Document 3248
 DOCN  M94A3248
 TI    Encounter of unprimed CD4+ T lymphocytes with HIV-1 gp120-expressing
       cells results in lysis of both target and effector cells.
 DT    9412
 AU    Jassoy C; Heinkelein M; Sopper S; Institute for Virology and
       Immunobiology, Wurzburg University,; Germany.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):12 (abstract no. 020A). Unique
       Identifier : AIDSLINE ICA10/94369327
 AB    OBJECTIVE: To examine the mechanism underlying the lysis of HIV-1 and
       gp160 expressing cells by non-specific CD4+ T lymphocytes. METHODS: B
       lymphoblastoid cells infected with recombinant vaccinia viruses
       expressing HIV-1 gp 160 or control HIV-1 proteins and HIV-1-infected or
       uninfected T cell lines were used as targets in chromium release assays.
       Freshly prepared peripheral blood mononuclear cells (PBMC), CD4+ T
       cell-enriched cultures, and CD4+ T cell clones derived from
       HIV-1-infected and uninfected individuals were used as effectors. Lysis
       of CD4+ effector cells and gp160 expressing target cells were determined
       by radioactive labeling of both cell types in parallel assays. Cell
       lysis and syncytium formation were determined in the presence and
       absence of monoclonal antibodies (mAb) against CD4, soluble (s) CD4 and
       other reagents. RESULTS: CD4+ T cell preparations from HIV-1-infected
       and uninfected donors efficiently lysed gp 160 and HIV-1-expressing
       cells. Lysis was HLA-unrestricted. In contrast to CD8+ CTL-mediated or
       NK cell-mediated lysis, lysis was not inhibited by EDTA. In addition,
       lysis was not inhibited by incubation with NK-sensitive cold targets or
       by anti TNF-alpha mAb. Encounter of CD4+ T cells with HIV-1
       gp160-expressing cells resulted in significant lysis of the uninfected
       CD4+ cells. Both, lysis of CD4+ effector and gp 160-expressing target
       cells could be inhibited by soluble CD4 and by mAb against CD4. Although
       lysis of gp 160 expressing cells was observed with all CD4+ T cell
       preparations used, syncytium formation was not detectable with certain
       CD4+ T cell lines indicating that formation of syncytia was not required
       for this type of lysis. CONCLUSION: Lysis of HIV-1-infected and
       uninfected CD4+ T cells by these unique mechanisms could account for the
       depletion of CD4+ cells in the infected individual.
 DE    Antibodies, Monoclonal/IMMUNOLOGY  Cell Death  Cell Line  Edetic
       Acid/PHARMACOLOGY  Human  *HIV Envelope Protein gp120  *HIV-1  Killer
       Cells, Natural  T-Lymphocytes,
       Suppressor-Effector/*MICROBIOLOGY/PATHOLOGY  Transfection  T4
       Lymphocytes/*MICROBIOLOGY/PATHOLOGY  Vaccinia Virus  MEETING ABSTRACT

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