FIG. 3.

Stimulation with recombinant CIDR1α activates B cells. (A) CIDR1α induces the expression of B-cell activation markers and increased B-cell size. B cells incubated in medium alone (black) and in medium containing 50 μg of either GST (green) or CIDR1α (red) per ml for 72 h were stained with FITC- or PE-conjugated MAbs and analyzed by flow cytometry. Dotted-black-line histograms represent control staining with irrelevant Ab. Results are representative of at least 10 independent experiments. (B) CIDR1α stimulates B cells to produce IgM, IL-6, and TNF-α. Supernatants of B cells cultured in medium alone and in medium containing 50 μg of either GST or CIDR1α per ml were analyzed for the content of TNF-α (24 h), IL-6 (72 h), or IgM (10 days) by specific ELISA. For further details, see Materials and Methods. FSC, forward scatter.