Figure 6.

LTβR signaling regulates IL-6 pathway in liver regeneration. (A) Reduced IL-6 levels in serum of WT mice treated with LTβR inhibitors. Wild-type mice were treated with the LTβR fused to the human Fc portion of IgG (LTβR-Ig) or anti-LTβ antibody (100 μg) 2 hours before partial hepatectomy. (B) Increased IL-6 mRNA expression in livers of Rag mice after anti-LTβR stimulation. The levels of IL-6 in Rag mice treated with anti-LTβR agonistic antibody (ACH6, 75 μg) and control hamster antibody (H4/8, 75 μg) were measured in livers at 6 hours after PH by real-time RT-PCR (5 mice per group). (C) Increased IL-6 production in serum of Rag mice after anti-LTβR stimulation. IL-6 levels in Rag mice injected with anti-LTβR (ACH6, 75 μg) and control hamster antibody (H4/8, 75 μg) were measured in serum at 6 hours after PH by cytokine bead assay (BD Biosciences, San Jose, CA). (D) LIGHT and TNF synergistically induce IL-6 in a LTβR-dependent manner. WT mouse embryonic fibroblasts were incubated with DMEM and 0.3% FCS with the indicated concentrations of recombinant LIGHT and TNF for 24 hours. Supernatants were analyzed in triplicates for the presence of IL-6 by sandwich ELISA. LTβR-Ig (1 μg/mL) effectively blocked IL-6 expression induced by LIGHT and TNF. (E) Anti-LTβR stimulation promotes TNF production by macrophages. TNF levels were measured in supernatants of thioglycolate-elicited peritoneal macrophages stimulated in vitro with indicated doses of anti-LTβR antibody (ACH6) by cytokine bead assay (BD Biosciences) (F) Increased expression of TNF in livers of Rag mice after anti-LTβR stimulation. Increased TNF mRNA expression in livers of Rag mice after anti-LTβR stimulation. IL-6 levels in control untreated Rag and anti-LTβR agonistic antibody (ACH6, 75 μg) Rag-treated mice (5 mice per group) were measured in livers at 6 hours after partial hepatectomy by real-time RT-PCR. All panels represents 1 of 2 independent experiments.