Fig. 5.

Activation of Toll-like receptors (TLRs) by probiotic bacteria. Chinese hamster ovary (CHO) cell lines transfected with human CD14, TLR-2 and TLR-4 were stimulated with live and heat-inactivated bacteria in a 50 : 1 bacteria : cell ratio. Expression of CD25 on the cell surface induced via a transfected nuclear factor kappa B construct was used via a read-out and determined by flow cytometric analysis. The negative control is the unstimulated transfected CHO-cell line which has been left unstained. Heat-inactivated Neisseria meningitidis was used as positive control in all cell lines. (a) Expression of CD25 indicated as mean fluorescence intensity (MFI) after activation of TLR-2. Negative control is CHO/CD14/TLR-2 cell line. (b) Expression of CD25 indicated as MFI after activation of TLR-4. Negative control is CHO/CD14/TLR-4 cell line. Results are representative of two separate experiments.