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A defect in HIV‐1 transgenic murine macrophages results in deficient nitric oxide production
Author(s) -
Dickie Peter,
Roberts Amanda,
Lee Raymond
Publication year - 2001
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.70.4.592
Subject(s) - biology , nitric oxide , nitric oxide synthase , transgene , genetically modified mouse , macrophage , in vivo , in vitro , arginase , microbiology and biotechnology , tumor necrosis factor alpha , gene , immunology , arginine , endocrinology , biochemistry , amino acid
HIV transgenic mice bearing multiple copies of a noninfectious(Δ gag/pol ) proviral DNA were tested for the systemicproduction of nitric oxide (NO). Serum levels of NO metabolites werereduced about 50% in HIV transgenic mice compared with nontransgenicsibling mice. This difference persisted when NO production was inducedwith peritoneal injections of bacterial endotoxin (LPS). Peritonealinflammatory macrophages, but not resident peritoneal macrophages, derived from HIV‐1 transgenic mice and activated in vitro with LPS andIFN‐γ (or tumor necrosis factor α and IFN‐γ) also produced about50% less NO than did macrophages harvested from nontransgeniclittermates. Isogenic, transgenic mice bearing mutated nef or vpr genes had normal serum levels of NO metabolites andtheir macrophages produced normal levels of NO when stimulated. Anexplanation for the reduced NO response of HIV[Vpr+Nef+] macrophageswas not apparent from measured levels of iNOS expression, viral geneexpression, or arginase activity in activated macrophages. Inhibitionof nitric oxide synthase (NOS) isoforms with l ‐NAME oraminoguanidine blocked time‐dependent increases in HIV gene expressionin activated macrophages cultured ex vivo. Inhibition with l ‐NAME occurred despite high levels of NO generated byiNOS, and exogenously supplied NO induced HIV gene expression onlyweakly, suggesting that cNOS had the greater influence on proviral geneinduction. This system is presented as a model of HIV‐1 proviral geneexpression and dysfunction in macrophages.