acase@tulane.edu / The humoral arm of the adaptive immune system involves the production of antibodies by cells of the B cell lineage, which bind and in some cases neutralize or enhance infectivity of pathogens, including viruses. Humoral immune responses to each of the Lassa virus (LASV) structural proteins have been detected[1, 2]. However, there have been few efforts to perform fine structure epitope mapping of the antigenic sites recognized by LASV-specific antibodies. Murine monoclonal antibodies (MAbs) have been produced against several arenaviruses [1-4]. Some MAbs to Lassa virus proteins react broadly with arenaviruses demonstrating there may be an epitope or epitopes conserved among arenaviruses. Neutralizing antibody epitopes of LASV recognized by humans remains essentially unexplored. Therefore, my project will focus on identifying, characterizing and better understanding the antigen-antibody binding relationship of LASV structural proteins. We hypothesize that humans exposed to LASV differ quantitatively and qualitatively in their ability to produce antibodies that recognize potential binding epitopes on LASV proteins, and these differences can be explored via the identification and characterization of these epitopes using LASV recombinant proteins and synthetic peptides. We expect that a panel of unique human MAbs that bind specifically to LASV and LASV recombinant proteins will be isolated and prove to be valuable tools in characterizing the humoral response to LASV. The human MAbs must be characterized to determine how binding occurs. A fundamental understanding of mechanisms of antibody binding of LASV may have significant implications for the generation of antibody-based therapeutics / 1 / Rachael Yenni