Song Hee Jin, Lee Si Hyub, Choi Gwang Seong, Shin Jeonghyun
Department of Dermatology, Inha University School of Medicine, Incheon, Korea.
Photodermatol Photoimmunol Photomed. 2018 Mar;34(2):145-151. doi: 10.1111/phpp.12359. Epub 2017 Dec 5.
Human melanocytes express Toll-like receptor 4 (TLR4), which regulates ultraviolet (UV)-induced cutaneous immunosuppression in Langerhans cells. Lipopolysaccharide (LPS) stimulation increases melanocyte pigmentation and TLR4 expression, while inducing local innate inflammatory responses.
We investigated whether UV radiation induces TLR4 expression in neonatal human melanocytes (NHMs) and how this affects the immune system.
We cultured NHMs with LPS treatment or with one-time or repeated UVA or UVB exposure, and investigated and compared the effects on TLR4 expression, melanin contents, and cytokine production.
NHMs in the resting state did not express TLR4. LPS stimulation induced TLR4 expression and increased pigmentation. TLR4 expression was not detected after single-dose UVA or UVB treatment, but pigmentation increased. Repeated UV treatment induced TLR4 expression and increased pigmentation. LPS stimulation and repeated UV treatment increased IL-6 secretion, and repeated UVB treatment increased IL-10 secretion.
These results suggest that human melanocytes may actively participate in UV-induced immune modulation.
人类黑素细胞表达Toll样受体4（TLR4），其可调节紫外线（UV）诱导的朗格汉斯细胞皮肤免疫抑制。脂多糖（LPS）刺激可增加黑素细胞色素沉着和TLR4表达，同时诱导局部先天性炎症反应。
我们研究了紫外线辐射是否会诱导新生儿人类黑素细胞（NHM）中TLR4的表达，以及这如何影响免疫系统。
我们用LPS处理NHM，或一次性或反复进行UVA或UVB照射，研究并比较对TLR4表达、黑色素含量和细胞因子产生的影响。
静息状态下的NHM不表达TLR4。LPS刺激可诱导TLR4表达并增加色素沉着。单剂量UVA或UVB处理后未检测到TLR4表达，但色素沉着增加。反复紫外线处理可诱导TLR4表达并增加色素沉着。LPS刺激和反复紫外线处理可增加IL-6分泌，反复UVB处理可增加IL-10分泌。
这些结果表明，人类黑素细胞可能积极参与紫外线诱导的免疫调节。
