Bodman-Smith Katherine B, Mbuchi Margaret, Culley Fiona J, Bates Paul A, Raynes John G
Immunology Unit, Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
Parasite Immunol. 2002 Sep-Oct;24(9-10):447-54. doi: 10.1046/j.1365-3024.2002.00486.x.
C-reactive protein (CRP) is an acute phase protein that binds to surface structures of a number of different organisms. Leishmania donovani express CRP ligand when first entering the mammalian host and CRP has been shown to alter macrophage function. The aim of this study was to investigate the functional significance of CRP-mediated uptake of L. donovani on survival of the parasite within human macrophages and macrophage cell responses to the infection. CRP opsonized L. donovani uptake was inhibitable by including excess CRP in the fluid phase, suggesting Fc receptor usage rather than indirect complement-mediated uptake. Comparing equivalent initial infection loads, parasite survival over 72 h within peripheral blood derived macrophages (PBMs) and differentiated U937 cells was unaltered by CRP. Whereas CRP increased macrophage responses to phosphorylcholine coated erythrocytes, no significant alteration in tumour necrosis factor-alpha, interleukin (IL)-10 or IL-12 production from PBMs was observed between CRP opsonized or unopsonized L. donovani promastigotes. Thus, in contrast to other systems, where CRP opsonization results in macrophage activation, Leishmania can use CRP to improve infection without inducing detrimental macrophage activation.
C反应蛋白（CRP）是一种急性期蛋白，可与多种不同生物体的表面结构结合。杜氏利什曼原虫在首次进入哺乳动物宿主时会表达CRP配体，并且已证明CRP会改变巨噬细胞的功能。本研究的目的是调查CRP介导的杜氏利什曼原虫摄取对该寄生虫在人类巨噬细胞内生存以及巨噬细胞对感染的细胞反应的功能意义。CRP调理的杜氏利什曼原虫摄取可通过在液相中加入过量CRP来抑制，这表明其利用的是Fc受体而非间接补体介导的摄取。比较同等初始感染量时，CRP对来自外周血的巨噬细胞（PBMs）和分化的U937细胞内72小时以上的寄生虫存活没有影响。虽然CRP增加了巨噬细胞对磷酸胆碱包被红细胞的反应，但在CRP调理或未调理的杜氏利什曼原虫前鞭毛体感染的PBMs中，未观察到肿瘤坏死因子-α、白细胞介素（IL）-10或IL-12产生有显著变化。因此，与其他CRP调理导致巨噬细胞活化的系统不同，利什曼原虫可利用CRP来改善感染，而不会诱导有害的巨噬细胞活化。
