Immunomodulatory Effect of 1,25- Dihydroxyvitamin D3 on Interferon Gamma (INFγ) Secretion by TH1 Lymphocyte in Normal Population in-vitro

Abstract

Background: Vitamin D as 1,25(OH)2D functions by binding to a nuclear vitamin D receptor VDR and retinoid X receptor to regulate gene transcription. Aim of the Work: The aim of this study is to assess the role of Vitamin D3 in modulating the in-vitro, production of IFNγ by Th1 lymphocytes in normal Egyptian population. Subjects and Methods: The study was conducted at Clinical Pathology Department, Ain Shams University Hospitals. Thirty healthy individuals were enrolled in the study. They were 23 males and 7 females with age ranges from 25 to 50 years old (29.57 mean±10.02 2SD years old). Exclusion criteria for the subjects included abnormal liver and/or kidney functions. Result: IFN-γ levels in culture supernatants in presence of vitamin D ranged from 0.07 to 0.64 ng/ml with 0.37 mean±0.16 2SD. This difference proved to be highly statistically significant (p<0.001) being lower in presence of vitamin D. Conclusion: a highly significant decrease in the culture supernatant IFN-γ levels in presence of vitamin D which may explain the role of vitamin D as immunomodulatory agent that can suppress Th1 cytokine production in-vivo and polarize adaptive immune system away from Th1 towards Th2 responses. Recommendations: Assessment of vitamin D as an immunomodulatory agent and role of vitamin D supplements in prevention and therapy of related diseases. Key words: vitamin D, 1,25(OH)2D, lymphocytes, VDR, immunomodulatory agents