Okada T, Konishi H, Ito M, Nagura H, Asai J
Biochemical Research Institute, Nippon Menard Cosmetic Co., Ltd., Ogaki, Japan.
J Invest Dermatol. 1988 May;90(5):648-51. doi: 10.1111/1523-1747.ep12560807.
Secretory immunoglobulin A (sIgA) plays an important role in local immune defense mechanisms. Although skin is always exposed to external antigens, the role of local immune defenses involving sIgA in the skin has not been adequately studied. In order to evaluate the presence of sIgA in sweat, we have measured the concentration of sIgA in human sweat by enzyme immunoassay and have localized the components of sIgA in the sweat glands of human axillary skin. The concentration of sIgA in sweat was found to be 10 times higher in men than in women (13.0 +/- 0.9 micrograms/ml versus 1.6 +/- 0.9 micrograms/ml). Secretory component (SC) was localized immunohistochemically in protein synthetic organelles, such as the perinuclear spaces and Golgi complex, in cytoplasmic vesicles, and along the external surface membranes of mucous cells on the terminal segment of eccrine sweat glands. IgA and J chain were present in plasma cells in the protein synthetic organelles. The luminal aspects of eccrine sweat ducts also strongly express SC, as well as IgA and J chain. Neither SC, IgA, or J chain were identified in epithelial cells of apocrine sweat glands. These findings are consistent with the theory that J chain complexed with dimeric IgA is synthesized in plasma cells and is transported by SC-mediated endocytosis transfer across mucous cells of eccrine sweat glands and thus into sweat.
分泌型免疫球蛋白A（sIgA）在局部免疫防御机制中发挥着重要作用。尽管皮肤始终暴露于外部抗原，但涉及sIgA的局部免疫防御在皮肤中的作用尚未得到充分研究。为了评估汗液中sIgA的存在情况，我们通过酶免疫测定法测量了人汗液中sIgA的浓度，并对人腋窝皮肤汗腺中sIgA的成分进行了定位。结果发现，男性汗液中sIgA的浓度比女性高10倍（分别为13.0±0.9微克/毫升和1.6±0.9微克/毫升）。分泌成分（SC）通过免疫组织化学方法定位在蛋白质合成细胞器中，如核周间隙和高尔基体复合体、细胞质小泡以及外分泌汗腺终末段黏液细胞的外表面膜上。IgA和J链存在于蛋白质合成细胞器中的浆细胞内。外分泌汗腺导管的管腔面也强烈表达SC、IgA和J链。在顶泌汗腺的上皮细胞中未发现SC、IgA或J链。这些发现与以下理论一致，即与二聚体IgA结合的J链在浆细胞中合成，并通过SC介导的内吞作用穿过外分泌汗腺的黏液细胞转运至汗液中。
