Document 0124
 DOCN  M95B0124
 TI    Purification and characterization of a Shiga toxin A subunit-CD4 fusion
       protein cytotoxic to human immunodeficiency virus-infected cells.
 DT    9511
 AU    al-Jaufy AY; King SR; Jackson MP; Department of Immunology and
       Microbiology, Wayne State University; School of Medicine, Detroit,
       Michigan 48201, USA.
 SO    Infect Immun. 1995 Aug;63(8):3073-8. Unique Identifier : AIDSLINE
       MED/95347825
 AB    In a previous paper, we reported that a chimeric toxin composed of the
       enzymatic domain of the Shiga toxin A polypeptide (StxA1) genetically
       fused to the human CD4 (hCD4) molecule selectively kills cells infected
       with human immunodeficiency virus type 1 (HIV-1). Although other
       hCD4-containing chimeras cytotoxic to HIV-infected cells have been
       developed, there is limited information regarding their receptor binding
       and internalization. Therefore, the goals of this study were to purify
       the StxA1-hCD4 fusion protein, identify the receptor(s), and investigate
       the cytosolic trafficking route used by the chimeric toxin. Sufficient
       quantities of the StxA1-hCD4 hybrid were isolated for this investigation
       by using the pET expression and purification system. Cos-1 cells were
       rendered sensitive to the StxA1-hCD4 chimera by transfection with the
       env gene, which encodes HIV-1 envelope glycoproteins. The entry and
       translocation pathway used by the StxA1-hCD4 hybrid toxin was
       investigated by assessing the protective capacities of chemical reagents
       which interfere with microfilament movement, acidification of endosomes,
       and the integrity of the Golgi apparatus. Our findings indicated that
       the chimera uses HIV-1 glycoprotein gp120, and perhaps gp41, as a
       receptor which directs its entry through receptor cycling. Uptake is pH
       independent, and the StxA1-hCD4 hybrid is apparently translocated to the
       Golgi complex as with other bipartite toxins.
 DE    Ammonium Chloride/PHARMACOLOGY  Animal  Antigens, CD4/*CHEMISTRY
       Bacterial Toxins/*CHEMISTRY  Base Sequence  Cell Compartmentation/DRUG
       EFFECTS  Cell Line  Cercopithecus aethiops  Chimeric Proteins
       Chloroquine/PHARMACOLOGY  Cyclopentanes/PHARMACOLOGY
       Cytotoxins/*CHEMISTRY  DNA Primers/CHEMISTRY  Human  HIV
       Infections/*THERAPY  In Vitro  Molecular Sequence Data  Support,
       Non-U.S. Gov't  Support, U.S. Gov't, P.H.S.  Vero Cells  JOURNAL ARTICLE

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