Penicillin is an antibody

With antibodies instead of antibiotics against pneumonia

When children suffer from bacterial pneumonia, so-called mycoplasmas are often to blame. In order to switch off these very small bacteria, specific cells of the immune system, the so-called B cells, are particularly important, researchers from the University Children's Hospital and the University of Zurich recently reported with international colleagues in the "Journal of Infectious Diseases".

The B cells produce antibodies that help clear out the mycoplasma in the lungs. In the nasopharynx, however, the bacteria can survive for weeks, the university wrote in a statement on Tuesday. This is because the immune response to the presence of the pathogen differs in the two locations.

The researchers led by Patrick Meyer Sauteur came to this conclusion by marking the bacteria with a fluorescent dye and infecting mice with it. This enabled them to visually follow the pathogens as the infection progressed and study the immune system.

Different defense reactions

A major difference in the immune defense in the two places in the body: In the lungs, B cells are activated in the adjacent lymph nodes and multiply, but not in the upper airways. Sauteur and colleagues also found a difference in the composition of the antibodies released: different types of antibodies are active in the lungs than in the nasopharynx.

These differences mean that the pathogen is effectively switched off in the lungs, but not in the upper airways. "These are the first data to prove that the antibody-mediated immune response is essential for a lung infection with mycoplasma," Sauteur said according to the announcement.

This knowledge also paves the way for new vaccines to prepare the immune system to defend against mycoplasma and to prevent infection, said Sauteur. Because mycoplasmas, like other bacteria, are becoming increasingly insensitive to antibiotics, there are no longer any suitable drugs for small children in some regions of the world. A vaccine could help.