Involvement of the Gal β1 - 3GalNAcβ structure in the recognition of apoptotic bodies by THP-1 cells

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Item Type:	Article
Title:	Involvement of the Gal β1 - 3GalNAcβ structure in the recognition of apoptotic bodies by THP-1 cells
Creators Name:	Rapoport, E., Khaidukov, S., Baidina, O., Bojenko, V., Moiseeva, E., Pasynina, G., Karsten, U., Nifantev, N., LePendu, J. and Bovin, N.
Abstract:	A specific apoptotic glycosylation pattern may play an assistant or even a causative role in phagocytosis of apoptotic bodies. To elucidate the role of macrophages in lectin-mediated phagocytosis, an experimental system was used, where monocyte-derived THP-1 cells engulf the apoptotic bodies from the melanoma cell line MELJUSO. A flow cytometry assay was performed to reveal lectin expression and quantify the phagocytosis of apoptotic bodies. Taking into account that siglecs, a mannose receptor and galectins expressed on macrophages could be involved in engulfment of apoptotic bodies we studied their potential expression on THP-1 cells by means of polyacrylamide glycoconjugates. A strong binding of the cells to siglec ligands (3′SiaLac, 6′SiaLac, [Neu5Ac{alpha}2-8] 2) and galectin ligands (LacNAc, GalNAc{beta}1-4GlcNAc, Gal{beta}1-3GalNAc{beta} and asialoGM1) was observed. To reveal the corresponding targets on apoptotic bodies, the carbohydrate pattern of MELJUSO cells was analyzed. The apoptotic membrane was characterized by a high level of glycans terminated by galactose or sialic acid. To study lectin-mediated phagocytosis of apoptotic bodies by THP-1 cells, an inhibitory phagocytosis assay was performed. Binding of Gal{beta}1-3Gal-NAc- or LacNAc-specific reagents (lectins and antibodies) to apoptotic bodies abolished their engulfment by the THP-1 cells whereas blocking of Neu5Ac{alpha}2-6 or Neu5Ac{alpha}2-3 sites by the corresponding lectins was not effective. Furthermore, Gal{beta}1-3GalNAc{beta}-PAA or asialoGM1-PAA binding to the THP-1 cells decreased phagocytosis, whereas two other potent THP-1-binding probes, LacNAc-PAA and GalNAc{beta}1-4GlcNAc-PAA did not inhibit phagocytosis. Thus, Gal{beta}1-3GalNAc{beta}-terminated chains represented on the apoptotic bodies but not the other tested galectin ligands appear to be a target for THP-1 cells.
Keywords:	Apoptosis, Galactose-Specific Lectin, Macrophages, Neoglycoconjugates, Phagocytosis
Source:	European Journal of Cell Biology
ISSN:	0171-9335
Publisher:	Wissenschaftliche Verlagsgesellschaft
Volume:	82
Number:	6
Page Range:	295-302
Date:	June 2003
Official Publication:	https://doi.org/10.1078/0171-9335-00314
PubMed:	View item in PubMed

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