A facile hydrothermal method is utilized to synthesize zinc oxide-reduced graphene oxide nanocomposites for an electrochemical hydrazine sensor.

Background: HVR1 spans 27 residues at the N terminus of the HCV envelope glycoprotein E2 and is the most variable region within the HCV polyprotein. Results: Three independent functional microdomains were identified in HCV HVR1. Conclusion: Different microdomains in HVR1 cooperate to mediate HCV cell entry and immune evasion. Significance: The data provide novel insights into understanding the mechanisms of HCV infection and immune evasion.

Antimicrobial peptides are promising alternatives to traditional antibiotics. A group of selfassembling lipopeptides was formed by attaching an acyl chain to the N-terminus of α-helix forming peptides with the sequence C x -G(IIKK) y I-NH 2 (C x G y , x = 4-12 and y = 2). C x G y selfassemble into nanofibers above their critical aggregation concentrations (CACs). With increasing x, the CACs decrease and the hydrophobic interactions increase, promoting secondary structure transitions within the nanofibers. Antimicrobial activity, determined by the minimum inhibition concentration (MIC), also decreases with increasing x, but the MICs are significantly smaller than the CACs, suggesting effective bacterial membrane disrupting power. Unlike conventional antibiotics, both C 8 G 2 and C 12 G 2 can kill S. aureus and E. coli after only minutes of exposure. C 12 G 2 nanofibers have considerably faster killing dynamics and lower cytotoxicity than their non-aggregated monomers. Antimicrobial activity of peptide aggregates has to date been underexploited and it is found to be a very promising mechanism for peptide design. Detailed evidence for the molecular mechanisms involved are provided, based on super-resolution fluorescence microscopy, ss-NMR, AFM, neutron scattering/reflectivity, CD and Brewster angle microscopy.

Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes the most prevalent viral encephalitis in Asia. Since JEV is a neurotropic virus, it is important to identify key molecules that mediate JEV infection in neuronal cells and to investigate their underlying mechanisms. In this study, the critical role of Nedd4, an E3 ubiquitin ligase that is highly expressed in the central nervous system, was examined in JEV propagation. In SK-N-SH neuroblastoma cells, Nedd4 was up-regulated in response to JEV infection. Moreover, down-regulation of Nedd4 resulted in a significant decrease in JEV replication without alterations in virus attachment and internalization or in JEV pseudotyped virus infection, suggesting that Nedd4 participates in the replication but not in the entry stage of JEV infection. Further functional analysis showed that Nedd4 attenuated JEV-induced autophagy, which negatively regulates virus replication during infection. These results suggest that Nedd4 facilitates the replication of JEV by suppressing virus-induced autophagy. Taken together, our results indicate that Nedd4 plays a crucial role in JEV infection of neuronal cells, which provides a potential target for the development of novel treatment to combat JEV infection.

Hepatitis C virus (HCV) infection correlates with human immune disorders characterized by abnormal activation and proliferation of lymphocytes. Interaction of HCV major envelope protein E2 with susceptible cells occurs at an early stage of the viral infection. HCV tropism for susceptible cells may elicit cellular signaling events implicated in the viral pathogenicity, and E2 protein is known to be responsible for the tropism. We documented previously that HCV E2 protein was capable of activating extracellular signal-regulated kinase (ERK) in human hepatoma Huh-7 cells. Here, ERK and p38 mitogen-activated protein kinase (MAPK) signaling pathways were investigated in human T lymphoma cell line Molt-4 in response to HCV E2 protein. Binding of HCV E2 protein to Molt-4 cells was detectable, and such interaction was a determinant for recognition and delivery of the E2 signal to intracellular pathways. Activation of ERK and p38 MAPK was specifically induced following the HCV E2-cell interaction. CD81 and low-density lipoprotein receptor (LDLR), proposed cellular receptors for HCV, were expressed naturally on Molt-4 cells. CD81 and LDLR were shown to mediate HCV E2-induced activation of ERK and p38 MAPK. In CD81-deficient U937 cells, levels of ERK and p38 MAPK activation and cell proliferation induced by HCV E2 protein were lower than those in Molt-4 cells. Furthermore, cell proliferation and secretion of interferon-gamma and interleukin-10 by Molt-4 cells were promoted by HCV E2 protein. Therefore, ERK and p38 MAPK signaling pathways were up-regulated by HCV E2 protein without synergetic stimulation, which was accompanied by alterations of cell behavior.