Effect of the Gc-derived macrophage-activating factor precursor (preGcMAF) on phagocytic activation of mouse peritoneal macrophages

Anticancer Res. 2011 Jul;31(7):2489-92.


Background: The 1f1f subtype of the Gc protein (Gc(1f1f) protein) was converted into Gc-derived macrophage-activating factor (GcMAF) by enzymatic processing in the presence of β-galactosidase of an activated B-cell and sialidase of a T-cell. We hypothesized that preGc(1f1f)MAF, the only Gc(1f1f) protein lacking galactose, can be converted to GcMAF in vivo because sialic acid is cleaved by residual sialidase. Hence, we investigated the effect of preGc(1f1f)MAF on the phagocytic activation of mouse peritoneal macrophages.

Results: We examined the sugar moiety of preGc(1f1f)MAF with a Western blot using peanut agglutinin (PNA) and Helix pomatia agglutinin (HPA) lectin. We also found that preGc(1f1f)MAF significantly enhanced phagocytic activity in mouse peritoneal macrophages but only in the presence of the mouse peritoneal fluid; the level of phagocytic activity was the same as that observed for GcMAF.

Conclusion: PreGc(1f1f)MAF can be used as an effective macrophage activator in vivo.

MeSH terms

  • Animals
  • Drug Evaluation, Preclinical
  • Female
  • Galactose / metabolism
  • Glycosylation
  • Macrophage Activation / drug effects*
  • Macrophage-Activating Factors / biosynthesis
  • Macrophage-Activating Factors / chemistry
  • Macrophage-Activating Factors / pharmacology*
  • Macrophages, Peritoneal / drug effects*
  • Macrophages, Peritoneal / physiology
  • Mice
  • Mice, Inbred ICR
  • Molecular Structure
  • N-Acetylneuraminic Acid / metabolism
  • Neuraminidase / metabolism
  • Phagocytosis / drug effects*
  • Protein Precursors / chemistry
  • Protein Precursors / pharmacology*
  • Protein Processing, Post-Translational
  • Vitamin D-Binding Protein / chemistry
  • Vitamin D-Binding Protein / metabolism


  • Macrophage-Activating Factors
  • Protein Precursors
  • Vitamin D-Binding Protein
  • preGc1f1fMAF protein, human
  • Neuraminidase
  • N-Acetylneuraminic Acid
  • Galactose