EVIDENCE FOR PRESENCE OF THY-1 ON CULTURED THYMIC EPITHELIAL-CELLS OF MICE AND RATS

Thymic tissue of C57BL/6 mice and DA rats was cultured. After 6–8 weeks, cultures were analyzed for their capacity to absorb anti‐Thy‐1 serum, and for the expression of Thy‐1 on the surface of different cell types by means of the indirect peroxidase labeling method. Three main cell types were identified: epithelium‐like cells, fibrocyte‐like cells and macrophages, but no lymphocytes were found. The presence of Thy‐1 on cultured nonlymphocytic thymus‐derived cells was demonstrated by their ability to absorb the cytotoxic activity of the appropriate anti‐Thy‐1 sera. Electron microscopical analyses of labeling experiments revealed that Thy‐1 was predominantly expressed on epithelium‐like cells with preference for their cell protrusions. The possible role of Thy‐1 expression, both on thymocytes and thymus epithelium for cellular interaction, is discussed. Copyright © 1978 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim