Ghali Shadi, Bhatt Kirit A, Dempsey Marlese P, Jones Deidre M, Singh Sunil, Arabi Shahram, Butler Peter E, Gallo Robert L, Gurtner Geoffrey C
Stanford and San Diego, Calif.; and London, United Kingdom From the Department of Surgery, Division of Plastic Surgery, Stanford University School of Medicine, the Department of Plastic and Reconstructive Surgery, Royal Free Hospital, and the Division of Dermatology, University of California, San Diego.
Plast Reconstr Surg. 2009 Apr;123(4):1157-1168. doi: 10.1097/PRS.0b013e31819f25a4.
The success of antimicrobial therapy has been impaired by the emergence of resistant bacterial strains. Antimicrobial peptides are ubiquitous proteins that are part of the innate immune system and are successful against such antibiotic-resistant microorganisms. The authors have previously demonstrated the feasibility of protein delivery via microvascular free flap gene therapy and here they examine this approach for recalcitrant infections.
The authors investigated the production of the human cathelicidin antimicrobial peptide-LL37, delivered by ex vivo transduction of the rodent superficial inferior epigastric free flap with Ad/CMV-LL37. The vascular permeabilizing agent vascular endothelial growth factor (VEGF) was co-administered during ex vivo transduction with adenoviral vectors in an attempt to augment transduction efficiency. A rodent model of chronic wound/foreign body infection seeded with bioluminescent Staphylococcus aureus was used to assess the biological efficacy of delivering therapeutic antimicrobial genes using this technology.
The authors were successful in demonstrating significant LL37 expression, which persisted for 14 days after ex vivo transduction with Ad/CMV-LL37. Transduction efficiency was significantly improved with the co-administration of 5 micrograms of VEGF during transduction without significantly increasing systemic dissemination of adenovirus or systemic toxicity. They were able to demonstrate in the rodent model of chronic wound/foreign body infections a significant reduction in bacterial loads from infected catheters following transduction with Ad/CMV-LL37 and increased bacterial clearance.
This study demonstrates for the first time that microbicidal gene therapy via microvascular free flaps is able to clear chronic infections such as occurs with osteomyelitis resulting from trauma or an infected foreign body [corrected]
耐药菌株的出现削弱了抗菌治疗的效果。抗菌肽是先天性免疫系统的一部分，广泛存在的蛋白质，对这类抗生素耐药微生物有效。作者之前已经证明了通过微血管游离皮瓣基因治疗进行蛋白质递送的可行性，在此他们研究了这种方法用于治疗顽固性感染。
作者研究了通过用Ad/CMV-LL37对啮齿动物腹壁下浅游离皮瓣进行离体转导来递送人cathelicidin抗菌肽-LL37。在离体转导期间，血管通透剂血管内皮生长因子（VEGF）与腺病毒载体共同给药，试图提高转导效率。使用接种了生物发光金黄色葡萄球菌的慢性伤口/异物感染的啮齿动物模型来评估使用该技术递送治疗性抗菌基因的生物学疗效。
作者成功证明了显著的LL37表达，在用Ad/CMV-LL37进行离体转导后持续14天。在转导期间共同给予5微克VEGF可显著提高转导效率，而不会显著增加腺病毒的全身扩散或全身毒性。他们能够在慢性伤口/异物感染的啮齿动物模型中证明，用Ad/CMV-LL37转导后，感染导管中的细菌载量显著降低，细菌清除增加。
本研究首次证明，通过微血管游离皮瓣进行的杀菌基因治疗能够清除慢性感染，如创伤或感染异物引起的骨髓炎[校正后]
