Stimulation of differentiated THP-1 cells by insulin led to rapid accumulation of PtdIns(3,4,5)P $ , a product of PtdIns 3-kinase. Stimulation of the GTP-binding-protein-linked receptor by Nformylmethionyl-leucyl-phenylalanine (fMLP) also induced the accumulation of PtdIns(3,4,5)P $ in the cells. The effect of insulin was, while that of fMLP was not, accompanied by increased PtdIns 3-kinase act...

Stålhammar, M. 2016. Neutrophil Chemotaxis and Respiratory Burst in Term and Preterm Newborn Infants. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1265. 47 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9722-4. Neutrophil activation is the most important initial immune defense against invading microbes in newborn infants. The reduced neutro...

Inhibition of complement-mediated granulocyte aggregation has recently been proposed as a mechanism of action of high-dose corticosteroids in shock states. Such inhibition may be effected through alteration of receptor function. Methylprednisolone inhibits binding of the synthetic chemotaxin f-methionine-leucine-phenylalanine (FMLP) to its surface receptor on granulocytes in a dose-dependent ma...

We have used a cytofluorometric method to study the effect of tumor necrosis factor alpha (TNF) priming on the oxidative burst, FMLP-receptor expression and actin polymerization of whole blood polymorphonuclear neutrophils (PMN). This technique permits the study of single cells and, thus, allowed us to examine the responsiveness of PMN to TNF in whole blood. We found that TNF in whole blood str...

BACKGROUND Previous studies from our laboratory have shown that the expression of L-selectin on polymorphonuclear neutrophils (PMN) decreases as the cell ages in the circulation and that these older PMN have more fragmented DNA and show morphological features of apoptosis. METHODS AND RESULTS The present study was designed to compare the functional capabilities of PMN expressing low levels of...

Patients with refractory carcinoma were treated with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) by intravenous (IV) infusion. During the period of treatment, studies of polymorphonuclear leukocyte superoxide (O2-) release in response to formylmethionylleucylphenylalanine (fMLP) and phorbol myristate acetate (PMA) and studies of chemotaxis in response to fMLP a...

This study addresses the role of store-operated Ca2+ influx in the regulation of exocytosis in inflammatory cells. In HL-60 granulocytes, which do not possess voltage-operated Ca2+ channels, the chemotactic peptide fMet-Leu-Phe (fMLP) was able to stimulate store-operated Ca2+ influx and to trigger exocytosis of primary granules. An efficient triggering of exocytosis by fMLP required the presenc...

Human polymorphonuclear leukocytes (PMN) activated by n-formyl-methionyl-leucyl-phenylalanine (fMLP), in the presence of cytochalasin B, are able to induce activation of coincubated autologous platelets "via" cathepsin G released from the azurophilic granules. However, thromboxane (Tx) B2 production in this system cannot be completely explained by cathepsin G-stimulated platelet arachidonate me...

Chemoattractants are thought to be the first mediators generated at sites of bacterial infection. We hypothesized that signaling through G protein-coupled chemoattractant receptors may stimulate cytokine production. To test this hypothesis, a human mast cell line (HMC-1) that normally expresses receptors for complement components C3a and C5a at low levels was stably transfected to express physi...