Fig. 4: CSPGs and its prominent member, versican-V1, promote Th17 differentiation and IL-17 production.

To assess the effect of ECM molecules on T cells, naïve CD4⁺ T cells were cultured on ECM-coated wells (10 µg/ml) and were then activated and polarized to Th1, Th17 or Treg subset. The frequency of IFN-γ, IL-17 or FOXP3 expressing T cells was determined using flow cytometry 4 days later. a Representative histograms showing the frequency of IFN-γ, IL-17 or FOXP3 immunopositive T cells in control (green) or following CSPG treatment (red); isotype antibody control (blue) is also displayed. b The fold change of Th1 (71.7% Vs & 72.13%; n = 10 replicates), Th17 (18.64% Vs 23.61%; n = 11 replicates) and Treg (21.34% Vs 21.98%; n = 9 replicates) frequency is shown as a bar graph across 3 experiments. Data are presented as mean ± SEM, two-way ANOVA - Bonferroni post hoc; ***p < 0.001. c, d Bar graph presenting the percentage of IL-17⁺RORγ⁺ Th cells resulting from a commercial mixed CSPG preparation (10 µg/ml) compared to purified versican-V1 (20 µg/ml) (Control:9.6%, CSPG:12.31%, Versican-V1: 13.53%) c or other ECM molecules (10 µg/ml) d; n = 9 replicates over three separate experiments. e Level of IL-17 in the conditioned medium of Th17 polarized cells measured by ELISA (Control: 1948 pg/ml, CSPG: 2800 pg/ml); n = 9 replicates over three separate experiments. f Frequency of Th17 cells after exposing cultures to signaling pathway inhibitors of CSPG receptors (PTPσ and LAR) using intercellular peptide (ISP and ILP, respectively, 2.5 μM), n = 11 replicates for control and CSPGs, n = 9 replicates for other conditions, over three separate experiments. g Frequency of Th17 cells after exposing cultures to function blocking antibodies to the integrin β1, β3, or β6 (50 µg/ml); n = 9 replicates over three separate experiments. Data presented as mean ± SEM. One-way ANOVA - Bonferroni post hoc; *p = 0.01, ***p < 0.001. Source data are provided in the source data file.