Critical roles of pDCs in central tolerance and intestinal immunity
Plasmacytoid dendritic cells (pDCs) fulfill key functions in intrinsically opposing immunological tasks: to mediateantiviral immunity and to induce tolerance. We here dissectphenotype and function of pDCs in both settings. We show that immature pDCs take up antigen in the periphery and present it within the thymus to induce clonal deletion. Trafficking to the thymus is dependent on CCR9- expression. CCR9 is only present on naïve pDCs, preventing central tolerance induction in response to immune stimulatory agents.In addition to thymic homing, CCR9 also directs cells to the gut. Hence, pDCs are highly abundant within the small intestine. The gut is an intriguing site to study immune balance as immune stimulation and immune homoeostasis are constantly opposing. We chose rotavirus as viral model system as rotavirus infects specifically the small intestine. Using this system, we show that B cell activation and virus-specific secretory antibody production in response to mucosal viral infection occur as a direct result of pDC-derived type I IFN.
Who is Katharina Lahl?
• Postdoctoral fellow, Stanford University, School of Medicine, Department of Pathology, Stanford, CA.
• Stanford ITI Young Investigator Award 2011
• Postdoctoral fellowship DFG in 2009
• Before: PhD student, Technical University of Munich, Institute for Immunology, Microbiology and Hygiene.
Twincore Lecture Hall, Feodor-Lynen-Str.7, 30625 Hannover
Katharina Lahl, PhD
Prof. Dr. Tim Sparwasser, Twincore, Centre For Experimental and Clinical Infection Research