Alpha-galactosylceramide (αGC), a lipid antigen present on CD1d molecules, is predicted to have clinical applications as a new class of adjuvant, because αGC strongly activates natural killer T (NKT) cells which produce large amounts of IFN-γ. Here, we incorporated αGC into stearylated octaarginine-modified liposomes (R8-Lip), our original delivery system developed for vaccines, and investigated the effect of nanoparticulation. Unexpectedly, the systemic administered R8-Lip incorporating αGC (αGC/R8-Lip) failed to improve the immune responses mediated by αGC compared with soluble αGC in vivo, although αGC/R8-Lip drastically enhanced αGC presentation on CD1d in antigen presenting cells in vitro. Thus, we optimized the αGC/R8-Lip in vivo to overcome this inverse correlation. In optimization in vivo, we found that size control of liposome and R8-modification were critical for enhancing the production of IFN-γ. The optimization led to the accumulation of αGC/R8-Lip in the spleen and a positive therapeutic effect against highly malignant B16 melanoma cells. The optimized αGC/R8-Lip also enhanced αGC presentation on CD1d in antigen presenting cells and resulted in an expansion in the population of NKT cells. Herein, we show that R8-Lip is a potent delivery system, and size control and R8-modification in liposomal construction are promising techniques for achieving systemic αGC therapy.

SummaryAbscisic acid (ABA) is a phytohormone that plays a key role as a stress signal, regulating water relations during drought conditions, by inducing stomatal closure. However, to date, no putative ABA receptor(s) has been reported at the protein sequence, gene family, or cellular localization levels. We used biotinylated ABA (bioABA) to characterize the ABA-perception sites in the stomatal guard cells of Vicia faba. Treatment with bioABA induced stomatal closure and shrinkage of guard cell protoplasts (GCPs). The ABA-perception sites were visualized by fluorescence microscopy and confocal laser scanning microscopy (CLSM), using bioABA and fluorescence-labeled avidin. Fluorescent particles were observed in patches on the surface of the GCPs. Fluorescence intensity was quantified by flow cytometry (FCM) as well as by CLSM. Binding of bioABA was inhibited by ABA in a dose-dependent manner. Pre-treatment of GCPs with proteinase K also blocked the binding of bioABA. Binding of bioABA was inhibited by RCA-7a, an ABA analog that induces stomatal closure, but not by RCA-16, which has no effect on stomatal aperture. Another ABA analog, PBI-51, inhibited ABA-induced stomatal closure. This ABA antagonist also inhibited binding of bioABA to the GCPs. These results suggest that ABA is perceived on the plasma membrane of stomatal guard cells, and that the present experimental methods constitute valuable tools for characterizing the nature of the ABA receptor(s) that perceives physiological ABA signals. These imaging studies allow us to demonstrate the spatial distribution of the ABA-perception sites. Visualization of the ABA-perception sites provides new insights into the nature of membrane-associated ABA receptor(s).

8-Oxo-7,8-dihydroguanine (G(O), 8-hydroxyguanine) in DNA is one of the most important oxidatively damaged bases and causes G:C → T:A substitution mutations. The Werner syndrome protein (WRN) is a cancer-related RecQ DNA helicase and plays many roles in DNA replication and repair. To examine the relationships between G(O)-induced mutations and WRN, shuttle plasmid DNA containing a G(O):C pair in the supF gene was transfected into human U2OS cells, in which WRN was knocked down. The plasmid DNA replicated in the knockdown cells was introduced into an Escherichia coli indicator strain. The knockdown of WRN increased the mutant frequency of the G(O)-plasmid DNA. Unexpectedly, however, the WRN knockdown only slightly enhanced the targeted G:C → T:A mutation. Instead, base-substitution mutations at various positions were more frequently detected, with statistical significance. The results obtained in this study suggested that the reduction of the cancer-related WRN induced action-at-a-distance mutagenesis by the G(O):C pair in human cells. In addition, the WRN knockdown decreased the G(O):A-induced A:T → C:G mutations, suggesting that WRN may enhance the mutations caused by G(O) in the nucleotide pool.

Ascites total protein concentration (A-TP) affects the performance of cell-free and concentrated ascites reinfusion therapy (CART). As the factors determining A-TP remain unclear, we examined peritoneal and liver metastasis. Among 98 patients who received CART, 68 with cancer, ascites from no other apparent cause, and complete CT and A-TP data were recruited. Sixty-six patients (97%) with peritoneal and/or liver metastasis on CT were divided into the peritoneal metastasis group (PM group), peritoneal and liver metastasis group (PM + LM group), and liver metastasis group (LM group). A-TP was highest in the PM group (3.9 g/dL [3.4-4.4]), lowest in the LM group (1.0 g/dL [0.9-2.0]), and broadly dispersed in the PM + LM group (3.3 g/dL [2.0-3.8]). All differences were statistically significant. The percentage of metastasis volume occupying the liver was negatively and significantly related to A-TP in the PM + LM group. Taken together, the presence and severity of peritoneal and liver metastasis may influence A-TP.

Major factors that decrease soybean yields in Japan include excessive soil moisture and drought stress. In the present study, a WI (Wet Index) was developed using soil moisture estimates based on the FAO56 model to evaluate both risks of soil dryness and wetness. In addition, to assess the risk of wet losses, the days when ratio of WI was equal to one (RWI), which implied that soil moisture content reached a maximum, was adopted for every growth stage. When the relationship between WI or RWI and yield was evaluated using a partial correlation coefficient, WI had a positive correlation with emergence period approximately 30 -40 days after emergence, seed filling phase, and maturity phase, and RWI had a negative correlation with emergence period approximately 20 -30 days after emergence and approximately one week before flowering period. We evaluated moisture and drought stress risks, which present challenges in farmers' fields, and revealed the growing stages at which moisture and drought pose the highest risks. The results could offer critical insights for the estimation of dryness and wetness losses in the field.