Document 0107
 DOCN  M9480107
 TI    Surface expression of the HIV-1 envelope proteins in env
       gene-transfected CD4-positive human T cell clones: characterization and
       killing by an antibody-dependent cellular cytotoxic mechanism.
 DT    9410
 AU    Ahmad A; Yao XA; Tanner JE; Cohen E; Menezes J; Laboratory of
       Immunovirology, University of Montreal, Quebec,; Canada.
 SO    J Acquir Immune Defic Syndr. 1994 Aug;7(8):789-98. Unique Identifier :
       AIDSLINE MED/94293160
 AB    The env gene of the human immunodeficiency virus-type 1 (HIV-1) was
       transfected in CEM-nkr, a human lymphoid cell line of T lineage that is
       resistant to the activity of natural killer cells, and for the first
       time, transfected T cell clones were established that stably express
       gp160 intracellularly and gp120 on the surface as demonstrated by
       radioimmunoprecipitation as well as by indirect membrane
       immunofluorescence. The regulatory protein vpu was not detected by
       radioimmunoprecipitation in these clones. The surface expression of
       gp120 without vpu in these clones provides direct evidence that gp160 is
       processed and cleaved (without vpu) in CD4+ cells. The CD4 antigens of
       these cells coprecipitated gp160; interestingly, no reduction of the
       surface CD4 expression (detectable by flow cytometric analysis of
       membrane immunofluorescence with OKT4) in the transfected cells was
       observed. However, decreased reactivity of the transfected clones with
       OKT4A was observed. The gp120-expressing cells did not form syncytia on
       coculture with other CD4+ human cell lines. These observations suggest
       the binding of gp120 to the surface CD4 antigen of the transfected
       cells. The transfected cells retained their resistance to the activity
       of the natural killer cells but showed a significant (p < 0.05) lysis
       when they were preincubated with AIDS patients' serum containing
       anti-gp120/41 antibodies. Thus, the expressed gp120/41 in these cells
       made them susceptible to killing by an antibody-dependent cellular
       cytotoxicity (ADCC) mechanism. To our knowledge, these are the first
       reported CD4+ T cell lines that stably express HIV envelope proteins.
       These cell lines would be useful as targets in exploring
       gp120/41-specific immune responses, especially in conducting
       gp120/41-specific ADCC studies in HIV-infected or gp120/41
       (gp160)-vaccinated individuals.
 DE    *Antibody-Dependent Cell Cytotoxicity  Antigens, CD4/IMMUNOLOGY  Cell
       Line  Clone Cells  Fluorescent Antibody Technique  Gene Expression
       Regulation, Viral  Gene Products, env/*BIOSYNTHESIS/GENETICS/IMMUNOLOGY
       *Genes, env  Giant Cells  Human  HIV Envelope Protein
       gp120/BIOSYNTHESIS/GENETICS/IMMUNOLOGY  HIV-1/GENETICS/*IMMUNOLOGY
       Killer Cells, Natural/IMMUNOLOGY  Protein
       Precursors/BIOSYNTHESIS/GENETICS/IMMUNOLOGY  Radioimmunoprecipitation
       Assay  Support, Non-U.S. Gov't  Transfection  T4
       Lymphocytes/*MICROBIOLOGY  JOURNAL ARTICLE

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