SBIR-STTR Award

Bacteria employ a vast array of virulence factors that enable them to confront and damage the host cell during the infectious process. Identification of these virulence factors is essential to understanding pathogenisis and defining targets for future development of more efficacious next-generation therapeutic agents and vaccines. Thus, there is an urgent need for a rapid, relatively inexpensive, comprehensive, high-throughput platform for the discovery of virulence factors. To this end, Vital Probes, Inc. has developed Rapid Virulence Factor Discovery System (RVFDS) which expresses virtually all of the open reading frames of a pathogen which can then be screened for interaction with host components. This proteomic-based system circumvents the drawbacks of laboratory-grown conditions, host environment simulations, and isolation of pathogens from biological specimens or host anatomical sites in the identification of the virulence factors. A typical RVFDS experiment can be accomplished in less than a month. This proposal intent to assess the feasibility of RVFDS to identify the novel virulence factors of methicillin-resistant Staphylococcus aureus (MRSA) which is the causal agent of a wide range of human diseases. This system is intended to not only feed VPI’s product pipeline with new target candidates for therapeutic and vaccine development but to also provide this discovery platform as a service to outside companies, government research institutions, and academic institutions.

Keywords:
Pathogenic Mechanisms, Virulence Factors, Mrsa, Proteomics, Drug Discovery, Vaccine Development

Rapid Virulence Factor Discovery System (RVFDS) is virulence factor-discovery platform in which all of the genes of a pathogen are expressed generating a random expression library (REL). The REL is then screened for the presence of potential virulence factors with an array of pull-down assays that employ components of the host?s extracellular matrix, mucus, and basement membrane as bait. The host bait proteins interact with and capture pathogen prey proteins that may play a role in the pathogenic process. The potential virulence factors are then identified by mass spectrometry and proteomic methodologies. RVFDS can also define the immunome or complete repertoire of immunogenic proteins of a pathogen using antibodies from convalescent patients as bait in pull-down assays. Presently investigations into the host-pathogen relationship are severely hampered by the fact that the pathogen is grown under laboratory conditions that simulate the host environment, and thus, many of the virulence factors that are expressed in response to the true host environment are overlooked. RVFDS circumvents this overwhelming challenge because virtually all of the open reading frames of a pathogen are expressed and are easily and rapidly identified.

Keywords:
Virulence Factors, Recombinant Protein Library, Immunogenic Proteins, Vaccine Candidates, Host Tissue Invasion, Pathogenicity, And Proteomics