title: The persisting (P) cell: histamine content, regulation by a T cell-derived factor, origin from a bone marrow precursor, and relationship to mast cells.
abstract: Histamine was detected at levels of 100 ng/10(6) cells in the metachromatic granules of the persisting (P) cell, which appears in cultures of murine lymphoid or bone marrow cells and is capable of long-term growth in vitro in the presence of a T cell-derived growth factor. This factor, which we termed P-cell stimulating factor, was distinct from t-cell growth factor and had an apparent molecular weight of 25,000-30,000. P cells did not originate from Thy.1-positive cells nor was the thymus necessary for the development of their precursors. Moreover, P cells grew directly from colonies generated in agar cultures of bone marrow cells, the nature of the colonies indicating that P cells shared a common precursor with hemopoietic cells. Mutant Wf/Wf mice, although deficient in certain mast cells, possessed P-cell precursors. It is hypothesized that P cells are related to a specialized subset of mast cells, derived from a bone marrow progenitor but regulated by activated T cells.
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells; D002454:Cell Differentiation; D003208:Concanavalin A / Q000494:pharmacology; D003470:Culture Media; D003594:Cytoplasmic Granules / Q000032:analysis; D006412:Hematopoietic Stem Cells; D006632:Histamine / Q000032:analysis*; D006822:Hybrid Cells / Q000378:metabolism; D007376:Interleukin-2 / Q000302:isolation & purification; D008407:Mast Cells / Q000032:analysis / Q000276:immunology*; D051379:Mice; D013601:T-Lymphocytes / Q000378:metabolism*
chemical_list: D003470:Culture Media; D007376:Interleukin-2; D003208:Concanavalin A; D006632:Histamine