Phagocytosis of tumor cells by human monocytes cultured in recombinant macrophage colony-stimulating factor. Academic Article uri icon

Overview

abstract

  • Macrophages and cultured human monocytes can mediate efficient antibody-dependent cytotoxicity (ADCC) against human tumor cells using monoclonal antibodies (mAbs). The mechanism of this killing is usually assumed to involve secreted factors (reactive oxygen intermediates, tumor necrosis factor, or other cytotoxic factors) leading to target cell lysis. In this study, we present evidence that phagocytosis of intact target cells is the principal mechanism of antitumor cytotoxicity in our in vitro model of ADCC by cultured monocytes. Human monocytes cultured in recombinant human macrophage colony-stimulating factor ingested up to 100% of fluorochrome-labeled melanoma and neuroblastoma target cells, in the presence of an appropriate antitumor mAb. Electron microscopy demonstrated phagocytosis of intact tumor cells by cultured monocytes during ADCC. All of the radionuclide in radiolabeled target cells was taken up by monocytes during phagocytosis. By preventing the release of radioisotope tracers, phagocytosis thus prevents the detection of this very efficient form of cytotoxicity by most conventional assays.

publication date

  • July 1, 1990

Research

keywords

  • Antibody-Dependent Cell Cytotoxicity
  • Colony-Stimulating Factors
  • Monocytes
  • Neoplasms
  • Phagocytosis

Identity

PubMed Central ID

  • PMC2188164

Scopus Document Identifier

  • 0025326953

PubMed ID

  • 2193096

Additional Document Info

volume

  • 172

issue

  • 1