title: Interferons inhibit LTC4 production in murine macrophages.
abstract: Mouse resident peritoneal macrophages (M phi) produce the highly bioactive eicosanoid LTC4 when stimulated in vitro with zymosan or with the calcium ionophore A23187. This production was dramatically inhibited in M phi pre-exposed to IFN-alpha, IFN-beta, or IFN-gamma. Although all IFN were able to decrease the availability in M phi of the LTC4 precursor AA, this decrease was not the only cause of the IFN-induced inhibition of LTC4. In fact, further analysis of the different steps of the LTC4 biosynthetic pathway revealed that IFN-gamma could inhibit the formation of LTA4, thus of its derivatives LTC4 and LTB4, possibly acting at the level of the enzyme LTA4-synthetase. In contrast, IFN-alpha and IFN-beta only depressed the ability of M phi to metabolize AA into LTC4, leaving unaltered the synthesis of LTB4. However, IFN-alpha and IFN-beta did not influence directly the activity of any of the enzymes involved in LTC4 biosynthesis, indicating that they may act through some indirect, as yet unidentified regulatory mechanism. These data suggest that IFN-alpha and IFN-beta and, in different situations, IFN-gamma can be potentially useful in vivo in antagonizing localized anaphylactic or inflammatory reactions.
mesh_terms: D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D000001:Calcimycin / Q000494:pharmacology; D003864:Depression, Chemical; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D007372:Interferons / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D010529:Peritoneal Cavity / Q000166:cytology; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D013189:SRS-A / Q000096:biosynthesis*; D015054:Zymosan / Q000494:pharmacology
chemical_list: D001095:Arachidonic Acids; D011993:Recombinant Fusion Proteins; D013189:SRS-A; D016718:Arachidonic Acid; D000001:Calcimycin; D007372:Interferons; D015054:Zymosan