Analysis of cell surface antigens on glucocorticoid-treated rat thymocytes with monoclonal antibodies

Abstract

The effects of glucocorticoid (GC) on thymocytes have been utilized to investigate the maturation and differentiation of thymocytes, but these experiments have mainly been performed on mouse thymocytes. We investigated the cell surface antigens expressed by LEW rat thymocytes during thymic reconstitution after GC treatment. Three-color flow cytofluorometric analysis of CD4, CD8 and the T cell antigen receptor (TCRαβ) clearly demonstrated that normal rat thymocytes contain CD4 −8 + TCR αβ − and CD4 +8 − TCR αβ − cells. After GC treatment, we observed significant increases in the percentages of CD4 −8 + TCR αβ − and CD4 +8 − TCR αβ − cells. The extent of the increase in the percentage of CD4 −8 + TCR αβ − cells was greater than that of CD4 +8 − TCR αβ − thymocytes. Two-color analysis of TCRαβ and major histocompatibility complex (MHC) class I antigen showed that GC treatment significantly increased the percentage of TCR αβ − MHC class I hi cells. Three-color analysis of CD4, CD8 and MHC class I demonstrated that normal rat thymocytes contain CD4 −8 − MHC class I hi cells, which increased in number after GC treatment. These results indicate that rat thymocytes contain no fewer CD4 −8 + TCR αβ − and CD4 +8 − TCR αβ + cells than do mouse thymocytes, and that CD4 −8 + TCR αβ − cells predominate over CD4 +8 − TCR αβ − cells in LEW rat thymus. Rat CD4 −8 − cells seemed to be divided into two subsets of TCR αβ − MHC class I hi and TCR αβ − MHC class I − cells.