Fig. 5.

SXR modulates signaling of the B-1a compartment, and ligand activation inhibits proliferation signals. A–D, SXR positively regulates negative regulators of B-1 cell proliferation. Expression levels of Siglec-G, PTPN6, Lck, and Zap-70 as measured by qRT-PCR relative to controls. E and F, Phosflow detection of Lck and Zap-70 phosphorylation events on IgM⁺ peritoneal B cells. Representative experiments for Lck Y505 and Zap-70 Y319 are shown, and the mean fluorescent intensity and sem for all animals is indicated. G and H, SXR activation inhibits B-1a cell proliferation signaling. Expression levels of Siglec-G, PTPN6, Lck, and Zap-70 are measured by qRT-PCR after 3 d PCN treatment via ip injection (10 mg/kg).