Antibodies Protect Against Respiratory Infections

Antibodies produced in the lung can prevent respiratory infections from becoming severe.

Lung infections cause only a small subset of people to become very sick. However, the prediction of the risk in an individual or its mechanism remains unclear, as observed in the context of COVID-19.

Lungs generally consist of their own specialized immune system, that is different from the rest of the body. It is now found that after recovering from a respiratory infection, new cells get deposited in lung tissue, persist there, and then become antibody-secreting cells very quickly if the lungs later get re-infected by something similar, as per research at the Boston University School Of Medicine.

New Way to Block Viruses That Cause Respiratory Infections
Researchers have developed a new method in rodent models to help keep children healthy from respiratory infections.

‘Antibodies produced in the lung can prevent respiratory infections from becoming severe. Understanding how antibodies and antibody-secreting cells can fight against lung infection will provide new directions for improving vaccines to prevent severe respiratory infection and for designing treatments that cure respiratory infections.’

The study team analyzed a combination of infections in experimental models and cells collected from human lungs.

"We found lungs that had recovered from infections had new cells that were not there before infection, capable of quickly producing antibodies when stimulated. We showed that antibodies in the lungs helped fight microbes and removing the cells making these antibodies compromised lung defense against respiratory pathogens," says the corresponding author Joseph Mizgerd, ScD, professor of medicine, microbiology, and biochemistry at Boston University School of Medicine.

The team thereby speculates that these differences in lung-specific antibodies and antibody-secreting cells might be one of the important factors in determining who will become very ill or instead experience mild or even no symptoms when infected by a respiratory pathogen.

Coronavirus
Coronaviruses infect animals, humans, and birds. Human coronaviruses, such as SARS, MERS, and 2019-nCoV cause respiratory distress and even death. The S protein is the infectious agent of the virus.

Also, the immunity that is lung-localized differs from more conventional types of immunity as it prevents severe disease instead of preventing infection altogether and is effective against a wider range of microbes instead of against only one single virus or bacteria.

"With a better understanding of the components of lung immunity that prevent severe infections, we will be able to identify who is prone to severe disease when infected. Leveraging this knowledge may provide opportunities to develop novel types of vaccines that prevent severe disease caused by a broader spectrum of microbes, such as for all coronaviruses or all influenza viruses."

High Levels of Cadmium Increase the Severity of Respiratory Infections
Higher levels of cadmium in COVID-19, pneumonia, and influenza patient increase the severity of infection and the mortality rate.

Source-Medindia