Protocol to infect differentiated human primary bronchial epithelial cells with live mycobacteria and determine intracellular load.

Lung epithelial cells present the first line of defense against pathogens like Mycobacterium tuberculosis and other related species. Studying their responses is instrumental to understand early infection stages of tuberculosis. We present a protocol to study the infection potential of mycobacteria in differentiated primary human bronchial epithelial cell cultures. We describe mycobacterial and epithelial cell culture techniques. We then detail how to perform infections in epithelial cells and determine intracellular bacterial load using flow cytometry and colony-forming unit assays. For complete details on the use and execution of this protocol, please refer to Barclay et al.1,2.