Préparation et forme sérique de la protéine réactive C de lapin

Pontet, Michel; Ayrault-Jarrier, M; Burdin, J.; Gelin, M.; Engler, R

doi:10.1016/s0300-9084(80)80288-4

Cited by 14 publications

(6 citation statements)

References 29 publications

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“…Pontet et al (38) have suggested that CRP in acute-phase rabbit serum exists entirely in a high molecular weight form due to complexing with LDL, but like Kushner and Somerville (26), we have been unable to reproduce this observation using either gel fltration or density gradient ultracentrifugation (M. L. Baltz and M. B. Pepys, unpublished observations).…”

Section: Discussionmentioning

confidence: 61%

Low density lipoprotein and very low density lipoprotein are selectively bound by aggregated C-reactive protein.

Beer¹,

Soutar²,

Baltz³

et al. 1982

The Journal of Experimental Medicine

157

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C-reactive protein (CRP), the classical acute-phase protein, can bind phospholipids by virtue of its specific, calcium-dependent reactivity with phosphorylcholine residues. However, analysis of acute-phase serum by gel filtration and by density gradient ultracentrifugation showed that the CRP was in a free, uncomplexed form, despite the coexistent presence of the various classes of serum lipoproteins, all of which contain phospholipids. In contrast, when isolated CRP was aggregated by immobilization at a sufficient density on a solid phase and then exposed to normal human serum, it selectively bound low density lipoprotein (LDL) and traces of very low density lipoprotein. The reaction was calcium dependent and reversible by free phosphorylcholine but not by heparin. LDL isolated from normal plasma was also bound by aggregated CRP. CRP reacts in vitro with a wide variety of different ligands both of extrinsic and of autogenous origin, e.g., microbial products and damaged cell membranes, respectively. If CRP aggregated in vivo by complexing with these ligands than acquires the capacity to selectively bind LDL, the phenomenon may have significant implications for the function of CRP and for the metabolism, clearance, and deposition of LDL.

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Section: Discussionmentioning

confidence: 61%

Low density lipoprotein and very low density lipoprotein are selectively bound by aggregated C-reactive protein.

Beer¹,

Soutar²,

Baltz³

et al. 1982

The Journal of Experimental Medicine

157

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“…Interaction of pentraxins with lipoproteins has been suggested in previous studies, although the results have appeared inconsistent. Interaction between CRP and LDL or VLDL that contain apolipoprotein B or apoE have been reported (Pontet et al, 1979;Cabana et al, 1982). The greatest correlation appeared for apolipoprotein B (Rowe et al, 1984a).…”

Section: Discussionmentioning

confidence: 98%

“…While early studies suggested that human CRP was associated with lipids or lipoproteins (McLeod & Avery, 1941; Wood, 1963;Saito & Hara, 1968), more recent results suggest that interaction is limited to aggregated CRP (DeBeer et al, 1982b;Rowe et al, 1984a;Saxena et al, 1987) or abnormal lipoproteins (Rowe et al, 1984a,b). Rabbit CRP usually shows a complex with low-density lipoproteins (Pontet et al, 1979;Cabana et al, 1982), and affinity adsorption showed CRP-dependent removal of lipoproteins containing apolipoproteins E (apoE) and B (Rowe et al, 1984a). Interaction of rabbit pentraxins with lipoproteins may be of low affinity and is not detected by sucrose density gradient ultracentrifugation [reviewed in Pepys et al (1985)].…”

mentioning

confidence: 99%

Association of Rat C-Reactive Protein and Other Pentraxins with Rat Lipoproteins Containing Apolipoproteins E and A1

Schwalbe

Coe²,

Nelsestuen

1995

Biochemistry

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C-Reactive protein (CRP) is a member of the pentraxin family of proteins, ubiquitous components of animal serum. This study suggests that, in serum, rat CRP is complexed with lipoprotein and may interact directly with apolipoprotein E. When mixed with diluted rat serum, radiolabeled rat CRP showed a slightly higher sedimentation coefficient (about 15%) than that of the free protein. Elimination of calcium or addition of O-phosphorylethanolamine (O-PE), a low molecular weight compound that binds tightly to rat CRP in a calcium-dependent manner, abolished this difference. Adsorption of rat serum on a rat CRP affinity gel and elution with PE resulted in the isolation of material containing high levels of apolipoproteins E and A1. The affinity-purified preparation interacted with rat CRP and altered the sedimentation coefficient of the latter to the value observed in whole serum. Conversely, rat CRP increased the sedimentation coefficient of the major component of the affinity-purified material or to diluted rat serum, human serum amyloid P (SAP) and hamster female protein (FP), two other members of the pentraxin protein family, also had slightly higher sedimentation coefficients. In contrast, human CRP showed no evidence of an interaction in rat serum or with the affinity-purified proteins. This selectivity coincided with the ability of these pentraxins to bind to O-PE with high affinity. The sedimentation properties of serum lipoproteins, radiolabeled with [3H]cholesterol, also suggested an interaction with rat CRP.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…Another possibility is that an acute-phase apolipoprotein could be responsible for the binding. Three LPSinduced, lipoprotein-associated, acute-phase proteins are serum amyloid A (17,35), C-reactive protein (7,27), and arylesterase (5). Serum amyloid A is present in affinitypurified complexes of LPS-LP formed in acute-phase sera (35), but it is not known whether it leads to formation of the complexes or whether it is present on lipoprotein particles that bind to LPS through a different mechanism.…”

Section: Methodsmentioning

confidence: 99%

Control of endotoxin activity and interleukin-1 production through regulation of lipopolysaccharide-lipoprotein binding by a macrophage factor

et al. 1988

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Lipopolysaccharides (LPSs) extracted from gram-negative bacteria are much less active when bound to serum lipoproteins. We present evidence here that the binding of radiolabeled LPS extracted from Escherichia coli 0113 and Salmonella typhimurium to lipoproteins in rabbit serum is increased 8 to 24 h after a single intravenous injection of homologous or heterologous LPS. Supernatants of activated macrophages containing interleukin-1 also stimulate increased binding. The isolated product of this binding does not induce the production of interleukin-1 by macrophages in vivo or in vitro and is unable itself to stimulate increased binding of LPS to lipoprotein. Normal rabbit sera spiked with lipoprotein fractions prepared from tolerant but not normal rabbit sera bind increased amounts of LPS. These data suggest that there may exist a self-regulated mechanism for decreasing the toxicity of LPS and the production of LPS-induced interleukin-1; this mechanism is controlled by a macrophage factor and functions through altering the binding of LPS to certain serum lipoproteins.The biological activities of bacterial lipopolysaccharide (LPS) have been studied for decades. Much of this information stems from experiments performed with extracted LPS dissolved in aqueous solutions. Recently, however, it has been shown that LPS binds to high-density lipoproteins in serum and plasma (39,40) and that the resulting LPSlipoprotein complex (LPS-LP) is markedly less active than unbound LPS in many systems studied including LPSinduced neutropenia (39), thrombocytopenia (40), complement activation (39), fever (24, 39), rate of development of hypotension (19), and death in adrenalectomized mice (39). As the LPS structure remains intact within these complexes (23,39), the loss of activity presumably occurs by a masking of the toxic lipid A moiety of the molecule by the lipoprotein particle.There have been several studies suggesting that the transformation of LPS to LPS-LP can be modulated by serum elements that are induced by injections of LPS. Tobias et al. have reported that the binding of radiolabeled LPS from rough mutant Salmonella minnesota Re 595 to lipoprotein is slowed in "acute-phase" rabbit (37) and human (34) sera.

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Préparation et forme sérique de la protéine réactive C de lapin

Cited by 14 publications

References 29 publications

Low density lipoprotein and very low density lipoprotein are selectively bound by aggregated C-reactive protein.

Low density lipoprotein and very low density lipoprotein are selectively bound by aggregated C-reactive protein.

Association of Rat C-Reactive Protein and Other Pentraxins with Rat Lipoproteins Containing Apolipoproteins E and A1

Control of endotoxin activity and interleukin-1 production through regulation of lipopolysaccharide-lipoprotein binding by a macrophage factor

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