IMMUNExplore - New approaches to analyze and exploit the human B and T cell response against viruses
Immunological memory confers long term protection against pathogens and is the basis of successful vaccination. Following antigenic stimulation long lived plasma cells and memory B cells are maintained for a lifetime, conferring immediate protection and enhanced responsiveness to the eliciting antigen. However, in the case of variable pathogens such as influenza virus, B cell memory is only partially effective, depending on the extent of similarity between the preceding and the new viruses. The B cell response is dominated by serotype-specific antibodies and hetero-subtypic antibodies capable of neutralizing several serotypes appear to be extremely rare. Understanding the basis of broadly neutralizing antibody responses is a critical aspect for the development of more effective vaccines. In this project, we will explore the specificity and dynamics of human antibody responses to influenza virus by using newly developed technological platforms to culture human B cells and plasma cells and to analyze the repertoire of human naïve and memory T cells. High throughput functional screenings, structural analysis and testing in animal models will provide a thorough characterization of the human immune response. The B cell and T cell analysis aims at understanding fundamental aspects of the immune response such as: the selection and diversification of memory B cells; the individual variability of the antibody response, the mechanisms of T-B cooperation and the consequences of the original antigenic sin and of aging on the immune response. This analysis will be complemented by a translational approach whereby broadly neutralizing human monoclonal antibodies will be developed and used: i) for passive vaccination against highly variable viruses; ii) for vaccine design through the identification and production of recombinant antigens to be used as effective vaccines; and iii) for active vaccination in order to facilitate T cell priming and jump start the immune responses.