Phase I/II study of immunotherapy using tumor antigen-pulsed dendritic cells in patients with hepatocellular carcinoma.

Dendritic cells (DCs) are increasingly used as adjuvants for vaccination strategies; however, there has been very little development in DC vaccines for patients with hepatocellular carcinoma (HCC). In this study, we assessed the safety, feasibility and efficacy of a multiple tumor-associated antigen (TAA)-pulsed DC vaccine in 5 patients with advanced HCC. DCs were generated by culturing blood monocytes in the presence of granulocyte macrophage-colony stimulating factor and interleukin-4 for 5 days. The DC vaccine was prepared by pulsing DCs with cytoplasmic transduction peptide-attached α-fetoprotein, glypican-3 and MAGE-1 recombinant fusion proteins and cultivating them in the presence of maturation cocktail. DCs were injected subcutaneously near the inguinal lymph nodes, followed by topical application of toll-like receptor-7 agonist around the injection site. We showed that our DC vaccine was safe and well-tolerated over 6 vaccinations in 5 patients. All 5 patients showed T cell responses against TAAs. Clinical benefit was observed in one of the 5 patients. In conclusion, the feasibility, safety and immune activity of DCs pulsed with TAAs were confirmed in HCC patients. However, clinical response was detected only in one patient. Future trials may consider applying this therapy in a less advanced stage to obtain better clinical responses.

Purification, pH-dependent conformational change, aggregation, and secretory granule membrane binding property of secretogranin II (chromogranin C).

Secretogranin II (SgII) is one of the three major proteins, the other two being chromogranins A (CGA) and B (CGB), of secretory granules of neuroendocrine cells. The Ca(2+) storage proteins CGA and CGB not only are coupled to the IP(3) receptor (IP(3)R)/Ca(2+) channels that exist on the secretory granule membrane but also are known to play key roles in secretory granule biogenesis. Unlike the better studied CGA and CGB, secretogranin II has never been completely purified in the native state and studied. We have therefore purified SgII in native form from bovine adrenal medulla and subjected it to biochemical characterization. Secretogranin II consisted of largely beta-sheet and random coil structures with a low level of alpha-helicity. Like CGA and CGB, it also underwent pH-dependent conformational changes, showing 9.5% alpha-helicity at pH 7.5 and 17.0% alpha-helicity at pH 5.5. Secretogranin II also underwent acidic pH- and Ca(2+)-dependent aggregation, and it was approximately 8-fold more sensitive than CGA to Ca(2+) in its pH-dependent aggregation but was 8-fold less sensitive than CGB. Further, similar to CGA and CGB that had interacted with the secretory granule membrane at the intragranular pH 5.5, SgII also interacted with the secretory granule membrane at pH 5.5 and dissociated from it at near-physiological pH 7.5, implying similar roles of SgII in the cell as those of CGA and CGB. Secretogranin II hence appeared to actively participate in secretory granule biogenesis as has been proposed for CGA and CGB.