Objective Bacteria use various mechanisms to combat competitors and colonize new niches. The Type VI Secretion System (T6SS), a contact-dependent protein delivery apparatus, is a widespread, recently discovered machine used by Gram-negative bacteria to target competitors. Its toxicity is mediated by secreted proteins called effectors, yet the identity of many effectors, the mechanism of secretion of different effector classes, and their toxic activities remain largely unknown. I recently uncovered a widespread class of T6SS effectors that share a domain called MIX. MIX-effectors are polymorphic proteins carrying various toxin domains, many of which with unknown activities. Many bacterial pathogens have acquired resistance to contemporary antibiotic treatments, becoming a public health threat and necessitating the development of novel antibacterial strategies. Thus, as a relatively untapped antibacterial system, studying the T6SS and its MIX-effectors presents a double incentive: 1) previously uncharacterized antibacterial activities of MIX-effectors can illuminate novel cellular targets for antibacterial drug development; 2) the T6SS machinery can be used as a novel toxin delivery platform to combat multi-drug resistant bacterial infections, using polymorphic MIX-effectors. In this proposal, I will focus on T6SS MIX-effectors and elucidate their activities, mechanism of secretion, and utilization as antibacterial agents, by combining microbiology, molecular biology, genetic, biochemical, and proteomic approaches. Specifically, the goal of this proposal is to utilize T6SSs and MIX-effectors to develop a novel T6SS-based, antibacterial therapeutic platform in which a nonpathogenic bacterium will be engineered to carry a T6SS that can secrete a diverse repertoire of polymorphic antibacterial MIX-effectors. This innovative platform has several advantages over current antibacterial strategies, and can be used as an adjustable tool to combat multi-drug resistant bacteria. Fields of science medical and health sciencesbasic medicinepharmacology and pharmacydrug discoverynatural sciencesbiological sciencesmicrobiologybacteriologymedical and health scienceshealth sciencespublic healthepidemiologyepidemics preventionmedical and health sciencesbasic medicinepharmacology and pharmacypharmaceutical drugsantibioticsmedical and health sciencesbasic medicinepharmacology and pharmacydrug resistancemultidrug resistance Keywords Type VI secretion system effector proteins antibacterial toxins Protein delivery platform Bacterial infection treatment Programme(s) H2020-EU.1.1. - EXCELLENT SCIENCE - European Research Council (ERC) Main Programme Topic(s) ERC-2016-STG - ERC Starting Grant Call for proposal ERC-2016-STG See other projects for this call Funding Scheme ERC-STG - Starting Grant Coordinator TEL AVIV UNIVERSITY Net EU contribution € 1 484 375,00 Address Ramat aviv 69978 Tel aviv Israel See on map Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Other funding € 0,00 Beneficiaries (1) Sort alphabetically Sort by Net EU contribution Expand all Collapse all TEL AVIV UNIVERSITY Israel Net EU contribution € 1 484 375,00 Address Ramat aviv 69978 Tel aviv See on map Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Other funding € 0,00