Figure 3

Individuals with AA and AG genotypes are less susceptible to TNFα-mediated loss of CD28 expression. CD4⁺CD25⁻ T cells were activated with aCD3/aCD28 beads (two cycles of activation) in the presence or absence of TNFα and in the presence or absence of 1,25(OH)₂D₃ for 14 and 21 days. (A and B) Data show the proportion of CD4⁺CD25⁻ T cells that lost CD28 expression in the presence (TNFα) and absence of TNFα (Untreated) and in the presence or absence of 1,25(OH)₂D₃ after 14 and 21 days. (C) Data show the proportion of CD4⁺CD25⁻ T cells that lost CD28 expression in the presence of TNFα and in the simultaneous presence of TNFα and 1,25(OH)₂D₃ after 14 and 21 days in culture. Healthy individuals homozygous (AA) (n = 14) or heterozygous (AG) (n = 14) for the PSC risk SNP “rs7426056” in the CD28 locus and n = 14 homozygous for the protective allele (GG). Data show mean with SEM. *p < 0.05, **p < 0.01, ***p < 0.001 with Wilcoxon matched-pairs signed rank test.