[2016 Spring Life Sciences & IBB Regular Seminar] ▶Subject: Deciphering the role of chromatin insulator CTCF in dendritic cells ▶Speaker: Prof. Hyoung-Pyo Kim (Department of Environmental Medical Biology, Yonsei University College of Medicine) ▶Date: 4:10PM/Apr. 15(Fri.)/2016 ▶Place: Auditorium(1F), Postech Biotech Center *Abctract Langerhans cells (LCs) are skin-resident dendritic cells (DCs) that orchestrate skin immunity. Regulation of LC homeostasis depends on several extra- and intra-cellular factors. CTCF is a highly-conserved DNA-binding protein that modulates cell differentiation and function through modifying chromatin architectures and subsequent gene expressions. A possible role of CTCF controlling LC homeostasis and function remains to be determined. Herein, by using conditional gene deletion mouse system, we show that CTCF is critically involved in homeostatic maintenance and migration of LCs in vivo. DC-specific CTCF deletion led to a reduced pool of systemic DCs, and the LC was the most severely affected DC subtype. Decreases in epidermal LC number were specifically associated with defects in self-turnover. Interestingly, CTCF-deficient LCs demonstrated the impaired migration out of the epidermis. Whole transcriptome analyses revealed that genes that promoted cell adhesion were highly expressed, but C-C chemokine receptor 7 was down-regulated in CTCF-depleted LCs. LC-specific CTCF deficient mice showed that hapten-induced CHS responses were more sustained while epicutaneous sensitization to protein antigen was attenuated, indicating that CTCF-dependent LC homeostasis is required for the optimal immune function of LCs in a context-dependent manner. Our results show that CTCF positively regulates the homeostatic pool and the efficient emigration of LCs, which modulates the functional immune network of the skin. ▶Inquiry: Prof. Yoontae Lee(279-2354) * This seminar will be given in English. please refrain from taking photos during seminars. *