title: bcl-2 inhibits apoptosis of neutrophils but not their engulfment by macrophages.
abstract: Neutrophils, the most common inflammatory leukocytes, have the most limited life span of all blood cells. After they undergo apoptosis, they are recognized and engulfed by macrophages. bcl-2, a proto-oncogene rearranged and deregulated in B cell lymphomas bearing the t(14;18) translocation, is known to inhibit programmed death. bcl-2 expression is localized in early myeloid cells of the bone marrow but is absent in mature neutrophils. Transgenic mice that expressed bcl-2 in mature neutrophils showed that bcl-2 blocked neutrophil apoptosis. Despite this, homeostasis of neutrophil population is essentially unaffected. In fact, macrophage uptake of neutrophils expressing bcl-2 still occurred. This transgenic model indicates that the mechanism that triggers phagocytosis of aging neutrophils operates independently of the process of apoptosis regulated by bcl-2.
authors.affiliation: Department of Pathology and Developmental Biology, Stanford University School of Medicine, California 94305.
authors.forename: E
authors.initials: E
authors.lastname: Lagasse
authors.forename: I L
authors.initials: IL
authors.lastname: Weissman
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001853:Bone Marrow / Q000378:metabolism; D002478:Cells, Cultured; D015870:Gene Expression; D006801:Humans; D007700:Kinetics; D016393:Lymphoma, B-Cell; D017737:Macrophages, Peritoneal / Q000502:physiology*; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D008822:Mice, Transgenic; D009504:Neutrophils / Q000166:cytology / Q000502:physiology*; D010587:Phagocytosis; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2; D011519:Proto-Oncogenes; D013154:Spleen / Q000378:metabolism
chemical_list: C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011505:Protein-Tyrosine Kinases