Sørensen Ole E, Gram Lone, Johnsen Anders H, Andersson Emma, Bangsbøll Susanne, Tjabringa G Sandra, Hiemstra Pieter S, Malm Johan, Egesten Arne, Borregaard Niels
Granulocyte Research Laboratory, the Department of Hematology, Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark.
J Biol Chem. 2003 Aug 1;278(31):28540-6. doi: 10.1074/jbc.M301608200. Epub 2003 May 20.
The human cathelicidin, hCAP-18, is expressed both in neutrophils and in epithelial cells. hCAP-18 is processed to the antimicrobial peptide LL-37 by proteinase 3 in neutrophils. hCAP-18 is highly expressed in the epididymis with a subsequent high concentration in seminal plasma where the protein is present in its unprocessed and antimicrobially inactive form. We report here that hCAP-18 in seminal plasma is processed to generate a 38-amino acid antimicrobial peptide ALL-38 by the prostate-derived protease gastricsin when incubated at a pH corresponding to the vaginal pH. In accordance with this, seminal plasma derived hCAP-18 was found in its processed form in the vagina following sexual intercourse. The antimicrobial activity of ALL-38 against a variety of microorganisms tested is equal to that of LL-37. This enzymatic activation of a proantimicrobial substance in seminal plasma following exposure to the vaginal milieu represents a novel mechanism to prevent infection following sexual intercourse.
人源杀菌肽hCAP - 18在中性粒细胞和上皮细胞中均有表达。在中性粒细胞中，hCAP - 18被蛋白酶3加工成抗菌肽LL - 37。hCAP - 18在附睾中高度表达，随后在精浆中浓度很高，在精浆中该蛋白以未加工且无抗菌活性的形式存在。我们在此报告，当在与阴道pH值对应的pH下孵育时，精浆中的hCAP - 18被前列腺来源的蛋白酶胃蛋白酶加工生成一种38个氨基酸的抗菌肽ALL - 38。与此一致的是，性交后在阴道中发现精浆来源的hCAP - 18呈加工后的形式。ALL - 38对多种测试微生物的抗菌活性与LL - 37相当。精浆中的一种前抗菌物质在暴露于阴道环境后发生这种酶促激活，代表了一种预防性传播感染的新机制。
