Defective Killing Activity Against gp120/41-expressing Human Erythroleukaemic K562 Cell Line by Monocytes and Natural Killer Cells From HIV-infected Individuals

AIDS. 1996 Feb;10(2):143-9. doi: 10.1097/00002030-199602000-00003.


Objective: To determine the role of natural cellular cytotoxicity of peripheral blood mononuclear cells (PBMC) in killing of HIV-1 envelope protein-expressing, natural killer (NK)-sensitive human target cells, and to investigate this effector function in HIV-infected individuals.

Design and methods: An HIV-1 env gene-containing expression vector was transfected into NK-sensitive K562 cells, and cell clones expressing gp120/41 were selected and used as targets in natural cytotoxicity assays using PBMC from both HIV-seropositive and seronegative individuals. A 16h 51Cr-release assay was used to determine the susceptibility of the gp120/41-expressing K562 as well as control vector-transfected cells. To identify the cell types involved in the killing of the transfected cells, PBMC depleted for a specific cell type as well as enriched or purified cell types were used as effector cells.

Results: Endogenous expression of gp120/41 by target cells increased their susceptibility to lysis by PBMC of HIV-seronegative individuals. The two cell types responsible for this enhanced killing, NK cells and monocytes, were found severely compromised in HIV-seropositive individuals in their ability to kill both env gene-transfected and control cells; killing by monocytes occurred via CD4.

Conclusions: The present results illustrate for the first time that the transfected gp120/41 serves as target for both NK and monocyte-mediated killing and that cytocidal activity of these two effector cell types is defective in HIV-infected subjects. Strengthening this innate cytotoxic activity in these individuals may represent a valuable approach in controlling HIV infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • CD4 Antigens / immunology
  • CD4-Positive T-Lymphocytes / immunology
  • Cell Fusion / immunology
  • Cytotoxicity, Immunologic / immunology*
  • Genes, env / genetics
  • HIV Envelope Protein gp120 / biosynthesis
  • HIV Envelope Protein gp120 / immunology*
  • HIV Envelope Protein gp41 / biosynthesis
  • HIV Envelope Protein gp41 / immunology
  • HIV Infections / immunology*
  • HIV-1 / immunology*
  • Humans
  • Killer Cells, Natural / immunology*
  • Leukemia, Erythroblastic, Acute
  • Leukocytes, Mononuclear / immunology
  • Lymphocyte Subsets
  • Monocytes / immunology*
  • Transfection
  • Tumor Cells, Cultured


  • CD4 Antigens
  • HIV Envelope Protein gp120
  • HIV Envelope Protein gp41