ラット胸腺ナース細胞(TNC)株の樹立とその胸線内T細胞分化における役割の解析:とくに未熟CD4?D8?SinglePositive細胞分化への関与

Abstract

Little is yet known about the precise roles of the epithelial cells including TNC in the complex process of differentiation of T cells. We have established a rat TNC cell line which we designate RWTE-1 with the aim of examining the function of TNC in vitro. Phenotypically, RWTE-1 was Class I, Class II and ICAM-I positive under stimulation with γ-IFN. Fine to-nofilaments were observed in the cytoplasm of RWTE-1 under the electron microscope. The only antigen identified on this cell so far is RE-4D8, which is common to nearly all thymus epithelial cells ; RE-5C6, wihch is in the medullary epithelium, was not found. Cellectively, these data sug-gented the established cell line was compatible with TNC derived from the thymus cortex. When RWTE-1 was co-cultured with fetal or adult thymocytes in a hanging drop culture, fetal thymocytes were the only to be harbored. A cell fractionation study was performed with CD4 and CD8 mAb using magnetic beads ; among fetal thymocytes depleted of CD4, CD8, and both CD4 and CD8 ; CD4 depleted adult thymocytes ; or CD4 depleted adult T lymphocytes, the CD4 depleted fetal thy mocytes were the only to be harbored within the RWTE-1. These data suggested that a TNC function might be involved in one of the early stages of intra-thymic T cell differentiation from immature CD4?CD8? to CD4?CD8? double positive thymocytes.