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Oestrus ovis (Diptera: Oestridae): effects of larval excretory/secretory products on nitric oxide production by murine RAW 264·7 macrophages
Author(s) -
Tabouret G.,
Vouldoukis I.,
Duranton C.,
Prevot F.,
Bergeaud J.P.,
Dorchies P.,
Mazier D.,
Jacquiet P.
Publication year - 2001
Publication title -
parasite immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 75
eISSN - 1365-3024
pISSN - 0141-9838
DOI - 10.1046/j.1365-3024.2001.00355.x
Subject(s) - biology , nitric oxide , lipopolysaccharide , nitrite , griess test , oestrus ovis , microbiology and biotechnology , macrophage , biochemistry , immunology , andrology , larva , endocrinology , in vitro , ecology , nitrate , medicine , myiasis
Larvae of Oestrus ovis (Insecta: Diptera: Oestridae) are common parasites of nasal and sinus cavities of sheep and goats. Previous studies revealed that crude extracts of larvae modify NO synthesis by ovine monocyte derived macrophages. The aim of this study was to investigate the larval excretory/secretory products effects on nitric oxide production by murine tumour macrophages RAW 264·7. Stimulation of RAW macrophages by excretory/secretory products of the three instars larvae (25 µg/ml) significantly increased nitrite concentrations in culture supernatants compared to negative and positive Escherichia lipopolysaccharide control. This effect was time and dose dependent. Nitrite production in culture supernatants was due to induction of isoform NOS‐2 because both N G monomethyl l ‐arginine (100 µ m ) and dexamethasone (20 µ m ) inhibited, by 60 and 50%, respectively, nitrite accumulation in culture supernatants. First steps of purification, by ion exchange chromatography, indicated that one protein of 29 kDa was able to induce NO synthesis by macrophages. Further studies are needed for a better characterization of these molecule and to investigate their immunogenicity for a vaccine approach.