Bacon K B, Fincham N J, Camp R D
Institute of Dermatology, St. Thomas's Hospital, London, GB.
Eur J Immunol. 1990 Mar;20(3):565-71. doi: 10.1002/eji.1830200316.
Normal human skin contains an extravascular population of lymphocytes which have been proposed to play a central role in immunosurveillance. The hypothesis that physiologic lymphocyte chemoattractants induce the migration of these cells has been tested by analysis of samples from normal human skin by an in vitro lymphocyte migration assay in combination with high-performance liquid chromatography (HPLC). Dilution-related lymphocyte migration was seen on assay of aqueous extracts of stratum corneum, analysis after ultrafiltration consistently demonstrating activity in less than 1-kDa fractions. Similar results were obtained with chamber fluid from abraded normal skin and with normal plasma. A novel, polar, low-molecular weight component in plasma and chamber fluid was purified to homogeneity by reverse-phase HPLC. Material from the two sources possessed identical retention times on reverse-phase HPLC and similar ultraviolet (UV) absorbance spectra (UV maximum 274 nm). The factor has been termed plasma-associated lymphocyte chemoattractant (PALC). When purified to homogeneity, PALC induced concentration-related lymphocyte migration, was extractable in lipid solvents and was not peptide in nature, as determined by mass spectrometric and amino acid analyses and proteolytic enzyme digestion. It is proposed that PALC may play a role in mediating physiologic margination, adherence and migration of lymphocytes in normal human skin.
正常人类皮肤含有一群血管外淋巴细胞，有人提出这些细胞在免疫监视中起核心作用。通过体外淋巴细胞迁移试验结合高效液相色谱法（HPLC）对正常人类皮肤样本进行分析，检验了生理性淋巴细胞趋化因子诱导这些细胞迁移的假说。在对角质层水提取物进行检测时，观察到与稀释相关的淋巴细胞迁移，超滤后的分析始终表明活性存在于分子量小于1 kDa的组分中。用正常皮肤磨损后的腔室液和正常血浆也得到了类似结果。通过反相HPLC将血浆和腔室液中的一种新型极性低分子量成分纯化至同质。来自这两种来源的物质在反相HPLC上具有相同的保留时间和相似的紫外（UV）吸收光谱（UV最大值274 nm）。该因子被称为血浆相关淋巴细胞趋化因子（PALC）。纯化至同质后，PALC诱导了与浓度相关的淋巴细胞迁移，可在脂质溶剂中提取，根据质谱分析、氨基酸分析和蛋白水解酶消化确定其本质不是肽。有人提出，PALC可能在介导正常人类皮肤中淋巴细胞的生理性边缘化、黏附和迁移中发挥作用。
