       Document 0105
 DOCN  M9610105
 TI    Cellular immune response of rhesus monkeys infected with a partially
       attenuated nef deletion mutant of the simian immunodeficiency virus.
 DT    9601
 AU    Dittmer U; Nisslein T; Bodemer W; Petry H; Sauermann U; Stahl-Hennig C;
       Hunsmann G; Department for Virology and Immunology, German Primate
       Center,; Gottingen.
 SO    Virology. 1995 Oct 1;212(2):392-7. Unique Identifier : AIDSLINE
       MED/96010211
 AB    To date the vaccines most successful in the simian immunodeficiency
       virus (SIV) model of AIDS are live attenuated viruses. However, the
       virus-specific immune response induced after infection of monkeys with
       attenuated SIV has not been described comprehensively. Therefore, we
       investigated the cellular immune response of eight rhesus macaques
       infected with a nef deletion mutant of SIVmac32H (pC8). In contrast to
       monkeys infected with pathogenic SIV, pC8-infected macaques developed a
       virus-specific T-cell proliferation. In addition, all animals showed a
       proliferative T-cell response to recall antigen and mitogens. In six of
       eight monkeys virus-specific cytotoxic T-cells directed against
       different SIV polypeptides were detected. In two animals, however, the
       truncated nef gene reverted to full length 12 weeks after pC8 infection.
       These two monkeys developed hematological alterations, indicating an
       immunodeficiency. Simultaneously with the onset of disease the animals
       lost their T-cell responsiveness against recall antigens. Eight weeks
       later their T-cell reactivity against mitogens was also abrogated. The
       results indicate that live attenuated SIV induced a virus-specific
       cellular immune response in monkeys which might be associated with the
       previously reported resistance to superinfection with pathogenic SIV.
       Paradoxically, if the attenuated SIV reverts in vivo to a more virulent
       virus, the SIV-specific immune response was inefficient to prevent the
       onset of immunodeficiency in the animals.
 DE    Animal  Base Sequence  CD4-CD8 Ratio  CD4-Positive
       T-Lymphocytes/IMMUNOLOGY  Fusion Proteins, gag-pol/IMMUNOLOGY  Gene
       Products, env/IMMUNOLOGY  *Genes, nef  Hemocyanin/IMMUNOLOGY  Immunity,
       Cellular  Lymphocyte Transformation  Macaca mulatta  Molecular Sequence
       Data  *Sequence Deletion  Simian Acquired Immunodeficiency
       Syndrome/*IMMUNOLOGY  Support, Non-U.S. Gov't
       SIV/GENETICS/*IMMUNOLOGY/PATHOGENICITY  T-Lymphocytes,
       Cytotoxic/IMMUNOLOGY  JOURNAL ARTICLE

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

