title: Constitutive apoptosis in equine peripheral blood neutrophils in vitro.
abstract: The aim of this study was to characterise constitutive apoptosis in equine peripheral blood neutrophils, including assessment of factors that potentially modulate neutrophil survival through alteration of the rate of constitutive apoptosis. Cells underwent spontaneous time-dependent constitutive apoptosis when aged in culture for up to 36 h, developing the structural and functional features of apoptosis observed in many cell types, including human neutrophils. Neutrophils undergoing apoptosis also had diminished zymosan activated serum (ZAS)-stimulated chemiluminescence, but maintained responsiveness to phorbol myristate acetate (PMA). The constitutive rate of equine neutrophil apoptosis was promoted by lipopolysaccharide (LPS), tumour necrosis factor α and phagocytosis of opsonised ovine erythrocytes, while it was inhibited by dexamethasone and ZAS (a source of C5a). Formyl-Met-Leu-Phe, leukotriene B4, platelet activating factor and PMA had no demonstrable effect on equine neutrophil apoptosis. There was a difference between equine and human neutrophil apoptosis in response to LPS and the time-dependence of the response to dexamethasone.
authors.affiliation: Royal (Dick) School of Veterinary Studies and the Roslin Institute, University of Edinburgh, Roslin, Midlothian EH25 9RG, UK.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Brazil
authors.affiliation: Royal (Dick) School of Veterinary Studies and the Roslin Institute, University of Edinburgh, Roslin, Midlothian EH25 9RG, UK.
authors.forename: Padraic M
authors.initials: PM
authors.lastname: Dixon
authors.affiliation: Queen's Medical Research Institute (QMRI), Medical School, University of Edinburgh, Edinburgh EH16 4TJ, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Haslett
authors.affiliation: Rayne Laboratory, Medical School, University of Edinburgh, Teviot Place, Edinburgh EH8 9AG, UK.
authors.forename: Joanna
authors.initials: J
authors.lastname: Murray
authors.affiliation: Royal (Dick) School of Veterinary Studies and the Roslin Institute, University of Edinburgh, Roslin, Midlothian EH25 9RG, UK. Electronic address: bruce.mcgorum@ed.ac.uk.
authors.forename: Bruce C
authors.initials: BC
authors.lastname: McGorum
mesh_terms: D000818:Animals; D017209:Apoptosis; D002478:Cells, Cultured; D006736:Horses; D009504:Neutrophils / Q000502:physiology*
keywords: Apoptosis; Equine; Neutrophil; Polymorphonuclear leucocyte