The Lung Immune Niche in Tuberculosis: Insights from Studies on Human Alveolar Macrophages

Tuberculosis (TB) is a disease that continues to cause global mortality and morbidity. Transmission of Mycobacterium tuberculosis (Mtb) occurs by aerosol transmission from an infected case, making the lung the primary portal of entry for the bacterium. Alveolar macrophages are the frontline cells involved in the control of subsequent replication and spread of disease. Although animal models have provided important information in the field of macrophage immunology and cell biology, human TB disease has several unique features. Therefore, an understanding of human alveolar macrophage biology and their interactions with Mtb is important, not only to understand how to address TB control at various stages of the disease but also to develop optimal future vaccination and drug strategies. Despite limitations of human sample access, technical expertise in cell processing, and access to reagents, significant advances have been made in the field providing critical insights into host-pathogen interactions This review describes the unique features and the immune responses of human alveolar macrophages in the context TB infection.