Macrophages Exhibit a Large Repertoire of Activation States via Multiple Mechanisms of Macrophage-activating Factors

Anticancer Res. 2016 Jul;36(7):3619-23.

Abstract

Background/aim: Macrophages are important components of human defense systems and consequently key to antitumor immunity. Human-serum macrophage activation factor (serum MAF) can activate macrophages, making it a promising reagent for anticancer therapy.

Materials and methods: We established four different macrophage subtypes through introduction of different culture conditions to THP-1- and U937-derived macrophages. We assessed phagocytic activity to understand subtype responses to typical macrophage activation factors (MAFs) and the activation mechanisms of serum MAF.

Results: All four macrophage subtypes differed in their response to all MAFs. Moreover, serum MAF had two different activation mechanisms: N-acetylgalactosamine (GalNAc)-dependent and GalNAc-independent.

Conclusion: Macrophage activation states and mechanisms are heterogeneous.

Keywords: Immunotherapy; THP-1 cell line; U937 cell line; macrophage-activating factor; phagocytic activity.

MeSH terms

  • Humans
  • Lipopolysaccharides / pharmacology
  • Macrophage Activation*
  • Macrophage-Activating Factors / pharmacology*
  • Macrophage-Activating Factors / physiology
  • Macrophages / drug effects
  • Macrophages / physiology*
  • U937 Cells

Substances

  • Lipopolysaccharides
  • Macrophage-Activating Factors