Chakrabarty R, Mukherjee S, Lu H G, McGwire B S, Chang K P, Basu M K
Biomembrane Division, Indian Institute of Chemical Biology, Calcutta, India.
J Parasitol. 1996 Aug;82(4):632-5.
Specific receptors may be involved in the process of attachment of Leishmania donovani promastigotes to macrophage surfaces and their subsequent internalization. Two virulent strains of Indian L. donovani (AG83 and GE-I) were found to enter into macrophages much faster than the avirulent ones (UR6). These virulent promastigotes express surface glycoprotein (gp63) and lipophosphoglycan (LPG) to a greater extent than avirulent strains. We examined their interaction with macrophages as a function of time by preblocking the macrophage receptors with the exogenous addition of gp33 or LPG. In experiments where gp63 was used as the blocking agent, the entry of one virulent strain (GE-I) was affected. In other experiments where LPG was used, the entry of another virulent strain (AG83) was affected. Entry of the avirulent strain (UR6) was unaffected by either of these treatments. Exposed LPG or gp63 on the surface of promastigotes thus appear to expedite their recognition and entry into the host cell. To assess the role of gp63 further in the entry of Leishmania into the macrophages, an avirulent UR6 strain was transfected with the gp63 gene cloned from L. amazonensis. The transfected UR6 as expected expressed more GP63 at a faster rate and entered into the macrophages like the virulent strain when compared to the nontransfected UR6 or UR6 transfected with vector alone. Thus, the expression of the gp63 gene is involved in the recognition and intracellular entry of visceral Leishmania into the macrophages in addition to the cutaneous species demonstrated previously.
特定受体可能参与杜氏利什曼原虫前鞭毛体附着于巨噬细胞表面及其随后的内化过程。发现两株印度致病力强的杜氏利什曼原虫（AG83和GE-I）比无毒株（UR6）进入巨噬细胞的速度快得多。这些致病力强的前鞭毛体比无毒株更大量地表达表面糖蛋白（gp63）和脂磷酸聚糖（LPG）。我们通过外源添加gp33或LPG来预先阻断巨噬细胞受体，以此研究它们与巨噬细胞随时间变化的相互作用。在使用gp63作为阻断剂的实验中，一株致病力强的菌株（GE-I）的进入受到影响。在使用LPG的其他实验中，另一株致病力强的菌株（AG83）的进入受到影响。无毒株（UR6）的进入不受这两种处理中任何一种的影响。因此，前鞭毛体表面暴露的LPG或gp63似乎加速了它们被宿主细胞识别和进入的过程。为了进一步评估gp63在利什曼原虫进入巨噬细胞过程中的作用，用从亚马逊利什曼原虫克隆的gp63基因转染了无毒的UR6菌株。与未转染的UR6或仅用载体转染的UR6相比，转染后的UR6如预期那样以更快的速度表达更多的GP63，并且像致病力强的菌株一样进入巨噬细胞。因此，除了先前已证明的皮肤利什曼原虫种类外，gp63基因的表达还参与内脏利什曼原虫被巨噬细胞识别和进入细胞内的过程。
