白殭菌粗抗原對大鼠之過敏性反應

Allergic response to crude antigen of Beauveria bassiana in Sprague-Dawley rats

"白殭菌（Beauveria bassiana）是一種具有廣泛宿主的蟲生真菌，在某些國家已被開發成為微生物製劑，部分白殭菌成品以餌劑方式使用於室內防治蟻害，使得此類微生物製劑易存在於人類居住的環境中，可能經由呼吸系統進入體內而造成潛在的系統性過敏反應。因此，本研究目的即探討白殭菌粗抗原對大鼠Sprague-Dawley品系可能的過敏性反應。將菌絲及孢子製備成可溶性的白殭菌粗抗原後，對每隻大鼠先以腹腔途徑給予含佐劑的白殭菌粗抗原0、3.25、7.5、15μg誘導劑量（sensitizing dose），於第14天後再以氣管途徑給予不含佐劑的白殭菌粗抗原0、12μg攻擊劑量（challenge dose），在氣管途徑給後第1或7天測定肺泡灌洗液（bronchoalveolar lavage fluid; BAL fluid）中的細胞總數、過敏抗體1gE、過敏細胞素IL-4濃度以及總蛋白（total protein, TP）乳酸脫氫酶（lactate dehydrogenase, LDH）等濃度。結果顯示，在攻擊劑量處理後第1、7天，中、高劑量（7.5、15μg）處理組大鼠肺泡灌洗液中的細胞總數、嗜酸性球數目、過敏抗體IgE及過敏細胞素IL-4均比佐劑對照組明顯地上升；而TP、LDH並無顯著影響。另外，在肺臟組織切片下，亦可見高劑量組大鼠呈現局部肺臟組織明顯的多型態核白血球（polymorphonuclear neutrophils, PMNs）及嗜酸性球浸潤。綜合試驗結果顯示，高劑量的白殭菌粗抗原對大鼠呼吸系統具潛在的過敏性反應。因此，此微生物製劑若在田間的用暴露下，是否引發工作人員潛在的過敏風險性，仍須加以探討。"

"Beauveria bassiana (BA) is a fungal pesticide for controlling many kinds of insects in the field or indoors. The purpose of this work is to evaluate the allergenicity of crude antigen of BA in Sprague-Dawley rats. Rats were intratracheally (IT) challenged with 12 μg crude antigen after 14 days treatment by intraperitoneal sensitization with the crude antigen (0, 3.25, 7.5, 15 μg) in adjuvant. Additionally, rats were sensitized with adjuvant alone as control group. The bronchoalveolar lavage (BAL) fluid were harvested at 1 and 7 days post IT challenge (DPIT), and then measured total cell counts, eosinophils, IgE, IL-4, total protein and LDH activity. The results showed that the total cell counts, eosinophils, IgE, and IL-4 significantly increased in medium and high doses of crude antigen-sensitized rats at both 1 and 7 DPIT as compared with adjuvant controls. However the total protein and LDH concentrations had no significant differences between treated and control animals. Besides, histopathology micrographs of rat lungs showed alveolar spaces, perivascuar and peribrochial infiltration in rats sensitized with crude antigen of Beauveria bassiana at high dose. These data demonstrated that the crude antigen of Beauveria bassiana might have the latent allergenicity to the SD rats."