FIG. 5.

Bacterial internalization is required to generate a cytokine response to B. hermsii in the absence of TLR2. Bone marrow-derived macrophages (BMDMs) (A) or peritoneal exudate cells (B) of either wild-type or TLR2^−/− mice were stimulated for 24 h with Dulbecco's phosphate-buffered saline (DPBS) or B. hermsii at a multiplicity of infection of 10 (A) or 1 (B) with or without preincubation with cytochalasin D, an actin polymerization inhibitor that blocks endocytosis (3 μM [A]; 1 μM [B]). IL-6 levels in the culture supernatant were measured by ELISA.