The N-linked oligosaccharide at FcγRIIIa Asn-45: an inhibitory element for high FcγRIIIa binding affinity to IgG glycoforms lacking core fucosylation
| Autor: | Shingo Kakita, Mitsuo Satoh, Shigeru Iida, Koichi Kato, Yutaka Kanda, Seiji Saitou, Kenya Shitara, Mami Shibata-Koyama, Akira Okazaki, Katsuhiro Mori, Kazuko Kitajima-Miyama |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
IgG1 lacking core fucosylation
N-linked Fc oligosaccharides Glycosylation FcγRIIIa binding affinity Oligosaccharides CHO Cells Biochemistry Models Biological Fucose Antibodies law.invention chemistry.chemical_compound Cricetulus law Cricetinae FcγRIIIa Asn-45 Animals Humans Amino Acid Sequence Fucosylation chemistry.chemical_classification Antibody-dependent cell-mediated cytotoxicity Binding Sites biology N-linked FcγRIIIa oligosaccharides Receptors IgG Original Articles Oligosaccharide Surface Plasmon Resonance Antigens CD20 Fragment crystallizable region Molecular biology chemistry Immunoglobulin G biology.protein Recombinant DNA Antibody |
| Zdroj: | Glycobiology |
| ISSN: | 1460-2423 0959-6658 |
| Popis: | Human leukocyte receptor IIIa (Fc gamma RIIIa) plays an important role in mediating therapeutic antibodies' antibody-dependent cellular cytotoxicity (ADCC), which is closely related to the clinical efficacy of anticancer processes in humans in vivo. The removal of the core fucose from oligosaccharides attached to the Fc region of antibodies improves Fc gamma RIIIa binding, allowing the antibodies to enhance dramatically the antibody effector functions of ADCC. In this study, the contribution of Fc gamma RIIIa oligosaccharides to the strength of the Fc gamma RIIIa/antibody complex was analyzed using a serial set of soluble human recombinant Fc gamma RIIIa lacking the oligosaccharides. A nonfucosylated antibody IgG1 appeared to have a significantly higher affinity to the wild-type Fc gamma RIIIa fully glycosylated at its five N-linked oligosaccharide sites than did the fucosylated IgG1, and this increased binding was almost abolished once all of the Fc gamma RIIIa glycosylation was removed. Our gain-of-function analysis in the Fc gamma RIIIa oligosaccharide at Asn-162 (N-162) confirmed that N-162 is the element required for the high binding affinity to nonfucosylated antibodies, as previously revealed by loss-of-function analyses. Interestingly, beyond our expectation, the Fc gamma RIIIa modified by N-162 alone showed a significantly higher binding affinity to nonfucosylated IgG1 than did the wild-type Fc gamma RIIIa. Attachment of the other four oligosaccharides, especially the Fc gamma RIIIa oligosaccharide at Asn-45 (N-45), hindered the high binding affinity of Fc gamma RIIIa to nonfucosylated IgG1. Our data clearly demonstrated that N-45 is an inhibitory element for the high Fc gamma RIIIa binding affinity mediated by N-162 to nonfucosylated antibodies. This information can be exploited for the structural-based functional study of Fc gamma RIIIa. |
| Databáze: | OpenAIRE |
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