Lipopolysaccharide and serum cause the translocation of G-protein to the membrane and prime neutrophils via CD14.
Lipopolysaccharide (LPS) in combination with human serum, in the absence of a second stimulus, causes an increase in the amount of the alpha -subunit (Gi alpha 2) of the guanine nucleotide binding protein Gi2 associated with the membrane. The LPS-serum complex also primes human neutrophils for O2- production in response to stimulation by the chemotactic factor fMet-Leu-Phe. Added serum factor is essential for priming at low concentrations of LPS. In the presence of serum, significant potentiation can be observed at LPS concentration as low as 0.1 ng/ml. The priming is dose and time dependent. Furthermore, the observed actions of the LPS-serum complex are not reversible since they cannot be overcome by washing. Monoclonal antibody against CD14 inhibits both the direct and priming actions of the LPS-serum complex. On the other hand, neither the antibody against CD11b nor the antibody against TNF-alpha inhibits the action of this complex.
Yasui
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Department of Physiology, University of Connecticut Health Center, Farmington 06030.
Becker
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Sha'afi
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D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000276:immunology; D015214:Antigens, Differentiation, Myelomonocytic / Q000276:immunology; D001693:Biological Transport, Active; D001769:Blood / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006801:Humans; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000378:metabolism*; D015398:Signal Transduction; D013347:Subcellular Fractions / Q000737:chemistry; D013997:Time Factors
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D009240:N-Formylmethionine Leucyl-Phenylalanine; D019204:GTP-Binding Proteins