New insights into programmed cell death protein 1 blockade-associated cutaneous immune-related adverse events.

Multiple ligand-receptor interactions between antigen-specific T cells and macrophages in the dermis could help explain how PD-1 controls the location of self-antigen-specific T cells and compartmentalizes T cells away from self-antigens. For example, anti-PD-1 antibody leads to activation of CD8 SP + sp T cells recognizing hair follicle autoantigens on keratinocytes in checkpoint-associa--ted alopecia areata.[13] However, the origin of these autoantigen recognizing T cells and whether they derive from previously tolerant T cells or arise I de novo i is unclear. (Right) PD-1 blockade leads to loss of T-cell tolerance to self-antigen, localization of self-antigen-specific T cells to the epidermis, increased cytokine release, keratinocyte death and skin inflammation. [Extracted from the article]