The mouse macrophage receptor for C3bi (CR3) is a major mechanism in the phagocytosis of Leishmania promastigotes.
The mouse macrophage receptor for C3bi (CR3) is a major mechanism in the phagocytosis of Leishmania promastigotes.
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DOI：
10.4049/jimmunol.135.4.2785
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发表时间：
1985-10
影响因子：
4.4
通讯作者：
D. Mosser;P. Edelson
中科院分区：
文献类型：
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作者：
D. Mosser;P. Edelson
我们研究了巨噬细胞受体C3 bi，CR 3，在利什曼原虫主要前鞭毛体的吞噬作用的作用，并报告说，M1/70，单克隆抗体的CR 3，抑制利什曼原虫巨噬细胞的结合时，在正常血清的存在下，并在其情况下进行的测定。在血清中，利什曼原虫激活补体并固定C3。固定和随后裂解为C3 bi迅速发生，并且早在5分钟就可以在寄生虫的表面上鉴定出两种形式的分子。补体结合导致小鼠巨噬细胞对利什曼原虫前鞭毛体的吞噬作用增强。在L。主要是，63%的这种血清增强的结合可被M1/70所抑制。结合试验也在不存在血清的情况下使用彻底洗涤的前鞭毛体进行。在这些条件下，添加M1/70可抑制54%的结合。针对巨噬细胞质膜上不同抗原的另外两种大鼠单克隆抗体不抑制结合。M1/70不抑制前鞭毛体与大鼠骨髓细胞的结合，也不抑制IgG-SRBC与小鼠腹腔巨噬细胞的结合。这些数据表明，在存在M1/70的情况下观察到的抑制对CR 3具有特异性，并且即使在不存在血清的情况下，C3 bi的巨噬细胞受体在利什曼原虫主要前鞭毛体的吞噬作用中也起主要作用。
We examined the role of the macrophage receptor for C3bi, the CR3, in the phagocytosis of Leishmania major promastigotes and report that M1/70, a monoclonal antibody to the CR3, inhibited the binding of leishmania to macrophages both when the assays were performed in the presence of normal serum and in its absence. In serum, leishmania activate complement and fix C3. Fixation and subsequent cleavage to C3bi occurs rapidly, and by as early as 5 min both forms of the molecule can be identified on the parasites' surface. Complement fixation results in an enhanced phagocytosis of leishmania promastigotes by mouse macrophages. In the case of L. major, 63% of this serum-enhanced binding is inhibitable by M1/70. Binding assays were also performed in the absence of serum with the use of thoroughly washed promastigotes. The addition of M1/70 inhibited binding under these conditions by 54%. Two other rat monoclonal antibodies directed against different antigens on the macrophage plasma membrane did not inhibit binding. M1/70 did not inhibit the binding of promastigotes to rat bone marrow cells, nor did it inhibit IgG-SRBC binding to mouse peritoneal macrophages. These data indicate that the inhibition observed in the presence of M1/70 was specific for the CR3 and that the macrophage receptor for C3bi plays a major role in the phagocytosis of Leishmania major promastigotes, even in the absence of serum.