Tuesday June 15, 2010, from 12.00 to 13.00, Point Centre, Auditorium Albert Claude
Caetano Reis e Sousa, London Research Institute, Immunobiology Laboratory, London, United Kingdom
(this seminar will be followed by a lunch from 13.00 to 14.00)
"Innate regulation of immunity by dendritic cells"
Direct sensing of pathogen components is a major trigger of dendritic cell (DC) activation, leading to immunity. We have been studying multiple pattern-recognition pathways that mediate DC activation. One pathway for sensing infection by RNA viruses involves recognition of viral genomes or virally-infected cells in endosomal compartments and utilises members of the toll-like receptor (TLRs) family, including TLR9, 7, or 3. Viral genomes can additionally be recognised in the cytosol by DExD/H-box helicases such as RIG-I, which are activated by RNAs bearing 5' tri-phosphates. Finally, a distinct pathway involves cell surface and phagosomal recognition of fungi by C-type lectins, which signal via Syk kinase. Notably, some of these pathways are involved not only in direct sensing of pathogens but also in the recognition of self alterations that might accompany infection, such as induction of cell death. These studies help build a global picture of the receptors and signalling pathways that regulate DC activation and have applications in immunotherapy of cancer and infectious diseases.