Tanaka A, Emori K
Am J Pathol. 1980 Mar;98(3):733-48.
A synthetic muramyl dipeptide (MDP, N-acetylmuramyl-L-alanyl-D-isoglutamine) is a minimal essential structure that is contained generally in bacterial cell walls and is responsible for their many biologic activities such as adjuvant activity, pyrogenicity, and a capacity to confer resistance against bacterial and viral infections. We found that this MDP evoked dose-dependently massive organized epithelioid granulomas in guinea pigs, when injected in the form of Freund-type water-in-oil emulsion. Granuloma formation reached a peak at 3 weeks. A minimal effective dose of MDP was 0.1 microgram. Essentially, no difference was observed qualitatively among granulomas evoked by MDP, MDP plus antigen, and killed tubercle bacilli incorporated in the emulsion. Quantitatively, however, MDP was stronger in its granulomagenic capacity than tubercle bacilli. Antigenicity of MDP was not detectable. These findings support our proposal that MDP may be a chemical structure in tubercle bacilli essential for epithelioid granuloma formation and that the MDP-induced epithelioid granuloma may be of a nonallergic nature.
合成的胞壁酰二肽（MDP，N-乙酰胞壁酰-L-丙氨酰-D-异谷氨酰胺）是一种基本的最小结构，通常存在于细菌细胞壁中，并具有多种生物学活性，如佐剂活性、致热原性以及赋予抗细菌和病毒感染的能力。我们发现，当以弗氏油包水乳液的形式注射时，这种MDP能在豚鼠中剂量依赖性地诱发大量有组织的上皮样肉芽肿。肉芽肿形成在3周时达到高峰。MDP的最小有效剂量为0.1微克。从本质上讲，由MDP、MDP加抗原以及乳液中掺入的死结核杆菌诱发的肉芽肿在质量上没有观察到差异。然而，从数量上看，MDP的肉芽肿形成能力比结核杆菌更强。未检测到MDP的抗原性。这些发现支持了我们的提议，即MDP可能是结核杆菌中对于上皮样肉芽肿形成至关重要的一种化学结构，并且MDP诱导的上皮样肉芽肿可能是非过敏性的。
