Department of Hygiene, Kawasaki Medical School, Kurashiki, Japan.
J Immunotoxicol. 2010 Oct-Dec;7(4):268-78. doi: 10.3109/1547691X.2010.512579. Epub 2010 Sep 20.
Silica and asbestos cause pneumoconioses known as silicosis and asbestosis, respectively, that are each characterized by progressive pulmonary fibrosis. While local effects of inhaled silica particles alter the function of alveolar macrophages and sequential cellular and molecular biological events, general systemic immunological effects may also evolve. One well-known health outcome associated with silica exposure/silicosis is an increase in the incidence of autoimmune disorders. In addition, while exposure to silica--in the crystalline form--has also been seen to be associated with the development of lung cancers, it remains unclear as to whether or not silicosis is a necessary condition for the elevation of silica-associated lung cancer risks. Since asbestos is a mineral silicate, it would be expected to also possess generalized immunotoxicological effects similar to those associated with silica particles. However, asbestos-exposed patients are far better known than silicotic patients for development of malignant diseases such as lung cancer and mesothelioma, and less so for the development of autoimmune disorders. With both asbestos and crystalline silica, one important dysregulatory outcome that needs to be considered is an alteration in tumor immunity that allows for silica- or asbestos- (or asbestos-associated agent)-induced tumors to survive and thrive in situ. In this review, the immunotoxicological effects of both silica and asbestos are presented and contrasted in terms of their abilities to induce immune system dysregulation that then are manifest by the onset of autoimmunity or by alterations in host-tumor immunity.
二氧化硅和石棉分别导致矽肺和石棉肺，这两种疾病的特征均为进行性肺纤维化。虽然吸入的二氧化硅颗粒的局部作用改变了肺泡巨噬细胞的功能和随后的细胞和分子生物学事件，但一般的全身免疫效应也可能会演变。与二氧化硅暴露/矽肺相关的一个众所周知的健康后果是自身免疫性疾病的发病率增加。此外，虽然已经观察到暴露于结晶形式的二氧化硅与肺癌的发展有关，但仍不清楚矽肺是否是提高与二氧化硅相关的肺癌风险的必要条件。由于石棉是一种硅酸矿物，因此预计它也具有与二氧化硅颗粒相关的一般免疫毒性作用。然而，与矽肺患者相比，石棉暴露患者更易患恶性疾病，如肺癌和间皮瘤，而不易患自身免疫性疾病。对于两者，都需要考虑一个重要的失调结果，即肿瘤免疫的改变，这使得二氧化硅或石棉（或石棉相关剂）诱导的肿瘤能够在原位存活和生长。在这篇综述中，介绍了二氧化硅和石棉的免疫毒性作用，并根据它们诱导免疫系统失调的能力进行了对比，这些失调表现为自身免疫的发作或宿主-肿瘤免疫的改变。
