Antibody blockade of IL-23 attenuates proinflammatory cytokine production and decreases gene expression of IL-23 and IL-23R in the colon microenvironment. (A) Lethally irradiated Balb/c mice were transplanted with B6 BM plus spleen cells adjusted to yield 0.225 to 0.4 × 106 T cells. Cohorts of mice were then treated with either isotype control (n = 11) or p19 antibody (n = 15) once weekly. Mice were killed 32 to 35 days after transplantation, and colon explant tissue was assayed for levels of proinflammatory cytokines by multiplex. Data are derived from cumulative results from 3 experiments and are the mean amount of cytokine divided by the weight of cultured colon tissue ± SEM. (B-C) RNA was extracted from colon tissues obtained from animals transplanted in panel A that were treated with either isotype control or p19 antibody. Gene expression of IL-23 (B) or IL-23R (C) mRNA levels was analyzed by real-time quantitative PCR as described in “Real-time quantitative PCR.” Data are normalized for 18S ribosomal RNA and presented as fold increase over 18S RNA ± SEM. Data are cumulative results from 3 independent experiments for mice treated with either isotype control or p19 antibody. *P ≤ .05. **P < .01.
