Figure 4

Involvement of IL-17A, TNF-α in the increase of the proliferation of T cells co-cultured with SMSCs. (A1, B1) In synovial T cells proliferation assay, the differences of absorbance between 0 days and 5 days without PHA were not significant (P > 0.05), whereas the value for 5 days with PHA was significantly higher than the value at 0 days (P < 0.05); in SMSCs proliferation assay, no differences were noted between 0 days and 5 days with or without PHA; in the coculture of synovial T cells and SMSCs, the absorbance for 5 days with PHA was significantly lower than the value at 0 days or 5 days without PHA (P < 0.05). (A2, B2) In synovial T cells activated by PHA and SMSCs cocultured in the presence of cytokines assay, the increase of the proliferation (% proliferation) of T cells was significant in the presence of IL-17A or TNF-α (P < 0.05). However, no effect was observed when IFN-γ was added (P > 0.05). In addition, the increase of proliferation was significant when cytokines were added in combination (P < 0.05). (A3, B3) IL-17A and TNF-α had no effect on RA-SMSC or synovial T-cells cultured alone at 5 days with or without PHA (P > 0.05). Results were recorded as mean absorbance (optical density (OD)) ± standard deviation (SD) and as mean counts per minute (CPM) ± SD, respectively. The percentage proliferation values were calculated by using the following formulae: % proliferation = (OD(exp) − OD(adj))/OD(bla) or % proliferation = (CPM(exp) − CPM(adj))/CPM(bla). OD(exp), OD(adj), and OD(bla) represent the mean absorbance of experimental wells, adjusted wells (only SMSCs), and blank wells, respectively, and CPM(exp), CPM(adj), and CPM(bla) represent the mean counts per minute of the corresponding wells. Results were finally expressed as the mean (% proliferation) ± SD.