Valore E V, Park C H, Quayle A J, Wiles K R, McCray P B, Ganz T
Department of Medicine, University of California, Los Angeles School of Medicine, Los Angeles, California 90095, USA.
J Clin Invest. 1998 Apr 15;101(8):1633-42. doi: 10.1172/JCI1861.
Antimicrobial peptides are widely distributed mediators of innate host defense in animals and plants. A 36 amino acid antimicrobial peptide belonging to the defensin family, and named human beta-defensin-1 (HBD-1), was purified recently from hemodialysate fluid, but its tissue sources were not identified. By Northern blotting, we found the highest concentrations of HBD-1 mRNA in the kidney and the female reproductive tract. In situ hybridization localized the HBD-1 mRNA in the epithelial layers of the loops of Henle, distal tubules, and the collecting ducts of the kidney and the epithelial layers of the vagina, ectocervix, endocervix, uterus, and fallopian tubes in the female reproductive tract. Using a novel technique designed to detect cationic peptides in urine, we recovered several forms of HBD-1 ranging in length from 36 to 47 amino acid (aa) residues and differing from each other by amino terminal truncation. The total concentration of HBD-1 forms in voided urine was estimated at 10-100 microg/liter, with individual variations in the total amount of HBD-1 peptides and the relative proportion of HBD-1 forms. Multiple forms of HBD-1 (size 36-47 aa) were also found in the blood plasma, bound to carrier macromolecules that released the peptide under acid conditions, and in vaginal mucosal secretions (39, 40, and 44 aa). By immunostaining, HBD-1 was located in the kidney within the lumen of the loops of Henle, but no intracellular storage sites were identified in renal or female reproductive tissues. Recombinant HBD-1 forms (36, 39, and 42 aa) and natural HBD-1 forms were antimicrobial to laboratory and clinical strains of Escherichia coli at micromolar concentrations. HBD-1 activity was not changed appreciably by low pH, but was inhibited by high salt conditions. Some of the HBD-1 peptides retained their activity against E. coli in unconcentrated (low conductance) urine, and the 36 aa form was microbicidal even in normal (high conductance) urine. Production of HBD-1 in the urogenital tract could contribute to local antimicrobial defense.
抗菌肽是动植物先天性宿主防御中广泛分布的介质。一种属于防御素家族、由36个氨基酸组成的抗菌肽，名为人类β-防御素-1（HBD-1），最近从血液透析液中纯化得到，但其组织来源尚未确定。通过Northern印迹法，我们发现肾脏和女性生殖道中HBD-1 mRNA的浓度最高。原位杂交将HBD-1 mRNA定位在肾脏髓袢、远曲小管和集合管的上皮层，以及女性生殖道中阴道、宫颈外口、宫颈内口、子宫和输卵管的上皮层。使用一种旨在检测尿液中阳离子肽的新技术，我们回收了几种长度从36到47个氨基酸（aa）残基不等、因氨基末端截短而彼此不同的HBD-1形式。晨尿中HBD-1各种形式的总浓度估计为10 - 100微克/升，HBD-1肽的总量和HBD-1各种形式的相对比例存在个体差异。在血浆中也发现了多种形式的HBD-1（大小为36 - 47 aa），它们与载体大分子结合，在酸性条件下释放出肽；在阴道黏膜分泌物中也发现了多种形式的HBD-1（39、40和44 aa）。通过免疫染色，发现HBD-1位于肾脏髓袢的管腔内，但在肾脏或女性生殖组织中未发现细胞内储存位点。重组HBD-1形式（36、39和42 aa）和天然HBD-1形式在微摩尔浓度下对实验室和临床大肠杆菌菌株具有抗菌作用。低pH对HBD-1的活性没有明显影响，但高盐条件会抑制其活性。一些HBD-1肽在未浓缩（低电导率）尿液中仍保留对大肠杆菌的活性，36 aa形式即使在正常（高电导率）尿液中也具有杀菌作用。泌尿生殖道中HBD-1的产生可能有助于局部抗菌防御。
