Figure 1.

In response to lipopolysaccharide (LPS) stimulation, hepatic B cells exhibit greater expression of activation markers and produce more interferon (IFN)-γ, interleukin (IL)-6 and tumour necrosis factor (TNF)-α, but less IL-10 than those from secondary lymphoid tissue. (a,b) Expression of cell surface activation markers on murine B cells following in-vivo LPS stimulation. C57BL/6 (B6) mice were injected intraperitoneally (i.p.) with LPS. On days 0, 1 and 3 post-injection, the mice were examined for the expression of the indicated cell surface molecules on spleen versus hepatic B cells; n = 3 mice per group. On day 1, liver but not splenic B cells up-regulated expression of CD39, CD40, CD80 and CD86. (a) Histogram overlay of day 1 and controls. (b) Data are graphed to compare the spleen and liver B cells on days 0 (control), 1 and 3; *P < 0·05. Data are representative of two independent experiments. (c) Spleen and hepatic B cells were purified from three individual mice using immunomagnetic beads, then cultured with 500 ng/ml phorbol myristate acetate (PMA), 1 μM ionomycin and 10 μg/ml LPS for 48 h before measuring the concentration of secreted IFN-γ, IL-6, TNF-α and IL-10 using cytometric bead assay (CBA) Flex Sets. Splenic B cells produced significantly greater amounts of IL-10 than hepatic B cells; ***P < 0·001; n = 3. Data are representative of two independent experiments. (d,e) Liver or spleen cells from normal B/6 or IL-10 reporter mice were cultured with 500 ng/ml PMA, 1 μM ionomycin and 10 μg/ml LPS in the presence of GolgiStop for 5 h. They were then tested for the frequency of B10 cells in normal B/6 mice by intracellular staining of IL-10 and surface staining of CD19 and the frequency of B10 cells in IL-10 reporter mice by green fluorescent protein (GFP)-IL-10 and surface staining of CD19. A greater proportion of splenic B cells than hepatic B cells produced IL-10; n = 3 mice. Data are representative of two independent experiments.