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CD84 functions as a homophilic adhesion molecule and enhances IFN-gamma secretion: adhesion is mediated by Ig-like domain 1.
- Source :
-
Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2001 Oct 01; Vol. 167 (7), pp. 3668-76. - Publication Year :
- 2001
-
Abstract
- CD84 is a member of the CD2 subset of the Ig superfamily of cell surface molecules. Its cytoplasmic tail binds to Src homology 2 domain-containing protein 1A (signaling lymphocytic activation molecule-associated protein), a protein encoded by the X-linked lymphoproliferative disease gene. It is preferentially expressed on B lymphocytes, monocytes, and platelets. We show that it is also expressed on thymocytes and T cells. CD84 was positive on CD4-CD8- thymocytes, and its expression decreased with cell maturation. It is expressed on mature T cells preferentially on CD45RO+. To identify the CD84 ligand, we generated a soluble Ig fusion protein containing the human CD84 extracellular domains (CD84-Ig). Because receptor-ligand interactions occur between several members of this subfamily, we assayed CD84-Ig binding with all members of the CD2 family. CD84-Ig bound to CD84-transfected cells, whereas no binding was detected with cells expressing other CD2 subfamily receptors, showing that CD84 binds to itself. Anti-CD84 mAbs recognizing epitopes wholly within domain 1 of CD84 blocked the binding of the CD84-Ig fusion protein to CD84-transfected cells and platelets. Data from CD84 domain human/mouse chimeras further revealed that only the first extracellular domain of the molecule is involved in the ligand receptor recognition. The CD84-CD84 interaction was independent of its cytoplasmic tail. Finally, concurrent ligation of human CD84 with mAbs or CD84-Ig and CD3 enhanced IFN-gamma secretion in human lymphocytes. Thus, CD84 is its own ligand and acts as a costimulatory molecule.
- Subjects :
- Animals
Antibodies, Monoclonal immunology
Antigens, CD immunology
Binding, Competitive
COS Cells
Cell Adhesion Molecules chemistry
Cells, Cultured
Child
Child, Preschool
Humans
Immunoglobulins chemistry
Lymphocyte Activation
Mice
Protein Structure, Tertiary
Signaling Lymphocytic Activation Molecule Family
Thymus Gland immunology
Tumor Cells, Cultured
Antigens, CD chemistry
Antigens, CD physiology
Cell Adhesion
Cell Adhesion Molecules physiology
Interferon-gamma biosynthesis
Membrane Glycoproteins
T-Lymphocytes immunology
Subjects
Details
- Language :
- English
- ISSN :
- 0022-1767
- Volume :
- 167
- Issue :
- 7
- Database :
- MEDLINE
- Journal :
- Journal of immunology (Baltimore, Md. : 1950)
- Publication Type :
- Academic Journal
- Accession number :
- 11564780
- Full Text :
- https://doi.org/10.4049/jimmunol.167.7.3668