Immunoevasins
Under Immunoevasinen refers to proteins that there viruses allow the immune response to suppress their host or to get around. Many virus families have their own immunoevasins, the mechanisms of which can be divided into four main classes (here related to antigen processing and presentation ):
- Preventing the entry of the antigen - peptide into the endoplasmic reticulum (ER)
- Retention of MHC class I complexes in the ER
- Degradation of the MHC class I complexes
- Binding of the MHC class I complexes to the cell surface
| virus | protein | category | mechanism |
|---|---|---|---|
| Herpes simplex virus 1 | ICP 47 | Prevents the peptide from entering the ER | Prevents the peptide from binding to TAP |
| Human cytomegalovirus | US6 | Prevents the peptide from entering the ER | Inhibits the ATPase activity of the TAP |
| Bovine herpes virus | UL 49.5 | Prevents the peptide from entering the ER | Inhibits the transport of TAP peptides |
| Adenovirus | E19 | Retains MHC-I in the ER | Competitive tapasin inhibitor |
| HCMV | US3 | Retains MHC-I in the ER | Inhibits the function of tapasin |
| Murine cytomegalovirus | M152 | Retains MHC-I in the ER | Unknown |
| HCMV | US2 | Degrades MHC-I | Transports some of the newly synthesized MHC-I molecules into the cytosol |
| Murine gamma herpes virus | mK3 | Degrades MHC-I | E3 ubiquitin ligase activity |
| Murines CMV | m4 | Binds MHC-I to the cell surface | Prevents recognition by cytotoxic lymphocytes via an unknown mechanism |
literature
- Janeway: "Immunobiology", 7th edition, Garland Science 2008