Arginase activity in a murine macrophage cell line (RAW264.7) stimulated with lipopolysaccharide from Actinobacillus actinomycetemcomitans

  • Oral Microbiol Immunol. 2006 Jun;21(3):145-50. doi: 10.1111/j.1399-302X.2006.00262.x.
W Sosroseno  1 ,  M Musa ,  M Ravichandran ,  M Fikri Ibrahim ,  P S Bird ,  G J Seymour
Affiliations
  • 1. Department of Oral Biology, School of Dental Sciences, University Sains Malaysia, Kota Bharu, Malaysia. [email protected]
PMID: 16626370 DOI: 10.1111/j.1399-302X.2006.00262.x
Abstract

Aims: The aim of the present study was to determine whether or not lipopolysaccharide from Actinobacillus actinomycetemcomitans could stimulate Arginase activity in a murine macrophage cell line (RAW264.7 cells).

Methods: RAW264.7 cells were treated with A. actinomycetemcomitans-lipopolysaccharide or lipopolysaccharide from Escherichia coli for 24 h. The effect of polymyxin B, l-norvaline, dl-norvaline, dexamethasone and cytokines (interferon-gamma and interleukin-4) on Arginase activity in A. actinomycetemcomitans-lipopolysaccharide-stimulated cells was also determined. The cells were pretreated with anti-CD14, anti -toll-like receptor 2, or anti-toll-like receptor 4 antibody prior to stimulation with A. actinomycetemcomitans-lipopolysaccharide. Arginase activity was determined by a colorimetric assay.

Results: A. actinomycetemcomitans-lipopolysaccharide stimulated Arginase activity in RAW264.7 cells in a dose-dependent manner, but was less potent than E. coli-lipopolysaccharide. Polymyxin B and l-norvaline, but not dl-norvaline, blocked the Arginase activity in A. actinomycetemcomitans-lipopolysaccharide-stimulated cells. Dexamethasone and interleukin-4 but not interferon-gamma augmented Arginase activity in A. actinomycetemcomitans-lipopolysaccharide-stimulated cells. Treatment of the cells with anti-CD14 and anti-toll-like receptor 4 but not anti-toll-like receptor 2 antibody decreased Arginase activity in A. actinomycetemcomitans-lipopolysaccharide-stimulated cells.

Conclusion: The results of the present study suggest that lipopolysaccharide from A. actinomycetemcomitans via CD14/Toll-like Receptor 4 complex molecules and the regulatory control of glucocorticoid and cytokines may stimulate Arginase activity in RAW264.7 cells.

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