Immunologic functions of Ia-bearing epidermal Langerhans cells.
Immunologic functions of Ia-bearing epidermal Langerhans cells.
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携带 Ia 的表皮朗格汉斯细胞的免疫功能。
DOI：
10.4049/jimmunol.121.5.2005
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发表时间：
1978
影响因子：
4.4
通讯作者：
E. Shevach
中科院分区：
文献类型：
--
作者：
G. Stingl;Stephen I. Katz;L. Clement;Ira Green;E. Shevach
朗格汉斯细胞（LC）构成了哺乳动物表皮的一个形态特征良好的次要亚群，其功能作用仍然是一个猜想的问题。LC代表单核细胞-巨噬细胞-组织细胞系列细胞的表皮等同物的假设得到了最近观察结果的支持，即在人类和豚鼠中，LC是表达Fc-IgG受体、C3受体和Ia抗原的唯一表皮细胞。本研究以近交系2和13豚鼠为实验材料，探讨了LC是否能介导与含Ia巨噬细胞相同的免疫功能。通过在密度梯度上分离Fc-IgG玫瑰花结表皮细胞来制备LC富集和LC耗尽的表皮细胞。当这两个群体进行了测试的生物合成的同种异体抗原的免疫沉淀技术，Ia抗原的合成被限制在LC富集的部分。功能研究表明，抗原脉冲的LC富集的表皮细胞诱导免疫T细胞的增殖反应，其在幅度上与巨噬细胞相当。此外，免疫相关抗原的有效呈递需要富含LC的表皮细胞和应答淋巴细胞之间的协同作用。在混合白细胞反应（MLR）中，富含LC的表皮细胞是与巨噬细胞一样有效的刺激物。相比之下，LC耗尽的表皮细胞在两种测定系统中诱导很少或没有刺激。抗原呈递和MLR刺激能力的LC-富集的表皮细胞可以废除预处理抗Ia血清和补体。在表皮中的存在下，能够介导的免疫功能的IA轴承的巨噬细胞，具有重要的临床意义方面的作用，LC作为敏化细胞在接触性超敏反应和皮肤移植排斥反应。
Langerhans cells (LC) constitute a morphologically well-characterized minor subpopulation of the mammalian epidermis whose functional role is still a matter of conjecture. The hypothesis that LC represent an epidermal equivalent to cells of the monocyte-macrophage-histiocyte series is supported by the recent observations that in humans and guinea pigs LC are the only epidermal cells that express Fc-IgG receptors, C3 receptors, and Ia antigens. Using inbred strain 2 and strain 13 guinea pigs, we investigated in this study whether LC can mediate the same immunologic functions as Ia-bearing macrophages. LC-enriched and LC-depleted epidermal cells were prepared by separation of Fc-IgG rosetting epidermal cells on density gradients. When both populations were tested for the biosynthesis of alloantigens by immunoprecipitation techniques, Ia antigen synthesis was restricted to the LC-enriched fraction. Functional studies demonstrated that antigen-pulsed LC-enriched epidermal cells induce a proliferative response in immune T cells that is comparable in magnitude to that seen with macrophages. Moreover, effective presentation of immunologically relevant antigen requires syngeneity between LC-enriched epidermal cells and responder lymphocytes. In the mixed leukocyte reaction (MLR), LC-enriched epidermal cells were as effective stimulators as macrophages. LC-depleted epidermal cells, by contrast, induced little or no stimulation in both assay systems. Both the antigen-presenting and the MLR-stimulatory capacities of LC-enriched epidermal cells could be abrogated by pretreatment with anti-Ia sera and complement. The presence in the epidermis of Ia-bearing LC, capable of mediating the immunologic functions of Ia-bearing macrophages, has important clinical implications with regard to the role of LC as sensitizing cells in both contact hypersensitivity and skin graft rejection.