Risco C, Pinto da Silva P
Biological Carcinogenesis and Development Program, NCI-Frederick Cancer Research and Development Center, Maryland 21702-1201, USA.
Microsc Res Tech. 1995 Jun 1;31(2):141-58. doi: 10.1002/jemt.1070310206.
Bacterial endotoxins (lipopolysaccharides or LPS) are active components of Gram-negative bacteria that act on numerous cellular functions through the processes of cell activation and damage. The molecular mechanisms involved in the "endotoxic phenomenon" are not defined yet, although extensive studies have been carried out. Immunogold and electron microscopy (EM) have contributed to identify the primary target cells of endotoxins and the subcellular systems that receive the direct action of these bacterial agents. Here, we review our studies on immunogold detection of endotoxins in cellular and subcellular systems. The analysis of the interaction between endotoxins and cells was focussed on the following aspects: (1) morphological characteristics of the LPS aqueous suspensions used in experimental work; (2) binding of endotoxins to the plasma membrane of type II pneumocytes and alveolar macrophages (two of their cellular targets), and influence of the state of aggregation of the LPS; (3) movement and distribution of endotoxins inside the cell, from the plasma membrane to the nucleoplasm; and (4) interaction of LPS with microtubules and its effects on the integrity of the microtubular network. These approaches provide information at the molecular level as well as data for the establishment of physiological models of endotoxicity.
细菌内毒素（脂多糖或LPS）是革兰氏阴性菌的活性成分，通过细胞激活和损伤过程作用于多种细胞功能。尽管已经进行了广泛研究，但“内毒素现象”所涉及的分子机制尚未明确。免疫金和电子显微镜（EM）有助于确定内毒素的主要靶细胞以及接受这些细菌制剂直接作用的亚细胞系统。在此，我们回顾我们在细胞和亚细胞系统中对内毒素进行免疫金检测的研究。对内毒素与细胞之间相互作用的分析集中在以下几个方面：（1）实验工作中使用的LPS水悬浮液的形态特征；（2）内毒素与II型肺细胞和肺泡巨噬细胞（它们的两个细胞靶标）的质膜结合，以及LPS聚集状态的影响；（3）内毒素在细胞内从质膜到核质的移动和分布；（4）LPS与微管的相互作用及其对微管网络完整性的影响。这些方法在分子水平上提供了信息，并为建立内毒素毒性的生理模型提供了数据。
