Macrophages in Peyer's patches are important in the initiation of gastrointestinal immune responses to enteric pathogens. To examine their potential role in giardiasis, murine mononuclear cells were isolated from collagenase-treated Peyer's patches by their adherence to glass. These cells were incubated with Giardia lamblia trophozoites in the presence of nonimmune or immune (anti-Giardia antibody titer, greater than or equal to 1:1,024) mouse serum. Macrophages ingested trophozoites at low levels when they were incubated with nonimmune mouse serum. Ingestion was significantly increased at all time points (P less than 0.01) when cells and parasites were incubated in 5% immune mouse serum; the number of Giardia trophozoites ingested per 100 macrophages was 21.6 +/- 7.1 (standard error of the mean) at 1 h and increased to 59.0 +/- 16.4 at 8 h. Electron microscopy documented trophozoite destruction within macrophages. Association of G. lamblia with macrophages elicited an oxidative response; 50.9 +/- 3.6% of macrophages with trophozoites attached or ingested reduced the dye Nitro Blue Tetrazolium, compared with 13.0 +/- 5.2% for cells without associated trophozoites (P less than 0.04). These results demonstrate that macrophages are capable of ingesting G. lamblia in vitro and may play an important role in host defense in giardiasis.
派尔集合淋巴结中的巨噬细胞在启动针对肠道病原体的胃肠道免疫反应中起重要作用。为了研究它们在贾第虫病中的潜在作用，通过贴壁法从经胶原酶处理的派尔集合淋巴结中分离出小鼠单核细胞。将这些细胞与蓝氏贾第鞭毛虫滋养体在非免疫或免疫（抗贾第虫抗体效价大于或等于1:1024）小鼠血清存在的情况下孵育。当与非免疫小鼠血清孵育时，巨噬细胞对滋养体的摄取水平较低。当细胞和寄生虫在5%免疫小鼠血清中孵育时，在所有时间点摄取量均显著增加（P<0.01）；每100个巨噬细胞摄取的蓝氏贾第鞭毛虫滋养体数量在1小时时为21.6±7.1（平均标准误差），在8小时时增加到59.0±16.4。电子显微镜记录了巨噬细胞内滋养体的破坏。蓝氏贾第鞭毛虫与巨噬细胞的结合引发了氧化反应；附着或摄取滋养体的巨噬细胞中有50.9±3.6%使染料硝基蓝四氮唑还原，而未与滋养体结合的细胞中这一比例为13.0±5.2%（P<0.04）。这些结果表明巨噬细胞在体外能够摄取蓝氏贾第鞭毛虫，并且可能在贾第虫病的宿主防御中发挥重要作用。
