| First Author | VanOosten RL | Year | 2007 |
| Journal | Cancer Res | Volume | 67 |
| Issue | 24 | Pages | 11980-90 |
| PubMed ID | 18089829 | Mgi Jnum | J:129272 |
| Mgi Id | MGI:3768964 | Doi | 10.1158/0008-5472.CAN-07-1526 |
| Citation | VanOosten RL, et al. (2007) Activation of tumor-specific CD8+ T Cells after intratumoral Ad5-TRAIL/CpG oligodeoxynucleotide combination therapy. Cancer Res 67(24):11980-90 |
| abstractText | CD8(+) T-cell activation via cross-presentation of antigens from apoptotic tumor cells is controversial. Dendritic cells capture naturally shed tumor antigens and cross-present them to CD8(+) T cells; unfortunately, the frequency of activated CD8(+) T cells is often too low to mount an effective response against the tumor. By increasing the amount of antigen for presentation, a larger T-cell response can be theoretically elicited. We used a recombinant adenovirus encoding full-length murine tumor necrosis factor-related apoptosis-inducing ligand (Ad5-mTRAIL) to induce tumor cell apoptosis, and when given intratumorally to mice bearing experimental renal cell carcinoma (Renca) tumors, Ad5-mTRAIL minimally prolonged survival and induced a low level of CTL activity. To enhance dendritic cell efficiency, an immunostimulatory CpG oligodeoxynucleotide (CpG ODN) was combined with Ad5-mTRAIL. This combination therapy significantly augmented in vivo antigen-specific T-cell proliferation and CTL activity, as well as prolonged survival of Renca tumor-bearing mice. Interestingly, depletion of CD4(+) or CD25(+) cells before therapy further enhanced survival and in vivo CTL activity. In addition, tumor-free mice depleted of CD4(+) cells were also able to reject a subsequent challenge of Renca cells, but not MHC-matched RM-11 prostate tumor cells, demonstrating the existence of immunologic memory. These results collectively show that local treatment with Ad5-mTRAIL and CpG ODN can augment tumor antigen cross-presentation resulting in T-cell proliferation, enhanced CTL activity, and increased animal survival. |
