Schriever F, Dennis R D, Riethmüller G, Johnson J P
Institute of Immunology, University of Munich, West Germany.
Cancer Res. 1988 May 1;48(9):2524-30.
MacG1 is a mouse monoclonal antibody (mAb) directed against a ganglioside, which is differentially expressed by macrophages infiltrating malignant melanomas and benign melanocytic lesions. mAb MacG1 was obtained by immunization with liposomes containing a mixture of gangliosides extracted from malignant melanoma. The antibody was selected for binding to melanoma gangliosides and for reactivity with frozen tissue sections of malignant melanoma. mAb MacG1 showed reactivity in 25 of 46 melanomas examined but in only 1 of 51 nevi tested. The mAb did not react with melanoma cells but did with cytoplasmic granules and deposits associated with large dispersed cells, which were also found in some nonmelanomatous tumors and in some lymphoid tissues. Using mAbs directed against differentiation antigens these cells were identified as macrophages. In nearly all reactive tissues MacG1-positive macrophages accounted for a minority of the total macrophages. The difference in reactivity between malignant melanomas and nevi could not be explained by the variable numbers of total macrophages in these lesions. It is suggested that mAb MacG1 may define a functionally distinct subpopulation of tumor-infiltrating macrophages. Staining of cells other than macrophages was observed in some normal and malignant neural tissues. MacG1 bound to a monosialoganglioside extracted from melanoma and reacted only with NeuAc alpha 2-3Gal beta 1-4Glc-Cer when tested with a panel of ganglioside standards.
MacG1是一种针对神经节苷脂的小鼠单克隆抗体（mAb），浸润恶性黑色素瘤和良性黑素细胞病变的巨噬细胞会差异性表达该神经节苷脂。mAb MacG1是通过用含有从恶性黑色素瘤中提取的神经节苷脂混合物的脂质体免疫制备得到的。该抗体因能与黑色素瘤神经节苷脂结合以及与恶性黑色素瘤的冰冻组织切片发生反应而被筛选出来。在检测的46例黑色素瘤中，mAb MacG1在25例中表现出反应性，但在检测的51例痣中仅在1例中有反应。该单克隆抗体不与黑色素瘤细胞反应，但与大的分散细胞相关的细胞质颗粒和沉积物反应，这些细胞也存在于一些非黑色素瘤肿瘤和一些淋巴组织中。使用针对分化抗原的单克隆抗体，这些细胞被鉴定为巨噬细胞。在几乎所有反应性组织中，MacG1阳性巨噬细胞占总巨噬细胞的少数。恶性黑色素瘤和痣之间反应性的差异不能用这些病变中巨噬细胞总数的变化来解释。提示mAb MacG1可能定义了肿瘤浸润巨噬细胞中一个功能上不同的亚群。在一些正常和恶性神经组织中观察到除巨噬细胞外的细胞染色。MacG1与从黑色素瘤中提取的单唾液酸神经节苷脂结合，在用一组神经节苷脂标准品检测时仅与NeuAcα2-3Galβ1-4Glc-Cer反应。
