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Tumor necrosis factor (TNF) primes platelet activating factor (PAF)-induced superoxide generation by human neutrophils (PMN): Consequences in promoting PMN-mediated endothelial cell (EC) damages
PROSTAGLANDINS
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m PKJwlmE lut-l4mATm -IAL CELL (Bc) EMIAmB B!rBLIMNEommmx(~):coIGDpopRcEs MoniquePAUBERT-BRAQUBT, Marie-OdileLONCRAMPT",PhilippeKLOTZ and Jean GDILBAUD. des briX8.sF 92141 Clamart Unit& de Recherche Clinique, H.I.A. Percy Centre de trait-t (France). *I.H.B. ResearchLabs, 17 Avenue DescartesF 92350 Le Plessis (France). Amplification of PNN responseto a stimulusby prior exposureof the cells to an agonist is known as "priming".EnhancedPMN responsesto thrombinand FMLP occur after pre-exposureto PAF (Vercelottiet al., 1987) ; similarly'INFalso primes FMN to various agonists (Berkawet al., 1986, Abst.). Thus we reasonedthat TNF might prime superoxidegenerationinducedby PAF (and vice-versa)and therebypromote neutrophil-mediated endothelialdamage. Indeed, PAF is produced by endothelialcells under TNF stimulation(Camussiet al., 1987). Both normal PNMs (N) and neutrophilsfrom severe TI patients(50 % mean TBSA) were used in this study. In b&h PWN series, TNF [l, 10, 100 and 1000 "g/ml] induced dose-dependent superoxidegeneration,this being maximal at 100 and 1000 ng/ml TNF respectively,for the N and TI series. Steady&a: ;:pM;tzd ;; observedafter 2 h incubationwith TNF. A 10 min incubationwith PAP [lo -8 -16 - 10 M] inducea significantincreasein superoxideproductionper. In contrast,PAF [lo added at the end of the TNF incubationcaused a significantdose-dependentamp~~$icati~~oof -10 M superoxideproductionrelativeto TNF alone, the maximum effect being noted at 10 decreasedin the TI PAF. The PAF-inducedamplification of 0 '- generationwas (i) significantly group (+ 50 - 70 % at Day 5 followingd vs 170 - 200 % in the N group), (ii) depended on the time followingTI in PMNs from burn-injuredpatients,the maximum effectbeing observedin the first week, and (iii) was inhibitedby the specificPAF antagonistsBN 52021, Kadsurenone,BN 52111 and WEB 2086. In addition,preincubation(30 min.) of normal PNXs with plasma from TI patientsinducedthese cells to respondsimilarto those as PMNs from bum-injured patients.This suggeststhat some plasmaticfactorsappearingafter burn may decreasePAF-induced0 '- generation. Since PAF is synthesizedand present on surfacesof endothelialcells under d F stimulation, the ether lipid may produce an amplificationfeed-back involvingmarginatedPMNs that eventuallybecomesdamagingto the PAF-synthesizing endotheliumitself.
PAF ENHANCES ERYTROPHAGOCYTIC ACTIVITY OF HUMAN MONOCYTES BY THE PROTEIN KINASE C DEPENDENT PHOSPHORYLATION OF C3b RECEPTOR (CRI). ROLE OF PAF mEwoR ANTAGONISTS. Bussolino F.,F. Turrini, E. Fischer, D.Alessi, M.D. Kazatchkine and %':Arese. Dip. Genetica Biologia e Chimica Medica. Universita' di Torino.Torino, Italy. Unite' A'Immunopatologie. Hop. Broussais. Paris, France.
PAF, with a IC50 of 12 uM and 5 uM, respectively. l)H.U.Lutz, F.Bussolino, R:Fle& P.Arese. Proc. Natl. Acad.Scl. U This work Project
MAY
was on
S.Fasler P.Stammler, M.D. Kazatchkine, 84,5767 (1987)
su ported by C.N.R. (Grant o;6.02606.5! to PA ,Special & Iseases. InherIted Basis ti? e Molecular
1988 VOL.
35 NO. 5
803
nnxt
lscmBIs
FAcla?
(llw)
Aulgs
PLA¶ELEr
AcrIvAm
PtcTu?
(PAF)-ItalKs
slmRalm
GQlwlllIoR
m PKJwlmE lut-l4mATm -IAL CELL (Bc) EMIAmB B!rBLIMNEommmx(~):coIGDpopRcEs MoniquePAUBERT-BRAQUBT, Marie-OdileLONCRAMPT",PhilippeKLOTZ and Jean GDILBAUD. des briX8.sF 92141 Clamart Unit& de Recherche Clinique, H.I.A. Percy Centre de trait-t (France). *I.H.B. ResearchLabs, 17 Avenue DescartesF 92350 Le Plessis (France). Amplification of PNN responseto a stimulusby prior exposureof the cells to an agonist is known as "priming".EnhancedPMN responsesto thrombinand FMLP occur after pre-exposureto PAF (Vercelottiet al., 1987) ; similarly'INFalso primes FMN to various agonists (Berkawet al., 1986, Abst.). Thus we reasonedthat TNF might prime superoxidegenerationinducedby PAF (and vice-versa)and therebypromote neutrophil-mediated endothelialdamage. Indeed, PAF is produced by endothelialcells under TNF stimulation(Camussiet al., 1987). Both normal PNMs (N) and neutrophilsfrom severe TI patients(50 % mean TBSA) were used in this study. In b&h PWN series, TNF [l, 10, 100 and 1000 "g/ml] induced dose-dependent superoxidegeneration,this being maximal at 100 and 1000 ng/ml TNF respectively,for the N and TI series. Steady&a: ;:pM;tzd ;; observedafter 2 h incubationwith TNF. A 10 min incubationwith PAP [lo -8 -16 - 10 M] inducea significantincreasein superoxideproductionper. In contrast,PAF [lo added at the end of the TNF incubationcaused a significantdose-dependentamp~~$icati~~oof -10 M superoxideproductionrelativeto TNF alone, the maximum effect being noted at 10 decreasedin the TI PAF. The PAF-inducedamplification of 0 '- generationwas (i) significantly group (+ 50 - 70 % at Day 5 followingd vs 170 - 200 % in the N group), (ii) depended on the time followingTI in PMNs from burn-injuredpatients,the maximum effectbeing observedin the first week, and (iii) was inhibitedby the specificPAF antagonistsBN 52021, Kadsurenone,BN 52111 and WEB 2086. In addition,preincubation(30 min.) of normal PNXs with plasma from TI patientsinducedthese cells to respondsimilarto those as PMNs from bum-injured patients.This suggeststhat some plasmaticfactorsappearingafter burn may decreasePAF-induced0 '- generation. Since PAF is synthesizedand present on surfacesof endothelialcells under d F stimulation, the ether lipid may produce an amplificationfeed-back involvingmarginatedPMNs that eventuallybecomesdamagingto the PAF-synthesizing endotheliumitself.
PAF ENHANCES ERYTROPHAGOCYTIC ACTIVITY OF HUMAN MONOCYTES BY THE PROTEIN KINASE C DEPENDENT PHOSPHORYLATION OF C3b RECEPTOR (CRI). ROLE OF PAF mEwoR ANTAGONISTS. Bussolino F.,F. Turrini, E. Fischer, D.Alessi, M.D. Kazatchkine and %':Arese. Dip. Genetica Biologia e Chimica Medica. Universita' di Torino.Torino, Italy. Unite' A'Immunopatologie. Hop. Broussais. Paris, France.
PAF, with a IC50 of 12 uM and 5 uM, respectively. l)H.U.Lutz, F.Bussolino, R:Fle& P.Arese. Proc. Natl. Acad.Scl. U This work Project
MAY
was on
S.Fasler P.Stammler, M.D. Kazatchkine, 84,5767 (1987)
su ported by C.N.R. (Grant o;6.02606.5! to PA ,Special & Iseases. InherIted Basis ti? e Molecular
1988 VOL.
35 NO. 5
803