| First Author | Xiao Z | Year | 2007 |
| Journal | J Exp Med | Volume | 204 |
| Issue | 11 | Pages | 2667-77 |
| PubMed ID | 17954566 | Mgi Jnum | J:126126 |
| Mgi Id | MGI:3760576 | Doi | 10.1084/jem.20062376 |
| Citation | Xiao Z, et al. (2007) Detuning CD8 T cells: down-regulation of CD8 expression, tetramer binding, and response during CTL activation. J Exp Med 204(11):2667-77 |
| abstractText | CD8 is critical for T cell recognition of peptide/class I major histocompatability complex ligands, yet is down-regulated during activation of CD8 T cells. We report that loss of CD8 expression early during in vivo responses to vaccinia virus or Listeria monocytogenes (LM) correlates with decreased T cell staining with specific class I/peptide tetramers and reduced CD8 T cell sensitivity for antigen. Loss of CD8 cell surface expression occurs despite sustained mRNA expression, and CD8 levels return to normal levels during differentiation of memory cells, indicating a transient effect. We determined that during response to LM, CD8 down-regulation is regulated by T cell reactivity to type I interferon (IFN-I) because CD8 loss was averted on IFN-I receptor-deficient T cells. IFN-I alone was not sufficient to drive CD8 down-regulation, however, as antigen was also required for CD8 loss. These results suggest that CD8 effector T cell differentiation involves a transient down-regulation of antigen sensitivity (CTL 'detuning'), via reduced CD8 expression, a feature that may focus the effector response on target cells expressing high levels of antigen (e.g., infected cells), while limiting collateral damage to bystander cells. |
