Document 0296
 DOCN  M9650296
 TI    Selenium and cellular immunity. Evidence that selenoproteins may be
       encoded in the +1 reading frame overlapping the human CD4, CD8, and
       HLA-DR genes.
 DT    9605
 AU    Taylor EW; Computational Center for Molecular Structure and Design,;
       University of Georgia, Athens 30602-2352, USA.
 SO    Biol Trace Elem Res. 1995 Aug-Sep;49(2-3):85-95. Unique Identifier :
       AIDSLINE MED/96087332
 AB    Selenium deficiency can lead to impaired immune function and reduced
       T-cell counts, as well as various specific disorders. Significantly, in
       ARC and AIDS patients, a progressive decline in plasma Se, paralleling
       T-cell loss, has been widely documented. Since evidence now suggests
       that there is an extremely high turnover of CD4+ T-cells in AIDS
       patients, with billions of new cells lost and replaced daily, any
       exceptional requirement for Se in lymphocytes could contribute to this
       progressive Se depletion. Thus, it may be significant that, overlapping
       the known genes in the +1 reading frame, the mRNAs of several T-cell
       associated genes (CD4, CD8, HLA-DR p33) have open reading frames (ORFs)
       with as many as 10 in-frame UGA codons (CD4, p33), a clustering that is
       highly improbable by chance alone, and reminiscent of selenoprotein P,
       the predominant plasma form of Se. The presence of these ORFs, along
       with potential stem-loop RNA structures displaying consensus
       selenocysteine insertion sequences, AUG(N)mAAA(N)nUGR, suggests that
       these mRNAs may encode selenoproteins, in addition to the known T-cell
       glycoproteins. If so, the roles of Se in the immune system may be more
       diverse than previously suspected.
 DE    Amino Acid Sequence  Antigens, CD4/*GENETICS  Antigens, CD8/*GENETICS
       Base Sequence  Codon/GENETICS  Computer Simulation  Human
       HIV-1/GENETICS  HLA-DR Antigens/GENETICS  Immunity, Cellular  Lymphocyte
       Transformation  Molecular Sequence Data  *Open Reading Frames
       Proteins/BIOSYNTHESIS/*GENETICS/PHYSIOLOGY  RNA,
       Messenger/*GENETICS/METABOLISM  Selenium/BLOOD/*DEFICIENCY/IMMUNOLOGY
       Support, U.S. Gov't, P.H.S.  T-Lymphocytes/CYTOLOGY/METABOLISM  JOURNAL
       ARTICLE  REVIEW  REVIEW, TUTORIAL

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