Sunday September 25, 2022 – Author:
dr
Research into the coronavirus disease is still in its infancy. Scientists from Freiburg have now found out why the course of the disease is often particularly difficult in older people – and what you can do about it with available drugs.
An immune response that is impaired in old age, the production of antiviral interferons, is likely to be responsible for the fact that patients of advanced age are more susceptible to severe Covid 19 courses. Researchers from the Medical Faculty of the University of Freiburg found this out in animal experiments with mice. According to the scientists, it was previously unclear which age-related changes are responsible for the fact that older patients are much more susceptible to severe Covid 19 courses.
Immune defenses: Older bodies produce fewer ininterferons
The study, which has just been published in the journal “Journal of Experimental Medicine” (JEM), shows that older mice infected with the Sars coronavirus 2 produce fewer of these antiviral interferons in the body. At the same time, the research project showed that treatment with medicinal interferons can, conversely, also protect them from a serious illness. “This suggests that the clinical use of interferons in older people with Covid-19 could be very effective,” says a statement from the University Hospital Freiburg.
Coronavirus infection: how young and old bodies react
“We found that younger animals build up a very fast and well-coordinated innate and adaptive immune response to effectively fight off the viral infection, while older animals showed a reduced, delayed and inefficient inflammatory response,” explains study leader Daniel Schnepf from the Institute of Virology at the University Hospital Freiburg.
Interferons: directors of the immune response
The immune system’s response to Sars-CoV-2 is coordinated by a group of antiviral signaling proteins called interferons. These help stop the virus from multiplying. At the same time, they are involved in activating various immune cells that help clear the virus from the body. There are three different types of interferon proteins known as Type I, II and III. Estimates assume that up to 20 percent of Sars-CoV-2-related deaths can be attributed to defects in interferon signal transmission, for example due to genetic mutations or auto-antibodies that prevent the correct course of an interferon response.
Interferons as medicine against severe corona cases in old age
The Freiburg researchers found that the type I and type II interferon responses in old mice were greatly reduced, which in turn explained the uninhibited virus replication. They also showed that therapeutic treatment with type II interferon in combination with the particularly well-tolerated type III interferon is efficient severe disease progression in particularly vulnerable mice with old age and genetic immune defects.
Research results – translated into a treatment strategy
Researchers translate “Our data show that a disrupted interferon-mediated immune response can be responsible for the high SARS-CoV-2 mortality rate in older mice and possibly also in older people,” says study leader Daniel Schnepf from the Institute of Virology at the University Hospital Freiburg. Working group leader Prof Dr. Martin Schwemmle adds: “Through our research, we have identified the age-related impairment of type I and type II interferon responses as a critical pathomechanism that makes SARS-CoV-2 particularly dangerous for old individuals.” claim to have successfully translated these findings into a treatment strategy that prevents mortality from Sars-CoV-2 in a highly sensitive disease model.