Since IRX-2 up-regulated DC migration and IL-12p70 production, it is likely that a synergistic effect of INF-c and other cytokines included in IRX-2 was responsible for the observed effects. Recently, Lopez-Albeitero et al reported that cross-presentation of the MAGE3271-279 peptide correlated with TAP1 and TAP2 expression in APC in that higher expression of these APM components resulted in more effective presentation of the peptide to T cells. In addition, it has been shown, that a higher density of MHC-class-I-peptide complexes on the surface of APC leads to more effective induction and expansion of the peptide-specific CTL. We hypothesized, that DC matured in the presence of IRX-2 have a higher density of non-self-peptide-MHC Class I complexes on their surface and thus are more efficient in loading, transporting and presentation of these peptides. Indeed, using tumor-reactive CTL generated via IVS with PCI-13-loaded DC we showed that IRX-2 matured DC induced high-potency CTL. Although we found higher levels of the co-stimulatory molecules CD80 and CD86 on conventionally-matured DC, CTL generated in IVS cultures with IRX-2-matured DC turned out to be more effective in killing PCI-13 targets which served as an antigen source for cross-priming. It also appears that CTL generated in IVS with IRX-2-matured mDC, which have enhanced crosspriming capabilities, are more responsive to tumor-derived antigens in ELISPOT assays. These CTL gave the highest number of IFN-c spots upon co-incubation with IRX-2-matured DC presenting the antigen. We, therefore, suggest that the superior cross-priming capacity of IRX-2 matured DC is due to better cross-presentation of tumor cell-derived antigens likely resulting from up-regulated expression of APM components. In turn, this suggests that APM plays the LY2109761 central role in regulating the density of tumor-derived peptides present on the surface of mDC and that this step is of critical importance in the preparation of DC-based anti-cancer vaccines. However, effective cross-priming of T cells by APC is also critically dependant on cytokine-mediated signaling. IL-12p70 appears to be essential for CTL priming by DC. Okada et al. recently reported that clinical responses to DC-based vaccines correlated with IL-12p70 production by the DC used for therapy. In contrast, IL-10, which is considered to be an inhibitory cytokine, has negative effects on priming of T-cell responses. A higher ratio of IL12p70/IL-10 in supernatants of IRX-2-matured DC suggests that these DC are more likely to prime CTL responses. Since IRX-2 clearly increases the in vitro potency of moDC obtained from the peripheral circulation of cancer patients and might also do so in vivo, it appears to be a promising component of future DC-based anti-tumor vaccines. For vaccine production, its ability to enhance IL-12p70 production, migratory response to CCL-21, APM component expression and crosspresentation of tumor antigens to T cells by DC are especially important. In immunotherapy of cancer, IRX-2 delivery alone or together with DC-based vaccines could be considered in future randomized clinical trials to improve the efficacy of currently available treatments. It is actually an OV-gene therapy. The CTGVT has potent antitumor effect, which is the result of the inserted genes to be replicated several-hundred fold along with the replication of the oncolytic virus in cancer cells. Usually, the order of antitumor effect is better by CTGVT than the effect by OV and Ad-gene.