Red-cell ICAM-4 is a ligand for the monocyte/macrophage integrin CD11c/CD18: characterization of the binding sites on ICAM-4

Eveliina Ihanus, Liisa M Uotila, Anne Toivanen, Minna Varis, Carl G Gahmberg

    Forskningsoutput: TidskriftsbidragArtikelVetenskapligPeer review

    Sammanfattning

    Intercellular adhesion molecule 4 (ICAM-4) is a unique member of the ICAM family because of its specific expression on erythroid cells and ability to interact with several types of integrins expressed on blood and endothelial cells. The first reported receptors for ICAM-4 were CD11a/CD18 and CD11b/CD18. In contrast to these 2, the cellular ligands and the functional role of the third 02 integrin, CD11c/CD18, have not been well defined. Here, we show that ICAM-4 functions as a ligand for the monocyte/macrophage-specific CD11c/CD18. Deletion of the individual immunoglobulin domains of ICAM-4 demonstrated that both its domains contain binding sites for CD11c/CD18. Analysis of a panel of ICAM-4 point mutants identified residues that affected binding to the integrin. By molecular modeling the important residues were predicted to cluster in 2 distinct but spatially close regions of the first domain with an extension to the second domain spatially distant from the other residues. We also identified 2 peptides derived from sequences of ICAM-4 that are capable of modulating the binding to CD11c/CD18. CD11c/CD18 is expressed on macrophages in spleen and bone marrow. Inhibition of erythrophagocytosis by anti-ICAM-4 and antiintegrin antibodies suggests a role for these interactions in removal of senescent red cells. (c) 2007 by The American Society of Hematology
    Originalspråkengelska
    TidskriftBlood
    Volym109
    Nummer2
    Sidor (från-till)802-810
    Antal sidor9
    ISSN0006-4971
    DOI
    StatusPublicerad - 2007
    MoE-publikationstypA1 Tidskriftsartikel-refererad

    Vetenskapsgrenar

    • 1182 Biokemi, cell- och molekylärbiologi
    • 3111 Biomedicinska vetenskaper

    Citera det här