The neuronal glycoprotein telencephalin is a cellular ligand for the CD11a/CD18 leukocyte integrin.
Many leukocyte functions depend on interactions between the leukocyte-specific beta2 integrins CD11/CD18 and their ligands, the intercellular adhesion molecules (ICAMs). Telencephalin (TLN) is a novel member of the Ig superfamily expressed in the central nervous system. The NH2-terminal five Ig-like domains of TLN show the highest homology with the Ig domains of ICAM-1, ICAM-2, ICAM-3, and LW (ICAM-4), the known cellular ligands for CD11a/CD18. Here, we demonstrate that TLN interacts with CD11a/CD18. Peripheral blood T cells, Jurkat T cells, and B lymphoblastoid cells bound to immunopurified recombinant human TLN proteins. This adhesion was through CD11a/CD18 and was significantly inhibited by an Ab to CD11a/CD18. Reciprocally, TLN-transfected L cells also bound to purified CD11a/CD18. Recombinant TLN proteins comprising either the first five Ig domains (TLN(1-5)) or the entire extracellular portion (TLN(1-9)) showed binding to CD11a/CD18. We conclude that TLN is a novel neuronal cell adhesion molecule that may be important in integrin-mediated cell-cell interactions in the central nervous system, and that the CD11a/CD18-dependent recognition site of human TLN is located within the NH2-terminal five domains of this molecule.
Tian
L
L
Department of Biosciences, Division of Biochemistry, University of Helsinki, Finland.
Yoshihara
Y
Y
Mizuno
T
T
Mori
K
K
Gahmberg
C G
CG
D000595:Amino Acid Sequence; D001402:B-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D018821:CD18 Antigens / Q000187:drug effects* / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D016167:Integrin alphaXbeta2 / Q000187:drug effects / Q000378:metabolism; D019169:Jurkat Cells / Q000187:drug effects / Q000378:metabolism; D008024:Ligands; D016169:Lymphocyte Function-Associated Antigen-1 / Q000187:drug effects* / Q000378:metabolism*; D016177:Macrophage-1 Antigen / Q000187:drug effects / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D014162:Transfection / Q000235:genetics
D018821:CD18 Antigens; D015815:Cell Adhesion Molecules; C086747:ICAM5 protein, human; D016167:Integrin alphaXbeta2; D008024:Ligands; D016169:Lymphocyte Function-Associated Antigen-1; D016177:Macrophage-1 Antigen; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins