Characterization of Innate Binding Specificities of Peptidoglycan Binding Protein

描述(由申请人提供)：由免疫公司开发的用于检测细菌的BacTx(R)技术，采用了一种独特和创新的检测化学方法来检测革兰氏阳性和革兰氏阴性细菌。这项技术是基于烟草天牛(Manduca Sexta)天然免疫系统的组成部分，特别是酚氧化酶原的级联，在该级联中，丝氨酸蛋白酶将酚氧化酶原裂解成酚氧化酶，酚氧化酶随后氧化色素原生成有色反应产物。作为对血小板细菌污染的质量控制测试，BacTx(R)细菌检测试剂盒于2012年6月获得了FDA(CBER)的510(K)批准。对于六翅目和其他鳞翅目昆虫，最有效的原酚氧化酶级联激发子是肽聚糖，它是细菌细胞壁的主要结构成分。在这一应用中，我们建议对这种关系进行生化表征 在存在特定的细菌细胞壁特征和逃避存在于六分枝杆菌血淋巴中的病原体识别蛋白的检测之间。这些特征在抑制酚氧化酶原激活中的作用将被研究，长期目标是潜在地 提高检测性能并开辟BacTx(R)技术的新应用，包括用于诊断败血症、脑膜炎和医院感染的潜在用途。由于昆虫的先天免疫系统与人类补体系统有着惊人的相似性，这项研究也可能对阐明细菌感染引起的炎症与癌症、自身免疫性疾病和感染性休克等衰弱疾病之间的关系具有重要意义。

DESCRIPTION (provided by applicant): BacTx(R) technology, developed by Immunetics for detection of bacteria, employs a unique and innovative assay chemistry to detect Gram-positive and Gram-negative bacteria. The technology is based on components of the innate immune system of the tobacco hornworm (Manduca sexta), in particular the prophenoloxidase cascade, in which serine proteases cleave prophenoloxidase to phenoloxidase, which subsequently oxidizes chromogen to generate a colored reaction product. The BacTx(R) Bacterial Detection Kit received 510(k) clearance from the FDA (CBER) in June 2012 as a quality control test for bacterial contamination in platelets. For M. sexta and other Lepidoptera, the most potent elicitor of the prophenoloxidase cascade is peptidoglycan, which is a major structural component of bacterial cell walls. In this application we propose to biochemically characterize the relationship between the presence of specific bacterial cell wall features and evasion of detection by pathogen recognition proteins present in M. sexta hemolymph. The role of these features in inhibiting prophenoloxidase activation will be investigated, with the long term goal of potentially enhancing assay performance and opening up new applications of BacTx(R) technology, including potential use for diagnosis of sepsis, meningitis, and nosocomial infections. Due to the striking similarities between the insect innate immune system and human complement system, this research may also prove significant to elucidating the relationship between inflammation due to bacterial infection and debilitating disorders such as cancer, autoimmune diseases, and septic shock.