Uncovering the Bronchoalveolar Single-Cell Landscape of Patients with Pulmonary Tuberculosis with Human Immunodeficiency Virus Type 1 Coinfection.

Background Coinfection of human immunodeficiency virus type 1 (HIV-1) is the most significant risk factor for tuberculosis (TB). The immune responses of the lung are essential to restrict the growth of Mycobacterium tuberculosis and avoid the emergence of the disease. Nevertheless, there is still limited knowledge about the local immune response in people with HIV-1-TB coinfection.Methods We employed single-cell RNA sequencing (scRNA-seq) on bronchoalveolar lavage fluid from 9 individuals with HIV-1-TB coinfection and 10 with pulmonary TB.Results A total of 19 058 cells were grouped into 4 major cell types: myeloid cells, T/natural killer (NK) cells, B cells, and epithelial cells. The myeloid cells and T/NK cells were further divided into 10 and 11 subsets, respectively. The proportions of dendritic cell subsets, CD4+ T cells, and NK cells were lower in the HIV-1-TB coinfection group compared to the TB group, while the frequency of CD8+ T cells was higher. Additionally, we identified numerous differentially expressed genes between the CD4+ and CD8+ T-cell subsets between the 2 groups.Conclusions HIV-1 infection not only affects the abundance of immune cells in the lungs but also alters their functions in patients with pulmonary TB. We utilized single-cell RNA sequencing technology to provide a detailed analysis of immune cells in the lungs of patients with tuberculosis (TB) or with HIV-TB coinfection. Our findings revealed notable variations in immune response between these 2 disease types.