B cell cytokine expression.

<p>(A) B cell subsets are sort purified from healthy control peripheral blood and then stimulated for 4 days with 2.5 μg/ml CPG 2006, 2.5 μg/ml anti-CD40, and 50 U/ml IL-2 followed by PMA/ionomycin for 4.5 hours. Intracellular expression of TNF versus IL10 in each subset is quantitated. TNF expression is significantly higher in the USM and SM than the transitional B cells. IL-10 is significantly lower in the SM than in naïve, transitional, and USM B cells. SM B cells have a significantly higher ratio of TNF+ to IL10+ B cells than naïve and transitional (*p<0.05, **p<0.005) (Paired t-test). N = 6 healthy controls. (B) Total PBMCs are stimulated for 4 hours with PMA/ionomycin to compare B cell cytokine expression in untreated RA (n = 6) versus RA after BCD and reconstitution (n = 6) ranging from 15 to 32 months after rituximab (mean = 22 months) versus HC (n = 8). The intracellular expression of TNF, IL10, and IL6 is examined in CD19 gated B cells. B cell expression of TNF is significantly reduced in RA after reconstitution (**p<0.005) (Mann-Whitney). There are no significant differences in IL10 and IL6 producing B cells. The ratio of TNF to IL10 producing B cells is significantly lower in RA after BCD/reconstitution (*p<0.05). Data is expressed as the mean +/- SEM.