Stem-like PD-1+TCF-1+ CD8+ T cells result from helpless priming and rely on CD4+ T-cell help to complete their cytotoxic effector differentiation

Background <p>Antigen-specific CD8⁺ T cells can be in a stem-like programmed cell death protein-1 (PD-1)⁺TCF-1⁺ differentiation state that progresses into terminal exhaustion in cancer and chronic infection. These stem-like cells are important, since they are the responders to PD-1 targeted immunotherapy and a potential resource for antitumor immunity.</p> Methods <p>We use a mouse vaccination model to delineate by spectral flow…