title: Lysis of uninfected HIV-1 gp120-coated peripheral blood-derived T lymphocytes by monocyte-mediated antibody-dependent cellular cytotoxicity.
abstract: Previous reports from our laboratory have demonstrated that peripheral blood monocytes (PBM) from HIV-1 infected individuals are de novo activated and are cytotoxic in vitro. Significant monocyte-antibody-dependent cellular cytotoxicity (ADCC) was obtained against HIV-1 inactivated CD4+ CEM target cells coated with HIV-1 in the presence of autologous seropositive serum. Based on these findings, we hypothesized that in HIV-seropositive individuals the monocytes may play an important role in vivo in the autodestruction of non-infected CD4+ T lymphocytes. The present study was designed to test this hypothesis. Monocytes from normal donors activated with M-CSF lysed CD4+ T cells (CEM) coated with gp120 sensitized by plasma from asymptomatic HIV-1+ individuals in a 8 h 51Cr release assay. ADCC cytotoxic activity varied from one individual to another and was a function of the dilution of the individual seropositive plasma used. We then used circulating CD3+ T lymphocytes as targets for ADCC following treatment with actinomycin D to facilitate the release of radioactive 51Cr. Like CEM, ADCC was obtained with CD3+ T cells coated with gp120 in the presence of HIV seropositive plasma and monocytes. Lysis was specific as T cells that were not coated with gp120 were not destroyed. These findings demonstrate that activated peripheral blood derived monocytes can destroy non-infected gp120-coated circulating T lymphocytes by an ADCC-mediated mechanism. Thus, these findings suggest that ADCC may be one mechanism operating in vivo for the destruction of non-infected CD4+ T lymphocytes.
authors.affiliation: Department of Microbiology and Immunology, UCLA School of Medicine, University of California 90024, USA.
authors.forename: D
authors.initials: D
authors.lastname: Hober
authors.forename: A
authors.initials: A
authors.lastname: Jewett
authors.forename: B
authors.initials: B
authors.lastname: Bonavida
mesh_terms: D000920:Antibody-Dependent Cell Cytotoxicity; D015496:CD4-Positive T-Lymphocytes / Q000473:pathology*; D002460:Cell Line; D015699:HIV Envelope Protein gp120 / Q000502:physiology*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D009000:Monocytes / Q000276:immunology*
chemical_list: D015699:HIV Envelope Protein gp120