Figure 4.

Arthritis in TLR7^-/- mice is associated with decreased IL-17 levels and increased T_reg cells. (a) Mice from Figure 3 were bled on day 10, and serum levels of IgG₁ and IgG_2a/c anti-collagen antibodies were measured by enzyme-linked immunosorbent assay as described in Materials and methods. (b, c) Draining lymph node cells (DLNCs) were isolated 10 days after disease onset and stimulated with 100 ng/mL anti-CD3 monoclonal antibody or 50 μg/mL chicken collagen, and supernatants were collected for the measurement of IL-17 (b) and interferon-gamma (IFNγ) (c). (d) DLNCs or cells liberated from the affected joints (e) were stained with conjugated antibodies to CD4 and foxp3 to determine the percentage of T_reg cells. *P < 0.05, **P < 0.01. IL-17, interleukin-17; LN, lymph node; No stim, no stimulation; N.S., not significant; TLR, Toll-like receptor; T_reg, T regulatory; WT, wild-type.