Up-regulation of surface biomarkers of BMDCs by either TcdA rRBD or its truncated fragments.

<p>BMDCs from C57BL/6 were collected and treated with GM-CSF at days 0 and 3. TcdA rRBD was added at day 6 for 18 h, and then, DCs were collected to analyze their surface markers, including CD40 (A), CD80 (B), CD86 (C), and MHC II (D), by flow cytometry. All groups were divided as polymyxin B-treated (PMB) (black-net bar) or non-treated (gray-net bar) to exclude LPS contamination. All surface marker signaling was normalized by calculating the ratio of mean fluorescence intensity (MFI) between the medium control and treatments. The symbols *, ** and ns indicate <i>p</i><0.05, <i>p</i><0.01 and no significant difference, respectively.