Fig. 3.

IgG production by PBLs in direct co-culture with IVD and MSCs. After 7 days, 70% of IVD analyzed responded to IVD stimulation and MSC immunosuppressive action (a) (data normalized to disc alone). IVD and PBLs co-culture produced unequal increase in IgG production among different samples (individual samples depicted by a line). The addition of MSCs in co-cultures reduced this increase by more than one-third on an average (b). IgG production by PBLs stimulated by PWD and in co-culture with IVD. Only after 7 days, IgG production was strongly stimulated by PWD (32-fold increase when compared with day 1) (c), IVD immediately doubled the IgG production by PBLs (data normalized to negative control of the respective day). After 7 days, MSCs reduced by 83% and by 31% the IgG production by PWD and, respectively, IVD stimulated PBLs (d) (data normalized to positive control of the respective day; represented as a mean ± SD, *p < 0.05; when compared with day 1)