Establishment and assessment of the delayed-type hypersensitivity (DTH)-arthritis model. (a) Protocol for induction of DTH arthritis in mice. (b) Paw swelling (calculated as Δpaw swelling = left paw swelling - right paw swelling) on days 0 to 28 after antigen (Ag) challenge for the group that received anti-type II collagen antibody cocktail (anti-CII) + challenge. For the other two groups, paw swelling until day 14 after arthritis induction is shown. Mean ± standard error of the mean (SEM) is displayed (n = 9 per group). (c) Clinical score of the Ag-challenged paw on days 0 to 28 after Ag challenge for the group that received anti-CII + challenge. For the other two groups, area under the curve (AUC) of the paw swelling until day 14 after arthritis induction is shown. The median is shown (n = 9 per group). (d) Titration of anti-CII. AUC for days 0 to 11 after DTH-arthritis induction is shown for the groups receiving anti-CII + challenge. For the group receiving anti-CII and no challenge and the group receiving isotype cocktail and challenge, AUC for days 0 to 9 after DTH-arthritis induction is shown. Mean ± SEM is shown (n = 6 to 19 per group). (e) Ag-specific proliferation assay of cells isolated from the popliteal lymph node draining either the Ag-challenged or the phosphate-buffered saline (PBS)-challenged paw from mice receiving either anti-CII or isotype cocktail. Counts per minute (CPM) relative to the degree of 3H incorporation are shown with mean ± SEM (n = 3) in triplicate wells. (f) Serum levels of interleukin-6 (IL-6) on selected time points after DTH-arthritis induction. Mean ± SEM is shown (n = 5 per time point). (g) Serum levels of acute-phase protein serum amyloid P component (SAP) on selected time points after DTH-arthritis induction. Mean ± SEM is shown (n = 5 per time point). ***P ≤ 0.001. αCII, anti-type II collagen monoclonal antibody cocktail; i.v., intravenous; mAb, monoclonal antibody; mBSA, methylated bovine serum albumin.