Neutrophil generation of inflammatory precursors is not modulated by docosahexaenoic acid.
OBJECTIVE
It is believed that correction of membrane fatty acid deficiency in cystic fibrosis (CF) downregulates the synthesis of proinflammatory mediators. We tested the hypothesis that an increase of the proportion of docosahexaenoic acid (DHA) in the membrane in vitro changes the neutrophil response to Pseudomonas aeruginosa lipopolysaccharide (LPS).


RESULTS
Treatment with DHA increased the secretion of interleukin(IL)-1|*alpha*| by CF neutrophils, but the secretion of other cytokines, CD11b expression, and arachidonic acid (AA) release were not affected either in CF or control (CT) neutrophils. Both with and without DHA, only one out of eight CF neutrophils responded to LPS with an increase of released AA, while five out of seven CT cells released more AA (CF vs. CT P < 0.05 by Fisher test).


CONCLUSIONS
These results indicate that in neutrophils the beneficial effects of DHA on immune response are not directly related to the generation of proinflammatory precursors, and suggest that in CF the lower neutrophil AA generation in response to activation could cause insufficient production of lipid mediators involved in the resolution of lung inflammation.
Quattrucci
Serena
S
Department of Pediatrics, Centro di Riferimento Fibrosi Cistica Regione Lazio, Università La Sapienza, Viale Regina Elena 324, 00161, Rome, Italy.
Napolitano
Mariarosaria
M
Valentini
Sara Benedetti
SB
Giuliani
Alessandro
A
Bravo
Elena
E