A signal molecule that helps to boost inflammation in the lungs could have an important role in the aggravation of some symptoms of Long-Covid Symptoms, as a study shows that has analyzed the lung tissue sample of people with this disease.

The results, published on July 17th in Science Translational Medicine 1 Scientists help, more effective treatments for long-covide to develop that causes symptoms such as" brain fog ", fatigue, shortness of breath and lung damage and for months or years after an infection with SARS-COV-2, which virus behind Covid-19, can remain.

by inhibiting the molecule-called Interferon-Gamma (IFN-γ)-for mice with Covid-19, "we were able to weaken the chronic conditions after the infection," says studyist Jie Sun, an immunologist at the University of Virginia in Charlottesville. "In the future we could target this path as a potential treatment of long-covid."

inflammatory protein

ifn-γ is one of many proteins that the body releases to combat infections. If it is released by white blood cells, so-called T cells, it sends signals to other immune cells and promotes Inflammation . In the short term, this increases blood flow into the infected area to support the healing process - but chronic inflammation can lead to damage to cells and tissues.

Earlier examinations have shown that People with Long-Covide have increased mirrors of ifn-γ have 2 , and there is also indications that the protein for injuries in the lung bubbles 3 can contribute-the sensitive air spaces in the lungs, the gases transport in and from the bloodstream. However, these studies could not determine whether IFN-γ is a cause of the lung injuries associated with long-covid or just an indication of a different mechanism.

To examine this, Sun and his colleagues went into two steps. First they recruited people with long-covid and compared cell samples of their lungs with those of people who recovered a few weeks before the study of Covid-19, as well as with control persons who were not infected. They used a technology called single cell RNA sequencing to analyze the composition of the lung cell samples. They discovered that rehearsals of people with long-covid showed higher mirrors of IFN-γ-producing T cells than rehearsals of people without covid-19 or those who had recovered from the infection.

Then the researchers infected mice with Sars-Cov-2. Twenty-one days after the infection, the mice had a cellular reaction in their lungs that resembles people with long-covid, including increased mirrors of IFN-γ-producing T cells.

The researchers treated some of the infected mice with a fabric inhibits IFN-γ. They noticed a significant improvement in the health of the animals - an overall reduced inflammation in the lungs, lower levels of immune cells that promote inflammation, and less deposits of collagen, a substance that can damage and scarred the lung tissue.

future treatments

The team hopes that the goal of IFN-γ could have similar advantages for people with long-covid. "The next step would be to see whether we can use a treatment that influences this path to check whether the symptoms are improved in patients," says Stéphanie Longet, an immunologist at the International Center for Infection Research in Lyon, France, which suffers from Long-Covid. It adds that there are already IFN-γ-inhibiting medication on the market, such as Baricitinib, which is currently being used to treat heavy covid-19 and to reduce inflammation by rheumatoid arthritis.

The researchers also emphasize the importance of the investigation of other potential drivers of long-covid , which is believed to affect millions of people worldwide. "What we found here is probably a factor in a long-covide state," says Sun. "We want to examine more mechanisms to identify more goals in the future."