Fig. 2

Differential effects of human and mouse CD28 stimulation in Treg cell expansion and pro-inflammatory function of naïve and effector CD4⁺ T cells. a CD4⁺CD25^highFOXP3⁺ Treg expansion by 2 μg ml⁻¹ isotype control Abs (Ig) or superagonistic anti-CD28 Abs (ANC28.1 or D665) in CD4⁺ T lymphocytes from human HD (n = 5) or mouse (n = 4). The percentage of CD4⁺CD25^highFOXP3⁺ Treg cells were calculated. Lines represent mean values ± SD and p-values were calculated by Student’s t-test. mRNA levels of IL-8 (b), TNF (c), IL-2 (d), IL-1β (e), and IFN-γ (f) in naïve (CD45RA+) or effector/memory (CD45RO+) CD4⁺ T cells from HD (n = 3) stimulated for 1 h (c, e) or 6 h (b, d, f) with 2 μg ml^-1 of crosslinked CD28.2 (b) or ANC28.1 (c–f) Abs. Cytokine mRNA levels were measured by real-time PCR after normalisation to GAPDH (human) or RLP32 (mouse). Fold inductions (F.I.) were calculated over the basal level of cells stimulated with control Ig. Bars indicate mean F.I. ± SD. Statistical significance was calculated by Student’s t-test. NS not significant