Thymocyte rosettes: multicellular complexes of lymphocytes and bone marrow-derived stromal cells in the mouse thymus.
We describe the isolation and purification of multicellular complexes composed of lymphocytes and bone marrow-derived stromal cells ("thymocyte rosettes") from the mouse thymus. These rosettes are the structural in vitro correlate of in vivo associations between lymphoblasts and I-A/E negative macrophages or medullary I-A/E positive dendritic-like cells. Both types of rosettes are preformed in vivo. The rosette-associated thymocytes display a surface antigen phenotype typical of immature thymocytes. In radiation chimeras, replacement of host thymocytes by injected bone marrow cells follows a regular pattern: donor type T cells appear first at day 11 as clusters around I-A negative macrophages and approximately 2 days later as similar clusters associated with either I-A positive cortical epithelial cells or I-A positive medullary dendritic cells. These data suggest (a) a defined sequence of lymphostromal interactions during intrathymic maturation and (b) a rapid proliferation of thymocytes after interaction with stromal cells.
D000818:Animals; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000276:immunology; D001853:Bone Marrow / Q000276:immunology*; D002470:Cell Survival / Q000528:radiation effects; D003433:Crosses, Genetic; D051379:Mice; D008815:Mice, Inbred Strains; D010641:Phenotype; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000276:immunology* / Q000528:radiation effects; D013950:Thymus Gland / Q000276:immunology* / Q000528:radiation effects
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface