Endotoxin-induced early gene expression in C3H/HeJ (Lpsd) macrophages.
C3H/HeJ (Lpsd) macrophages have been shown to respond to certain LPSs, especially from rough mutant bacteria. C3H/OuJ (Lpsn) macrophages are induced by wild-type LPS, rough LPS, or lipid A to express many genes, including TNF-alpha, TNFR-2, IL-1 beta, IP-10, D3, and D8. C3H/HeJ macrophages failed to induce any of these genes when cultured with wild-type LPS or synthetic lipid A, even when pretreated with IFN-gamma. However, rough mutant Salmonella minnesota Ra, Rc, and Rd LPS, and Escherichia coli D31 m3 Rd LPS induced Lpsd macrophages to express a subset of genes within the gene panel. Because bioactive preparations contained trace quantities of endotoxin protein(s), a deoxycholate-modified, phenol-water method was used to repurify rough LPS into an aqueous phase, and extract endotoxin proteins into a phenol phase. Repurified LPS failed to stimulate Lpsd macrophages; however, phenol fractions were approximately 10% as potent in Lpsd macrophages as crude rough LPS. Full potency was restored in C3H/HeJ macrophages when aqueous phase LPS and phenol-phase proteins were co-precipitated, suggesting that LPS and endotoxin proteins interact synergistically. Endotoxin proteins alone induced TNF-alpha, TNFR-2, and IL-1 beta, but not IP-10, D3, and D8 genes in both Lpsd and Lpsn macrophages. Tyrosine phosphorylation of three 41- to 47-kDa proteins was induced by endotoxin proteins, but not by LPS, in Lpsd macrophages. Thus, endotoxin proteins seem to activate a signaling pathway(s) that converges (distal to the Lps gene product) with a subset of LPS-signaling pathways.
Manthey
C L
CL
Department of Microbiology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814.
Perera
P Y
PY
Henricson
B E
BE
Hamilton
T A
TA
Qureshi
N
N
Vogel
S N
SN
D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D004731:Endotoxins / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D015151:Immunoblotting; D007371:Interferon-gamma / Q000502:physiology; D008050:Lipid A / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H / Q000235:genetics; D019000:Phosphotyrosine; D014443:Tyrosine / Q000031:analogs & derivatives / Q000276:immunology
D004731:Endotoxins; D008050:Lipid A; D008070:Lipopolysaccharides; D019000:Phosphotyrosine; D014443:Tyrosine; D007371:Interferon-gamma