Receptor-operated activation of polymorphonuclear leukocytes: different effects of NAP-1/IL-8 and fMet-Leu-Phe or C5a.
We examined the production of PAF and LTB4 by PMN in response to NAP1/IL-8 alone, or after preincubation with GM-CSF, which has been shown to enhance PMN responsiveness and to prime PMN for production of those bioactive lipids. NAP-1/IL-8 does not induce the synthesis of PAF and LTB4 from endogenous phospholipid precursors, even after preincubation with GM-CSF. In addition and again in contrast to fMLP and C5a, NAP-1/IL-8 fails to induce an enhanced oxidative burst in GM-CSF primed PMN. Exogenously added PAF or LTB4 can mimic the priming effect of GM-CSF for an enhanced oxidative burst in response to all examined chemotactic peptides including NAP1/IL-8. Our data reveal a possible autocrine role of PAF and LTB4 in the enhanced responsiveness of GM-CSF primed PMN towards fMLP or C5a, but not NAP-1/IL-8.
Wirthmueller
U
U
Institute of Clinical Immunology, University of Bern, Switzerland.
Baggiolini
M
M
de Weck
A L
AL
Dahinden
C A
CA
D001094:Arachidonate 5-Lipoxygenase / Q000097:blood; D015936:Complement C5a / Q000378:metabolism / Q000494:pharmacology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism / Q000494:pharmacology*; D007975:Leukotriene B4 / Q000494:pharmacology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000378:metabolism / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D010972:Platelet Activating Factor / Q000096:biosynthesis; D044042:Receptors, Formyl Peptide; D011971:Receptors, Immunologic / Q000502:physiology*; D013481:Superoxides / Q000097:blood
D016209:Interleukin-8; D010972:Platelet Activating Factor; D044042:Receptors, Formyl Peptide; D011971:Receptors, Immunologic; D013481:Superoxides; D007975:Leukotriene B4; D009240:N-Formylmethionine Leucyl-Phenylalanine; D015936:Complement C5a; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D001094:Arachidonate 5-Lipoxygenase