Tie C, Golomb C, Taylor J R, Streilein J W
Department of Microbiology and Immunology, Miami Veterans Affairs Medical Center, Florida.
J Invest Dermatol. 1995 Jan;104(1):18-22. doi: 10.1111/1523-1747.ep12613454.
Ultraviolet B (UVB) radiation has multiple effects on the immune system, and these effects contribute to the development of UVB-induced skin cancers in mice, and probably man. Depending upon dose and duration of UVB exposure, the resultant immune aberrations may be strictly local (at the irradiated skin site) or systemic. One important local effect of acute, low-dose UVB regimens is impaired induction of contact hypersensitivity (CH). Because a significant proportion of humans who develop CH when hapten is painted on UVB-exposed skin fall to display a primary allergic reaction at that site, we inquired into the effects of UVB radiation on the expression of CH in man. A high proportion of individuals who were first exposed to a sensitizing dose of hapten via UVB-exposed skin displayed CH when challenged on unirradiated (normal) skin 11 d later. However, only 50% of these subjects developed CH when challenged simultaneously on skin that had been exposed to UVB radiation 11 d previously. Because the density of epidermal antigen-presenting cells was comparable in both responders and non-responders, we interpret these findings to mean that UVB radiation can create a sustained immunosuppressive microenvironment that inhibits the expression of CH. In separate experiments, when normal volunteers were sensitized with hapten via unirradiated (normal) skin, expression of CH at UVB-exposed challenge sites 11 d later was found to be enhanced, at least in some individuals, compared to expression of CH at unirradiated challenge sites. Thus, the local effects of UVB radiation on expression of CH in man may be enhancing or inhibitory, depending upon whether initial sensitization occurred through normal or through UVB-exposed skin.
紫外线B（UVB）辐射对免疫系统有多种影响，这些影响促使小鼠以及可能在人类中引发UVB诱导的皮肤癌。根据UVB暴露的剂量和持续时间，所产生的免疫异常可能严格局限于局部（在受辐射的皮肤部位）或全身性的。急性、低剂量UVB照射的一个重要局部效应是接触性超敏反应（CH）诱导受损。因为当在UVB暴露的皮肤上涂抹半抗原时出现CH的很大一部分人在该部位没有出现初次过敏反应，所以我们探究了UVB辐射对人类CH表达的影响。很大一部分首先通过UVB暴露的皮肤接触致敏剂量半抗原的个体在11天后在未受辐射（正常）的皮肤上受到激发时表现出CH。然而，当在11天前暴露于UVB辐射的皮肤上同时受到激发时，这些受试者中只有50%出现CH。因为表皮抗原呈递细胞的密度在反应者和非反应者中相当，我们将这些发现解释为UVB辐射可以创造一个持续的免疫抑制微环境，抑制CH的表达。在单独的实验中，当正常志愿者通过未受辐射（正常）的皮肤用半抗原致敏时，发现11天后在UVB暴露的激发部位CH的表达与在未受辐射的激发部位相比至少在一些个体中有所增强。因此，UVB辐射对人类CH表达的局部影响可能是增强性的或抑制性的，这取决于初始致敏是通过正常皮肤还是通过UVB暴露的皮肤发生。
