STRUCTURE OF LAM IN RELATION TO BIOLOGY AND BIOSYNTHESIS

描述(改编自申请人的摘要)：重新出现 结核病作为一个公共卫生问题，由于缺乏 有效化疗药物与耐药的发展 菌株。它的病原体结核分枝杆菌的细胞壁， 已知是一些最有效的抗分枝杆菌的靶标 包括乙胺丁醇在内的药物，已知可抑制 细胞壁本身的阿拉伯聚糖及其相关的脂阿拉伯甘露聚糖(LAM)。 在过去的几年里，一系列不同的生物学研究 共同提供了令人信服的证据，证明LAM是关键表面 宿主-病原菌相互作用中的分子。截断LAM的产生 导致LAM生物合成缺陷的细胞壁突变体 乙胺丁醇抗药性为这两种药物提供了宝贵的模型化合物 结构和功能研究，旨在确定LAM在 发病机制。 具体地说，阿拉比南组件及其附件的精细细节 对磷脂酰肌醇甘露聚糖核进行表征和结构 与特定生物学属性呈正相关的基序 将对临床分离株进行鉴定。量身定制的合成低聚糖 将产生探针和定义明确的单抗用于 LAM的结构、生物合成和遗传研究，以及定义 其在活菌细胞壁框架内的地位和定位 杆菌。将研究T细胞对LAM的CD1限制性识别 细胞免疫在结核病和麻风中的背景和 其伴随的细胞因子分泌诱导。化学和/或 酶改性阿拉伯聚糖和甘露聚糖将从LAM中衍生出来用于 详细的结构分析，并进一步用于描述特定的表位 T细胞识别的LAM。因此，这项研究的统一主题是 建议是对LAM的结构分析和操纵，并补充 将产生的其他合成探针和单抗，以确定 其一级结构、构象和超细胞定位 到它的生物合成和生物学。

DESCRIPTION (Adapted from applicant's abstract): The re-emergence of tuberculosis as a public health problem has been complicated by the lack of effective chemotherapeutic agents and the development of drug resistant strains. The cell wall of its causative agent, Mycobacterium tuberculosis, is known to be the target of some of the most effective antimycobacterial drugs including ethambutol which is known to inhibit the biosynthesis of the arabinan of the cell wall proper and the associated lipoarabinomannan (LAM). A diverse range of biological studies over the past few years has collectively provided compelling evidence implicating LAM as a key surface molecule in host-pathogen interactions. The production of truncated LAM variants by cell wall mutants defective in LAM biosynthesis as a consequence of ethambutol resistance provides invaluable model compounds for both structural and functional studies aiming at defining the relevance of LAM in pathogenesis. Specifically, the fine details of the arabinan assembly and its attachment to the phosphatidylinositol mannan core will be characterized and structural motifs positively correlating with particular biological attributes of clinical isolates will be identified. Tailor-made synthetic oligosaccharide probes and well defined monoclonal antibodies will be generated for structural, biosynthesis, and genetic studies of LAM, as well as to define its situation and orientation within the cell wall framework of viable bacilli. CD1 restricted recognition of LAM by T cells will be examined in the context of cell mediated immunity in both tuberculosis and leprosy and its concomitant induction of cytokine secretion. Chemically and/or enzymatically modified arabinan and mannan will be derived from LAM for detailed structural analysis and further used to delineate specific epitopes of LAM recognized by T cells. Thus, the unifying theme of this Research Proposal is the structural analysis and manipulation of LAM, supplemented by other synthetic probes and monoclonal antibodies to be generated, to define its primary structure, conformation and ultracellular location, in relation to its biosynthesis and biology.