Ward M D, Sailstad D M, Selgrade M K
University of North Carolina, Chapel Hill, North Carolina 27599, USA.
Toxicol Sci. 1998 Oct;45(2):195-203. doi: 10.1006/toxs.1998.2479.
Metarhizium anisopliae is used as a microbial pesticide to control cockroaches and other insects. M. anisopliae has demonstrated neither infectivity nor toxicity in mammals. However, allergenicity has not been assessed. M. anisopliae is a prototype for other organisms released into the environment for pesticide or other beneficial applications. Hence this study is part of an effort to develop methods for screening such organisms for allergenic potential. Soluble factors from fungal components were combined in equal protein amounts to form a crude fungal antigen (MACA). Balb/c mice were intratracheally (IT) challenged with 25 micrograms fungal antigen 13 days post intraperitoneal sensitization with the fungal antigen in alhydrogel adjuvant. Additionally, mice were sensitized with adjuvant alone or chitin media in adjuvant as experimental controls. Serum and bronchoalveolar lavage fluid (BALF) were harvested prior to challenge and at 1 and 7 days post IT challenge (DPIT). These mice exhibited immune and pulmonary inflammatory responses to MACA characteristic of allergy. Total serum IgE for antigen-sensitized animals increased 7.6- and 14.7-fold over that for chitin media and adjuvant controls, respectively, at 7 DPIT. Less striking increases were seen at 24 DPIT and prior to challenge. BALF IL-4 was dramatically elevated only in MACA-sensitized and challenged mice and only at 1 DPIT. Additionally, there was a dose-dependent increase in BALF eosinophils from MACA-sensitized mice at both 1 and 7 DPIT. While lymphocyte counts were increased for all treatment groups at 1 DPIT, by 7 DPIT lymphocyte counts for MACA-sensitized mice only were significantly elevated compared to controls. Pulmonary inflammation, edema, and cell damage were apparent at 1 DPIT (25 micrograms MACA), as indicated by a neutrophilic influx and elevated levels of total protein and LDH, in both sensitized and control groups. These effects were significantly decreased, but not eliminated by reduction of the challenge dose to either 10 or 5 micrograms MACA. While BALF IL-4 was also reduced at the lower challenge doses, eosinophilia and total IgE were unchanged. The data suggest that the crude fungal extract MACA contains one or more potent allergens and that total IgE may be useful in the identification of the allergen(s).
绿僵菌被用作微生物杀虫剂来控制蟑螂和其他昆虫。绿僵菌在哺乳动物中既未表现出传染性也未表现出毒性。然而，其致敏性尚未评估。绿僵菌是用于农药或其他有益用途而释放到环境中的其他生物的原型。因此，本研究是开发筛选此类生物致敏潜力方法的努力的一部分。将来自真菌成分的可溶性因子以相等的蛋白量混合，形成粗制真菌抗原（MACA）。在腹腔内用真菌抗原在氢氧化铝佐剂中致敏13天后，用25微克真菌抗原对Balb/c小鼠进行气管内（IT）攻击。此外，小鼠分别用单独的佐剂或佐剂中的几丁质培养基致敏作为实验对照。在攻击前以及IT攻击后1天和7天（DPIT）采集血清和支气管肺泡灌洗液（BALF）。这些小鼠对MACA表现出过敏特征的免疫和肺部炎症反应。在IT攻击后7天，抗原致敏动物的总血清IgE分别比几丁质培养基和佐剂对照增加了7.6倍和14.7倍。在IT攻击后24天和攻击前观察到的增加不太明显。BALF IL-4仅在MACA致敏和攻击的小鼠中显著升高，且仅在攻击后1天升高。此外，在攻击后1天和7天，MACA致敏小鼠的BALF嗜酸性粒细胞呈剂量依赖性增加。虽然在攻击后1天所有治疗组的淋巴细胞计数均增加，但到攻击后7天，只有MACA致敏小鼠的淋巴细胞计数与对照组相比显著升高。在攻击后1天（25微克MACA），致敏组和对照组均出现肺部炎症、水肿和细胞损伤，表现为中性粒细胞浸润以及总蛋白和乳酸脱氢酶水平升高。将攻击剂量降低至10或5微克MACA后，这些效应显著降低，但未消除。虽然在较低攻击剂量下BALF IL-4也降低，但嗜酸性粒细胞增多和总IgE未改变。数据表明，粗制真菌提取物MACA含有一种或多种强效过敏原，总IgE可能有助于识别过敏原。
