Research: Improved protection once morest deadly SARS-CoV-2 infections
The new infections with SARS-CoV-2 are still at a very high level. Although most infected people develop only mild symptoms or no symptoms at all, some people still become seriously ill with COVID-19. Researchers are now reporting on a new strategy that can significantly reduce the frequency of severe disease progression.
Only some of the people who contract the SARS-CoV-2 coronavirus become seriously ill. A new strategy might help ensure that even fewer infected people develop severe COVID-19 courses. Researchers are now reporting better protection once morest deadly corona infections.
- SARS-CoV-2 viruses can camouflage themselves to such an extent that they are not recognized by the immune system.
- Researchers have now shown in a study that the antiviral immune receptor RIG-I can be stimulated, which improves protection once morest deadly SARS-CoV-2 infections.
- The frequency of severe COVID-19 disease progression is also significantly reduced.
Antiviral drugs urgently needed
As in a current Message of the Rheinische Friedrich-Wilhelms-Universität Bonn, the corona pandemic has revealed an urgent need for antiviral drugs and vaccines.
However, while vaccines have been available following a remarkably short period of time, the development of direct antiviral treatments has been comparatively slow. In view of the risk of future pandemics, however, there is still a great need for drugs and treatment methods that work directly once morest viral infections.
In addition, newly emerging SARS-CoV-2 variants that camouflage themselves from the immune system are worrying. Because they can cause high numbers of infections even in a vaccine-immunized population, antiviral drugs are urgently needed to treat COVID-19.
Virus can bypass immune system
The SARS-CoV-2 coronavirus belongs to the betacoronavirus genus. Like other members of this genus, this pathogen is equipped with several molecular tools that allow it to evade recognition by the immune system.
SARS-CoV-2 carries the information to produce a number of proteins capable of inhibiting antiviral recognition systems of the infected cell.
The immune system can actually identify viral genetic material (here: ribonucleic acids/RNA) and sound the alarm, but proteins of the coronavirus can change the viral ribonucleic acids in such a way that they can no longer be distinguished from the body’s own RNA.
In this way, viral RNAs are camouflaged by attaching a methyl residue, for example. In this way, the viral RNA escapes early detection by the central antiviral immune receptor RIG-I.
This receptor triggers what is known as an innate immune response, in which antiviral proteins, cell signals and messenger substances – such as type I interferon (IFN) – are produced.
Activation of the innate antiviral response
“Robust, early Type I IFN production is key to eradicating SARS-CoV-2 infection. If it does not occur, the disease progresses and can take a serious course,” explains Prof. Dr. Eva Bartok from the Institute for Clinical Chemistry and Clinical Pharmacology at the University Hospital Bonn (UKB).
The doctoral student Samira Marx and first author of the in the journal “Molecular Therapy – Nucleic AcidsThe published study adds: “Activation of the innate antiviral response, including the release of type I and type III IFNs, is also extremely important for the development of an adequate antiviral adaptive immune response.”
According to the information, this response of the immune system, which is adapted to the threat, only takes place a few days following infection and includes the activation of further immune cells and finally the formation of antibodies.
Drastically reduced proportion of fatal infections
The immune receptor RIG-I has previously been recognized as a suitable target for the prophylactic induction of antiviral effects. According to the experts, it was possible to show in mouse models that prophylactic stimulation of RIG-I mice can protect once morest a fatal influenza virus infection.
“Such RIG-I stimulating RNAs that mimic viral RNA can be chemically synthesized and used as therapeutics to activate the innate immune response once morest numerous diseases including cancer and viral infections,” says Prof. Dr. Martin Schlee from the Institute for Clinical Chemistry and Clinical Pharmacology.
In the present study, the scientists examined the effect of synthetic 5’triphosphorylated dsRNA (3pRNA) on the course of infection with SARS-CoV-2 in a mouse model.
Because mice are generally not susceptible to SARS-CoV-2, genetically modified mice that produce the coronavirus-binding protein ACE2 had to be used. “The mouse model we used recreates important aspects of the human COVID-19 disease,” explains Prof. Dr. Hiroki Kato from the Institute for Cardiovascular Immunology at the UKB.
Using this model, the researchers were able to show that systemic application of 3pRNA one to seven days before infection with SARS-CoV-2 drastically reduced the proportion of fatal infections. A similar observation was also made with the therapeutic application of 3pRNA one day following infection.
“Our results clearly show that the targeted influencing of RIG-I, both prophylactically and therapeutically, is a promising approach to the treatment of COVID-19,” summarizes study leader Prof. Dr. Gunther Hartmann together.
“However, further studies must be carried out before it can be used in humans,” says the scientist from the Institute for Clinical Chemistry and Clinical Pharmacology and spokesman for the Cluster of Excellence ImmunoSensation2 at the University of Bonn. (ad)
Author and source information
This text corresponds to the requirements of medical specialist literature, medical guidelines and current studies and has been checked by medical professionals.
Swell:
- Rheinische Friedrich-Wilhelms-Universität Bonn: New strategy for COVID-19 prophylaxis, (accessed: March 8th, 2022), University of Bonn
- Samira Marx, Beate M. Kümmerer, Christian Grützner, Hiroki Kato, Martin Schlee, Marcel Renn, Eva Bartok & Gunther Hartmann: RIG-I-induced innate antiviral immunity protects mice from lethal SARS-CoV-2 infection; in: Molecular Therapy – Nucleic Acids, (veröffentlicht online: 12.02.2022 und in: Volume 27, P1225-1234, 08.03.2022), Molecular Therapy – Nucleic Acids
Important NOTE:
This article contains general advice only and should not be used for self-diagnosis or treatment. He can not substitute a visit at the doctor.
