Programmable vaccines

MIT has developed RNA vaccines programmed for various diseases
Tests on mice have shown the effectiveness of vaccines against Ebola virus, H1N1 virus, Toxoplasma gondii

marks, Geektimes

Scientists from the Massachusetts Institute of Technology (MIT) have developed a new type of vaccine that can be "programmed" for various diseases. The production of the vaccine takes a week, which allows you to quickly set up its release when a disease spreads (see the press release of Engineers design programmable RNA vaccines).

The vaccine contains strands of matrix RNA. This genetic material may contain information about any viral or bacterial protein. The RNA strands are "packed" into molecules that deliver RNA to cells, where the translation process takes place, followed by the synthesis of proteins that activate the host's immune system.

According to the developers, in addition to infectious diseases, this vaccine can be used to fight cancer. With the help of an RNA vaccine, the host's immune system can be taught to recognize and destroy cancer cells.

"This achievement allows us to develop vaccines against new diseases in just seven days, opening up the opportunity to quickly respond to unexpected outbreaks of viral diseases, as well as modify or improve vaccines," says Daniel Anderson, one of the project participants. The scientist and his colleagues published their work on vaccines in the Proceedings of the National Academy of Sciences on July 4 (Anderson et al., Dendrimer-RNA nanoparticles generate protective immunity against lethal Ebola, H1N1 influenza, and Toxoplasma gondii challenges with a single dose).

Customizable vaccines

Inactivated vaccines are usually used to fight viral diseases. The composition of vaccines of this type includes viral particles that were originally grown in culture, after which they were killed by thermal exposure or formaldehyde. Viruses for vaccines are grown in laboratories – thus reducing their activity and infectivity is achieved. In order for the body to develop immunity to such a virus, it is necessary to inject fairly large doses. To enhance the effect of the vaccine, it is sometimes necessary to add adjuvants (substances that enhance the immune response) Multiple rounds of vaccination are also required. In addition, "live" vaccines with weakened viruses are also used.

As for RNA vaccines, they cause the production of foreign copies of proteins by the host body in an amount sufficient to effectively combat the pathogen of the disease. The idea of creating programmable vaccines based on matrix RNA is not new, it is about 30 years old. But all this time it was not possible to create a reliable RNA vaccine. The main reason is that scientists could not find a safe and effective way to deliver matrix RNA to the cells of the host organism.

Omar Khan, one of the authors of the work, proposed packing the RNA vaccine into a nanoparticle created from a dendrimer. It is a macromolecule with a symmetrical tree-like structure with regular branches. Dendrimers are capable of forming complexes with other molecules, and the stability of such complexes is controlled by the state of the external environment. This opens up the possibility of using dendrimers in medicine as carriers for the targeted delivery of genes or drugs. The key advantage of the dendrimer is the ability to charge such molecules positively, which will allow them to interact with RNA with a negative charge. After the dendrimers and RNA combine, the resulting complex is folded into a spherical structure with a diameter of 150 nanometers. This is similar to the size of many viruses, and RNA vaccine molecules pass into the cells of the body in much the same way as virus proteins.

By changing the RNA sequence, scientists can create vaccines that initiate the production of almost any proteins in the host cells. RNA molecules also include instructions for RNA amplification, so that cells produce even more proteins.

A vaccine of this type is injected into the body by a conventional injection. As soon as the dendrimer-RNA complex penetrates into the cell, the translation process is performed and the cell begins to produce a protein that provokes an immune response. At the same time, the host's immune system forms a response of two types: there is a simultaneous production of antibodies and T cells.

MIT scientists have already performed a number of tests with mice and received an encouraging result: just one injection of an RNA vaccine causes a strong immune response of the body. The body of mice gave a powerful immune response to the Ebola virus, H1N1 influenza, Toxoplasma gondii.

"Regardless of which antigen we chose, we received a complete immune response with the production of antibodies and T cells," says Khan.

Researchers believe their vaccines are safer than DNA vaccines, another alternative to conventional vaccines. Unlike DNA, RNA cannot be incorporated into the host genome and cause mutations.

Rapid vaccine production

The creators of the vaccine are confident that their product can be especially useful for fighting the flu. The fact is that the production of a conventional flu vaccine, when viruses are grown in chicken eggs, takes months. That is, the vaccine can be ready after the epidemic of a certain type of flu has already passed. Here we are talking about the week.

According to experts who got acquainted with the work of the creators of the RNA vaccine, this is a real revolution in the fight against infectious diseases. The fact is that such a vaccine can also be used to fight still unknown diseases – it is enough to study the pathogen and change the RNA sequence.

Now the authors of the work have founded a company and started the process of licensing the technology. They are going to start commercial production of their vaccines in the near future. And not only against the diseases already mentioned, but also against the Zika virus and Lyme disease.

Portal "Eternal youth" http://vechnayamolodost.ru  05.07.2016