Synthetic innate defense regulator peptide combination using CpG ODN as a novel adjuvant induces long­lasting and balanced immune responses.

Vaccines are critical tools for the prevention and treatment of several diseases. Adjuvants have been traditionally used to enhance immunity to vaccines and experimental antigens. In the present study, the adjuvant combination of CpG oligodeoxynucleotides (CpG ODN) and the innate defense regulator (IDR) peptide, IDR­HH2, was evaluated for its ability to enhance and modulate the immune response when formulated with alum and the recombinant hepatitis B surface antigen (HBsAg). The CpG­HH2 complex enhanced the secretions of tumor necrosis factor­α, monocyte chemotactic protein 1 and interferon­Î³ by human peripheral blood mononuclear cells and promoted murine bone marrow dentritic cell maturation. In addition, the present study demonstrated that IDR­HH2 was chemotactic for human neutrophils, THP­1 cells and RAW264.7 cells at concentrations between 2.5 and 40 µg/ml. The present study also observed that significantly higher anti­HBs antibody titers, which were sustained at high levels for as long as 35 weeks following the boost immunization, were induced by the combination adjuvant, even when co­administered with a commercial hepatitis B vaccine at a low antigen dose (0.1 µg HBsAg). Notably, the level of IgG2a was almost equal to the level of IgG1, indicating that a balanced T helper (Th)1/Th2 immune response was elicited by the novel vaccine, which was consistent with the ELISpot results. These data suggest that the CpG­HH2 complex may be a potential effective adjuvant, which facilitates a reduction in the dose of antigen and induces long­lasting, balanced immune responses.

Ad-endostatin treatment combined with low-dose irradiation in a murine lung cancer model.

Radiation therapy is a conventional strategy for treating advanced lung cancer yet is accompanied by serious side-effects. Its combination with other strategies, such as antiangiogenesis and gene therapy, has shown excellent prospects. As one of the potent endogenous vascular inhibitors, endostatin has been widely used in the antiangiogenic gene therapy of tumors. In the present study, LL/2 cells were infected with a recombinant adenovirus encoding endostatin (Ad-endostatin) to express endostatin. The results showed that LL/2 cells infected with the Ad-endostatin efficiently and longlastingly expressed endostatin. In order to further explore the role of Ad-endostatin combined with irradiation in the treatment of cancer, a murine lung cancer model was established and treated with Ad-endostatin combined with low-dose irradiation. The results showed that the combination treatment markedly inhibited tumor growth and metastasis, and prolonged the survival time of the tumor-bearing mice. Furthermore, this significant antitumor activity was associated with lower levels of microvessel density and anoxia factors in the Ad-Endo combined with irradiation group, and with an increased apoptotic index of tumor cells. In addition, no serious side-effects were noted in the combination group. Based on our findings, Ad-endostatin combined with low-dose irradiation may be a rational alternative treatment for lung cancer and other solid tumors.