'Couch potato' Macrophage (IMAGE) University of Cambridge Caption Smoke-clogged alveolar macrophages of cigarette smokers are unable to move to engulf infecting TB bacilli, which may explain why cigarette smokers are more susceptible to tuberculosis. The image shows where TB bacilli accumulate near a 'couch-potato' smoker macrophage while a normal macrophage in the background is picking up infecting TB bacteria. Credit Kevin Takaki and drawn by Paul Margiotta Usage Restrictions The image can be viewed by all users and can be used freely, with appropriate credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.