Effects of tumor necrosis factor receptor 1 (TNFR1) silencing in the hepatic and splenic reticuloendothelial system. One day after collagen booster, mice negative for collagen-induced arthritis were injected intravenously with 3 × 108 ffu hairpin construct targeting TNFR1 (HpTNFR1) or hairpin non specific (HpNS). (a) Expression of indicated genes in liver isolated at day 26. Data are represented as mean (n = 5) of the difference in ΔCt values compared with the HpNS group (ΔΔCt). (b) Analysis of intra-cellular cytokine expression in T cells isolated from spleen at day 26. Data are represented as mean ± standard error of the mean (SEM) (n = 4) of the percentage of positive cells compared with the HpNS group. (c) Expression of indicated genes in isolated splenic T cells. Data are represented as mean (n = 5) of the difference in ΔCt values compared with the HpNS group (ΔΔCt). (d) Secreted cytokine levels from splenic antigen-presenting cells stimulated for 24 hours with 10 ng/mL mTNFα. Data are represented as mean ± SEM (n = 5). Statistical differences were calculated using analysis of variance with Bonferroni post-test. *P < 0.05, **P < 0.01. Ct, cycle threshold; IL, interleukin; TNF, tumor necrosis factor.