RT-PCR analysis of joint tissue at 2 weeks post infection with B. burgdorferi from B6 (N=8), B6 IL-10−/− (N=8), LY5.1→ B6 IL-10−/− chimeras (N=8), and B6 IL-10−/−→ B6 IL-10−/− chimeras (N=6). Expression of IL-10 (A), IFN-γ (B), CXCL9 (C), and CXCL10 (D), was normalized to β-actin. The term ‘ND’ indicates that IL-10 transcripts were not detected (A). Statistical analysis was performed as described in Materials and Methods.