A team of researchers from Tel Aviv University and the Biological Institute have developed an mRNA-based vaccine that is 100% effective against a bacterium that is fatal to humans. This is the first time that an mRNA-based vaccine delivered using fatty nanoparticles (lipids) provides immune protection against a deadly bacterium.
More on a similar matter
The study was conducted in an animal model and showed that all the animals treated with the vaccine remained protected and were not harmed by the bacteria. According to the researchers, the new technology they developed provides an infrastructure for the development of a quick and effective vaccine in the event of an emergency outbreak of diseases caused by bacteria, including bacteria resistant to antibiotics.
The new study was led by doctoral student Ido Kon and Prof. Dan Farr, head of the nanomedicine laboratory who also serves as the vice president for research and development at Tel Aviv University, in collaboration with researchers from the Institute for Biological Research. The results of the research are published today (Wednesday) in the journal Science Advances.
Prof. Dan Parr and PhD student Ido Kon, the leaders of the research. Photo: Shahar Shahar/ Tel Aviv University Spokesperson
Cohn explains: “mRNA vaccines – like the vaccines we received against the corona virus – are effective against viruses but not against bacteria. Beyond the effectiveness of the vaccines, the great advantage of these vaccines is the speed: from the moment the genetic sequence of the SARS-CoV2 virus was published to the first clinical trial of Only 63 days have passed since the vaccine was approved by the FDA. Until now, the explanation was that it is biologically impossible to develop mRNA vaccines against bacteria. We have proven that it is possible to develop a 100% effective mRNA vaccine against a deadly bacterium.”
Prof. Farr: “We tested the mRNA vaccine we developed in animals that were infected with a deadly bacteria. After a week, all the animals that did not receive the vaccine died, while all the animals that were vaccinated with the vaccine remained healthy”
The team of researchers explains that viruses depend on an external cell (“host”) and use our body cells as a factory to produce proteins based on their genetic sequence in order to reproduce. They infect the cell with an RNA molecule – mRNA – which contains production instructions for the virus’s proteins. The virus uses the cell as a factory to produce copies of itself. In an mRNA vaccine, this molecule is synthesized and wrapped in a fatty nano-envelope similar to the cell membrane in the human body. Thus, the envelope adheres to the cell, The cell produces the virus proteins and the immune system learns to recognize it and defend against it in case of exposure to the actual virus.
Kuhn adds: “Since viruses produce the proteins inside our cells, the proteins, which are translated from the genetic sequence of the virus or the mRNA sequence that we synthesize in the laboratory, turn out to be similar. A bacterium is a different story. The bacterium produces the proteins for itself, it does not need us. Following the different evolution of Humans and bacteria, proteins produced in bacteria can be different from the proteins produced in human cells, even though they are synthesized based on the same genetic sequence.”
According to him, “Researchers tried to synthesize bacterial proteins in human cells, but the exposure to them did not create antibodies in the body, that is, no immune effect was created. Although the protein produced is the same, since the instructions for its production are the same, in the process of its natural secretion from the human cell, it undergoes substantial changes, such as the addition of sugars .
“We developed a special method for expelling it from the cell while bypassing some of these pathways, and we saw a significant immune response: the body recognized the proteins as bacterial proteins. At the same time, we added to the bacterial protein a section of human protein that gives it stability, so that it does not break down in the body too quickly. The two breakthroughs These produced a full immune response.”
Prof. Parr concludes: “In general, there are many pathogenic bacteria for which there is no vaccine. In recent decades, due to the uncontrolled use of antibiotics, many bacteria have begun to develop resistance to antibiotics and therefore the effectiveness of antibiotic drugs is impaired.
“The development of new vaccines may make it possible to deal with this global problem. Even today, antibiotic-resistant bacteria are a real danger. We tested the mRNA vaccine we developed in animals that were infected with a deadly bacteria, after a week all the animals that did not receive a vaccine died, while all the animals that were vaccinated with the vaccine we developed remained health.
“Furthermore, in one of our vaccination methods, we saw that only one vaccine provides full protection in the vaccinated animals only two weeks after the vaccination. The ability to protect against a deadly bacteria based on only one vaccine dose is a very important tool in our ability to defend ourselves in the future against bacteria-based epidemics that break out quickly.” .
It is important to remember, Prof. Farr emphasizes, that “the reason why the vaccine against the corona virus was developed so quickly is that the vaccine is based on years of research in the development of mRNA vaccines for similar viruses. The lessons learned there saved valuable time. If a bacterial epidemic breaks out tomorrow morning, our research outlines the way for the development of fast, safe and effective mRNA vaccines”.
The research was financed with the help of research grants from the European Union (ERC; EXPERT) and by the Shemunis family (to Prof. Parr).