Construction of three-dimensional gel of extracellular matrices including type VI collagen and its role for immune reaction

表皮朗格汉斯细胞现在被认为是为T淋巴细胞提供抗原信号并触发免疫反应而设计的。这些细胞也存在于小鼠前胃和舌的复层鳞状粘膜上皮中。郎格汉斯细胞位于表皮，然后迁移到真皮，最后到达引流的淋巴结节，在那里它们向T淋巴细胞提供抗原信号。为了探索细胞外基质与免疫细胞之间的相互作用，研究郎格汉斯细胞在真皮中的迁移途径是非常有用的。它们广泛分布于结缔组织中。电子显微镜检查和氨基酸序列分析表明，VI型胶原可能作为细胞-基质或基质-基质相互作用的锚。我们研究了形成纤维的胶原蛋白或其他细胞外基质对巨噬细胞黏附的影响。巨噬细胞与塑料或纤维连接蛋白的黏附与酪氨酸磷酸化的诱导有关。相反，I型胶原蛋白酪氨酸磷酸化的诱导明显受到抑制。I型胶原是一种非粘附性细胞外基质，在免疫反应中引起细胞迁移。用原子力显微镜(AFM)观察了小鼠尾腱D-周期横纹胶原纤维的表面结构。将天然胶原纤维铺在盖板上，不经任何处理，用原子力显微镜观察。估算了谱带深度。利用原子力显微镜可以在纳米尺度上定量评价胶原蛋白的结构特征，这种显微镜也有助于研究由细胞外基质组成的凝胶的三维结构。

Epidermal Langerhans cells are now recognized as designed to present antigenic signals to Tlymphocytes and trigger an immunologic response. The cells also exist in the stratified squamous mucosal epithelium of mouse forestomach and tongue. Langerhans cells reside in the epidermis, and migrate into dermis, finally to the draining lymph nodes, where they present antigenic signals to T lymphocytes. For the search of interaction between extracellular matrices and immune cells, it is useful to study migration pathway of Langerhans cells in the dermis.Among many extracellular matrices, type VI collagen is a macromolecular component of extracellular matrices. They were widely distributed in connective tissues. Electron microscopic examinations and analysis of the amino acid sequences revealed that type VI collagen may work as an anchor in cell-matrix or matrix-matrix interaction.We investigated the effect of fibril-forming collagens or other extracellular matrices on the adhesion of macrophages. Adhesion of macrophages to plastic or fibronectin was associated with the induction of tyrosine phosphorylation. In contrast, the induction of protein tryosine phosphorylation was markedly inhibited on type I collagen. Type I collagen is a non-adhesive extracellular matrix causing cell migration on immuno reactions.The surface structure of D-periodic striated collagen fibrils of mouse tail tendon was examined by atomic force microscopy (AFM). Native collagen fibrils were spread on the cover glass and observed with AFM without any treatment. The band depth was estimated. A quantitative evaluation of collagen structural features in the nanometer scale is made possible by AFM.This microscopy is also useful to study three-dimensional structure of the gel composed of extracellular matrices.