Dexamethasone modulates melatonin MT2 receptor expression in splenic tissue and humoral immune response in mice

Abstract

Melatonin modulates immune function through its membrane-bound MT1 and MT2 receptors in mammalian system. Adrenal glucocorticoid, an important metabolic hormone is known as a immuno-compromising agent. In the present study, we investigated the effect of dexamethasone on melatonin receptor proteins in spleen tissue and anti-klh-IgG response in Swiss albino mice. Melatonin treatment increased the MT1 and MT2 receptor proteins and anti-klh-IgG than control mice. Dexamethasone treatment increased MT2 receptor protein and anti-klh-IgG than melatonin-treated group. Dexamethasone treatment to melatonin-treated mice showed additive effects and maximally increased the anti-klh-IgG than other experimental groups. A decrease in glucocorticoid receptor (GR) protein was noted in melatonin treated as well as dexamethasone-treated mice. Dexamethasone significantly increased MT2 melatonin receptor protein in spleen and anti-klh-IgG and additively increased anti-klh-IgG when supplemented along with melatonin. Therefore, the present study may suggest that dexamethasone increased humoral immune response permissively by enhancing MT2 receptor expression in splenic tissue of mice.

Keywords:

• Melatonin
• dexamethasone
• humoral response
• MT1 and MT2 receptor
• glucocorticoid receptor

Acknowledgment

Financial support from Council of Scientific and Industrial Research, New Delhi and, University Grants Commission, New Delhi and help from establishment of State Biotech Hub, Tripura University are gratefully acknowledged.