The nose houses a variety of Long-lasting immune cells that are ready to ward off viral and bacterial infections , according to the most detailed examination of the immune cells, which form the first line of defense of the lungs 1 .

The results published on July 31st in Nature show that the nose and the upper respiratory tract-to which mouth, sinuses and throat, but not the air tube-as Important training places serve where immune cells 'intruders' memorize . These memories enable the cells to defend themselves against future attacks by similar microorganisms. The data could be the development of Mukosa vaccines that are administered by the nose or throat , accelerate, of which immunologists say that they could be more effective than vaccines that are sprayed into the muscles.

This "exciting study" shows that an "arsenal of immune cells that are capable of warding off airway infections", reliably in the upper respiratory tract of young adults and Older people who usually have weaker immune reactions says Linda Wakim, an immunologist at the University of Melbourne In Australia, that was not involved in research.

on the nose

Previous research on the immune system has concentrated on immune cells in the blood and in the lower respiratory tract, mainly because these regions are relatively easily accessible through blood sampling and some types of biopsies and organ transplants, says the study maker Sydney Ramirez, an infectious cancellation doctor and immunologist La Jolla Institute for Immunology in California.

Then came the Covid-19 pandemic and the appearance of variants like Omicron , which are multiplying with high efficiency in the upper respiratory paths. These developments prompted Ramirez and her colleagues to find ways to investigate how immune cells interact with pathogenic in the upper respiratory tracts.

The team used nasopharynx smears, which extend to the back of the nose and were often used for SARS-COV-2 tests in wealthy countries. The researchers removed about 30 healthy adults every month for more than a year to see how their immune cell populations changed over time. They found millions of immune cells in these rehearsals, including cells, the immunological memory.

nasal immune system

The researchers also learned that they were able to dab hard -to -reach immune organs called adenoids that are hidden in the back of the nose. These organs analyze inhaled air and contain structures called nucleus centers. These structures, which also occur in other immune organs, serve as a training camp in which the ability to reflect B cells learn to produce effective antibodies.

The adenoids shrink in adulthood, but the researchers found active germ centers in the adenoids of study participants of all ages - results that should "be reassuring for all over 20 years old," says Ramirez. The researchers also unintentionally found information on the effectiveness of these germ centers: Several participants were infected with Covid-19 during the study, and the researchers found that the noses of these participants housed B cells that specialized in combating SARS-COV-2.

germ centers are usually only active during and shortly after acute infections or vaccinations, but the authors found active germ centers even if the participants did not provide information to feel sick. With this new advancement technique, researchers could soon understand what drives the activity of the centers and how the SARS-COV-2 infection shapes these immune responses, says Donna Farber, an immunologist at Columbia University in New York, which was not involved in the study.

These results can also offer a "very valuable" quantitative method to measure the changes in the immune response after vaccination, especially to test intranasal vaccination candidates, says Farber. But it adds that they also show how high the mountain is to climb: If the immune system is constantly active in the upper respiratory tract, existing antibodies could already be the protective effect of Block.