Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 21 4 2022 08 12 429 440 Marziyeh Mohammadi Kordkhayli Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran AND Hotchkiss Brain Institute, Department of Clinical Neurosciences, University of Calgary, Calgary, Canada Fatemeh Mansouri Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Farideh Talebi Immunoregulation Research Center, Shahed University, Tehran, Iran Farshid Noorbakhsh Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Ali Akbar Saboor-Yaraghi Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran 2022 04 20 2022 07 27 Vitamins A, D, and microRNAs contribute to T cell differentiation into TH2 phenotypes. We investigated the molecular mechanisms and effects of vitamin A and D on the expression of GATA3 and miR-27-3p isoforms in experimental autoimmune encephalomyelitis (EAE) animal model of multiple sclerosis. EAE was induced in C57BL/6 mice by immunization with myelin oligodendrocyte glycoprotein, mixed with Complete Freund's Adjuvant, together with injection of pertussis toxin. Treatments began one day before immunization with (200 μg and 100 ng of vitamin A and vitamin D per mouse, respectively, and vitamin A+D (100 μg+50 ng) per mouse. Expression levels of GATA3 and miR‑27‑3p isoforms were measured in the CNS and splenocytes by real-time RT-PCR. The expression level of GATA3 in the mice spinal cords and splenocytes was increased in the vitamin A and A+D-treated EAE mice at 24 h and 48 h after restimulation by 10 µg and 40 µg of myelin oligodendrocyte glycoprotein. Vitamins A and D and their combination upregulated the miR-27-3p isoforms compared with EAE mice with no treatments. We also demonstrated that miR-273p isoform expression was altered in splenocytes of vitamin-treated EAE mice. The results showed a positive correlation between splenocyte GATA3 levels and miR-27-3p isoform expression. The protective impacts of vitamins A and D in EAE mice may be mediated by the upregulation of GATA3. However, it is not specified whether suppression of GATA3-targeting miRNAs of the miR-27-3p family is involved in this effect. These results do not rule out the possibility that miR-27-3p isoforms might have beneficial effects by targeting other transcripts, such as GluA2 and NR2B. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/3527 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/3527/1873