Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO 63110, USA.
Infect Immun. 2010 Apr;78(4):1564-70. doi: 10.1128/IAI.00472-09. Epub 2010 Feb 9.
Previous studies have suggested that both inflammatory monocytes and neutrophils are important for controlling acute toxoplasmosis in the mouse model. To test the role of these cell types, we used monoclonal antibody (MAb) RB6-8C5 to deplete both subsets of cells or MAb 1A8 to selectively remove neutrophils. RB6-8C5 MAb-treated mice succumbed to oral infection with Toxoplasma gondii, similar to Ccr2(-/-) mice, which are deficient in monocyte recruitment but have normal neutrophils. In contrast, mice treated with MAb 1A8 controlled parasite replication and survived acute infection. Ccr2(-/-) mice suffered from acute ileitis and inflammation in the spleen that was associated with a lack of inflammatory monocytes and elevated numbers of neutrophils. RB6-8C5 MAb-treated C57BL/6 mice also suffered from intestinal pathology and splenic damage, although this was less extensive due to the reduced numbers of neutrophils. Neutrophil-depleted infected wild-type mice displayed no pathological changes, compared to untreated infected controls. Collectively, these observations demonstrate the critical role of inflammatory monocytes during the acute infection with the parasite T. gondii and reveal that neutrophils are not protective but rather contribute to the pathology.
先前的研究表明,炎性单核细胞和中性粒细胞对于控制小鼠模型中的急性弓形虫病都很重要。为了测试这些细胞类型的作用,我们使用单克隆抗体(MAb)RB6-8C5 来耗尽这两个细胞亚群,或使用 MAb 1A8 来选择性地去除中性粒细胞。RB6-8C5 MAb 处理的小鼠在口服感染弓形虫后死亡,类似于 Ccr2(-/-) 小鼠,后者缺乏单核细胞募集,但中性粒细胞正常。相比之下,用 MAb 1A8 处理的小鼠控制了寄生虫的复制并在急性感染中存活下来。Ccr2(-/-) 小鼠患有急性回肠炎和脾脏炎症,这与缺乏炎性单核细胞和中性粒细胞数量增加有关。RB6-8C5 MAb 处理的 C57BL/6 小鼠也患有肠道病理学和脾脏损伤,尽管由于中性粒细胞数量减少,损伤程度较轻。与未处理的感染对照相比,耗尽中性粒细胞的感染野生型小鼠没有显示出病理变化。综上所述,这些观察结果表明炎性单核细胞在寄生虫弓形虫的急性感染中起着关键作用,并揭示了中性粒细胞不是保护性的,而是导致病理学的原因。