Circuits between infected macrophages and T cells in SARS-CoV-2 pneumonia

The bulk transcriptomic profiling and single cell RNA-seq dataset of bronchoalveolar lavage fluid samples were compared between SARS-CoV-2 induced pneumonia and other pneumonia. The alveolar space in SARS-CoV-2 pneumonia was enriched in CD4+ or CD8+ T cells and monocytes. In these patients, SARS-CoV-2 infected to alveolar macrophages. The macrophages produced inflammatory cytokines by responding to the interferon-gamma released from T cells, which also promoted the T cell activation. This feedback between SARS-CoV-2 infected macrophages and T cells drives persistent alveolar inflammation.