title: Biochemical characterization of the human basophil-promoting activity.
abstract: Human T cells produce a factor that induces growth of metachromatically staining cells in human bone marrow cultures. These cultured cells contain metachromatically staining granules and release histamine upon triggering with IgE and anti-IgE antibody. Based on morphological criteria, these cultured cells were termed basophil-like cells. We have generated a human T hybridoma which produces this basophil-like cell-promoting activity (BaPA). BaPA has a molecular weight of approximately 20 kilodaltons and isoelectric points between pH 5.8 and 7.5, with a major peak at pH 7. BaPA is of protein nature and can be clearly separated from interleukin-1 (IL-1), IL-2, interferons, GM-CSF and M-CSF. BaPA is also clearly different from a human IL-3-like activity which by itself can induce growth of metachromatically staining cells containing lower histamine levels than the cells cultured in the presence of BaPA. The growth of human basophil/mast cell-like cells can furthermore be enhanced if human bone marrow cells are cultured in the presence of fibroblast feeder cells.
mesh_terms: D001854:Bone Marrow Cells; D002478:Cells, Cultured; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D005347:Fibroblasts / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects*; D006636:Histamine Release; D006801:Humans; D006825:Hybridomas / Q000378:metabolism; D007073:Immunoglobulin E / Q000276:immunology; D011506:Proteins / Q000302:isolation & purification*; D013194:Staining and Labeling; D013601:T-Lymphocytes / Q000032:analysis* / Q000378:metabolism
chemical_list: D011506:Proteins; D007073:Immunoglobulin E