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Sulfatide binding and activation of leukocytes through an L‐selectin‐independent pathway
Author(s) -
Ding Ziqiang,
Kawashima Hiroto,
Miyasaka Masayuki
Publication year - 2000
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.68.1.65
Subject(s) - biology , microbiology and biotechnology , p selectin , selectin , immunology , platelet activation , cell adhesion molecule , platelet
Sulfatide has been reported to activate leukocytes through L‐selectin. Here we provide evidence that sulfatide binds to and activates leukocytes through both L‐selectin‐dependent and ‐independent pathways. Rat leukocytes of various sources shed surface L‐selectin after phorbol myristate acetate (PMA) treatment, however, these cells retained the ability to bind sulfatide. In addition, sulfatide also bound to an L‐selectin‐negative cell line EL‐4, and the binding was up‐regulated by PMA. Sulfatide induced aggregation of L‐selectin‐positive lymphocytes, which was highly dependent on divalent cations, protein tyrosine kinases (PTK), and protein kinase C (PKC), but was independent of β 1 and β 2 integrins. In contrast, sulfatide‐induced EL‐4 cell aggregation required an LFA‐1/ICAM‐1 adhesion pathway but not PTK and PKC. A sulfatide receptor of 65 kDa was isolated from EL‐4 cells. Taken together, this study suggests that sulfatide can bind to and activate leukocytes through an L‐selectin‐independent molecule and triggers signal transduction pathways different from those induced by L‐selectin activation.