Using Immunopeptidomics and Immunoinformatics to identify novel antigens for Subunit Vaccines for Tuberculosis
Salem Almujri1, Paulo Bettencourt1, Iman Satti1, Nicola Ternette1, Helen McShane1
1The Jenner Institute, University of Oxford, UK.
There is an urgent need for an effective vaccine against TB. The discovery of new antigens is key to the development of a candidate subunit vaccine. We successfully identified 64 and 81 antigens derived from BCG and MTB respectively by using infected macrophages, as an in vitro model of TB. THP-1 cells were differentiated into macrophage-like cells by phorbol myristate acetate (PMA), stimulated with IFN-gamma and anit-IL10 to improve MHC-II presentation, infected with mycobacteria, and harvested one day post-infection. After lysing the cells, MHC molecules were immunoprecipitated and the peptide-MHC complex was dissociated followed by LC-MS/MS analysis to identify mycobacterial peptides presented by MHC molecules, from which precursor antigens can be identified. These antigens were further prioritised in silico using immunoinformatics tools, resulting in a list of ten potential protective antigens. These antigens will next be tested in vivo in murine challenge experiments.