Nugent K M, Fick R B
Infect Immun. 1987 Mar;55(3):541-6. doi: 10.1128/iai.55.3.541-546.1987.
Respiratory secretions provide an efficient method for protecting the large surface area of the lower respiratory tract. To determine whether lung secretions contribute to antifungal defenses, we tested bronchoalveolar lavage fluid for fungicidal activity. Candida albicans (blastoconidia) was incubated in unconcentrated cell-free lavage fluid from Swiss Webster mice and then cultured quantitatively to measure residual viability. In control buffer the residual fractions of viable fungi were 1.03 +/- 0.12 at 60 min and 0.84 +/- 0.05 at 120 min, whereas the residual fractions in lavage fluid were 0.64 +/- 0.07 and 0.23 +/- 0.05, respectively (P less than 0.05 by t tests). This activity was trypsin sensitive and heat stable (56 degrees C) and did not require divalent cations. It did not sediment with the surfactant fraction of lung lavage fluid. Unconcentrated lavage fluid reduced the adherence of C. albicans to serum-coated glass tubes to 2.3 +/- 1.5% of that of control Candida suspensions (n = 5, P less than 0.05 by t test). It did not alter Candida ingestion or intracellular processing by alveolar macrophages. Lavage fluid also killed clinical isolates of Candida tropicalis and Torulopsis glabrata but did not kill Candida krusei or Candida parapsilosis. Lavage fluid was concentrated and passed through an acrylamide-agarose gel matrix. The chromatogram indicated that the candidacidal activity eluted in a peak with a molecular weight range of 29,000 to 40,000. After electrophoresis on 15% sodium dodecyl sulfate-polyacrylamide gels, these fractions resolved into three bands. These were transferred to nitrocellulose and then eluted with Triton X-100; this procedure permitted the isolation of a single band of candidacidal activity with a molecular weight of 29,000. In summary, murine lavage fluid contains a heat-stable protein with direct antifungal activity. This soluble factor may contribute to lung defense processes by reducing fungal viability and adherence to tissue surfaces.
呼吸道分泌物为保护下呼吸道的大面积区域提供了一种有效的方法。为了确定肺分泌物是否有助于抗真菌防御，我们检测了支气管肺泡灌洗液的杀真菌活性。将白色念珠菌（芽生孢子）在来自瑞士韦伯斯特小鼠的未浓缩无细胞灌洗液中孵育，然后进行定量培养以测量残留活力。在对照缓冲液中，存活真菌的残留分数在60分钟时为1.03±0.12，在120分钟时为0.84±0.05，而灌洗液中的残留分数分别为0.64±0.07和0.23±0.05（t检验，P<0.05）。这种活性对胰蛋白酶敏感且热稳定（56℃），并且不需要二价阳离子。它不会与肺灌洗液的表面活性剂部分一起沉淀。未浓缩的灌洗液将白色念珠菌对血清包被玻璃管的粘附降低至对照念珠菌悬液的2.3±1.5%（n = 5，t检验，P<0.05）。它不会改变肺泡巨噬细胞对念珠菌的摄取或细胞内处理。灌洗液也能杀死热带念珠菌和光滑球拟酵母的临床分离株，但不能杀死克鲁斯念珠菌或近平滑念珠菌。将灌洗液浓缩并通过丙烯酰胺-琼脂糖凝胶基质。色谱图表明，杀念珠菌活性在分子量范围为29,000至40,000的峰中洗脱。在15%十二烷基硫酸钠-聚丙烯酰胺凝胶上进行电泳后，这些组分分离成三条带。将这些带转移到硝酸纤维素上，然后用 Triton X-100洗脱；此过程允许分离出一条分子量为29,000的具有杀念珠菌活性的带。总之，小鼠灌洗液含有一种具有直接抗真菌活性的热稳定蛋白。这种可溶性因子可能通过降低真菌活力和对组织表面的粘附而有助于肺部防御过程。
