Asialylated immunoglobulins and rheumatoid factors

Dodon, Madeleine Duc; Quash, G.

doi:10.1007/bf00541186

Cited by 7 publications

(2 citation statements)

References 11 publications

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“…Whether the A-glycolylneuraminic acid residues in rabbit IgG oligosaccharide are localized to a given glycosylation site or unique sugar structure is not known, but their presence must be taken into account when performing any analytical assay for sialic acid on rabbit IgG. The low level of Fc sialylation (and galactosylation) of rabbit IgG is inconsistent with the proposed role of desialylation in the clearance of IgG from serum (Winkelhake & Nicholson, 1976) and in experimental models of rheumatoid arthritis (Dodon & Quash, 1981). Moreover, studies using reporter groups attached to sialic acid to probe the Fc region in whole IgG (Winkelhake et al, 1984;Nezlin & Sykulev, 1982) must also be viewed with great caution due to the small proportion of Fc fragments actually containing sialic acid and the potential presence of non-Fc sialic acid moieties.…”

Section: Discussionmentioning

confidence: 99%

Structures of the sugar chains of rabbit immunoglobin G: occurrence of asparagine-linked sugar chains in Fab fragment

Taniguchi¹,

Mizuochi²,

Beale³

et al. 1985

Biochemistry

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The asparagine-linked sugar chains of rabbit immunoglobulin G (IgG) and its Fc and Fab fragments were quantitatively liberated from the polypeptide portions by hydrazinolysis followed by N-acetylation and NaB3H4 reduction. After fractionation by paper electrophoresis, lectin chromatography, and gel filtration, their structures were studied by sequential exoglycosidase digestion in combination with methylation analysis. Rabbit IgG was shown to contain 2.3 mol of asparagine-linked sugar chains per molecule distributed in both the Fc and Fab fragments. The sugar chains were of the biantennary complex type containing four cores: Man alpha 1----6(Man alpha 1----3)(+/- GlcNAc beta 1----4)Man beta 1----4GlcNAc beta 1----4(+/- Fuc alpha 1----6)-GlcNAc. A total of 16 distinct neutral oligosaccharide structures was found after sialidase treatment. The galactose residue in the monogalactosylated oligosaccharides was present on either the alpha 1----3 or alpha 1----6 side of the trimannosyl core. The Fab fragments contained neutral, monosialylated, and disialylated oligosaccharides, whereas the Fc fragment contained only neutral and monosialylated structures. The oligosaccharides isolated from the Fab fragments also contained more galactose and bisecting N-acetylglucosamine residues than those from the Fc fragments.

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Section: Discussionmentioning

confidence: 99%

Structures of the sugar chains of rabbit immunoglobin G: occurrence of asparagine-linked sugar chains in Fab fragment

Taniguchi¹,

Mizuochi²,

Beale³

et al. 1985

Biochemistry

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“…1 & 21 that sialic acids can mask antigenic sites of molecules and of normal or malignant cells. An additional example is asialylated rabbit IgG which becomes immunogenic in autologous hosts and thus shows a relationship to the rheumatoid factor (22). Sialic acids furthermore mask antigenic sites in the cornified layer of newborn rat epidermis (23) and on lymphocytes (24).…”

Section: Introductionmentioning

confidence: 99%

The anti-recognition function of sialic acids: studies with erythrocytes and macrophages

Schauer¹,

Shukla²,

Schröder³

et al. 1984

Pure and Applied Chemistry

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-Sialic acids have been found to mask antigens, receptors and other recognition sites on molecules and cells. This has been investigated best with hepatocyte and macrophage lectins which recognize 13-galactose and N-acetyl-13-galactosamine residues on molecules and cells exposed by sialidase treatment. The lectin on macrophages leads to the binding and phagocytosis of erythrocytes after the enzymic removal of a critical amount of sialic acids. New techniques (colorimetry, high--performance liquid chromatography, gas-liquid chromatographymass spectrometry) for the determination of the amount and nature of these sialic acids were developed. The interaction of partially desialylated rat erythrocytes with homologous peritoneal macrophages can be inhibited by 13-galactosyl glycosides in a degree depending on the structure of the oligosaccharides and glycoconjugates tested. Although homologous serum stimulates binding and phagocytosis, immunoglobulins and complement factors were found to play no role in this process. The main factor responsible for the masking effect of sialic acids on subterminal 13-galactosyl groups seems to be the carboxyl group of neuraminic acid, as reduction of this group to an alcohol largely abolishes this important function of sialic acids in the macrophage and hepatocyte systems studied. The anti-recognition function of sialic acids illuminates the pathophysiological role of serum sialidases in infectious and other diseases.

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Monocyte fc receptor function in rheumatoid arthritis. enhanced cell‐binding of igg induced by rheumatoid factors

MacKinnon

Starkebaum

1987

Arthritis & Rheumatism

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Asialylated immunoglobulins and rheumatoid factors

Cited by 7 publications

References 11 publications

Structures of the sugar chains of rabbit immunoglobin G: occurrence of asparagine-linked sugar chains in Fab fragment

Structures of the sugar chains of rabbit immunoglobin G: occurrence of asparagine-linked sugar chains in Fab fragment

The anti-recognition function of sialic acids: studies with erythrocytes and macrophages

Monocyte fc receptor function in rheumatoid arthritis. enhanced cell‐binding of igg induced by rheumatoid factors

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