Thy-1+ dendritic epidermal cells belong to the T-cell lineage.
The murine epidermis contains a population of dendritic, Thy-1+ cells (Thy-1+ DEC). Although it is now clear that these cells are of bone marrow origin, extensive morphological, histochemical, and cell-membrane marker studies have not definitively placed them in any known hematopoietic differentiation pathway. Based on the observation that Thy-1+ DEC can be propagated in vitro with Con A and interleukin 2, we have established three cell lines (Tehy 184, Tehy 245, and Yety 245) that can be continuously grown in medium with lectin-lymphokine-rich culture supernatants of rat spleen cells. With the exception of the loss of reactivity with anti-asialo-GM1 antibodies (Tehy 184 and Tehy 245) and the gain of interleukin 2 receptor expression, the cultured cell lines bear the same surface characteristics as freshly isolated Thy-1+ DEC: Thy-1+, Ly-5+, Lyt-1-, Lyt-2-, L3T4-, Ia-, sIg-. Using Southern and RNA gel blot analysis, we now demonstrate that these Thy-1+ DEC-derived cell lines exhibit various patterns of rearrangements in the gene complexes encoding the T-cell receptor (related) beta and gamma chains and contain mature and/or incomplete transcripts from the T-cell receptor alpha- and beta-chain genes, as well as transcripts from the receptor-related gamma-chain genes. Tehy 184 cells, the only cells containing both mature alpha- and beta-chain transcripts, react positively with the F23.1 monoclonal antibody, which recognizes the product of a subset of T-cell receptor beta-chain variable region gene segments. This antibody precipitates a surface protein of 84-88 kDa from these cells that after reduction separates into two 40- to 44-kDa chains, characteristic of Ti alpha/beta heterodimers. These data strongly suggest that Thy-1+ DEC belong to the T-cell lineage and point to the epidermis as a site either of immature thymocyte migration or of extrathymic T-cell differentiation.
D000818:Animals; D000954:Antigens, Surface / Q000032:analysis* / Q000235:genetics; D002460:Cell Line; D003713:Dendritic Cells / Q000276:immunology*; D004817:Epidermis / Q000276:immunology*; D005796:Genes; D051379:Mice; D008809:Mice, Inbred C3H; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D013601:T-Lymphocytes / Q000276:immunology*; D018800:Thy-1 Antigens; D014158:Transcription, Genetic
D000954:Antigens, Surface; D011948:Receptors, Antigen, T-Cell; D018800:Thy-1 Antigens