Bacci S, Alard P, Dai R, Nakamura T, Streilein J W
The Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
Eur J Immunol. 1997 Feb;27(2):442-8. doi: 10.1002/eji.1830270214.
In the induction of contact hypersensitivity (CH) to an epicutaneously applied hapten, we have previously proposed that low doses of hapten sensitize primarily through epidermal Langerhans' cells (LC), whereas high doses rely largely on dermal antigen-presenting cells (APC). To examine this issue further, we applied either high or low doses of dinitrofluorobenzene (DNFB) epicutaneously to mice. We observed reduced LC density at the site after 12 h (nadir), which returned to normal levels at 24 h only after a low dose of hapten. When a low dose of an unrelated hapten, oxazolone, was painted on skin that had been painted 12 h previously with high dose of DNFB, oxazolone-specific CH was impaired. When grafts of whole skin, dermis alone, and epidermis alone prepared from skin painted 2 h previously with low or high doses of DNFB were placed onto naive, syngeneic mice, CH was induced by whole skin after both types of doses, by epidermis only after a low dose, and by dermis only after high dose. When epidermal cell suspensions were derivatized in vitro with low or high doses of DNFB, only cells exposed to a low dose induced proliferation of hapten-specific Tcells. Thus, only a low dose of hapten reveals the APC functions of LC without the participation of dermal APC.
在对经皮应用的半抗原诱导接触性超敏反应（CH）的过程中，我们之前提出，低剂量半抗原主要通过表皮朗格汉斯细胞（LC）致敏，而高剂量则主要依赖真皮抗原呈递细胞（APC）。为了进一步研究这个问题，我们将高剂量或低剂量的二硝基氟苯（DNFB）经皮应用于小鼠。我们观察到，12小时后（最低点），该部位的LC密度降低，仅在低剂量半抗原作用下，24小时时才恢复到正常水平。当在12小时前已涂抹高剂量DNFB的皮肤上涂抹低剂量的无关半抗原恶唑酮时，恶唑酮特异性CH受到损害。当将2小时前用低剂量或高剂量DNFB涂抹过的皮肤制备的全皮、仅真皮和仅表皮移植物移植到同基因的未致敏小鼠身上时，两种剂量的全皮均可诱导CH，低剂量后仅表皮可诱导CH，高剂量后仅真皮可诱导CH。当用低剂量或高剂量的DNFB在体外使表皮细胞悬液衍生化时，只有暴露于低剂量的细胞能诱导半抗原特异性T细胞增殖。因此，只有低剂量半抗原能在无真皮APC参与的情况下揭示LC的APC功能。
