Reactivity of murine and human recombinant LPS-binding protein (LBP) within LPS and gram negative bacteria.
The serum lipopolysaccharide (LPS) binding protein, LBP, has been shown to greatly enhance cellular responses to low concentrations of LPS. Purified LBP facilitates the transfer of LPS to membrane-bound or soluble CD14; the CD14/LPS complex then triggers a signal in responsive cells. We have cloned and sequenced a cDNA encoding murine LBP, and produced recombinant murine LBP using a baculovirus expression system. Using either a solid-phase or a cytofluorometric assay, recombinant murine and human LBP were found to bind avidly to free LPS, but only weakly to live bacteria from most LPS-containing Gram negative strains. Binding correlated loosely with the length and composition of the polysaccharide O chains. However, recombinant LBP did bind well to all heat-killed bacterial preparations. These findings suggest that LBP could be implicated in the response to killed but not live Gram negative bacteria.
Lengacher
S
S
Division of Infectious Diseases, CHUV, Laussane, Switzerland.
Jongeneel
C V
CV
Le Roy
D
D
Lee
J D
JD
Kravchenko
V
V
Ulevitch
R J
RJ
Glauser
M P
MP
Heumann
D
D
D000209:Acute-Phase Proteins; D000595:Amino Acid Sequence; D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000378:metabolism; D015870:Gene Expression; D006090:Gram-Negative Bacteria / Q000378:metabolism*; D006358:Hot Temperature; D006801:Humans; D066298:In Vitro Techniques; D008070:Lipopolysaccharides / Q000737:chemistry / Q000378:metabolism*; D008562:Membrane Glycoproteins; D051379:Mice; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D018411:Spodoptera; D000099231:Lipopolysaccharide-Binding Protein
D000209:Acute-Phase Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D018076:DNA, Complementary; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D011994:Recombinant Proteins; D000099231:Lipopolysaccharide-Binding Protein