DC-based vaccination had KU-60019 ic50 presented efficient anti-tumor activity in numerous tumor models and in clinical studies. Kono K [17] reported that vaccines using DCs pulsed with HER-2/neu-peptides may represent a novel treatment of gastric cancer patients. DC migration

H 89 in vivo involves three steps: mobilization into the blood, recruitment from blood to peripheral tissues, and remobilization from peripheral to lymphoid tissues. Once there, immature DCs finally differentiate into fully mature DCs to promote immune responses. Although the first step has not received much attention, it is important to understand how this step is regulated in order to understand the pathologic role of DCs in various inflammatory diseases and in tumor development. Chemokines selectively direct the trafficking of subsets of leukocytes into various tissues in homeostasis as well as inflammatory states in vivo [18]. The capacity of DCs to migrate to sites of inflammation, where they capture antigens and subsequently migrate to local lymph nodes, is regulated by the expression of different chemokines and chemokine receptors [19, 20]. Mobilization of DCs and DC precursors into peripheral blood is of particular interest in research related

to NSC23766 in vitro DC-based immunotherapy. We have demonstrated that murine F4/80-B220-CD11c+ DC precursors rapidly appear in peripheral blood when animals are injected i.v. with CCL3 and CCL20 [7]. These F4/80-B220-CD11c+ cells subsequently differentiate into mature DCs when cultured ex vivo with GM-CSF and TNFα. The resultant DCs present the typical morphological characteristics, phenotypes, and antigen-presenting functions of DCs (as assessed in MLR assays). Because Masitinib (AB1010) injections of CCL3 and CCL20 did not induce any detectable inflammatory

response or liver injury in vivo (data not shown), we believe it is possible that CCL3 and CCL20 could be employed to efficiently recruit DC precursors for the purpose of DC-based cancer therapy. There are two considerably important factors involved in DC-based vaccination in the clinic: one is the way to effectively and practically obtain abundant DCs in peripheral blood; the other is a method to effectively modify DCs used as vaccines for tumor rejection and therapy [21]. Successful genetic modification of murine CCL3 and CCL20-recruited DCs with adenoviral vectors was demonstrated. Adenovrial-based gene therapy has many advantages over other forms of TAA delivery [22]. Adenoviral vectors allow local, highly efficient, albeit transient, gene expression, generating high-level, but limited, cytokine production in treated tumors. Adenoviral vectors are transduction agents in a heterogeneously growing population of tumor cells. In this study, murine DCs were transduced using cocultivation with adenoviral vectors.