Phenotypic and functional properties of murine thymocytes. III. Kinetic analysis of the recovery of intrathymic cytolytic T lymphocyte precursors after in vivo administration of hydrocortisone acetate.
The phenotypic and functional properties of cells in the C57BL/6 mouse thymus regenerating after a single dose of 100 mg/kg hydrocortisone acetate (H/C) are described. Functionally, the frequency of anti-H-2d cytolytic T lymphocyte precursors (CTL-P) in thymuses from individual mice was determined by limit dilution analysis of mixed leukocyte microcultures. The initial increase in CTL-P frequency, seen 48 hr post-H/C, was followed at 6 to 8 days by a phase of rapid decrease. The CTL-P frequency returned to a normal level by 28 days post-H/C. Analysis of the results from individual mice suggested that changes in total thymic CTL-P content were independent of the kinetics of thymus regeneration. Phenotypically, whereas the thymus 48 hr after H/C was considerably depleted of Lyt-2+ cells, there followed a rapid increase in the proportion of such cells to normal levels by 14 days post-H/C. In addition, as measured by FLS, a subpopulation of larger, predominantly Lyt-2+ cells was found during the phase of rapid thymic regeneration. With the use of a monoclonal anti-Thy-1.2 antibody, the weakly Thy-1-staining subpopulation of cells was absent from the thymus at 14 days post-H/C. These changes in the phenotypic properties of the post-H/C regenerating thymus were correlated with changes in their functional properties.
D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D002454:Cell Differentiation; D002478:Cells, Cultured; D005260:Female; D006183:H-2 Antigens; D006854:Hydrocortisone / Q000494:pharmacology*; D051379:Mice; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology*; D018800:Thy-1 Antigens; D013950:Thymus Gland / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D013997:Time Factors
D000954:Antigens, Surface; D006183:H-2 Antigens; D018800:Thy-1 Antigens; D006854:Hydrocortisone