Infected target cell degrades antigen into fragments 24.1Introduction ↓ Figure 24.2 In cell-mediated immunity killer T cells use Kiler: T: cell he T-cell receptor to recognize a fragment of the MHC presents T-cell receptor antiger foreign antigen which is presented on the surface of the target cell by the mhc protein Killer T cell hocyte reco 消当 ntigen fragmentFigure 24.2 In cell-mediated immunity, killer T cells use the T-cell receptor to recognize a fragment of the foreign antigen which is presented on the surface of the target cell by the MHC protein. 24.1 Introduction