| First Author | Clayton KL | Year | 2014 |
| Journal | J Immunol | Volume | 192 |
| Issue | 2 | Pages | 782-91 |
| PubMed ID | 24337741 | Mgi Jnum | J:228106 |
| Mgi Id | MGI:5705214 | Doi | 10.4049/jimmunol.1302663 |
| Citation | Clayton KL, et al. (2014) T cell Ig and mucin domain-containing protein 3 is recruited to the immune synapse, disrupts stable synapse formation, and associates with receptor phosphatases. J Immunol 192(2):782-91 |
| abstractText | CD8(+) CTLs are adept at killing virally infected cells and cancer cells and releasing cytokines (e.g., IFN-gamma) to aid this response. However, during cancer and chronic viral infections, such as with HIV, this CTL response is progressively impaired due to a process called T cell exhaustion. Previous work has shown that the glycoprotein T cell Ig and mucin domain-containing protein 3 (Tim-3) plays a functional role in establishing T cell exhaustion. Tim-3 is highly upregulated on virus and tumor Ag-specific CD8(+) T cells, and antagonizing Tim-3 helps restore function of CD8(+) T cells. However, very little is known of how Tim-3 signals in CTLs. In this study, we assessed the role of Tim-3 at the immunological synapse as well as its interaction with proximal TCR signaling molecules in primary human CD8(+) T cells. Tim-3 was found within CD8(+) T cell lipid rafts at the immunological synapse. Blocking Tim-3 resulted in a significantly greater number of stable synapses being formed between Tim-3(hi)CD8(+) T cells and target cells, suggesting that Tim-3 plays a functional role in synapse formation. Further, we confirmed that Tim-3 interacts with Lck, but not the phospho-active form of Lck. Finally, Tim-3 colocalizes with receptor phosphatases CD45 and CD148, an interaction that is enhanced in the presence of the Tim-3 ligand, galectin-9. Thus, Tim-3 interacts with multiple signaling molecules at the immunological synapse, and characterizing these interactions could aid in the development of therapeutics to restore Tim-3-mediated immune dysfunction. |
