| Presenting cell type | Antigen presented | MHC class | T cell type | T cell surface protein |
|---|---|---|---|---|
| Any cell | Intracellular protein fragment | Class I | Cytotoxic T cell (TC) | CD8 |
| Macrophages, dendritic cells, and B cells | Fragments from extracellular proteins | Class II | Helper T cell (TH) | CD4 |