Cell surface sialic acid affects immunoglobulin binding to macrophages

FEBS Letters

Gorczyca, Wojciech¹  Wieczorek, Zbigniew²  Lisowski, Józef¹ 

[1] Department of Immunochemistry, Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 12 Czerska, 53-114 Wrocław, Poland;Laboratory of Immunobiology, Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 12 Czerska, 53-114 Wrocław, Poland

关键词: Sialic acid;    Fey receptor;    Neuraminidase;    Macrophage;    IgG binding;    FcγR;    receptor for the Fc region of IgG;    NANA;    N-acetylneuraminic acid;    GPPM;    guinea pig peritoneal macrophages;    PBS;    phosphate-buffered saline;    pH 7.2;    K a;    apparent association constant;    B max;    binding capacity;    HBBS;    Hank's balanced salt solution;   

DOI  :  10.1016/0014-5793(89)81504-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We demonstrate that guinea pig peritoneal macrophages pretreated with neuraminidase from Vibrio cholerae bind more ¹²⁵I-IgG than non-treated cells. Estimation of binding constants (K _a and B _max) shows that the elevation of binding is the result of an increase in affinity and not in the number of receptors for IgG. The change of affinity is proportional to amounts of sialic acid liberated from the cells by increasing doses of neuraminidase. It is also shown that affinity of interactions of IgG with the macrophage receptor is pH dependent. These results indicate that electrostatic forces are important for IgG binding to the macrophage FcγR. The IgG-FcγR interaction can be modulated by changing the degree of sialylation of the macrophage surface glycoconjugates.

【 授权许可】

Unknown