Levy M H, Wheelock E F
J Immunol. 1975 Jul;115(1):41-8.
Silica, an agent toxic for macrophages, administered i.v. to DBA/2 mice rapidly depresses the clearance of colloidal carbon by the reticuloendothelial system and reduces the in vitro phagocytic activity of peritoneal macrophages harvested 3 days after silica injection. Silica blocks the humoral immune response to sheep erythrocytes and the cell-mediated immune response to allogeneic fibroblasts when given before antigen. Silica also induces complex alterations in spleen cell responsiveness to concanavalin A involving both local and serum factors. Silica had no significant effect on the induction of interferon by statolon or Newcastle disease virus. No unequivocal evidence was obtained that silica has a direct depressive effect on cells other that macrophages, but indirect effects on lymphocytes were produced most likely by factors released from silica-lysed macrophages. Intravenous silica may prove useful for the separation of interferon induction and immune response stimulation in studies of host resistance to infection and oncogenesis. Considerable variation exists in the immunodepressive effects of different preparations of silica.
二氧化硅是一种对巨噬细胞有毒的物质，静脉注射给DBA/2小鼠后，会迅速抑制网状内皮系统对胶体碳的清除，并降低注射二氧化硅3天后收获的腹腔巨噬细胞的体外吞噬活性。在抗原之前给予二氧化硅时，它会阻断对绵羊红细胞的体液免疫反应和对同种异体成纤维细胞的细胞介导免疫反应。二氧化硅还会诱导脾细胞对刀豆球蛋白A的反应性发生复杂变化，这涉及局部和血清因子。二氧化硅对司他洛或新城疫病毒诱导干扰素没有显著影响。没有确凿证据表明二氧化硅对除巨噬细胞外的其他细胞有直接抑制作用，但对淋巴细胞的间接影响很可能是由二氧化硅裂解的巨噬细胞释放的因子产生的。静脉注射二氧化硅可能被证明在宿主抗感染和肿瘤发生的研究中，对干扰素诱导和免疫反应刺激的分离有用。不同制剂的二氧化硅的免疫抑制作用存在相当大的差异。
