Cellular and humoral immunity protect against vaginal Zika virus infection in mice

ABSTRACT Zika virus (ZIKV), which can cause devastating disease in fetuses of infected pregnant women, can be transmitted by mosquito inoculation and sexual routes. Little is known about immune protection against sexually transmitted ZIKV. In this study, we show that previous infection through intravaginal or subcutaneous routes with a contemporary Brazilian strain of ZIKV can protect against subsequent intravaginal challenge with a homologous strain. Both routes of inoculation induced high titers of ZIKV-specific and neutralizing antibody in serum and the vaginal lumen. Virus-specific T cells were recruited to and retained in the female reproductive tract after intravaginal and subcutaneous ZIKV infection. Studies in mice with genetic or acquired deficiencies in B and/or T cells demonstrated that both lymphocyte populations redundantly protect against intravaginal challenge in ZIKV-immune animals. Passive transfer of ZIKV-immune IgG or T cells significantly limited intravaginal infection of naive mice, although antibody more effectively prevented dissemination throughout the reproductive tract. Collectively, our experiments begin to establish the immune correlates of protection against intravaginal ZIKV infection, which should inform vaccination strategies in nonpregnant and pregnant women. IMPORTANCE The recent ZIKV epidemic resulted in devastating outcomes in fetuses and may affect reproductive health. Unlike other flaviviruses, ZIKV can be spread by sexual contact as well as a mosquito vector. While previous studies have identified correlates of protection for mosquito-mediated infection, few have focused on immunity against sexual transmission. As exposure to ZIKV via mosquito bite has likely occurred to many living in areas where ZIKV is endemic, our study addresses whether this route of infection can protect against subsequent sexual exposure. We demonstrate that subcutaneous ZIKV infection can protect against subsequent vaginal infection by generating both local antiviral T cell and antibody responses. Our research begins to define the immune correlates of protection for ZIKV infection in the vagina and provides a foundation for testing ZIKV vaccines against sexual transmission. </jats:p

Development and application of distributed MEMS pressure sensor array for AUV object avoidance

A novel sensory system is being developed for AUVs to augment current sensory systems for navigation and operation in difficult environments. These environments are frequently cluttered and murky with substantial flow from currents or waves, frustrating sonar and vision systems while posing an increased risk to AUVs. In order to manage such situations, a better ability to locate and identify physical objects is needed. This gap could be filled by small low frequency pressure sensors distributed over the surface of the AUV in dense arrays.United States. National Oceanic and Atmospheric Administration (Grant NA06OAR4170019 Project R/RT-2/RCM-17

Lateral-Line Inspired MEMS-Array Pressure Sensing for Passive Underwater Navigation

This paper presents work toward the development of a novel MEMS sensing technology for AUVs. The proposed lateral line-inspired sensor system is a high-density array of pressure sensors for measuring hydrodynamic disturbances. By measuring pressure variations on a vehicle surface, a dense pressure sensor array will allow the AUV to detect, classify, and locate nearby obstacles and optimize its motion in unsteady environments. This approach is very similar to the canal lateral line system found in all fish, which allow them to function in dark or clouded environments. In order to lay the groundwork for developing the MEMS sensor and interpreting the pressure distributions, the paper also presents experiments demonstrating the discrimination between cylindrical obstacles of round and square cross sections with an array of off-the-shelf pressure sensors. Test objects with 5.1 cm and 7.6 cm diameters passed stationary sensors at 0.5 m/s and 0.75 m/s and with 1.3 and 5.1 mm separation. Hand chosen features and features chosen through a Principal Component Analysis are used to discriminate between object shapes under a variety of conditions. A classification error rate of under 2% is achieved across all velocities, sizes, and separations. These results lead to requirements for the density, sensitivity, and frequency response of the MEMS sensors, which fall well in the MEMS domain. The pressure sensor array proposed here consists of hundreds of MEMS pressure sensors with diameters near 1 mm spaced a few millimeters apart fabricated on etched silicon and Pyrex wafers; a fabrication process for producing the array is described. A strain-gauge pressure sensor is analyzed and shown to satisfy specifications as required by the results from the afore-mentioned experiments. The sensing element is a strain gauge mounted on a flexible diaphragm, which is a thin (20 µm) layer of silicon attached at the edges to a square silicon cavity 2000 µm wide on a side. A source voltage of 10 V produces a sensor with a sensitivity on the order of 1µV/Pa. Since the thermal noise voltage is near 0.7 µV, the pressure resolution of the sensors is on the order of 1 Pa.United States. National Oceanic and Atmospheric Administration (Grant NA06OAR4170019 Project R/RT-2/RMC-17

Epitope mapping of Japanese encephalitis virus neutralizing antibodies by native mass spectrometry and hydrogen/deuterium exchange

Japanese encephalitis virus (JEV) remains a global public health concern due to its epidemiological distribution and the existence of multiple strains. Neutralizing antibodies against this infection have shown efficacy in in vivo studies. Thus, elucidation of the epitopes of neutralizing antibodies can aid in the design and development of effective vaccines against different strains of JEV. Here, we describe a combination of native mass spectrometry (native-MS) and hydrogen/deuterium exchange mass spectrometry (HDX-MS) to complete screening of eight mouse monoclonal antibodies (MAbs) against JEV E-DIII to identify epitope regions. Native-MS was used as a first pass to identify the antibodies that formed a complex with the target antigen, and it revealed that seven of the eight monoclonal antibodies underwent binding. Native mass spectra of a MAb (JEV-27) known to be non-binding showed broad native-MS peaks and poor signal, suggesting the protein is a mixture or that there are impurities in the sample. We followed native-MS with HDX-MS to locate the binding sites for several of the complex-forming antibodies. This combination of two mass spectrometry-based approaches should be generally applicable and particularly suitable for screening of antigen-antibody and other protein-protein interactions when other traditional approaches give unclear results or are difficult, unavailable, or need to be validated

Interaction of Akt-Phosphorylated Ataxin-1 with 14-3-3 Mediates Neurodegeneration in Spinocerebellar Ataxia Type 1

AbstractSpinocerebellar ataxia type 1 (SCA1) is one of several neurological disorders caused by a CAG repeat expansion. In SCA1, this expansion produces an abnormally long polyglutamine tract in the protein ataxin-1. Mutant polyglutamine proteins accumulate in neurons, inducing neurodegeneration, but the mechanism underlying this accumulation has been unclear. We have discovered that the 14-3-3 protein, a multifunctional regulatory molecule, mediates the neurotoxicity of ataxin-1 by binding to and stabilizing ataxin-1, thereby slowing its normal degradation. The association of ataxin-1 with 14-3-3 is regulated by Akt phosphorylation, and in a Drosophila model of SCA1, both 14-3-3 and Akt modulate neurodegeneration. Our finding that phosphatidylinositol 3-kinase/Akt signaling and 14-3-3 cooperate to modulate the neurotoxicity of ataxin-1 provides insight into SCA1 pathogenesis and identifies potential targets for therapeutic intervention

Amino Acids Generated from Hydrated Titan Tholins: Comparison with Miller-Urey Electric Discharge Products

Various analogues of Titan haze particles (termed tholins) have been made in the laboratory. In certain geologic environments on Titan, these haze particles may come into contact with aqueous ammonia (NH3) solutions, hydrolyzing them into molecules of astrobiological interest. A Titan tholin analogue hydrolyzed in aqueous NH3 at room temperature for 2.5 years was analyzed for amino acids using highly sensitive ultra-high performance liquid chromatography coupled with fluorescence detection and time-of-flight mass spectrometry (UHPLC-FDToF-MS) analysis after derivatization with a fluorescent tag. We compare here the amino acids produced from this reaction sequence with those generated from room temperature Miller-Urey (MU) type electric discharge reactions. We find that most of the amino acids detected in low temperature MU CH4N2H2O electric discharge reactions are generated in Titan simulation reactions, as well as in previous simulations of Triton chemistry. This argues that many processes provide very similar mixtures of amino acids, and possibly other types of organic compounds, in disparate environments, regardless of the order of hydration. Although it is unknown how life began, it is likely that given reducing conditions, similar materials were available throughout the early Solar System and throughout the universe to facilitate chemical evolution

The X-ray Spectra of Black Hole X-ray Novae in Quiescence as Measured by Chandra

We present Chandra observations of black hole X-ray novae V404 Cyg, A0620-00, GRO J1655-40 and XTE J1550-564 in quiescence. Their quiescent spectra can be well fitted by a power-law model with slope $\alpha \sim 2$. While a coronal (Raymond-Smith) model is also a statistically acceptable representation of the spectra, the best fit temperatures of these models is $\sim 5$ times higher than that seen in active stellar coronae. These four spectra of quiescent X-ray novae are all consistent with that expected for accretion via an advection-dominated accretion flow (ADAF) and inconsistent with that expected from a stellar corona. This evidence for continued accretion in quiescence further strengthens the case for the existence of event horizons in black holes. Both A0620-00 and GRO J1655-40 were fainter than in previous observations, while V404 Cyg was more luminous and varied by a factor of 2 in a few ksec. A reanalysis of the X-ray data for XTE J1550-564 shows that (like V404 Cyg and A0620-00) its luminosity exceeds the maximum prediction of the coronal model by a large factor. The 0.3-7 keV luminosity of the four sources studied ranges from $\sim 10^{30}-10^{33}$ erg/s.Comment: 9 pages, 6 figures, accepted for publication in Ap

SUMO protease SENP6 protects the nucleus from hyperSUMOylation-induced laminopathy-like alterations

The small ubiquitin-like modifier (SUMO) protease SENP6 disassembles SUMO chains from cellular substrate proteins. We use a proteomic method to identify putative SENP6 substrates based on increased apparent molecular weight after SENP6 depletion. Proteins of the lamin family of intermediate filaments show substantially increased SUMO modification after SENP6 depletion. This is accompanied by nuclear structural changes remarkably like those associated with laminopathies. Two SUMO attachment sites on lamin A/C are close to sites of mutations in Emery-Driefuss and limb girdle muscular dystrophy. To establish a direct link between lamin SUMOylation and the observed phenotype, we developed proximity-induced SUMO modification (PISM), which fuses a lamin A/C targeting DARPin to a SUMO E3 ligase domain. This directly targets lamin A/C for SUMO conjugation and demonstrates that enhanced lamin SUMO modification recapitulates the altered nuclear structure manifest after SENP6 depletion. This shows SENP6 activity protects the nucleus against hyperSUMOylation-induced laminopathy-like alterations.<br/