Cholera toxin (CT), an exotoxin produced by Vibrio cholera, acts as a mucosal adjuvant. In a previous study, we showed that CT skews differentiation of CD4 T cells to IL-17-producing Th17 cells. Here, we found that intranasal administration of CT induced migration of migratory dendritic cell (DC) populations, CD103+ DCs and CD11bhi DCs, to the lung draining mediastinal lymph nodes (medLN). Among those DC subsets, CD11bhi DCs that were relatively immature had a major role in Th17 cell differentiation after administration of CT. CTtreated BMDCs showed reduced expression of MHC class II and CD86, similar to CD11bhi DCs in medLN, and these BMDCs promoted Th17 cell differentiation more potently than other BMDCs expressing higher levels of MHC class II and CD86. By analyzing the expression of activation markers such as CD25 and CD69, proliferation and IL-2 production, we determined that CT-treated BMDCs showed diminished antigen-presenting potential to CD4+ T cells compared with normal BMDCs. We also found that CT-stimulated BMDCs promote activin A expression as well as IL-6 and IL-1β, and activin A had a synergic role with TGF-β1 in CT-mediated Th17 cell differentiation. Taken together, our results suggest that CT-stimulated DCs promote Th17 cell differentiation by not only modulating antigen-presenting potential but also inducing Th polarizing cytokines.
Bibliographical noteFunding Information:
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2013R1A1A2060008) and by a grant of the Korean Health Technology Rand D Project, Ministry of Health and Welfare, Republic of Korea (Grant number: HI13C0826) to JC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
© 2016 Kang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.