Ionic Liquid-Based Transcutaneous Peptide Antitumor Vaccine: Therapeutic Effect in a Mouse Tumor Model.

Traditional vaccinations need to be injected with needles, and since some people have a strong aversion to needles, a needle-free alternative delivery system is important. In this study, we employed ionic liquids (ILs) for transcutaneous delivery of cancer antigen-derived peptides to obtain anticancer therapeutic effects in a needle-free manner. ILs successfully increased the in vitro skin permeability of a peptide from Wilms tumor 1 (WT1), one of the more promising cancer antigens, plus or minus an adjuvant, resiquimod (R848), a toll-like receptor 7 agonist. In vivo studies demonstrated that concomitant transcutaneous delivery of WT1 peptide and R848 by ILs induced WT1-specific cytotoxic T lymphocyte (CTL) in mice, resulting in tumor growth inhibition in Lewis lung carcinoma-bearing mice. Interestingly, administrating R848 in ILs before WT1 peptides in ILs increased tumor growth inhibition effects compared to co-administration of both. We found that the prior application of R848 increased the infiltration of leukocytes in the skin and that subsequent delivery of WT1 peptides was more likely to induce WT1-specific CTL. Furthermore, sequential immunization with IL-based formulations was applicable to different types of peptides and cancer models without induction of skin irritation. IL-based transcutaneous delivery of cancer antigen-derived peptides and adjuvants, either alone or together, could be a novel approach to needle-free cancer therapeutic vaccines.

Tag-assisted liquid-phase peptide synthesis using hydrophobic benzyl alcohols as supports.

A soluble tag-assisted liquid-phase peptide synthesis was successfully established based on simple hydrophobic benzyl alcohols, which can be easily prepared from naturally abundant materials. Excellent precipitation yields can be obtained at each step, combining the best properties of solid-phase and liquid-phase techniques. This approach can also be applied efficiently to fragment couplings, allowing chemical synthesis of several bioactive peptides.

Evaluation of the in vivo radiosensitizing activity of etanidazole using tumor-bearing chick embryo.

Chick embryos have been used as alternative experimental animals in various research fields, including virology, immunology, toxicology, oncology, and embryology. Until now, there have been no in vivo models using chick embryo to evaluate radiosensitizing activity. Here, the in vivo radiosensitizing activity of etanidazole, a well-known hypoxic cell radiosensitizer, was evaluated using tumor-bearing chick embryo. On the basis of tumor growth, drug administration and X-ray irradiation were performed on day 15 chick embryo, with the endpoint being day 18 chick embryo. In day 15 chick embryo, an X-ray irradiation dose of equal or less than 10 Gy did not cause significant tumor growth suppression. Intravenous administration of equal or less than 1.0 mg of etanidazole did not cause tumor growth suppression. Neither doses of equal or less than 8 Gy of irradiation nor 1.0 mg of etanidazole caused fatality of the chick embryo. On the basis of these results, we evaluated the radiosensitizing effect of a combination treatment with 8 Gy of irradiation and 1.0 mg of etanidazole. As noted above, 1.0 mg of etanidazole alone and 8 Gy of irradiation alone did not show tumor growth suppression. In contrast, a combination treatment with 8 Gy of irradiation and 1.0 mg of etanidazole showed 35% of significant tumor growth suppression. Thus, we succeeded in evaluating the in vivo radiosensitizing activity of etanidazole using tumor-bearing chick embryo. These results suggest that the use of tumor-bearing chick embryo may be part of a promising system for evaluating radiosensitizing activity.

A new murine model to define the critical pathologic and therapeutic mediators of polymyositis.

OBJECTIVE: To establish a new murine model of polymyositis (PM) for the understanding of its pathologic mechanisms and the development of new treatment strategies. METHODS: C protein-induced myositis (CIM) was induced by a single immunization of recombinant human skeletal C protein in C57BL/6 mice, as well as in CD4-depleted, CD8-depleted, and mutant mice as controls. Some mice were treated with high-dose intravenous immunoglobulin (IVIG) after disease induction. Muscle tissues were examined histologically. RESULTS: In mice with CIM, inflammation was confined to the skeletal muscles. Histologic examination revealed a common pathologic feature of CIM and PM, involving abundant infiltration of CD8 and perforin-expressing cells in the endomysial site of the injured muscle. Suppression of myositis was achieved by depletion of both CD4 and CD8 T cells. Despite the development of serum anti-C protein antibodies in wild-type mice, severe myositis was induced in mice deficient in B cells. Induction of myositis was suppressed in interleukin-1alpha/beta (IL-1alpha/beta)-null mutant mice, but not in tumor necrosis factor alpha (TNFalpha)-null mutant mice. Use of IVIG, a treatment with proven efficacy in PM, suppressed CIM in the subgroup of treated mice. CONCLUSION: CIM mimics PM pathologically and clinically. Infiltration of CD8 T cells is the most likely mechanism of muscle injury, and IL-1, but not B cells or TNFalpha, is crucial in the development of CIM. IVIG has therapeutic effects in CIM, suggesting that the effects of IVIG are not mediated by suppression of antibody-mediated tissue injury. This murine model provides a useful tool for understanding the pathologic mechanisms of PM and for developing new treatment strategies.

Synergistic Antibacterial Activity of a New Quinolone, T-3762, and Human Gamma Globulin Against Intracellular Salmonella.

The bactericidal activity of antibacterial agents against intracellular bacteria using a Salmonella-lined macrophage model (TtT/M-87), established from mouse pituitary tumor-associated macrophages, was investigated in this study. Because a virulent strain of Salmonella enteritidis 116-54 is able to proliferate in phagocytized macrophages, the bactericidal activity against intracellular bacteria can be determined using this model. We found that a new quinolone, T-3762, has strong bactericidal activity against virulent S. enteritidis in macrophages. The bactericidal activity of T-3762 was augmented by the addition of human γ-globulin. The combination of T-3762 and human γ-globulin showed significantly higher bactericidal activity than that of ofloxacin and human γ-globulin. These results suggest that T-3762 can penetrate mammalian cells in an active form and that human γ-globulin may be able to enhance the bactericidal activity of macrophages by opsonization of bacteria with antibody in the γ-globulin fraction.