Vaccine-mediated B cells responses to S. aureus hemolysin, and effect of different boosting intervals on functional humoral responses

Abstract

Event Abstract Back to Event Vaccine-mediated B cells responses to S. aureus hemolysin, and effect of different boosting intervals on functional humoral responses Giuseppe Lofano1*, Maria Teresa Fiorillo1 and Sylvie Bertholet2 1 University of Rome "Sapienza", Italy 2 Novartis V&D, Italy Although antibody titers are usually considered the best readout for vaccine efficacy, the importance of memory B-cell responses in conferring protection has remained controversial. Primary exposure to an antigen generates, along with antibody-secreting cells (ASCs), a heterogeneous B-cell memory compartment that changes over time and that may respond in different ways when re-encountering the cognate antigen. The goal of this study is to characterize B-cell responses after priming and the effect of different boosting intervals on the differentiation and function of ASCs and memory B cells. We used a vaccine model based on the alpha-Hemolysin (Hla) protein from Staphylococcus aureus, adjuvanted with Alum. This vaccine induced high antibody titers and was protective in sepsis and pneumonia animal infection models. We performed a time course analysis following one or two immunizations, two weeks apart: mice immunized twice had higher anti-Hla IgG titers compared to mice immunized once. ASCs measured by Elispot were increased in spleen 10 days after boosting and remained elevated in bone-marrow for at least 4 months. A similar trend was observed between the two groups when looking at the frequencies of Hla-specific memory B cells. Next steps will address the phenotypic and functional characterization of Hla-specific memory B cells to define a correlation between different boosting intervals and the protective humoral response. This work aims at providing new insights in the memory B-cell compartment that might benefit the design of new vaccination strategies. Keywords: Vaccine, B cells, S.aureus hemolysin, boosting intervals, Elispot Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Translational immunology and immune intervention Citation: Lofano G, Fiorillo M and Bertholet S (2013). Vaccine-mediated B cells responses to S. aureus hemolysin, and effect of different boosting intervals on functional humoral responses. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00019 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 08 Mar 2013; Published Online: 22 Aug 2013. * Correspondence: Mr. Giuseppe Lofano, University of Rome "Sapienza", Rome, Italy, giuseppe.lofano@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Giuseppe Lofano Maria Teresa Fiorillo Sylvie Bertholet Google Giuseppe Lofano Maria Teresa Fiorillo Sylvie Bertholet Google Scholar Giuseppe Lofano Maria Teresa Fiorillo Sylvie Bertholet PubMed Giuseppe Lofano Maria Teresa Fiorillo Sylvie Bertholet Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.