Single-cell transcriptomics identifies pathogenic T-helper 17.1 cells and pro-inflammatory monocytes in ICI-related pneumonitis

ICI-pneumonitis is a frequent serious adverse event of cancer immunotherapy hinging on a cell-mediated immune response, though the exact pathophysiology is currently unknown. Using single-cell transcriptomics, an enrichment of pathogenic (TBX21, RORC, IFNG, IL17A, CSF2 expressing) T-helper 17.1 cells and pro-inflammatory (TNF, IL1B, IL6, IL23A expressing) monocytes was identified in ICI-pneumonitis bronchoalveolar lavage fluid, putatively engaging in a feedforward inflammatory loop. This finding yields several novel therapeutic targets for the treatment of ICI-pneumonitis. Most notably repurposing anti-IL-23 merits further research as a potential efficacious and safe treatment for ICI-pneumonitis.EGA study EGAS00001006762