BACKGROUND: Vitamin D has immunomodulatory properties, such as regulation of FOXP3 expression and regulatory T-cell activity. Our aim was to investigate whether plasma 25-hydroxyvitamin D [25(OH)D] concentrations associate with the development of β-cell autoimmunity and the transcriptional activity of FOXP3 or vitamin D3 convertase gene (CYP27B1) in CD4+ memory T cells. METHODS: We studied 83 Finnish and 32 Estonian children participating in the DIABIMMUNE and DIPP studies. Twenty-nine Finnish and six Estonian children tested positive for at least one diabetes-associated autoantibody. The plasma concentrations of 25(OH)D and 1,25(OH)₂D were analysed with an enzyme immunoassay. Gene expression of FOXP3 and CYP27B1 in the isolated CD4+ memory T cells was studied with reverse transcription quantitative polymerase chain reaction. RESULTS: Vitamin D status did not differ between subjects positive and negative for β-cell autoantibodies. Finnish children had higher vitamin D status than Estonian children (p < 0.001). FOXP3 expression was higher in Estonian CD4+ memory T-cell samples than in Finnish samples (p < 0.01) even when including in both groups only children with serum 25(OH)D concentrations in the range of 50-80 nmol/L (p < 0.001). CONCLUSIONS: These findings do not support a crucial role of circulating 25(OH)D as a regulator of β-cell autoimmunity or FOXP3 expression.
BACKGROUND:Vitamin D has immunomodulatory properties, such as regulation of FOXP3 expression and regulatory T-cell activity. Our aim was to investigate whether plasma 25-hydroxyvitamin D [25(OH)D] concentrations associate with the development of β-cell autoimmunity and the transcriptional activity of FOXP3 or vitamin D3 convertase gene (CYP27B1) in CD4+ memory T cells. METHODS: We studied 83 Finnish and 32 Estonian children participating in the DIABIMMUNE and DIPP studies. Twenty-nine Finnish and six Estonian children tested positive for at least one diabetes-associated autoantibody. The plasma concentrations of 25(OH)D and 1,25(OH)₂D were analysed with an enzyme immunoassay. Gene expression of FOXP3 and CYP27B1 in the isolated CD4+ memory T cells was studied with reverse transcription quantitative polymerase chain reaction. RESULTS:Vitamin D status did not differ between subjects positive and negative for β-cell autoantibodies. Finnish children had higher vitamin D status than Estonian children (p < 0.001). FOXP3 expression was higher in Estonian CD4+ memory T-cell samples than in Finnish samples (p < 0.01) even when including in both groups only children with serum 25(OH)D concentrations in the range of 50-80 nmol/L (p < 0.001). CONCLUSIONS: These findings do not support a crucial role of circulating 25(OH)D as a regulator of β-cell autoimmunity or FOXP3 expression.
Authors: Marjaana Mäkinen; Juha Mykkänen; Maarit Koskinen; Ville Simell; Riitta Veijola; Heikki Hyöty; Jorma Ilonen; Mikael Knip; Olli Simell; Jorma Toppari Journal: J Clin Endocrinol Metab Date: 2015-12-22 Impact factor: 5.958
Authors: Helena H Hauta-Alus; Elisa M Holmlund-Suila; Hannu J Rita; Maria Enlund-Cerullo; Jenni Rosendahl; Saara M Valkama; Otto M Helve; Timo K Hytinantti; Heljä-Marja Surcel; Outi M Mäkitie; Sture Andersson; Heli T Viljakainen Journal: Eur J Nutr Date: 2017-03-02 Impact factor: 5.614
Authors: Sari Niinistö; Maija E Miettinen; David Cuthbertson; Jarno Honkanen; Leena Hakola; Reija Autio; Iris Erlund; Petra Arohonka; Arja Vuorela; Taina Härkönen; Heikki Hyöty; Jeffrey P Krischer; Outi Vaarala; Mikael Knip; Suvi M Virtanen Journal: Front Immunol Date: 2022-05-25 Impact factor: 8.786