Characterization of the MRC OX40 antigen of activated CD4 positive T lymphocytes--a molecule related to nerve growth factor receptor

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Colleges, School and Institutes


The antigen recognized by the monoclonal antibody (mAb) MRC OX40 is present on activated rat CD4 positive T lymphocytes but not other cells. cDNA clones were isolated from an expression library using the MRC OX40 mAb and the protein sequence for the OX40 antigen deduced. It contains a typical signal sequence and a single putative transmembrane sequence of 25 predominantly hydrophobic amino acids giving an extracellular domain of 191 amino acids and a cytoplasmic domain of 36 amino acids. The sequence of the extracellular domain includes a cysteine-rich region with sequence similarities with the low affinity nerve growth factor receptor (NGFR) of neurons and the CD40 antigen present on human B cells. Within this region three cysteine-rich motifs can be recognized in OX40 compared with four similar motifs in both NGFR and CD40. OX40, CD40 and NGFR constitute a new superfamily of molecules with expression including lymphoid cells (OX40, CD40) and neuronal cells (NGFR). This is reminiscent of the immunoglobulin superfamily whose molecules are variously found at the surface of lymphoid or brain cells or both.


Original languageEnglish
Pages (from-to)1063-8
Number of pages6
JournalThe EMBO journal
Issue number4
Publication statusPublished - Apr 1990


  • Amino Acid Sequence, Animals, Antibodies, Monoclonal, Antigens, CD4, Antigens, Surface, Base Sequence, Cell Line, Cell Membrane, Cloning, Molecular, Gene Library, Laminin, Molecular Sequence Data, Nerve Growth Factors, Protein Conformation, Protein Sorting Signals, Rats, Rats, Inbred Strains, Receptors, Cell Surface, Receptors, Nerve Growth Factor, Sequence Homology, Nucleic Acid, T-Lymphocytes, Transfection