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CD45 is a Major Receptor Involved in Galectin‐8 Signaling of Preaparesis in HL‐60 cells
Author(s) -
Gourdine Jean-Philippe Francois,
Stowell Sean R,
Cummings Richard D
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.795.1
Subject(s) - microbiology and biotechnology , galectin , signal transduction , apoptosis , receptor , galectin 1 , chemistry , jurkat cells , flow cytometry , biology , immune system , t cell , biochemistry , immunology
The mechanisms of leukocyte turnover during an inflammatory response and its resolution are poorly understood. We recently showed that upon interactions with Galectin‐8 (Gal‐8), a 34 kilodalton heterodimeric tandem‐repeat galectin expressed by endothelial and epithelial cells, activated leukocytes express phosphatidylserine (PS) on their surface in the absence of apoptosis or DNA fragmentation. This can lead to phagocytosis of the cells in a process termed preaparesis , which fundamentally differs from that induced by factors signaling apoptosis. To identify the surface receptors involved in Gal‐8 signaling we took a proteomic approach to identify Gal‐8‐binding glycoproteins from human HL‐60 cells, a promyelocytic leukemic cell line with many signaling pathways in common to human neutrophils. Our previous studies showed that glycans containing poly‐N‐acetyllactosamine (poly‐N‐LacNAc) on HL‐60 cells were important for signaling. One major glycoprotein identified as a Gal‐8‐binding receptor on HL‐60 cells is CD45, a membrane glycoprotein that bears poly‐N‐LacNAc. We further characterized CD45/Gal‐8 interaction, by Western‐Blot, flow cytometry and confocal microscopy. Inhibition of CD45 cytoplasmic phosphatase activity reduced Gal‐8 induced PS exposure indicating a possible role of CD45 in Gal‐8 signaling preaparesis in human leukocytes. This work was supported by National Institutes of Health Grant HL085607 to R.D.C.