FIGURE 6.

Modulation of cytokine secretion by Bmem cells. (A) Transiently transfected PBMCs with HCK p59 or FGR in the presence of FCRL4 wt or “empty vector” control were stimulated with CpG at 5 μg/ml or PBS as negative control for 48 h, followed by intracellular staining of Bmem cells for IL-10, TNF-α, IFN-γ, and IL-6, and assessment of changes in the percentage of cytokine-expressing cells. Bmem gating was set on CD3⁻/CD20⁺/CD27⁺ lymphocytes. Between 6 and 10 independent samples were cotransfected with plasmids encoding FCRL4 wt and the indicated src-family members (identified as mCD4⁺, as shown in Supplemental Fig. 1D). Statistically significant differences for CpG-induced cytokine expression in the presence or absence of FCRL4 wt are indicated by asterisks (*p < 0.05, **p < 0.01) and were determined using the paired Student t test. (B) Mutually exclusive pattern of expression of IL-10 and IFN-γ in transfected Bmem cells.