| First Author | Odorizzi PM | Year | 2015 |
| Journal | J Exp Med | Volume | 212 |
| Issue | 7 | Pages | 1125-37 |
| PubMed ID | 26034050 | Mgi Jnum | J:224770 |
| Mgi Id | MGI:5689053 | Doi | 10.1084/jem.20142237 |
| Citation | Odorizzi PM, et al. (2015) Genetic absence of PD-1 promotes accumulation of terminally differentiated exhausted CD8+ T cells. J Exp Med 212(7):1125-37 |
| abstractText | Programmed Death-1 (PD-1) has received considerable attention as a key regulator of CD8(+) T cell exhaustion during chronic infection and cancer because blockade of this pathway partially reverses T cell dysfunction. Although the PD-1 pathway is critical in regulating established "exhausted" CD8(+) T cells (TEX cells), it is unclear whether PD-1 directly causes T cell exhaustion. We show that PD-1 is not required for the induction of exhaustion in mice with chronic lymphocytic choriomeningitis virus (LCMV) infection. In fact, some aspects of exhaustion are more severe with genetic deletion of PD-1 from the onset of infection. Increased proliferation between days 8 and 14 postinfection is associated with subsequent decreased CD8(+) T cell survival and disruption of a critical proliferative hierarchy necessary to maintain exhausted populations long term. Ultimately, the absence of PD-1 leads to the accumulation of more cytotoxic, but terminally differentiated, CD8(+) TEX cells. These results demonstrate that CD8(+) T cell exhaustion can occur in the absence of PD-1. They also highlight a novel role for PD-1 in preserving TEX cell populations from overstimulation, excessive proliferation, and terminal differentiation. |