Thymus-derived stromal cell lines.
We derived stromal cell lines from mouse thymus using methods previously established for bone marrow stroma. Two main morphologically distinct groups of cell strains emerged: epithelioid and mixed fibroblast-macrophage. Transmission electron microscopy revealed frequent junctional-complex formations between adjacent cells, a feature that characterized almost all of the thymus stromal lines, but was confined to only one of the five distinct subtypes of cell lines from bone marrow. In contrast to marrow stromal cells, the thymus-derived cell lines were all negative with fat-detecting reagents, had low acid phosphatase and no basic phosphatase activities and were unable to support the in vitro proliferation of myeloid progenitor cells (CFU-gm). Leukemia cell inhibitory activity (LCIA) was detected in one of the thymus stromal cell lines. The differences observed between cell lines derived from the stroma of the thymus and those from bone marrow may relate to the functional specificities of these organs.
D000818:Animals; D001854:Bone Marrow Cells; D002460:Cell Line; D004847:Epithelial Cells; D005347:Fibroblasts / Q000166:cytology; D006410:Hematopoiesis; D007365:Intercellular Junctions / Q000648:ultrastructure; D008264:Macrophages / Q000166:cytology; D051379:Mice; D008854:Microscopy, Electron; D013950:Thymus Gland / Q000166:cytology*