Cigarette smoke can cause the body's immune system to attack lung tissue, causing damage that can lead to respiratory diseases, according to research from the University of Cincinnati.

The Cincinnati Enquirer reported Feb. 17 that researchers led by Michael Borchers examined genetically modified mice to study the link between cigarette exposure, the immune system, and chronic obstructive pulmonary disorder (COPD).

The researchers observed that after lung cells were damaged from cigarette smoke, the cells signaled to the immune system that the damaged cells must be destroyed.  COPD develops when the immune response overwhelms the body's ability to repair tissue.

"People have historically believed that if you smoke, you suppress the immune system," Borchers said. "We've shown that you actually activate certain parts of the immune system and it could potentially work against you."

Borchers said that the findings may help scientists develop a screening method to predict when smokers will develop the disease. "There's no cure for COPD," he said. "There's not even really any medicine to treat it."

The findings were published Feb. 9, 2009 in the Journal of Clinical Investigation.