Professor Mike Rogers, head of the Osteopathic Medicine Laboratory at the Garvan Institute.
“We found an additional potential benefit to this treatment – it could boost the immune function of lung cells, which could protect against respiratory infections and pneumonia. people at high risk for pneumonia and osteoporosis.”
Respiratory infections, such as acute pneumonia, are a major cause of death from infections worldwide. They increasingly affect aging populations, as our ability to generate protective immune responses against infectious diseases diminishes with age.
Dr Marcia Munoz, first author of the paper, said: “Previous clinical trials have shown that treatment with bisphosphonates has a beneficial effect in protecting against pneumonia. “In our study, we wanted to understand why that is.”
The researchers injected a bisphosphonate called zoledronic acid into mouse models and tracked how the drug moved into different cells.
“It was previously thought that bisphosphonates only act in bone, but we discovered that they are taken up by macrophages in the lungs, which are ‘first responder’ cells that can recognize, engulf and kill them. pathogens during the immune response,” said. Dr. Munoz.
The team then tested their model’s immune response by exposing them to LPS, a molecule found on the surface of bacteria that is commonly used to assess responses to infections. coincide. They found that even after just one dose of bisphosphonate, the activity of macrophages in the lungs was increased compared with untreated mice.
“In the skeleton, bisphosphonates prevent bone loss by blocking an enzyme needed for specialized cells to break down bone,” said graduate student Emma Fletcher, second author of the paper. “In immune cells in the lungs, we found that the treatment blocked the same enzyme, in this case boosting the immune response.”
Potential health effects
Professor Rogers said: “Macrophages are one of the first lines of defense against infection. “If bisphosphonates enhance the responsiveness of these cells when they encounter viral or bacterial infections, a stronger initial immune response could help clear the infection and lead to better outcomes.” This is something we will study next.”
“This makes it possible for a large number of individuals to receive additional benefits,” adds Professor Rogers. “Clinical trials are warranted to determine if bisphosphonates, in addition to preventing bone loss, can protect against pneumonia infection in vulnerable populations, such as patients in care homes. old.”