Diagram of cellular immune response

Diagram of cellular immune response where cytotoxic T-Cells (purple) attack compromised cells. At upper right, a macrophage processes antigens and presents them to a helper T-cell (purple). The Helper T-Cell then activates the cytotoxic T-Cells by releasing cytokines. The compromised cell (green) disintegrates after being attacked by the cytotoxic T-Cells