| First Author | Shen L | Year | 2004 |
| Journal | Immunity | Volume | 21 |
| Issue | 2 | Pages | 155-65 |
| PubMed ID | 15308097 | Mgi Jnum | J:93590 |
| Mgi Id | MGI:3487192 | Doi | 10.1016/j.immuni.2004.07.004 |
| Citation | Shen L, et al. (2004) Important role of cathepsin S in generating peptides for TAP-independent MHC class I crosspresentation in vivo. Immunity 21(2):155-65 |
| abstractText | The immune system detects viral infections and mutations in parenchymal cells when antigens from these cells are crosspresented on MHC class I molecules of professional antigen-presenting cells (APC). Exogenous antigens are crosspresented through TAP-dependent (cytosolic) or poorly understood TAP-independent (vacuolar) pathways. The TAP-independent pathway is blocked by the cysteine protease inhibitor, leupeptin, but not by proteasome inhibitors, which is opposite to the effects of these agents on the TAP-dependent pathway. Dendritic cells lacking the cysteine protease cathepsin S lack the TAP-independent pathway. Mice whose APC lack cathepsin S have reduced crosspriming to particulate and cell-associated antigens, as well as to influenza virus. Cathepsin S-deficient phagosomes generate a class I-presented peptide poorly. In contrast, cathepsin S-sufficient phagosomes and recombinant cathepsin S produce the mature epitope. Therefore, cathepsin S plays a major role in generating presented peptides for the vacuolar pathway of crosspresentation, and this mechanism is active in vivo. |
