title: Identification and molecular cloning of tactile. A novel human T cell activation antigen that is a member of the Ig gene superfamily.
abstract: We have identified and cloned cDNA for a novel cell-surface protein that we have named Tactile for T cell activation, increased late expression. It is expressed on normal T cell lines and clones, and some transformed T cells, but no other cultured cell lines tested. It is expressed at low levels on peripheral T cells and is strongly up-regulated after activation, peaking 6 to 9 days after the activating stimulus. It is also up-regulated on NK cells activated in allogeneic cultures. It is not found on peripheral B cells but is expressed at very low levels on activated B cells. Tactile-specific mAb immunoprecipitates a band of 160 kDa when reduced and bands of 240, 180, and 160 kDa nonreduced. Using an antiserum produced with affinity-purified Tactile protein to screen a lambda gt11 library, we have identified Tactile cDNA. Northern blot analysis shows an expression pattern similar to that of the protein and transfection of COS cells with the full-length 5.2-kb cDNA results in cell-surface expression. Comparison with the sequence databanks show that Tactile is a member of the immunoglobulin gene superfamily, with similarity to Drosophila amalgam, the melanoma Ag MUC-18, members of the carcinoembryonic Ag family, the poliovirus receptor, and the neural cell adhesion molecule. The deduced primary sequence encodes a protein with three Ig domains, a long serine/threonine/proline-rich region typical of an extensively O-glycosylated domain, a transmembrane domain, and a 45 residue cytoplasmic domain. These data suggest that Tactile may be involved in adhesive interactions of activated T and NK cells during the late phase of the immune response.
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, CA 94305.
authors.forename: P L
authors.initials: PL
authors.lastname: Wang
authors.forename: S
authors.initials: S
authors.lastname: O'Farrell
authors.forename: C
authors.initials: C
authors.lastname: Clayberger
authors.forename: A M
authors.initials: AM
authors.lastname: Krensky
mesh_terms: D000595:Amino Acid Sequence; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis / Q000235:genetics* / Q000502:physiology; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000302:isolation & purification; D005803:Genes, Immunoglobulin; D006801:Humans; D008213:Lymphocyte Activation; D008969:Molecular Sequence Data; D013601:T-Lymphocytes / Q000276:immunology; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D015854:Up-Regulation
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D004247:DNA