| First Author | Erkes DA | Year | 2017 |
| Journal | J Immunol | Volume | 198 |
| Issue | 7 | Pages | 2979-2988 |
| PubMed ID | 28202614 | Mgi Jnum | J:252719 |
| Mgi Id | MGI:5925730 | Doi | 10.4049/jimmunol.1601064 |
| Citation | Erkes DA, et al. (2017) Virus-Specific CD8+ T Cells Infiltrate Melanoma Lesions and Retain Function Independently of PD-1 Expression. J Immunol 198(7):2979-2988 |
| abstractText | It is well known that CD8+ tumor-infiltrating lymphocytes (TILs) are correlated with positive prognoses in cancer patients and are used to determine the efficacy of immune therapies. Although it is generally assumed that CD8+ TILs will be tumor-associated Ag (TAA) specific, it is unknown whether CD8+ T cells with specificity for common pathogens also infiltrate tumors. If so, the presence of these T cells could alter the interpretation of prognostic and diagnostic TIL assays. We compared TAA-specific and virus-specific CD8+ T cells in the same tumors using murine CMV, a herpesvirus that causes a persistent/latent infection, and vaccinia virus, a poxvirus that is cleared by the host. Virus-specific CD8+ TILs migrated into cutaneous melanoma lesions during acute infection with either virus, after a cleared vaccinia virus infection, and during a persistent/latent murine CMV infection. Virus-specific TILs developed independently of viral Ag in the tumor and, interestingly, expressed low or intermediate levels of full-length PD-1 in the tumor environment. Importantly, PD-1 expression could be markedly induced by Ag but did not correlate with dysfunction for virus-specific TILs, in sharp contrast to TAA-specific TILs in the same tumors. These data suggest that CD8+ TILs can reflect an individual's immune status, rather than exclusively representing TAA-specific T cells, and that PD-1 expression on CD8+ TILs is not always associated with repeated Ag encounter or dysfunction. Thus, functional virus-specific CD8+ TILs could skew the results of prognostic or diagnostic TIL assays. |
