Roberts R C, Nelles L P, Treuhaft M W, Marx J J
Infect Immun. 1983 May;40(2):553-62. doi: 10.1128/iai.40.2.553-562.1983.
The thermophilic actinomycetes are the most common etiological agents causing hypersensitivity pneumonitis. Antigen preparations of these organisms contain proteolytic activity. Further investigation of the proteinases of the thermophilic actinomycetes was undertaken to determine whether this activity may contribute directly to the pathogenesis of hypersensitivity pneumonitis and pulmonary mycotoxicosis. The presence of proteolytic activity in aerosolized dust from moldy silage was demonstrated, and antibodies to two proteolytic enzymes from Thermoactinomyces candidus were found in the blood of farmer's lung patients who had been sensitized to this organism. These two enzymes were isolated from culture filtrate antigen preparations that had been partially characterized with respect to the proteolytic activities and their interaction with human serum proteinase inhibitors. Both proteinases belonged to the serine class of endopeptidases. Neither proteinase was inhibited by alpha 1-proteinase inhibitor or alpha 1-antichymotrypsin. Both proteinases were inhibited by alpha 2-macroglobulin. One of the proteinases had elastase activity. Inhalation of these proteinases apparently does occur, and they may induce an inflammatory response in the lungs since they are not inhibited by the main proteinase inhibitors protecting the lung.
嗜热放线菌是引起超敏性肺炎最常见的病原体。这些微生物的抗原制剂具有蛋白水解活性。对嗜热放线菌的蛋白酶进行了进一步研究，以确定这种活性是否可能直接导致超敏性肺炎和肺霉菌毒素中毒的发病机制。已证实发霉青贮饲料中的气溶胶化粉尘中存在蛋白水解活性，并且在对该微生物致敏的农民肺患者的血液中发现了针对来自白色嗜热放线菌的两种蛋白水解酶的抗体。这两种酶是从培养滤液抗原制剂中分离出来的，这些制剂已就蛋白水解活性及其与人类血清蛋白酶抑制剂的相互作用进行了部分表征。这两种蛋白酶都属于丝氨酸内切肽酶类。这两种蛋白酶均不受α1-蛋白酶抑制剂或α1-抗胰凝乳蛋白酶的抑制。这两种蛋白酶均受α2-巨球蛋白的抑制。其中一种蛋白酶具有弹性蛋白酶活性。这些蛋白酶显然会被吸入，并且由于它们不受保护肺部的主要蛋白酶抑制剂的抑制，它们可能会在肺部引发炎症反应。
