Therapeutic efficacy of humanized monoclonal antibodies targeting dengue virus nonstructural protein 1 in the mouse model.

Dengue virus (DENV) which infects about 390 million people per year in tropical and subtropical areas manifests various disease symptoms, ranging from fever to life-threatening hemorrhage and even shock. To date, there is still no effective treatment for DENV disease, but only supportive care. DENV nonstructural protein 1 (NS1) has been shown to play a key role in disease pathogenesis. Recent studies have shown that anti-DENV NS1 antibody can provide disease protection by blocking the DENV-induced disruption of endothelial integrity. We previously demonstrated that anti-NS1 monoclonal antibody (mAb) protected mice from all four serotypes of DENV challenge. Here, we generated humanized anti-NS1 mAbs and transferred them to mice after DENV infection. The results showed that DENV-induced prolonged bleeding time and skin hemorrhage were reduced, even several days after DENV challenge. Mechanistic studies showed the ability of humanized anti-NS1 mAbs to inhibit NS1-induced vascular hyperpermeability and to elicit Fcγ-dependent complement-mediated cytolysis as well as antibody-dependent cellular cytotoxicity of cells infected with four serotypes of DENV. These results highlight humanized anti-NS1 mAb as a potential therapeutic agent in DENV infection.

Association of genetic variants in senataxin and Alzheimer's disease in a Chinese Han population in Taiwan.

Development of Alzheimer's disease (AD) is characterized by progressive neuronal death and a decline in learning and memory. Mutations in human senataxin (SETX), an ortholog yeast protein of Sen1, have been identified to cause the syndrome of ataxia with oculomotor apraxia type 2 (AOA2) and juvenile amyotrophic lateral sclerosis (ALS4), two types of progressive motor neuron degeneration. However, the relationship between the SETX gene, which is involved in the regulation of RNA processing and DNA repair, and the predisposition for AD remains unclear. In this research, potential association of polymorphisms in the SETX gene with AD was investigated. A case-control study of a Chinese Han population in Taiwan was performed. Three single-nucleotide polymorphisms (SNPs), 3455T>G (rs3739922), 3576T>G (rs1185193) and 7759A>G (rs1056899) were studied. The experimental data showed that upon genotyping of the exonic polymorphism in the SETX gene, the T allele appeared at a lower rate than the G allele at position 3455 in AD patients compared with normal groups (P < 0.05, odds ratio (OR), 0.59, 95% confidence interval (CI), 0.40-0.89). Subjects with the GA genotype at position 7759 have higher incidences of AD development than with the AA genotype (P < 0.05, OR, 6.45, 95% CI, 1.24 to 33.70). Our results also showed that with six haplotypes (Hts) observed from the analyzed polymorphisms, distributions of the Ht4-GAA and Ht5-GCA haplotypes appeared to be significant 'risk' haplotypes between AD patients and controls (both P < 0.05, OR, 8.44, 95% CI, 1.07-66.60). These observations suggest that genetic variations in the SETX gene may contribute to AD pathogenesis in the Taiwanese Han population.

8-Alkylcoumarins from the fruits of Cnidium monnieri protect against hydrogen peroxide induced oxidative stress damage.

Three new 8-alkylcoumarins, 7-O-methylphellodenol-B (1), 7-methoxy-8-(3-methyl- 2,3-epoxy-1-oxobutyl)chromen-2-one (2), and 3'-O-methylvaginol (3), together with seven known compounds (4-10) were isolated from the fruits of Cnidium monnieri. Their structures were determined by detailed analysis of spectroscopic data and comparison with the data of known analogues. All the isolates were evaluated the cytoprotective activity by MTS cell proliferation assay and the results showed that all the three new 8-alkylcoumarins exhibited cytoprotective effect on Neuro-2a neuroblastoma cells injured by hydrogen peroxide.

Association of glutathione S-transferase P1 (GSTP1) polymorphism with Tourette syndrome in Taiwanese patients.

The etiology of Tourette syndrome (TS) is multifactorial. TS vulnerability may be associated with genetic and environmental factors. From the genetic point of view, TS is heterogeneous. Previous studies showed that some single-nucleotide polymorphisms (SNPs) of the glutathione-S-transferase P1 (GSTP1) gene can affect cellular proliferation and apoptotic activity and TS is a neurodevelopmental disorder. We guessed that there was a relationship between TS and genetic variants of the GSTP1 gene. Therefore, in this study, we aimed to test the hypothesis that GSTP1 SNPs were associated with TS. We performed a case-control study. One hundred twenty-one TS children and 105 normal children were included in the study. Polymerase chain reaction was used to identify the GSTP1 gene polymorphism at position rs6591256 (A/G, promoter polymorphism) in TS patients and normal children. The polymorphism at position rs6591256 in the GSTP1 gene revealed significant differences in the allele (p=0.0135) and genotype (p=0.0159) distributions between the TS patients and the control group. The A allele was present at a higher frequency than the G allele in the TS patients compared with the control group (odds ratio [OR]=1.91, 95% confidence interval [CI]: 1.14-3.21). The AA genotype was associated with susceptibility to TS with an OR of 2.38 for the AA versus AG genotype (95% CI: 1.29-4.41). These findings suggest that variants in the GSTP1 gene may play a role in susceptibility to TS.

Synaptic scaffolding protein SYD-2 clusters and activates kinesin-3 UNC-104 in C. elegans.

Kinesin-3 motor UNC-104/KIF1A is essential for transporting synaptic precursors to synapses. Although the mechanism of cargo binding is well understood, little is known how motor activity is regulated. We mapped functional interaction domains between SYD-2 and UNC-104 by using yeast 2-hybrid and pull-down assays and by using FRET/fluorescence lifetime imaging microscopy to image the binding of SYD-2 to UNC-104 in living Caenorhabditis elegans. We found that UNC-104 forms SYD-2-dependent axonal clusters (appearing during the transition from L2 to L3 larval stages), which behave in FRAP experiments as dynamic aggregates. High-resolution microscopy reveals that these clusters contain UNC-104 and synaptic precursors (synaptobrevin-1). Analysis of motor motility indicates bi-directional movement of UNC-104, whereas in syd-2 mutants, loss of SYD-2 binding reduces net anterograde movement and velocity (similar after deleting UNC-104's liprin-binding domain), switching to retrograde transport characteristics when no role of SYD-2 on dynein and conventional kinesin UNC-116 motility was found. These data present a kinesin scaffolding protein that controls both motor clustering along axons and motor motility, resulting in reduced cargo transport efficiency upon loss of interaction.

Oral vaccination with recombinant Listeria monocytogenes expressing human papillomavirus type 16 E7 can cause tumor growth in mice to regress.

Listeria monocytogenes is a Gram-positive, facultative intracellular bacterium with the ability to present secreted proteins to the major histocompatibility complex class I pathway to stimulate cell-mediated immune response. In our study, we constructed the recombinant L. monocytogenes encoding human papillomavirus type 16 E7 gene (rLM-E7). When orally administered to syngeneic mice, rLM-E7 could induce a cytotoxic T-lymphocyte (CTL) response. Furthermore, in vitro flow cytometric assay and in vivo immune deficiency assays showed that rLM-E7 could prevent and eradicate tumor growth via CD8+-dependent CTLs. Hence, the potency of rLM-E7 as a therapeutic vaccine for cervical cancer is the result of the induction E7-specific cell-mediated immunity by L. monocytogenes. In addition to potency, this vaccine also offers ease of administration and reduced cost of production compared with other vaccines formulated for injection. Thus, L. monocytogenes encoding HPV-16 E7 may be a useful oral vaccine for cervical cancer treatment.