Ceramide is a product of agonist-induced sphingolipid metabolism in several cell types, including polymorphonuclear leukocytes (PMNs). In adherent PMNs, the kinetics of ceramide production correspond with the termination of fMLP-stimulated H2O2 release. Furthermore, short chain ceramides inhibit fMLP-mediated H2O2 release in adherent PMNs. In the present study, we investigated the effects of sh...

We investigated the effect of a major physiologic event, phagocytosis. on the ability of human neutrophils (PMN) to bind the synthetic chemotactic peptide, 3H-formyl-methionyl-leucyl-phenylalanine (3H-FMLP). We found that both latex and opsonized zymosan (OPZ) particles caused dosedependent suppression of 3H-FMLP binding and abolition of 3H-FMLP binding with concentrations of OPZ greater than 2...

INTRODUCTION Mononuclear phagocytes play a critical role during Alzheimer's disease (AD) pathogenesis due to their contribution to innate immune responses and amyloid beta (Aβ) clearance mechanisms. METHODS Blood-derived monocytes (BDMs) and monocyte-derived macrophages (MDMs) were isolated from blood of AD, mild cognitive impairment (MCI) patients, and age-matched healthy controls for molecu...

A factor has been derived from human leukocytes which irreversibly inhibits the response of human neutrophils to diverse chemotactic stimuli without impairing their viability. It is released by both polymorphonuclear and mononuclear leukocytes during incubation in acidic medium, after endotoxin exposure and subsequent incubation in low potassium medium, and during phagocytosis of particles. It ...

In the past differentiation of human neutrophils has been defined by morphology, cytochemistry, or surface markers. In our experiments we have sequenced the various events that occur during the functional differentiation of the normal human neutrophil and have also examined some of the functional properties in relationship to surface markers and biochemical events. Granulocytes were obtained fr...

It is commonly assumed that human neutrophils possess few, if any, functional mitochondria and that they do not depend on these organelles for cell function. We have used the fluorescent mitochondrial indicators, JC-1, MitoTracker Red, and dihydrorhodamine 123 to show that live neutrophils possess a complex mitochondrial network that extends through the cytoplasm. The membrane potential of thes...

Bovine milk-derived products, in particular whey proteins, exhibit beneficial properties for human health, including the acquired immune response. However, their effects on innate immunity have received little attention. Neutrophils are key cells of innate defenses through their primary functions of chemotaxis, phagocytosis, oxidative burst, and degranulation. A whey protein extract (WPE) purif...

Molluscs rely on an innate immune system for defence against infection. Invading organisms are phagocytosed by circulating hemocytes and neutralised by a combination of hydrolytic enzymes and the production of reactive oxygen species. Phagocytosis, the central feature of the molluscan innate immune system, is an energy-demanding process as a consequence of actin polymerisation which requires a ...

UNLABELLED We investigated the effect of thiopental, midazolam, and ketamine (at clinically relevant concentrations and at 0.1 and 10 times these concentrations) on several aspects of human neutrophil functions. The three intravenous (i.v.) anesthetics significantly decreased chemotaxis, phagocytosis, and reactive oxygen species (ROS) (O2-, H2O2, OH) production of neutrophils in a dose-dependen...