Involvement of regulatory T cells in the experimental autoimmune encephalomyelitis-preventive effect of dendritic cells expressing myelin oligodendrocyte glycoprotein plus TRAIL

We previously reported the protection from myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) by the adoptive transfer of genetically modified embryonic stem cell-derived dendritic cells (ES-DC) presenting MOG peptide in the context of MHC class II molecules and simultaneously expressing TRAIL (ES-DC-TRAIL/MOG). In the present study, we found the severity of EAE induced by another myelin autoantigen, myelin basic protein, was also decreased after treatment with ES-DC-TRAIL/MOG. This preventive effect diminished, if the function of CD4(+)CD25(+) regulatory T cells (Treg) was abrogated by the injection of anti-CD25 mAb into mice before treatment with ES-DC-TRAIL/MOG. The adoptive transfer of CD4(+)CD25(+) T cells from ES-DC-TRAIL/MOG-treated mice protected the recipient mice from MOG- or myelin basic protein-induced EAE. The number of Foxp3(+) cells increased in the spinal cords of mice treated with ES-DC-TRAIL/MOG. In vitro experiments showed that TRAIL expressed in genetically modified ES-DC and also in LPS-stimulated splenic macrophages had a capacity to augment the proliferation of CD4(+)CD25(+) T cells. These results suggest that the prevention of EAE by treatment with ES-DC-TRAIL/MOG is mediated, at least in part, by MOG-reactive CD4(+)CD25(+) Treg propagated by ES-DC-TRAIL/MOG. For the treatment of organ-specific autoimmune diseases, induction of Treg reactive to the organ-specific autoantigens by the transfer of DC-presenting Ags and simultaneously overexpressing TRAIL therefore appears to be a promising strategy.     

Augmentation of antigen-presenting and Th1-promoting functions of dendritic cells by WSX-1(IL-27R) deficiency

WSX-1 is the alpha subunit of the IL-27R complex expressed by T, B, NK/NKT cells, as well as macrophages and dendritic cells (DCs). Although it has been shown that IL-27 has both stimulatory and inhibitory effects on T cells, little is known on the role of IL-27/WSX-1 on DCs. LPS stimulation of splenic DCs in vivo resulted in prolonged CD80/CD86 expression on WSX-1-deficient DCs over wild-type DCs. Upon LPS stimulation in vitro, WSX-1-deficient DCs expressed Th1-promoting molecules higher than wild-type DCs. In an allogeneic MLR assay, WSX-1-deficient DCs were more potent than wild-type DCs in the induction of proliferation of and IFN-gamma production by responder cell proliferation. When cocultured with purified NK cells, WSX-1-deficient DCs induced higher IFN-gamma production and killing activity of NK cells than wild-type DCs. As such, Ag-pulsed WSX-1-deficient DCs induced Th1-biased strong immune responses over wild-type DCs when transferred in vivo. WSX-1-deficient DCs were hyperreactive to LPS stimulation as compared with wild-type DCs by cytokine production. IL-27 suppressed LPS-induced CD80/86 expression and cytokine production by DCs in vitro. Thus, our study demonstrated that IL-27/WSX-1 signaling potently down-regulates APC function and Th1-promoting function of DCs to modulate overall immune responses.     

Discovery of (-)-6-[2-[4-(3-fluorophenyl)-4-hydroxy-1-piperidinyl]-1-hydroxyethyl]-3,4-dihydro-2(1H)-quinolinone--a potent NR2B-selective N-methyl D-aspartate (NMDA) antagonist for the treatment of pain

(-)-6-[2-[4-(3-Fluorophenyl)-4-hydroxy-1-piperidinyl]-1-hydroxyethyl]-3,4-dihydro-2(1H)-quinolinone was identified as an orally active NR2B-subunit selective N-methyl-d-aspartate (NMDA) receptor antagonist. It has very high selectivity for NR2B subunits containing NMDA receptors versus the HERG-channel inhibition (therapeutic index=4200 vs NR2B binding IC(50)). This compound has improved pharmacokinetic properties compared to the prototype CP-101,606.     

Convergent synthesis and in vivo inhibitory effect on fat accumulation of (-)-ternatin, a highly N-methylated cyclic peptide

(-)-Ternatin (1), a highly N-methylated cyclic heptapeptide, is a potent inhibitor of fat accumulation against 3T3-L1 murine adipocytes (EC50 = 0.14 microg/mL) [Shimokawa, K.; Mashima, I.; Asai, A.; Yamada, K.; Kita, M.; Uemura, D. Tetrahedron Lett. 2006, 47, 4445]. Compound 1 was synthesized from Boc-protected amino acids in solution. Upon treatment with 1 at 5 mg/kg/day, increases in body weight and fat accumulation in high-fat-fed mice were both significantly suppressed.     

Homophilic Dscam interactions control complex dendrite morphogenesis

Alternative splicing of the Drosophila gene Dscam results in up to 38,016 different receptor isoforms proposed to interact by isoform-specific homophilic binding. We report that Dscam controls cell-intrinsic aspects of dendrite guidance in all four classes of dendrite arborization (da) neurons. Loss of Dscam in single neurons causes a strong increase in self-crossing. Restriction of dendritic fields of neighboring class III neurons appeared intact in mutant neurons, suggesting that dendritic self-avoidance, but not heteroneuronal tiling, may depend on Dscam. Overexpression of the same Dscam isoforms in two da neurons with overlapping dendritic fields forced a spatial segregation of the two fields, supporting the model that dendritic branches of da neurons use isoform-specific homophilic interactions to ensure minimal overlap. Homophilic binding of the highly diverse extracellular domains of Dscam may therefore limit the use of the same "core" repulsion mechanism to cell-intrinsic interactions without interfering with heteroneuronal interactions.     

Immunogenicity and safety of an inactivated quadrivalent influenza vaccine in healthy adults: a phase II,open‐label,uncontrolled trial in Japan

Two antigenically distinct B strain lineages of influenza virus have co‐circulated since the mid‐1980s; however, inactivated trivalent influenza vaccines contain only one B lineage. The mismatch between the circulating and vaccine lineages has been a worldwide issue. In this study, an inactivated quadrivalent influenza vaccine (QIV) candidate containing two B lineages was manufactured and its immunogenicity and safety evaluated in an open‐label, uncontrolled trial. In this phase II trial, 50 subjects aged 20–64 years received two doses of QIV s.c. 1 to 4 weeks apart. Sera were collected pre‐ and post‐vaccination and safety assessed from the first vaccination to 21 ± 7 days after the second vaccination. After the first vaccination, hemagglutination inhibition titers against each strain increased markedly; the seroconversion rate, geometric mean titer ratio and seroprotection rate being 94.0%, 24.93, and 100.0%, respectively, for the A/H1N1pdm09 strain; 94.0%, 12.47, and 98.0%, respectively, for the A/H3N2 strain; 54.0%, 4.99, and 66.0%, respectively, for B/Yamagata strain, and 72.0%, 6.23 and 80.0%, respectively, for the B/Victoria strain, thus fulfilling the criteria of the European Medical Agency's Committee for Medicinal Products for Human Use. Also, the QIV induced sufficient single radial hemolysis and neutralizing antibodies against all four vaccine strains. No noteworthy adverse events were noted. The results of this trial demonstrate that QIV is well tolerated and immunogenic for each strain, suggesting that QIV potentially improves protection against influenza B by resolving the issue of B lineage mismatch.     

Melanin biosynthesis inhibitors from Tarragon Artemisia dracunculus

The EtOH extract of tarragon Artemisia dracunculus, a perennial herb in the family Asteraceae, was found to potently inhibit α-melanocyte-stimulating hormone (α-MSH) induced melanin production in B16 mouse melanoma cells. Bioassay-guided fractionation led to the isolation of two alkamide compounds, isobutyl (1) and piperidiyl (2) amides of undeca-2E,4E-dien-8,10-dynoic acid. The respective EC(50) values for melanin biosynthesis inhibition were 1.8 and 2.3 μg/mL for 1 and 2.     

A necrosis-inducing elicitor domain encoded by both symptomatic and asymptomatic Plantago asiatica mosaic virus isolates, whose expression is modulated by virus replication

Systemic necrosis is the most destructive symptom induced by plant pathogens. We previously identified amino acid 1154, in the polymerase domain (POL) of RNA-dependent RNA polymerase (RdRp) of Plantago asiatica mosaic virus (PlAMV), which affects PlAMV-induced systemic necrosis in Nicotiana benthamiana. By point-mutation analysis, we show that amino acid 1,154 alone is not sufficient for induction of necrotic symptoms. However, PlAMV replicons that can express only RdRp, derived from a necrosis-inducing PlAMV isolate, retain their ability to induce necrosis, and transient expression of PlAMV-encoded proteins indicated that the necrosis-eliciting activity resides in RdRp. Moreover, inducible-overexpression analysis demonstrated that the necrosis was induced in an RdRp dose-dependent manner. In addition, during PlAMV infection, necrotic symptoms are associated with high levels of RdRp accumulation. Surprisingly, necrosis-eliciting activity resides in the helicase domain (HEL), not in the amino acid 1,154-containing POL, of RdRp, and this activity was observed even in HELs of PlAMV isolates of which infection does not cause necrosis. Moreover, HEL-induced necrosis had characteristics similar to those induced by PlAMV infection. Overall, our data suggest that necrotic symptoms induced by PlAMV infection depend on the accumulation of a non-isolate specific elicitor HEL (even from nonnecrosis isolates), whose expression is indirectly regulated by amino acid 1,154 that controls replication.