Multicellular complexes of thymocytes and different types of thymic stromal cells in the mouse.

The isolation of multicellular complexes of thymocytes and different types of thymic stromal cells from the mouse thymus is described. Isolated complexes were examined by light microscopy. Stromal cells, binding thymocytes at their surface, were identified using electron microscopy, and three types of epithelial cells, macrophages and interdigitating-like cells (IDC-like cells) were distinguished from their morphological characteristics. The epithelial cell types correspond morphologically to epithelial cells present in situ in various thymic regions. The type of thymocyte-contact with epithelial cells, macrophages and IDC-like cells indicated that the formation of multicellular complexes is common.