Discipline of Dermatology, Bosch Institute, The University of Sydney at Royal Prince Alfred Hospital, Camperdown, Sydney, NSW 2050, Australia.
J Dermatol Sci. 2010 Sep;59(3):192-7. doi: 10.1016/j.jdermsci.2010.07.005. Epub 2010 Aug 9.
Ultraviolet (UV) A radiation, which has both mutagenic and immune suppressive effects on the skin, is increasingly recognised as a key contributor to cutaneous carcinogenesis. Whilst short wavelength UVB (290-320 nm) is well-recognised as an environmental health hazard, the dangers of UVA (320-400 nm) are relatively unexplored.
Using the nickel model of recall immunity in healthy human volunteers, we determined the wavelength dependency for UV-induced immunosuppression across the UVA spectrum.
Dose-response curves were established for local suppression of contact hypersensitivity responses to nickel at 7 wavelengths between 331 and 392 nm.
We found a broad peak of UVA immune suppressive effectiveness at 364-385 nm. Whilst we had previously found linear dose-responses for UVB-induced immunosuppression in this model, long wavelength UVA caused bell-shaped, Gaussian dose-responses, suggesting different chromophores and mechanisms of immunosuppression for UVB and UVA.
The immunosuppressive peak induced by longwave UVA has not been described previously for any species and being close to the border with visible light indicates an unexpected role for these long wavebands in human health and disease.
紫外线（UV）A 辐射对皮肤既有致突变作用又有免疫抑制作用，越来越被认为是皮肤致癌作用的一个关键因素。虽然短波长 UVB（290-320nm）被公认为环境健康危害，但 UVA（320-400nm）的危害相对而言还没有被充分探索。
利用健康人类志愿者的镍记忆召回模型，我们确定了 UVA 光谱范围内紫外线诱导免疫抑制的波长依赖性。
在 331nm 至 392nm 之间的 7 个波长下，建立了局部抑制镍接触过敏反应的剂量反应曲线。
我们发现 364-385nm 处存在一个宽的 UVA 免疫抑制有效峰。虽然我们之前已经在该模型中发现了 UVB 诱导免疫抑制的线性剂量反应，但长波长 UVA 引起钟形、高斯剂量反应，表明 UVB 和 UVA 具有不同的光吸收物质和免疫抑制机制。
长波 UVA 诱导的免疫抑制峰以前没有在任何物种中被描述过，而它接近可见光的边界表明这些长波段在人类健康和疾病中具有意想不到的作用。
