Document 0520
 DOCN  M9590520
 TI    A 17-kDa CD4-binding glycoprotein present in human seminal plasma and in
       breast tumor cells.
 DT    9509
 AU    Autiero M; Cammarota G; Friedlein A; Zulauf M; Chiappetta G; Dragone V;
       Guardiola J; International Institute of Genetics and Biophysics, CNR,
       Naples,; Italy.
 SO    Eur J Immunol. 1995 May;25(5):1461-4. Unique Identifier : AIDSLINE
       MED/95293051
 AB    We previously isolated gp17, a human seminal plasma glycoprotein, which
       specifically interacts with the D1-D2 region of CD4, a T cell surface
       molecule involved in antigen recognition mediated by helper T cells also
       acting as a receptor for the human immunodeficiency virus. In this study
       we report that monoclonal antibodies (mAb) reacting with gp17 are able
       to inhibit the binding of gp17 to immobilized soluble CD4. An
       immunohistochemical analysis shows that gp17 is also expressed in
       mammary tumor cells upon hormone treatment and in biopsies from breast
       cancer patients. A structural characterization of gp17, including amino
       acid sequencing, indicates that the protein has an extensive structural
       similarity with a glycoprotein designated as seminal actin-binding
       protein (SABP), also secreted by male sexual glands. SABP is in turn
       identical to gross cystic disease fluid protein-15 (GCDFP-15) or
       prolactin-inducible protein (PIP), a factor known as a highly specific
       and sensitive marker of primary and metastatic apocrine breast cancer.
       To establish further the correspondence of gp17 and GCDFP-15/PIP/SABP,
       the latter was expressed in bacteria from a cloned cDNA and purified by
       affinity chromatography to either anti-gp17 mAb-Sepharose or
       CD4-Sepharose. The purified recombinant protein is shown to inhibit the
       binding of labeled, pure g17 to immobilized soluble CD4. The finding
       that breast cancer cells express a protein able to interact with the CD4
       domains involved in the recognition of class II major histocompatibility
       antigens suggests a possible mechanism by which a tumor may affect the
       activity of tumor-infiltrated CD4+ T cells.
 DE    Amino Acid Sequence  Antibodies, Monoclonal/IMMUNOLOGY/PHARMACOLOGY
       Antigens, CD4/*METABOLISM  Base Sequence  Breast Neoplasms/*CHEMISTRY
       Carcinoma, Infiltrating Duct/*CHEMISTRY  Carrier
       Proteins/CHEMISTRY/IMMUNOLOGY/*ISOLATION & PURIF/  METABOLISM  DNA,
       Complementary/GENETICS  Female  Glycoproteins/IMMUNOLOGY/*ISOLATION &
       PURIF/METABOLISM  Human  Male  Molecular Sequence Data  Neoplasm
       Proteins/IMMUNOLOGY/*ISOLATION & PURIF/METABOLISM  Peptide
       Fragments/METABOLISM  Protein Binding/DRUG EFFECTS  Recombinant Fusion
       Proteins/METABOLISM  RNA, Messenger/GENETICS  RNA, Neoplasm/GENETICS
       Semen/*CHEMISTRY  Sequence Homology, Amino Acid  Support, Non-U.S. Gov't
       Tumor Cells, Cultured  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).