NUBAD LLC — Department of Health and Human Services SBIR Phase I: NIAID

Description

DESCRIPTION provided by applicant The world is rapidly heading towards a pre andapos s scenario when it comes to fighting infectious disease Antimicrobial resistance is a growing problem on a global scale greatly hampering our abilities to quell worldwide epidemics such as tuberculosis and malaria as well as the simple staphylococcus infection The proposed project is significant and has huge potential for impact on public health because unless innovative strategies are developed to produce robust and effective new classes of antibiotics health care costs will continue to climb and we will completely lose our ability to combat even the most common infection Current antibiotic treatments originated predominantly from natural products produced by fungi and bacteria that were able to inhibit the growth of other organisms usually by inhibiting cell wall synthesis or maintenance or by inhibiting protein synthesis Since penicilln was first isolated by Fleming in most of the subsequent generations of antibiotics remain very similar to the original natural products with functional groups modified to increase their activity across a broader range of pathogens and decrease their side effect profiles Oxazolidones glycopeptides lactams and quinolones show some promise for the future but gram negative bacterial infections still remain problematic Nucleic acids are promising avenues for drug design both as therapeutics and as targets However specificity is often a problem with small molecule nucleic acid binders such as intercalators groove binders and even aminoglycosides Here we propose an innovative plan for identification of and both functional and mechanistic assaying of a novel class of aminoglycoside nucleic acid conjugate ligands that are specific for an aminoglycoside targeting riboswitch and render it inactive in vivo This riboswitch is a key switch in the mechanism responsible for conferring antibiotic resistance in dozens of pathogenic bacterial strains and has never before been targeted for possible therapeutic development to our knowledge The designed ligands which are aminoglycoside conjugates have the potential to be both specific for this riboswitch target and useful against a broad spectrum of infectious bacteria including gram negative strains First as outlined in Specific Aim we will obtain a model riboswitch aptamer domain that has been synthesized commercially with FRET donor and acceptor dyes in different regions of the construct We will perform a fluorescence assay to rapidly screen approximately novel aminoglycoside nucleic acid conjugates developed at NUBAD LLC for binding to the riboswitch target and identify promising ligands with high specificity and affinity for the target riboswitch as outlined in Specific Aim In vivo assays will be used Specific Aim to identify lead compounds that are uptaken by aminoglycoside resistant cells and render them susceptible aminoglycosides once again In order to verify that the compounds indeed inhibit the riboswitchandapos s mechanism of action mechanistic assays will be performed Specific Aim The riboswitch will be positioned within a reporter plasmid so that it is under control of an IPTG inducible tac promoter Ptac that will be positioned upstream of the gal reporter gene Function of the riboswitch will be assessed by agar diffusion analysis in the presence of aminoglycosides and selected identified conjugate ligand binders As a result of this study several lead compounds will be identified that are taken up by pathogenic bacteria restore aminoglycoside susceptibility to resistant bacteria and specifically target the aminoglycoside binding riboswitch as their primary mechanism of action Future phases of this project will focus on developing these lead compounds for development as therapeutics NUBAD LLC is a drug discovery company devoted to identifying therapeutic agents that target nucleic acids We develop novel probes assays and small molecule therapeutics targeting RNA and DNA structures identified as targets in human disease and this project is extremely well suited to NUBADandapos s aims and its employeesandapos specific skill sets PUBLIC HEALTH RELEVANCE Antimicrobial resistance occurs when microorganisms often infectious bacteria viruses and certain parasites are no longer sensitive to drugs that were previously used to treat them this is of global concern because it hampers our ability to control infectious disease and increases the costs of health care In order to combat this world wide problem innovative strategies for antibiotic drug design must be implemented The proposed research describes the in vitro identification and in vivo functional characterization of an extremely promising new class of molecules that can specifically target a region of bacterial RNA that is known to confer antibiotic resistance in many pathogenic bacterial strains