Stimulation of human neutrophils by chemotactic factors is associated with the activation of phosphatidylinositol 3-kinase gamma.
The activation of human polymorphonuclear neutrophil leukocytes (neutrophils) is associated with an increased synthesis of the highly phosphorylated phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P(3)). The aims of the present investigation were to determine whether the newly described, G protein-dependent phosphatidylinositol 3-kinase (PI3K), p110gamma, was involved in the responses to chemotactic factors interacting with G protein-coupled receptors. The presence of p110gamma in neutrophils was first established both at the protein and the mRNA level. Stimulation of the cells with fMet-Leu-Phe or interleukin-8 increased the PI3K activity in p110gamma, but not p85, immunoprecipitates. The time course of this effect (threshold within less than 5 s, maximal activation at 10-15 s) was consistent with that of the generation of PtdIns(3,4,5)P(3). Wortmannin, a PI3K inhibitor, abrogated the effects of fMet-Leu-Phe, which were also significantly inhibited by pertussis toxin. Finally, fMet-Leu-Phe also induced a significant translocation of p110gamma to a particulate fraction derived from these cells. These data indicate that p110gamma represent the major PI3K activated by fMet-Leu-Phe and interleukin-8 at very early time points following the stimulation of human neutrophils.
Naccache
P H
PH
Centre de Recherche en Rhumatologie et Immunologie and the Department of Medicine and Physiology, Laval University, Québec G1V 4G2, Canada. paul.naccache@crchul.ulaval.ca
Levasseur
S
S
Lachance
G
G
Chakravarti
S
S
Bourgoin
S G
SG
McColl
S R
SR
D000328:Adult; D000730:Androstadienes / Q000494:pharmacology; D001692:Biological Transport; D002451:Cell Compartmentation; D002630:Chemotactic Factors / Q000494:pharmacology*; D006801:Humans; D016209:Interleukin-8 / Q000494:pharmacology; D007527:Isoenzymes / Q000378:metabolism; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D018375:Neutrophil Activation / Q000502:physiology*; D037342:Pertussis Toxin; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D012333:RNA, Messenger / Q000032:analysis; D010566:Virulence Factors, Bordetella / Q000494:pharmacology; D000077191:Wortmannin
D000730:Androstadienes; D002630:Chemotactic Factors; D016209:Interleukin-8; D007527:Isoenzymes; D009240:N-Formylmethionine Leucyl-Phenylalanine; D037342:Pertussis Toxin; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D012333:RNA, Messenger; D010566:Virulence Factors, Bordetella; D000077191:Wortmannin