FIG 5.

Role of CD11b in adhesion and uptake of L. rhamnosus GG by RAW 264.7 cells and effect of TLR2 in the subsequent immunomodulatory response. (A) Role of CD11b in adhesion of the mutants to macrophages (left) and phagocytosis of the mutants by macrophages (right) relative to the results for the wild-type strain, which were set equal to 1. Bacterial strains (5 × 10⁷ CFU/ml) were coincubated for 1 h with 1 × 10⁶ RAW 264.7 cells that had previously been treated with anti-mouse CD11b monoclonal antibody (5 μg/ml) for 30 min. The data are presented as the mean relative adhesion or phagocytosis ± standard deviation. These experiments were done in triplicate. Asterisks represent statistically significant differences compared to the results for the controls (no antibody treatment). (B) The effect of TLR2 on the relative levels of IL-10 and IL-6 mRNA expression by RAW 264.7 macrophages was analyzed by pretreatment of macrophages with antibodies against TLR2 (5 to 10 μg/ml) for 30 min and then coincubation with L. rhamnosus GG strains for 3 h. Bacteria were administered at a ratio of 1:50 of cells to bacteria. The results are mean values ± standard deviations from three separate experiments. The values are normalized against those for GAPDH. Asterisks denote statistically significant differences from the results for the control (no antibody treatment).