Document 0969
 DOCN  M9460969
 TI    Characterization of a transcriptional activator in the envelope gene of
       mouse mammary tumor virus.
 DT    9406
 AU    Miller CL; Univ. of Alberta, Canada
 SO    Diss Abstr Int [B]; 54(3):1387 1993. Unique Identifier : AIDSLINE
       ICDB/94697102
 AB    Mouse mammary tumor virus (MMTV) is the causative agent of mammary
       carcinomas in certain mouse strains. There is also evidence indicating
       that it may be associated with the development of T lymphomas.
       Transcription of the complete MMTV proviral genome in mouse cells is
       controlled by a strong promoter in its long terminal repeat (LTR). In
       the mouse T lymphoma cell line EL4.E1, there is a second,
       activation-dependent, transcriptional activator sequence within the MMTV
       envelope (env) gene. Phorbol ester treatment of EL4.E1 cells generates a
       transcript initiating within the env gene, which includes the open
       reading frame gene of the 3' LTR. I have isolated and characterized a
       segment of the MMTV env gene (called META for MMTV env transcriptional
       activator). META was linked to the chloramphenicol acetyltransferase
       (CAT) gene for use in transient-expression assays. META induced
       activation-dependent, T lymphocyte-specific expression of the CAT gene.
       It was active in mouse and human T helper cell lines but not in other
       cell types. META activity was dependent on activation of the T helper
       cell line with the same stimuli which induced cytokine production and
       its activity was suppressible by the immunosuppressive drug, Cyclosporin
       A. META has been isolated from EL4.E1 cells, from a T cell hybridoma,
       and from BALB/c spleen cells. It was also demonstrated that a portion of
       META acts as an inducible, orientation-independent, CsA-sensitive
       enhancer when linked to a heterologous promoter. A model for the
       potential involvement of META in MMTV-induced T lymphomagenesis is
       presented. (Full text available from University Microfilms
       International, Ann Arbor, MI, as Order No. AADNN-77372)
 DE    Animal  Chloramphenicol Acetyltransferase/GENETICS
       Cyclosporine/PHARMACOLOGY  Gene Expression  Gene Products, env/*GENETICS
       Lymphocyte Transformation  Lymphoma, T-Cell/*GENETICS  Mammary Tumor
       Viruses, Mouse/DRUG EFFECTS/*GENETICS  Mice  Promoter Regions (Genetics)
       Repetitive Sequences, Nucleic Acid  T-Lymphocytes,
       Helper-Inducer/IMMUNOLOGY  *Trans-Activation (Genetics)  THESIS

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