The immunomodulatory effect of minocycline on gene expression of inflammation related cytokines in lipopolysaccharide-treated human peripheral blood mononuclear cells

Abstract

To evaluate the immunomodulatory effect of minocycline, the present study was carried out on the gene expression of toll-like receptor type-4 (TLR4) and some pro-inflammatory (IL-1β, IL-6) and anti-inflammatory cytokines (IL-10) associated with lipopolysaccharide (LPS) -induced inflammation in human peripheral blood mononuclear cells (PBMCs). The PBMCs were collected and then 5.4 × 10⁶ PBMCs/mL were used in eight groups as follows: control group (only media), LPS group (only LPS), methylprednisolone (Pred) group (LPS plus Pred), meloxicam (Melo) group (LPS plus Melo), three minocycline groups [M1, M5 and M25] (LPS plus 1, 5, and 25 µg/mL minocycline, respectively) and minocycline control (MC) group (5 µg/mL minocycline). After incubation for 24 h, the PBMCs were subjected to quantitative PCR assays. Gene expression levels of TLR4 were not changed in any groups. The IL-1β levels were increased in the LPS group but the increases were much more intense in the other groups except Pred group. Compared with control group, IL-6 levels increased significantly in Melo, M1 and M25 groups. Significant increases of IL-10 levels were also observed in Melo, M25 and MC groups. It can be concluded that minocycline had dual pro- and anti-inflammatory activities with potential clinical immunomodulatory effects.

Keywords:

• Minocycline
• immunomodulatory
• cytokines
• gene expression
• in-vitro
• lipopolysaccharide

Acknowledgements

The authors wish to thank Dr. M.M. Dehghan, Dr. Z. Khaki, Dr. M. Taheri, Dr. V. Siavoshi and S. Yousefi for their assistance.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Authors also would like to acknowledge the partial financial support of Research Deputy, Faculty of Veterinary Medicine, University of Tehran [Grant No. 7506006/6/11].