Studies on the Candida albicans-tissues interaction in disseminated candidiasis

感染性疾病的微生物通常针对特定的宿主组织，而不是随机侵入器官。消散的念珠菌病发病机制的初始步骤是真菌粘附到宿主组织。我们采用了体外试验来研究白色念珠菌从血液传播到内脏器官的机制。白色念珠菌特异性结合于小鼠脾脏的边缘区巨噬细胞。白念珠菌细胞壁磷酸甘露糖蛋白复合物（PMPC）的酸稳定部分在白念珠菌酵母和菌丝形态细胞表面均质性分布，其甘露糖核心和寡甘露糖侧链参与白念珠菌与边缘区巨噬细胞的体外粘附。酵母细胞对脾边缘区的体内PMPC依赖性粘附通过与离体测定中的粘附相似的机制发生，这是因为边缘区巨噬细胞表达的甘露糖样受体。最后，我们从J774.E细胞系获得的结果表明，脾边缘区和淋巴结组织中的巨噬细胞表达一种独特的结合白色念珠菌酵母细胞的MR粘附系统。这种相互作用可能是重要的播散性念珠菌病的发病机制。

Infectious disease microorganisms usually target specific host tissues rather than invading organs randomly. An initial step in the pathogenesis of a dissiminated candidiasis is adherence of the fungus to the host tissue. We have adapted an ex vivo assay to study the mechanisms of Candida albicans dissemination from the blood into internal organs. C.albicans binds specifically to the marginal zone macmrophages of mouse spleen. The acid-stable part of C.albicans cell wall phosphomannoprotein complex (PMPC) displayed homogenously on the C.albicans yeast and hyphal form cell surface, and both mannan core and oligomannosyl side chains of the acid-stable part of PMPC are responsible for the adherence of this fungus to the marginal zone macrophages ex vivo. The in vivo PMPC-dependent adherence of yeast cells to the splenic marginal zone occurs by a similar mechanism as adherence in the ex vivo assay, which is because of a mannose-like receptor expressed by mmarginal zone macrophages. Finally, our results obtained from J774.E cell line suggest that macrophages in the splenic marginal zone and lymph node tissues express a MR adhesion system that uniquely binds C.albicans yeast cells. This interaction may be important in the pathogenesis of disseminated candidiasis.