Dominant negative down-regulation of endotoxin-induced tumor necrosis factor alpha production by Lps(d)/Ran.
We recently showed that adenoviral transfer and expression of the Lps(d)/Ran gene isolated from endotoxin-resistant C3H/HeJ mice could protect endotoxin-sensitive mice from endotoxic shock. Elevation of proinflammatory cytokines, such as tumor necrosis factor alpha (TNF-alpha), is thought to be essential for the development of septic shock. To investigate the extent to which Lps(d)/Ran affects TNF-alpha production, we transduced primary macrophages from endotoxin-sensitive and -resistant mice with adenoviral vectors expressing the wild-type and the mutant Lps/Ran cDNAs and other control genes, and compared the amount of TNF-alpha produced by these various transduced macrophages. Successful transfer and expression of Lps(d)/Ran cDNA in endotoxin-sensitive C3H/HeOuJ macrophages reduced TNF-alpha production upon lipopolysaccharide (LPS) stimulation, as compared with macrophages transduced with vectors expressing the wild-type Lps(n)/Ran cDNA, the green fluorescent protein gene, or the lacZ gene. On the other hand, successful transfer and expression of the wild-type Lps(n)/Ran cDNA in primary macrophages from endotoxin-resistant C3H/HeJ mice failed to induce TNF-alpha production to any significant extent unless a very high LPS concentration was used. Given our previous demonstration that Lps(n)/Ran functions effectively in restoring LPS responsiveness in B cells from C3H/HeJ mice, we conclude that Lps/Ran is involved in a CD14-independent signal transduction pathway. This dominant negative down-regulation by Lps(d)/Ran on TNF-alpha production by macrophages and probably other innate immune responses may be key to the development of an effective gene therapy for endotoxic or septic shock.
Yuan
Q
Q
Department of Pathology and Laboratory Medicine, Fels Institute, Temple University School of Medicine, Philadelphia, PA 19140, USA.
Zhao
F
F
Chung
S W
SW
Fan
P
P
Sultzer
B M
BM
Kan
Y W
YW
Wong
P M
PM
D000256:Adenoviridae / Q000378:metabolism; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D015153:Blotting, Western; D002454:Cell Differentiation; D002455:Cell Division; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D015536:Down-Regulation; D004731:Endotoxins / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005799:Genes, Dominant; D006801:Humans; D008070:Lipopolysaccharides / Q000378:metabolism*; D008264:Macrophages / Q000821:virology; D051379:Mice; D008809:Mice, Inbred C3H; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics; D020931:ran GTP-Binding Protein / Q000235:genetics*
D018076:DNA, Complementary; D004731:Endotoxins; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D020931:ran GTP-Binding Protein