TLR2 is necessary to inflammatory response in Coxiella burnetii infection.

The resolution of Q fever, a zoonosis caused by Coxiella burnetii, depends on efficient innate and adaptive immune responses. Such responses are influenced by Toll-like receptors (TLRs). TLR4 is involved only in part in immune responses against C. burnetii, suggesting a role for TLR2. We investigated C. burnetii infection in wild-type and TLR2(-/-) mice. C. burnetii organisms were similarly eliminated by wild-type and TLR2(-/-) mice. In contrast, the formation of granulomas, a marker for efficient cell-mediated immunity, was markedly impaired. These results show that TLR2 is required for inflammatory and immune response to C. burnetii, but is dispensable for bacterial clearance.