title: Phytohemagglutinin-induced acquisition of T-cell surface markers by rat bone marrow precursor cells in the absence of the thymic microenvironment.
abstract: Two monoclonal antibodies specific for different rat T-cell subpopulations, the anti-helper-T-cell antibody, W3/25, and the OX8 suppressor cell antibody were used to investigate lectin-stimulated T-lymphocyte differentiation of F-344 rat bone marrow cells in culture. Cytofluorometric analysis of freshly isolated lymphocytes from thymus and spleen revealed that these tissues contained both W3/25- and OX8-positive populations but differed with respect to the number of cells and receptor density distribution. By contrast, bone marrow-derived lymphocytes exhibited negligible W3/25- or OX8-associated fluorescence. However, several days after stimulation of bone marrow lymphocytes with phytohemagglutinin (PHA), cells appeared bearing these markers. Two-parameter histogram analysis of light scatter measurements with cell surface immunofluorescence indicated that this phenomenon represented the appearance of a new population of cells, presumably mature T cells, bearing an increased density of marker. These findings suggest an induction of differentiation of bone marrow T precursor cells by nonthymic factors (PHA) since lymphocytes lacking mature T-cell marker expression developed this characteristic after several days in culture.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology*; D001854:Bone Marrow Cells; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation; D008297:Male; D010835:Phytohemagglutinins / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D010835:Phytohemagglutinins