Can you explain the technology in layman terms?
Trana helps partners discover new anti-infectives that work through a unique mechanism of action: inhibition of the target pathogen’s ability to use transfer RNA (tRNA) essential for protein synthesis or replication.
How does the technology work?
The technology is applied to assays that are used to screen libraries of chemical compounds to identify those that have the ability to inhibit specific types of transfer ribonucleic acid (tRNA). Transfer RNA is essential for bacterial protein synthesis and viral replication of certain viruses, and if the normal role of tRNA is disrupted, these pathogens cannot survive. Until now, tRNA had not been exploited as a target for antibiotics, but the technology available for licensing makes this possible. As such, the technology represents both a drug target and a mechanism to identify compounds that affect the target. Inhibitors of tRNA specific for an identified pathogen, such as HIV, Staph aureus, or E. coli for example, are in turn potentially useful as antimicrobials to treat infections caused by these pathogens. Ultimately, Trana Discovery can help partners discover new antibiotics that work through this unique mechanism.
What is unique about this technology?
Trana Discovery’s patented technology is believed to be the only one of its kind that can directly detect compounds that inhibit the normal binding function of tRNA. Because of the vital importance of tRNA in bacteria and certain viruses, compounds with the ability to disrupt normal tRNA binding would represent entirely new classes of antimicrobial agents. This detection is a low risk, low cost means to deliver drug candidates with a high certainty of effectiveness.
Where would a company use this technology?
Any entity with an interest in discovering new anti-infective agents and a library of chemical compounds could use the assays to screen for compounds that inhibit tRNA.
Are there any competing technologies?
There are other methods for drug discovery, but none involve the use of tRNA.
Why would a company want to use this technology?
Nearly every significant human pathogen is resistant to at least one class of commonly used antibiotics, so new drug classes would represent a significant advance in the treatment of infectious diseases. New drug discoveries made using this technology will represent novel, first-in-class drugs with a unique mechanism of action. In addition, orgainzations that successfully use our technology may have exclusive rights to these new drug classes. Moreover, the drugs discovered using our technology would give companies who already have anti-infective products in their portfolios a way to sustain their market share by introducing new classes of effective drugs. Similarly, a company that is interested in entering the anti-infective market would be able to find novel drugs that meet significant unmet needs in the marketplace.
What is the difference between Trana Discovery technology and RNA interference or RNAi?
Basically, Trana Discovery is developing drug discovery assays to identify small molecule compounds that disrupt the use of specific tRNAs by disease-causing microorganisms. While one of the respective assay components is a short oligonucleotide, which is a synthetic mimic of a portion of the anti-codon stem loop of the selected tRNA, compounds discovered by this process for eventual development as new drugs are easy-to-administer small molecules.
On the other hand, RNAi technology involves the use of similar oligonucleotides called mRNAs (microRNAs) or siRNAs (short interfering RNAs) as both the research tools and as the therapeutic interventions. These oligonucleotides, which typically require special forms of delivery, bind to and cleave specific disease-associated host mRNAs (messenger RNAs), resulting in suppression of their function and control of the disease.
Why are you focusing on HIV as the first assay?
Trana is focusing on HIV because of the ongoing need for new, effective compounds to treat the infection caused by this virus. Furthermore, considerable science indicates that the HIV virus depends on a specific tRNA for its replication, and disruption of the virus’s ability to use this tRNA will render it unable to replicate and survive. We are confident that Trana technology will lead to novel, effective anti-HIV treatments.
What is the regulatory process to get your technology approved?
Drug screening assays are not regulated like drug development, manufacturing, and marketing. Thus, there are no FDA regulations that control the use of our assays..
What is the make-up of the assays?
Our assays are synthetic copies of portions of specific tRNA molecules found in the micro-organisms selected as the targets for any potential anti-infectives that are discovered. There is a different assay for each pathogen. The technology centers on the anticodon stem loop (ASL) of tRNA and the importance of nucleotide modifications within the ASL.
What do you mean by “assaying a library of compounds?”
Pharmaceutical companies and certain other entities such as academic institutions own large collections, or libraries, of chemical compounds, some of which they hope can be developed into drugs. The collections are assayed or tested in numerous ways to look for properties that may make them suitable for development. Our assays look for one specific property – the ability to inhibit tRNA. If this property is detected in a compound that is also found to have anti-microbial activity using conventional microbiological testing procedures, chances are that it, or a chemically related analog, could be developed into an anti-infective drug.
How can the use of the technology lead to new classes of drugs?
Currently there are no classes of anti-infective compounds that specifically inhibit tRNA. The unique opportunity using the Trana discovery platform will uncover inhibitors of tRNA. tRNA is essential for a bacterial cell to create new proteins. Lacking new proteins the bacterial cell will not divide and thereby limit the spread of infection.
Is there a particular chemical structure or class of compounds likely to inhibit tRNA?
At present the structural relationship between a chemical and bio-activity based on the inhibition of tRNA is unclear. As lead compounds emerge from the initial series of screenings, we may know more about the possible structural activity relationships. Based on the size and shape of the conserved region on the tRNA molecule, small inhibitory molecules are possible.
Can this technology be used in other areas of research, for example, agriculture?
At least theoretically, the application of tRNA inhibition might have a role in veterinary medicine and crop science, and possibly in cancer research. Trana Discovery intends to evaluate these potential roles in due course.
Why do you work with the university in Poland?
The synthesis of tRNA mimics is a very complex process and the leading scientist in this field is Andrzej Malkiewicz, Ph.D. As one of the founders, Dr. Malkiewicz has been a research colleague from the start. While still on staff at Technical University, Dr. Malkiewicz continues to provide consulting expertise to Trana Discovery.
What is the licensing agreement with NCSU?
The terms of our agreement with NCSU are confidential; however Trana does have the exclusive rights to all technologies surrounding the discovery of tRNA inhibitors.
Why has it taken the technology 20 years to be ready for commercialization?
The research surrounding tRNA has progressed dramatically over the past several years. It took some of these break-throughs in understanding the complete function of tRNA to progress our technology. Additionally, the production of mimics that would remain stable in an assay environment also needed to be perfected.
Why is this particular management team unique?
Each member of our management team has been successful within the pharmaceutical industry in one’s own unique career paths. Each member has at least 25 years of industry experience from which Trana will draw from all these experiences to progress the company in a rapid and judicious fashion.
Why don’t you want to develop your own drugs?
Trana Discovery is focused on the development of assays that will identify inhibitors of tRNA among collections of existing compounds. Our ideal collaboration would cover the initial discovery of a series of inhibitors of tRNA from a partner’s compound library and then licensing the exclusive rights for that disease area to a company. So our business plan while not excluding independent drug discovery, emphasizes our desire to license a disease specific technology to a well established pharmaceutical company for their continued drug discovery and clinical development.
Additional Technical FAQs on the HIV Assay
The Trana Discovery business model is to develop and license high-throughput drug discovery assays that utilize RNA oligomers which contain modified base residues. One such example is the use of the human tRNALys3 by HIV where the hairpin region of the anticodon stem loop (ASL) contains 3 modified bases. Our assay structurally mimics the viral complex that forms between this segment of the tRNALys3 and the HIV RNA. In viral function the tRNA in the ASL hairpin is unfolded and adopts a bimolecular duplex conformation. This radical modification of the tRNA conformation alters the structure of the target molecule and changes the spatial distribution of the R groups making the site of the RNA-RNA interaction accessible to intervention by therapeutic compounds.
What data validates tRNA as a HIV drug target?
Sequence analysis of HIV genome collected from human isolates reveals that the primer binding site, PBS, is the most conserved region of the viral genome. The 18 nucleotides of the PBS are universally conserved in all mutants. Deletion of the PBS blocks the ability of the mutant to replicate in culture; thus, one can infer that blocking the PBS with a therapeutic compound would also be lethal to HIV. Mutation of the site by transferring the priming function to another tRNA results in poor viral transcription within the infected cell and marked loss in the ability to form infectious particles. All of the PBS mutants quickly revert back to tRNA lysine by selective mutation. Validation that the disruption of the PBS complex disrupts viral function has been demonstrated both by use of antisense oligonucleotides and siRNA.
Can HIV prime with any other tRNA albeit at lower efficiency?
No, HIV cannot prime with any other tRNA. Analysis of the RNA sequences for HIV isolates in the public domain contain no examples of a PBS complementary to any tRNA other than tRNALys3. The exclusive use of tRNALys3 as a primer extends to all lentiviruses. Extensive efforts to study mutated PBS found rapid reversion back to tRNALys3 in culture. Reversion back to Lys3 is observed, even when the entire sequence is mutated to one that is complementary to another tRNA.
Has anyone made a tRNAlys3 knock out cell (wobbling should make them viable)?
Over 450 transfer RNA (tRNA) genes have been annotated in the human genome. For tRNALys, 27 copies have been annotated, 12 for CTT anticodon and 15 for UUU. To our knowledge no attempt has been made to make a tRNA knockout in any organism. Related research has shown that while U is a wobble base, C is not. Knocking out of tRNALys3 would prevent the translation of the AAA lysine codon and likely be lethal to the cell.
Has there ever been a small molecule drug that binds a structural RNA motif?
Many effective antibiotics bind exclusively to RNA structural sites in the ribosome. Crystal structures of the drug and ribosome complex provide insight into mechanism of action of drug with RNA targets.
Do the prototype hits not intercolate into nucleic acids in general?
We have no specific data at this time in regards to these compounds. Please recall our objective is to demonstrate that this assay will identify compounds which inhibit this assay and that can serve as the basis for a drug discovery program. As with any drug discovery program, there will be classes of compounds that are more ‘druggable’ than others.
Do the hits bind to other tRNAs?
There are two basic reasons as to why we currently believe that our hits do not bind to other tRNAs.
First, based on our limited data set these compounds are not indiscriminate toxins; thus, they are most likely not indiscriminate binders to tRNA even though the compounds are active in our assay and inhibit HIV in a PBMC assay.
Second, HIV does not recognize normally configured tRNALys3, thus, the site of potential interaction of these compounds with other tRNA is not readily accessible. The normal configuration of the ultra conserved ASL loop of tRNALys3 looks much like the AIDS red ribbon lapel pin. This configuration is different when the HIV viral RNA forms a complex with the tRNALys3. The virus uncoils the “red ribbon” described above into a bimolecular duplex conformation that looks much like a short piece of a double helix.
