Bosetto Maira Cegatti, Giorgio Selma
Departamento de Parasitologia, Instituto de Biologia, Universidade Estadual de Campinas, Caixa Postal 6109, Cep 13083-970, Campinas, São Paulo, Brazil.
Exp Parasitol. 2007 Jul;116(3):306-10. doi: 10.1016/j.exppara.2007.01.003. Epub 2007 Jan 19.
In their mammalian hosts, Leishmania are obligate intracellular parasites that reside in macrophages and dendritic cells (DCs). In the present study, we have investigated in vitro the mechanisms of entry into human DCs of Leishmania amazonensis amastigotes isolated from lesions in nude mice (Am nude). The DC infection rate with Am nude was approximately 36%, while opsonization of Am nude with normal human serum and infected human serum increased the DC infection rates to 60% and 62%, respectively. Heat inactivation and depletion of antibodies in sera brought the DC infection rate down to 40%. The DC infection rate was inhibited after pre-treatment of Am nude with heparin. We were unable to implicate mannose-fucose receptors in the uptake of Am nude by DCs. Our data suggest that the ability of L. amazonensis amastigotes to infect human DCs involves the participation of at least three multiple receptor-ligand interactions, antibodies/FcR, complement components/CR and proteoglycans/heparin-binding protein.
在其哺乳动物宿主中，利什曼原虫是专性细胞内寄生虫，寄居于巨噬细胞和树突状细胞（DCs）中。在本研究中，我们对从裸鼠病变部位分离出的亚马逊利什曼原虫无鞭毛体（Am nude）进入人DCs的体外机制进行了研究。Am nude对DCs的感染率约为36%，而用人正常血清和感染人血清对Am nude进行调理后，DCs的感染率分别提高到了60%和62%。血清中抗体的热灭活和去除使DCs的感染率降至40%。用肝素预处理Am nude后，DCs的感染率受到抑制。我们未能证明甘露糖-岩藻糖受体参与了DCs对Am nude的摄取。我们的数据表明，亚马逊利什曼原虫无鞭毛体感染人DCs的能力涉及至少三种多受体-配体相互作用的参与，即抗体/FcR、补体成分/CR和蛋白聚糖/肝素结合蛋白。
