Carlos Serezani, PhD

American Lung Association Scholar: Other Lung Infections

Immune cells called alveolar macrophages (AM) are on the front line of defense against microbes that cause pneumonia. These cells are responsible for recognizing and killing infectious-causing agents. Carlos Serezani, PhD at University of Michigan is studying how these cells work, with the hope that the results will lead to better treatments for pneumonia.

Pneumonia-causing bacteria are present in some healthy throats. When body defenses are weakened in some way, by illness, old age, malnutrition, general debility or impaired immunity, the bacteria can multiply and cause serious damage. Usually, when a person's resistance is lowered, bacteria work their way into the lungs and inflame the air sacs.

With the help of an American Lung Association Senior Research Training Fellowship, Dr. Serezani is focusing on substances called lipid mediators that can enhance or decrease macrophage function during body's fight against pneumonia. Lipid mediators are produced when the body is fighting an inflammatory condition or an infection. They improve clearance of bacteria and bolster the immune system's response.

He is studying what happens to the AMs of mice infected with  Klebsiella pneumonia when they are treated with lipid mediators. He has found that when lipid mediators called leukotrienes are added, they enhance the macrophage's capacity to ingest and clear bacterial infection

Dr. Serezani is now studying how a lipid mediator called prostaglandin inhibits ingestion and clearance of bacteria.

Both parts of his research have implications for treatment of pneumonia. Drugs that increase leukotriene production, or that inhibit prostaglandin production, might have beneficial effects on pneumonia patients.  Since Ibuprofen and aspirin are prostaglandin inhibitors, "there is a great interest in how prostaglandin inhibitors could improve pneumonia treatment," Dr. Serezani said.

He is also planning on studying how leukotrienes affect the inflammatory response caused by infection. "Pneumonia leads to massive inflammation in the lung, which can lead to lung injury," he said. "If you can prevent the inflammation, it may improve patients' outlook."

Dr. Serezani says the American Lung Association grant has been instrumental in his career as a pulmonary researcher. "This grant was essential for me as a scientist, because it helped me to decide which direction to go in as an independent researcher," he said.