Comparison of T-cell and NK-cell alloimmune responses.
| Function . | T Cells . | NK Cells . |
|---|---|---|
| Abbreviations: APC, antigen-presenting cell; CD, cluster-determinant; GVHD, graft-versus-host disease; GVL, graft versus leukemia; KIR, killer immunoglobulin-like receptors; MHC, major histocompatibility complex; MICA/B, major histocompatibility complex class I-related chain A/B ; NK, natural killer; NKG2D, NK cell receptor D; TCR, T-cell receptor. | ||
| Recognition structure on stimulator | Self or nonself MHC class I or II + peptide antigen | Negative signals: self MHC class I HLA-C, HLA-B Positive signals: MICA/B, other ligands |
| Recognition structure on lymphocyte | T-cell receptor | Negative signal: KIR Positive signal: NKG2D and others |
| Clonal diversity | High: 1010 different TCR | Low: 17 KIR types identified4 |
| Costimulation | CD80, CD86/CD28 | NKG2D and other positive stimuli |
| APCs required to initiate response | Yes | No |
| Target cells | Hematopoietic cells other class I/II+ cells | Hematopoietic cells MHC negative or mismatched virus-infected/tumor cells |
| Proliferation required for effector function post-transplant | Yes | No |
| Cytotoxicity mediated by perforin and granzymes | Yes | Yes |
| Cytokine release on contact with with APCs or target | Yes | Yes |
| Fate of effectors after engaging target | Return to memory pool or cell death | Cell death, no proliferation |
| Transplant-related effects | ||
| HLA-matched alloresponses | Weak to powerul | Absent or weak |
| HLA-mismatched alloresponses | Strong | Strong |
| GVHD effect | Yes | None or minimal |
| GVL effect | Yes | Yes (mismatched transplants) |
| Involved in engraftment | Yes | Yes (mismatched transplants) |
| Function . | T Cells . | NK Cells . |
|---|---|---|
| Abbreviations: APC, antigen-presenting cell; CD, cluster-determinant; GVHD, graft-versus-host disease; GVL, graft versus leukemia; KIR, killer immunoglobulin-like receptors; MHC, major histocompatibility complex; MICA/B, major histocompatibility complex class I-related chain A/B ; NK, natural killer; NKG2D, NK cell receptor D; TCR, T-cell receptor. | ||
| Recognition structure on stimulator | Self or nonself MHC class I or II + peptide antigen | Negative signals: self MHC class I HLA-C, HLA-B Positive signals: MICA/B, other ligands |
| Recognition structure on lymphocyte | T-cell receptor | Negative signal: KIR Positive signal: NKG2D and others |
| Clonal diversity | High: 1010 different TCR | Low: 17 KIR types identified4 |
| Costimulation | CD80, CD86/CD28 | NKG2D and other positive stimuli |
| APCs required to initiate response | Yes | No |
| Target cells | Hematopoietic cells other class I/II+ cells | Hematopoietic cells MHC negative or mismatched virus-infected/tumor cells |
| Proliferation required for effector function post-transplant | Yes | No |
| Cytotoxicity mediated by perforin and granzymes | Yes | Yes |
| Cytokine release on contact with with APCs or target | Yes | Yes |
| Fate of effectors after engaging target | Return to memory pool or cell death | Cell death, no proliferation |
| Transplant-related effects | ||
| HLA-matched alloresponses | Weak to powerul | Absent or weak |
| HLA-mismatched alloresponses | Strong | Strong |
| GVHD effect | Yes | None or minimal |
| GVL effect | Yes | Yes (mismatched transplants) |
| Involved in engraftment | Yes | Yes (mismatched transplants) |