The rockefeller university

The HIV-1 envelope (Env) glycoprotein binds to host cell receptors to mediate membrane fusion. The prefusion Env trimer is stabilized by V1V2 loops that interact at the trimer apex. Broadly neutralizing antibodies (bNAbs) against V1V2 loops, exemplified by PG9, bind asymmetrically as a single Fab to the apex of the symmetric Env trimer using a protruding CDRH3 to penetrate the Env glycan shield. Here we characterized a distinct mode of V1V2 epitope recognition by the new bNAb BG1 in which two Fabs bind asymmetrically per Env trimer using a compact CDRH3. Comparisons between cryo-EM structures of Env trimer complexed with BG1 (6.2 A resolution) and PG9 (11.5 angstrom resolution) revealed a new V1V2-targeting strategy by BG1. Analyses of the EM structures provided information relevant to vaccine design including molecular details for different modes of asymmetric recognition of Env trimer and a binding model for BG1 recognition of V1V2 involving glycan flexibility.

Mesyl Salvinorin B (MSB) is a potent selective kappa opioid receptor (KOP-r) agonist that has potential for development as an anti-psychostimulant agent with fewer side-effects (e.g., sedation, depression and dysphoria) than classic KOP-r agonists. However, no such study has been done on alcohol. We investigated whether MSB alone or in combination with naltrexone (mu-opioid receptor antagonist) altered voluntary alcohol drinking in both male and female mice. Mice, subjected to 3 weeks of chronic escalation drinking (CED) in a two-bottle choice paradigm with 24-h access every other day, developed rapid escalation of alcohol intake and high preference. We found that single, acute administration of MSB dose dependently reduced alcohol intake and preference in mice after 3-week CED. The effect was specific to alcohol, as shown by the lack of any effect of MSB on sucrose or saccharin intake. We also used the drinking-in-the-dark (DID) model with limited access (4 h/day) to evaluate the pharmacological effect of MSB after 3 weeks of DID. However, MSB had no effect on alcohol drinking after 3-week DID. Upon investigation of potential synergistic effects between naltrexone and MSB, we found that acute administration of a combination of MSB and naltrexone reduced alcohol intake profoundly after 3-week CED at doses lower than those individual effective doses. Repeated administrations of this combination showed less tolerance development than repeated MSB alone. Our study suggests that the novel KOP-r agonist MSB both alone and in combination with naltrexone shows potential in alcoholism treatment models. (C) 2017 Elsevier B.V. All rights reserved.

Epithelial remodeling determines the structure of many organs in the body through changes in cell shape, polarity and behavior and is a major area of study in developmental biology. Accurate and high-throughput methods are necessary to systematically analyze epithelial organization and dynamics at single-cell resolution. We developed SEGGA, an easy-to-use software for automated image segmentation, cell tracking and quantitative analysis of cell shape, polarity and behavior in epithelial tissues. SEGGA is free, open source, and provides a full suite of tools that allow users with no prior computational expertise to independently perform all steps of automated image segmentation, semi-automated user-guided error correction, and data analysis. Here we use SEGGA to analyze changes in cell shape, cell interactions and planar polarity during convergent extension in the Drosophila embryo. These studies demonstrate that planar polarity is rapidly established in a spatiotemporally regulated pattern that is dynamically remodeled in response to changes in cell orientation. These findings reveal an unexpected plasticity that maintains coordinated planar polarity in actively moving populations through the continual realignment of cell polarity with the tissue axes.

Broadly neutralizing antibodies (bNAbs) offer promising opportunities for preventing HIV-1 infection in humans. Immunoprophylaxis with potent bNAbs efficiently protects non-human primates from mucosal transmission even after repeated challenges. However, the precise mechanisms of bNAb-mediated viral inhibition in mucosal tissues are currently unknown. Here, we show that immunoglobulin (Ig)G and IgA bNAbs do not interfere with the endocytic transport of HIV-1 across epithelial cells, a process referred to as transcytosis. Instead, both viruses and antibodies are translocated to the basal pole of epithelial cells, possibly in the form of an immune complex. Importantly, as opposed to free virions, viral particles bound by bNAbs are no longer infectious after transepithelial transit. Post-transcytosis neutralization activity of bNAbs displays comparable inhibitory concentrations as those measured in classical neutralization assays. Thus, bNAbs do not block the transport of incoming HIV-1 viruses across the mucosal epithelium but rather neutralize the transcytosed virions, highlighting their efficient prophylactic and protective activity in vivo.

We report on a measurement of the D+ -meson production cross section as a function of transverse momentum (p(T)) in proton-antiproton (p (p) over bar) collisions at 1.96 TeV center-of-mass energy, using the full data set collected by the Collider Detector at Fermilab in Tevatron Run II and corresponding to 10 fb(-1) of integrated luminosity. We use D-broken vertical bar -> K- pi(broken vertical bar) pi(broken vertical bar) decays fully reconstructed in the central rapidity region broken vertical bar y broken vertical bar < 1 with transverse momentum down to 1.5 GeV/c, a range previously unexplored in p<(p)over bar> collisions. Inelastic p (p) over bar -scattering events are selected online using minimally biasing requirements followed by an optimized offline selection. The K- pi(+) pi(+) mass distribution is used to identify the D+ signal, and the D+ transverse impact-parameter distribution is used to separate prompt production, occurring directly in the hard-scattering process, from secondary production from b-hadron decays. We obtain a prompt D+ signal of 2950 candidates corresponding to a total cross section sigma(D+), 1.5 < P-T < 14.5 GeV/c, vertical bar y vertical bar < 1) = 71.9 +/- 6.8 (stat) +/- 9.3 (syst) mu b.While the measured cross sections are consistent with theoretical estimates in each p(T) bin, the shape of the observed p(T) spectrum is softer than the expectation from quantum chromodynamics. The results are unique in p<(p)over bar> collisions and can improve the shape and uncertainties of future predictions.

How cells control the overall size and growth of membrane-bound organelles is an important unanswered question of cell biology. Fission yeast cells maintain a nuclear size proportional to cellular size, resulting in a constant ratio between nuclear and cellular volumes (N/C ratio). We have conducted a genome-wide visual screen of a fission yeast gene deletion collection for viable mutants altered in their N/C ratio, and have found that defects in both nucleocytoplasmic mRNA transport and lipid synthesis alter the N/C ratio. Perturbing nuclear mRNA export results in accumulation of both mRNA and protein within the nucleus, and leads to an increase in the N/C ratio which is dependent on new membrane synthesis. Disruption of lipid synthesis dysregulates nuclear membrane growth and results in an enlarged N/C ratio. We propose that both properly regulated nucleocytoplasmic transport and nuclear membrane growth are central to the control of nuclear growth and size.

Antibodies to Zika virus (ZIKV) can be protective. To examine the antibody response in individuals who develop high titers of anti-ZIKV antibodies, we screened cohorts in Brazil and Mexico for ZIKV envelope domain III (ZEDIII) binding and neutralization. We find that serologic reactivity to dengue 1 virus (DENV1) EDIII before ZIKV exposure is associated with increased ZIKV neutralizing titers after exposure. Antibody cloning shows that donors with high ZIKV neutralizing antibody titers have expanded clones of memory B cells that express the same immunoglobulin VH3-23/VK1-5 genes. These recurring antibodies cross-react with DENV1, but not other flaviviruses, neutralize both DENV1 and ZIKV, and protect mice against ZIKV challenge. Structural analyses reveal the mechanism of recognition of the ZEDIII lateral ridge by VH3-23/VK1-5 antibodies. Serologic testing shows that antibodies to this region correlate with serumneutralizing activity to ZIKV. Thus, high neutralizing responses to ZIKV are associated with pre-existing reactivity to DENV1 in humans.

The delivery of drugs to the brain is a constant challenge due to limitations imposed by the blood-brain barrier (BBB). Various methods of bypassing the BBB are under investigation. One approach is intranasal administration, where the olfactory region of the nasal cavity extends up to the cranial cavity and provides direct access to the brain. The pharmacokinetics of this transport and factors that determine transport rates and capacity is of vital importance for evaluating the clinical value of this route. Here, the pharmacokinetics of intranasally administered imatinib has been explored. Imatinib is distributed into the brain following intravenous administration, and then rapidly removed. Following intravenous administration, the brain/plasma ratio for imatinib was calculated to be 2% and remained at this ratio for 30 min. The brain/plasma ratio following intranasal administration, however, was found to be 5.3% and remained at this ratio for up to 90 min. Imatinib was found to be rapidly transported into the brain via the olfactory region, by shutting down the nose-to-blood-to-brain transport with epinephrine. The increased brain concentration of imatinib (0.33 mu g/g tissue) achieved by intranasal administration, compared with an IV injection, is likely to provide a model for developing a wide range of CNS active molecules that were previously removed from consideration as drug candidates due to their lack of CNS access. Furthermore, brain imatinib levels were increased by co-administration of the p-gp substrates, elacridar and pantoprazole, showing that both compounds were able to inhibit the elimination of imatinib from the brain. (C) 2017 Elsevier B.V. All rights reserved.

Background: Vitamin D deficiency, defined as a serum 25-hydroxy-vitamin D [25(OH) D] concentration,20 ng/mL, is correlated with a more atherogenic lipid profile. However, oral vitamin D supplementation does not lower LDL-cholesterol concentrations or raise HDL-cholesterol concentrations. This uncoupling between association and causation may result from a failure of oral vitamin D to mimic the effect of dermally synthesized vitamin D in response to ultraviolet type B (UVB) light. Objective: We tested the hypothesis that, in vitamin D-deficient adults, the replenishment of vitamin D with UVB exposure would lower LDL-cholesterol concentrations compared with the effect of oral vitamin D-3 supplementation. Design: We performed a randomized clinical trial in vitamin D-deficient adults and compared vitamin D replenishment between subjects who received oral vitamin D-3 (n = 60) and those who received narrow-band UVB exposure (n = 58) <= 6 mo. Results: There was no difference in the change from baseline LDL-cholesterol concentrations between oral vitamin D-3 and UVB groups (difference in median of oral vitamin D-3 minus that of UVB: 1.5 mg/dL; 95% CI: -5.0, 7.0 mg/dL). There were also no differences within groups or between groups for changes in total or HDL cholesterol or triglycerides. Transcriptional profiling of skin and blood, however, revealed significant upregulation of immune pathway signaling with oral vitamin D-3 but significant downregulation with UVB. Conclusions: Correcting vitamin D deficiency with either oral vitamin D-3 or UVB does not improve the lipid profile. Beyond cholesterol, these 2 modalities of raising 25(OH) D have disparate effects on gene transcription.