Fig. 1

CD28 stimulation strongly upregulates pro-inflammatory cytokine and chemokine gene expressions in human but not in mouse CD4⁺ T cells. mRNA levels of splenic CD4⁺ T cells from n = 13 mice or human peripheral blood CD4⁺ T cells stimulated for 1 h or 6 h with 2 μg ml⁻¹ isotype control mAb (Ig) or crosslinked agonistic Abs (human CD28.2 or mouse 37.51) or CD28SAbs (human ANC28.1 or mouse D665), or anti-CD3 (human UCHT1 or mouse  145-2C11) plus anti-CD28 (human CD28.2 or mouse 37.51) Abs. a TNF (1 h stimulation). b IL-6 (1 h stimulation). c IFN-γ (1 h stimulation). d IL-2 (6 h stimulation). e IL-1β (1 h stimulation). f IL-8 (6 h stimulation). Median values: TNF (n = 7), ANC28.1 = 102.3 vs. D665 = 2.77; IL-6 (n = 6), ANC28.1 = 69.7 vs. D665 = 8.5; IFN-γ (n = 7), ANC28.1 = 22.5 vs. D665 = 1.94; IL-2 (n = 6), ANC28.1 = 214 vs. D665 = 176; IL-1β (n = 6), ANC28.1 = 34.0; IL-8 (n = 6), ANC28.1 = 13.1. g IL-6 (n = 8, median = 138.9), IL-8 (n = 9, median = 19.5), IFN-γ (n = 3, median = 6.8), and IL-2 (n = 5, median = 1.1) mRNAs levels upon 6 h stimulation of human CD4⁺ T cells with isotype control Ig or crosslinked human CD28.2. h IL-6 (median = 6.6), IFN-γ (median = 4.3), IL-2 (median = 0.8), and TNF (median = 2.6) mRNAs levels upon 6 h stimulation of murine CD4⁺ T cells with isotype control Ig or crosslinked mouse 37.51. i Human IL-2 (n = 8, median = 36.6) and mouse IL-2 (median = 40.8), j human IFN-γ (n = 7, median = 51.1) and mouse IFN-γ (median = 2.4) mRNA levels upon 6 h stimulation of CD4⁺ T cells with isotype control Ig or crosslinked anti-CD3 plus anti-CD28 Abs. All mRNAs were measured by real-time PCR and values, normalised to GAPDH (human) or RLP32 (mouse), expressed as arbitrary units (AU) or fold induction (F.I.). Lines represent median values and statistical significance was calculated by Mann–Whitney test. Asterisks indicate *p < 0.05, **p < 0.01, ***p < 0.001, calculated on cells stimulated with isotype control Ig