Periodic Reporting for period 3 - PANDORA (Pandemics Outbreaks Rationalized: towards a universal therapy to eliminate intracellular pathogens and drug resistance)
Reporting period: 2023-10-01 to 2025-03-31
We are living a time where we believe antibiotics are the cornerstone of any infectious disease-based therapy. It is definitely out of question that antibiotics saved millions of people worldwide in the last century, and that they are still doing it very efficiently. Nevertheless, their extensive abuse, especially for zoonic applications, contributed to the rise of antibiotic resistance (AMR). AMR is one of the biggest threats in the current human history because it is estimated that the majority of the antibiotics, currently used in the clinics, will be completely ineffective for the eradication of infectious disease. This has been defined as "The New Dark Ages of Antibiotics", which is expected to start in the next decades if no actions will be taken now. There are several causes behind AMR, but one of the most relevant is the exposure of bacteria to sub-lethal doses of the antimicrobials. In this context, the presence of the drug at a lower-than-effective concentration does not extirpate the pathogens, which in turn can develop molecular determinants to resist the presence of the threats.
One of the big aims of this project is the design of a new generation of therapy that counteract this issue. It is based on the strategy exploited by a specific class of viruses that infect and kill bacteria only, called as bacteriophages, which are completely safe and unharmful to humans. The development of a new therapy possessing the requirements to avoid the rise in AMR represents a new legacy for the future generation in terms of anitibacterial therapies, exaclty in the same way antibiotics changed the human history in the 20th century.
One of the big aims of this project is the design of a new generation of therapy that counteract this issue. It is based on the strategy exploited by a specific class of viruses that infect and kill bacteria only, called as bacteriophages, which are completely safe and unharmful to humans. The development of a new therapy possessing the requirements to avoid the rise in AMR represents a new legacy for the future generation in terms of anitibacterial therapies, exaclty in the same way antibiotics changed the human history in the 20th century.
We copied and reproduced one of the proteins produced by the bacteriophages, the endolysin, responsible for binding the bacteria membrane, followed by the formation of a pore in the wall responsible for killing the pathogen. Moreover, we created several mutants of this endolysin having higher binding efficacy compared to the same one available in Nature. We proved that these synthetic proteins are extremely efficient in eradicating Mycobacterium abscessus infections, a crucial topics especially for cystic fibrosis patients. There are 2 reasons why the therapy developed here represent a new tool against AMR. 1) Endolysin target sugars, and not aminoacids, the latter being the ones undergoing mutations in bacteria and causing the rise in AMR; 2) in the remote chance bacteria might evolve a new resistance against an endolysin, also the bacteriophages will evolve themselves with new weapons against the mutated bacteria. With our approach, we would just need to copy the new version of the protein to quickly replace the therapy. We are now in the process of testing the drug in pre-clinical models of infection (in mice), the first step before the translation into the stages of clinical trials.
We believe the endolysin therapy represents a serious new alternative strategy for complementing, and even replacing, the current use of antibiotics soon.
In addition, we discovered how to efficiently deliver the endolysin in infected cells by using nanoparticles that selectively target only the infected cells, while leaving all other cells untouched. This is the concept of nanoparticles super-selectivity, where we avoid off-target effects, a crucial topic in drug delivery.
The combined use of super-selective nanoparticles, together with efficient endolysins, are the cornerstone for the future development of next generation of antimicrobial therapies, which are safer and more effective.
We believe the endolysin therapy represents a serious new alternative strategy for complementing, and even replacing, the current use of antibiotics soon.
In addition, we discovered how to efficiently deliver the endolysin in infected cells by using nanoparticles that selectively target only the infected cells, while leaving all other cells untouched. This is the concept of nanoparticles super-selectivity, where we avoid off-target effects, a crucial topic in drug delivery.
The combined use of super-selective nanoparticles, together with efficient endolysins, are the cornerstone for the future development of next generation of antimicrobial therapies, which are safer and more effective.
The endolysin-based therapy is a complete change in the paradigm of antibiotic discovery. In a typical process of drug development, in fact, there is a long preliminary in silico investigation where chemists screen for the best potential candidate molecules that can effectively inhibit a specific target (like a bacterial protein). Among thousands of molecules within a library, some of them are selected for the synthetic procedure, followed by purification processes and extensive physicochemical characterizations. These steps require years of efforts until few molecules are then produced for the next steps, where they are tested in vitro on relevant cell model. If they pass the in vitro screenings, the molecule will be tested then in vivo in animal models of infection (pre-clinical trials). All these processes require even a decade of time and millions of dollars of investment. With the phage-based therapy, all the steps of in silico screening and drug synthesis and purification will be completely avoided, as the endolysins are already present in Nature. The production methodology is already, per se, a significant step forward beyond the state of the art in terms of drug production. More importantly, the previously describe “standard drugs” are designed to target bacterial proteins, which are those undergoing the mutations in bacteria, thus leading to resistance towards the antimicrobial. Conversely, our endolysin targets sugar molecules on the external bacterial walls, and sugars do not mutate over time. It is indeed demonstrated that bacteria cell wall never mutated over the centuries, which makes it a perfect target for a future therapy.
We are sure that by the end of this project we will have a new therapy against tuberculosis infection which counteract the rise in AMR. More importantly, the big step forward of opur approach is that it can be translated to any other infectious disease: the only requirement will be to copy the endolysin killing another bacteria (like Staphylococcus aureus) to produce a therapy against that specific pathogens. This is why we called it as “universal therapy”.
We are sure that by the end of this project we will have a new therapy against tuberculosis infection which counteract the rise in AMR. More importantly, the big step forward of opur approach is that it can be translated to any other infectious disease: the only requirement will be to copy the endolysin killing another bacteria (like Staphylococcus aureus) to produce a therapy against that specific pathogens. This is why we called it as “universal therapy”.