Defining the Mechanism of Action of Sanglifehrin A

描述（由申请人提供）：Sanglifehrin A（SFA）是最近发现的天然化合物，其作为免疫抑制剂具有强生物活性，使其在治疗器官移植排斥和各种自身免疫性疾病中潜在有用。SFA的确切作用机制尚不清楚，但它的作用方式似乎与其他免疫抑制剂如FK 506和雷帕霉素明显不同。初步研究表明，SFA与亲环素A（CypA）形成复合物，然后作用于未知靶标。该提议的工作假设是SFA作用于导致T细胞活化的信号转导途径的先前未知成员。该假设将通过以下方式进行测试：（1）对含有SFA生物合成簇的BAG克隆进行测序以获得对分子生物合成的了解;（2）制备生物素标记的SFA衍生物;以及（3）将生物素化的探针与细胞提取物一起孵育，然后纯化并分析蛋白质混合物以鉴定SFA的靶标（TOS）。确定SFA-CypA复合物的生物靶标将阐明这种新型免疫抑制剂的作用机制，并丰富我们对免疫系统的理解。在基于这项工作的长期研究中，SFA的结构很可能成为一种新的支架，用于设计生物探针来研究免疫系统和改善人类健康。公共卫生相关性：Sanglifehrin A（SFA）是最近发现的一种天然化合物，作为免疫抑制剂具有很强的生物活性，使其在治疗器官移植排斥和各种自身免疫性疾病方面具有潜在的用途。人们对SFA在体内的作用机制知之甚少，但它似乎具有与目前医学上使用的其他免疫抑制剂明显不同的活性。本研究旨在阐明SFA发挥作用的机制，丰富我们对免疫系统和这种新型治疗剂的理解。

DESCRIPTION (provided by applicant): Sanglifehrin A (SFA) is a recently discovered natural compound that has strong biological activity as an immunosuppressant, making it potentially useful in the treatment of organ transplant rejection and various autoimmune diseases. The precise mechanism by which SFA operates is not known, but it appears to function in a manner distinctly different from other immunosuppressants such as FK506 and rapamycin. Preliminary studies have shown that that SFA forms a complex with cyclophilin A (CypA), which then acts on an unknown target(s). The working hypothesis of this proposal is that SFA acts on a previously unknown member of the signal transduction pathway leading to T cell activation. This hypothesis will be tested by: (1) sequencing a BAG clone containing the SFA biosynthetic cluster to obtain insights into the biosynthesis of the molecule; (2) preparing a biotin-tagged SFA derivative; and (3) incubating the biotinylated probe with a cell extract, then purifying and analyzing the protein mixture to identify the target of SFA (TOS). Identifying the biological target of the SFA-CypA complex will shed light on the mechanism of action of this novel immunosuppressant and enrich our understanding of the immune system. In long-term research based on this work, the structure of SFA may well present a new scaffold upon which to engineer biological probes to study the immune system and improve human health. PUBLIC HEALTH RELEVANCE: Sanglifehrin A (SFA) is a recently discovered natural compound that has strong biological activity as an immunosuppressant, making it potentially useful in the treatment of organ transplant rejection and various autoimmune diseases. Little is known about how SFA operates in the body, but it appears to have an activity distinctly different from other immunosuppressants currently used in medicine. This study aims to elucidate the mechanism by which SFA functions, enriching our understanding of the immune system and this novel therapeutic agent.