Human β-defensin-2 production in keratinocytes is regulated by interleukin-1, bacteria, and the state of differentiation
Human β-defensin-2 production in keratinocytes is regulated by interleukin-1, bacteria, and the state of differentiation
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DOI：
10.1046/j.0022-202x.2001.01651.x
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发表时间：
2002-02-01
影响因子：
6.5
通讯作者：
Ganz, T
中科院分区：
文献类型：
--
作者：
Liu, AY;Destoumieux, D;Ganz, T
完整的人类表皮抵抗病原微生物的入侵，但其抵抗力的生化基础还不清楚。最近，在发炎的表皮中发现了一种抗菌肽，人β-防御素-2。我们使用重组杆状病毒/昆虫细胞系统生产人β-防御素-2，并证实在微摩尔浓度下，它具有广谱的抗微生物活性，金黄色葡萄球菌是一个显著的例外。用针对人β-防御素-2的多克隆抗体进行的免疫染色表明，人角质形成细胞表达人β-防御素-2肽需要细胞分化（通过增加钙浓度或通过表皮器官型培养物中的生长和成熟）以及细胞因子或细菌刺激。白细胞介素-1 α、白细胞介素-1 β或活铜绿假单胞菌被证明是最有效的刺激物，而其他细菌和细胞因子几乎没有或没有诱导人β-防御素-2合成的能力。在白细胞介素-Ia刺激的表皮培养物中，人β-防御素-2首先出现在分化的皮肤基底上层的细胞质中，接着在表皮的上层中以更外周的网状分布，然后在几天内迁移到角质层。通过表皮裂解物的半定量Western印迹分析，在刺激的器官型表皮培养物中人β-防御素-2的平均浓度达到15 - 70 μ g/g组织，即，3.5 - 16 μ M，完全在抗微生物活性所需的范围内。由于人β-防御素-2在表皮中分布的有限模式，其局部浓度必须高得多。炎症表皮中的防御素等抗菌肽可能在宿主防御皮肤病原菌中发挥重要的抗菌作用。
Intact human epidermis resists invasion by pathogenic microbes but the biochemical basis of its resistance is not well understood. Recently, an antimicrobial peptide, human beta-defensin-2, was discovered in inflamed epidermis. We used a recombinant baculovirus/insect cell system to produce human beta-defensin-2 and confirmed that at micromolar concentrations it has a broad spectrum of antimicrobial activity, with the striking exception of Staphylococcus aureus. Immunostaining with a polyclonal antibody to human beta-defensin-2 showed that the expression of human beta-defensin-2 peptide by human keratinocytes required differentiation of the cells (either by increased calcium concentration or by growth and maturation in epidermal organotypic culture) as well as a cytokine or bacterial stimulus. Interleukin-1alpha, interleukin-1beta, or live Pseudomonas aeruginosa proved to be the most effective stimuli whereas other bacteria and cytokines had little or no ability to induce human beta-defensin-2 synthesis. In interleukin-la-stimulated epidermal cultures, human beta-defensin-2 first appeared in the cytoplasm in differentiated suprabasal layers of skin, next in a more peripheral web-like distribution in the upper layers of the epidermis, and then over a few days migrated to the stratum corneum. By semiquantitative Western blot analysis of epidermal lysates, the average concentration of human beta-defensin-2 in stimulated organotypic epidermal culture reached 15-70 mug per gram of tissue, i.e., 3.5-16 muM, well within the range required for antimicrobial activity. Because of the restricted pattern of human beta-defensin-2 distribution in the epidermis, its local concentration must be much higher. Defensins and other antimicrobial peptides of inflamed epidermis are likely to play an important antimicrobial role in host defense against cutaneous pathogens.