Figure 1.

1α,25-dihydroxyvitamin D3 (1,25(OH)₂D3) up-regulates CD73 expression on CD4⁺ T cells. CD4⁺ T cells stimulated with anti-CD3 and interleukin-2 (IL-2) for 7 or 14 days alone (−) or in the presence of the indicated concentration of 1,25(OH)₂D3 (10^−x m). (a) Relative gene expression of cd73 as determined by quantitative RT-PCR at days 7 (n = 8) and 14 (n = 6). (b) Representative histograms of CD73 expression (bold line) compared with isotype control (grey shaded). (c) Cumulative data of the percentage of CD4⁺ CD73⁺ T cells (c i) and CD73 mean fluorescence intensity (c ii) at days 7 (top; n = 8) and 14 (bottom, n = 6). Data assessed by repeated measures one-way analysis of variance with Tukey's multiple comparison test. *P ≤ 0·05; **P ≤ 0·01.