INVESTIGADORES
SALAMONE Gabriela Veronica
congresos y reuniones científicas
Título:
Molecular mechanisms involved in IL-1 release by human neutrophils
Autor/es:
MARIA LAURA GABELLONI, JUAN IGNACIO FUXMAN BASS, JORGE RAUL GEFFNER, GABRIELA SALAMONE, MARIANA CATALANO, ANALIA SILVINA TREVANI.
Lugar:
Viña del Mar Chile
Reunión:
Congreso; 9th Latin American Congress of Immunology,; 2009
Resumen:
IL-1 is released by proteolytic processing of its precursor, pro-IL-1. Stimulation of NOD cytosolic receptors by
microbial products or endogen stress signals leads to the formation of an inflammasome, which recruits and activates
caspase-1, the enzyme responsible for processing pro-IL-1. Alternatively, pro-IL-1 might be clived by a not yet
characterized caspase-1-independent mechanism. We have evaluated the capacity of human neutrophils to produce IL-1 is released by proteolytic processing of its precursor, pro-IL-1. Stimulation of NOD cytosolic receptors by
microbial products or endogen stress signals leads to the formation of an inflammasome, which recruits and activates
caspase-1, the enzyme responsible for processing pro-IL-1. Alternatively, pro-IL-1 might be clived by a not yet
characterized caspase-1-independent mechanism. We have evaluated the capacity of human neutrophils to produce IL-1. Alternatively, pro-IL-1 might be clived by a not yet
characterized caspase-1-independent mechanism. We have evaluated the capacity of human neutrophils to produce IL-1
and the underlying molecular mechanisms. LPS-pretreated neutrophils released IL-1b in response to ATP, PMA or
Pseudomonas aeruginosa culture supernatant (PaCS) stimulation and also in response to co-culture with the whole
bacteria (pg/ml IL-1 detected by ELISA: 15± 6; 85± 25; 521± 85; 361± 43; 231± 49; 218± 55; for media, LPS -200
ng/ml-, LPS+PMA 20 ng/ml; LPS+ATP 2mM; LPS+5% PaCS o 107 bacteria/ml, respectively; n=6, p<0.05). IL-1culture supernatant (PaCS) stimulation and also in response to co-culture with the whole
bacteria (pg/ml IL-1 detected by ELISA: 15± 6; 85± 25; 521± 85; 361± 43; 231± 49; 218± 55; for media, LPS -200
ng/ml-, LPS+PMA 20 ng/ml; LPS+ATP 2mM; LPS+5% PaCS o 107 bacteria/ml, respectively; n=6, p<0.05). IL-1 detected by ELISA: 15± 6; 85± 25; 521± 85; 361± 43; 231± 49; 218± 55; for media, LPS -200
ng/ml-, LPS+PMA 20 ng/ml; LPS+ATP 2mM; LPS+5% PaCS o 107 bacteria/ml, respectively; n=6, p<0.05). IL-1
release induced by all agonists except PMA was significantly reduced by caspase-1 inhibitor II (% inh. 19± 4; 59± 13;
76± 6; for PMA, ATP and PaCS, respectively; n= 8, p<0.05). Pretreatment of neutrophils with DPI, a NADPH oxidase
inhibitor, markedly reduced PMA and PaCS-induced IL-1 release, while pretreatment with catalase, a H2O2 scavenger,
increased ATP, PMA and PaCS-induced IL-1 release. Altogether, our results suggest that a mechanism involving
caspase-1 takes place in neutrophils for IL-1 release, even though they do not rule out that a caspase-1-independent
mechanism could also be operating. At least in response to PMA and PaCS, IL-1b release seems to require NADPH
oxidase activation. However, reactive oxygen species could also negatively regulate IL-1 release. release. Altogether, our results suggest that a mechanism involving
caspase-1 takes place in neutrophils for IL-1 release, even though they do not rule out that a caspase-1-independent
mechanism could also be operating. At least in response to PMA and PaCS, IL-1b release seems to require NADPH
oxidase activation. However, reactive oxygen species could also negatively regulate IL-1 release. release, even though they do not rule out that a caspase-1-independent
mechanism could also be operating. At least in response to PMA and PaCS, IL-1b release seems to require NADPH
oxidase activation. However, reactive oxygen species could also negatively regulate IL-1 release. release.