Influenza Induces Lung Lymphangiogenesis Independent of YAP/TAZ Activity in Lymphatic Endothelial Cells.

The lymphatic system consists of a vessel network lined by specialized lymphatic endothelial cells (LECs) that are responsible for tissue fluid homeostasis and immune cell trafficking. The mechanisms for organ-specific LEC responses to environmental cues are not well understood. We found robust lymphangiogenesis during influenza A virus infection in the adult mouse lung. We show that the number of LECs increases 2-fold at 7 days post-influenza infection (dpi) and 3-fold at 21 dpi, and that lymphangiogenesis is preceded by lymphatic dilation. We also show that the expanded lymphatic network enhances fluid drainage to mediastinal lymph nodes. Using EdU labeling, we found that a significantly higher number of pulmonary LECs are proliferating at 7 dpi compared to LECs in homeostatic conditions. Lineage tracing during influenza indicates that new pulmonary LECs are derived from preexisting LECs rather than non-LEC progenitors. Lastly, using a conditional LEC-specific YAP/TAZ knockout model, we established that lymphangiogenesis, fluid transport and the immune response to influenza are independent of YAP/TAZ activity in LECs. These findings were unexpected, as they indicate that YAP/TAZ signaling is not crucial for these processes.

Effects of Inotropes on the Mortality in Patients With Septic Shock.

BACKGROUND: Although surviving sepsis campaign guidelines recommend the use of inotropes in the presence of myocardial dysfunction, the effects of inotropes, including epinephrine, dobutamine, and milrinone, on in-hospital mortality in patients with septic shock remains unclear. MATERIALS AND METHODS: We conducted an international,2-center, retrospective cohort study. The Cox proportional hazards regression model with time-varying covariates was used to investigate whether epinephrine, milrinone, or dobutamine reduces in-hospital mortality in patients with septic shock. Sensitivity analysis was performed using propensity score matching. The primary outcome was in-hospital mortality. The secondary outcome included atrial fibrillation (Afib) with a rapid ventricular response (RVR) in the intensive care unit (ICU) and ICU-free days. RESULTS: A total of 417 patients with septic shock were included, 72 (17.3%) of whom received inotropes. The use of epinephrine and dobutamine was associated with significantly higher in-hospital mortality (epinephrine, hazard ratio [HR]: 4.79, 95% confidence interval [CI]: 2.12-10.82, P = .001; dobutamine, HR: 2.53, 95% CI: 1.30-4.95, P = .046). The effects of epinephrine and dobutamine were time- and dose-dependent. The use of milrinone was not associated with increased mortality (HR: 1.07, 95% CI: 0.42-2.68, P = .345). The use of epinephrine, dobutamine, and milrinone was associated with significantly increased odds of Afib with RVR (epinephrine, odds ratio [OR]: 3.88, 95% CI: 1.11-13.61, P = .034; dobutamine, OR: 3.95, 95% CI: 1.14-13.76; and milrinone, OR: 3.77, 95% CI: 1.05-13.59). On the other hand, the use of epinephrine, dobutamine, and milrinone was not associated with less ICU-free days (epinephrine, adjusted OR: 0.30, 95% CI: 0.09-1.01, P = .053; dobutamine, adjusted OR: 0.91, 95% CI: 0.29-2.84; and milrinone, adjusted OR: 0.60, 95% CI: 0.19-1.87). CONCLUSION: The present study showed that the use of epinephrine and dobutamine was associated with significantly increased in-hospital mortality in patients with septic shock. These effects were both time- and dose-dependent. On the other hand, the use of milrinone was not associated with increased in-hospital mortality.

Qß Virus-like particle-based vaccine induces robust immunity and protects against tauopathy.

Tauopathies, including frontotemporal dementia (FTD) and Alzheimer's disease (AD) are progressive neurodegenerative diseases clinically characterized by cognitive decline and could be caused by the aggregation of hyperphosphorylated pathological tau (pTau) as neurofibrillary tangles (NFTs) inside neurons. There is currently no FDA-approved treatment that cures, slows or prevents tauopathies. Current immunotherapy strategies targeting pTau have generated encouraging data but may pose concerns about scalability, affordability, and efficacy. Here, we engineered a virus-like particle (VLP)-based vaccine in which tau peptide, phosphorylated at threonine 181, was linked at high valency to Qß bacteriophage VLPs (pT181-Qß). We demonstrate that vaccination with pT181-Qß is sufficient to induce a robust and long-lived anti-pT181 antibody response in the sera and the brains of both Non-Tg and rTg4510 mice. Only sera from pT181-Qß vaccinated mice are reactive to classical somatodendritic pTau in human FTD and AD post-mortem brain sections. Finally, we demonstrate that pT181-Qß vaccination reduces both soluble and insoluble species of hyperphosphorylated pTau in the hippocampus and cortex, avoids a Th1-mediated pro-inflammatory cell response, prevents hippocampal and corpus callosum atrophy and rescues cognitive dysfunction in a 4-month-old rTg4510 mouse model of FTD. These studies provide a valid scientific premise for the development of VLP-based immunotherapy to target pTau and potentially prevent Alzheimer's diseases and related tauopathies.

Fragmented QRS and mortality in patients undergoing percutaneous intervention for ST-elevation myocardial infarction: Systematic review and meta-analysis.

BACKGROUND: Fragmented QRS reflects disturbances in the myocardium predisposing the heart to ventricular tachyarrhythmias. Recent studies suggest that fragmented QRS (fQRS) is associated with mortality in ST-elevation myocardial infarction (STEMI) patients who underwent percutaneous coronary intervention (PCI). However, a systematic review and meta-analysis of the literature has not been done. We assessed the association between fQRS and overall mortality in STEMI patients who subsequently underwent PCI by a systematic review and meta-analysis. METHODS: We comprehensively searched the databases of MEDLINE and EMBASE from inception to September 2017. Studies included in our analysis were published cohort (prospective or retrospective) and case-control studies that compared overall mortality among STEMI patient with and without fQRS who underwent PCI. Data from each study were combined using the random-effects, generic inverse variance method of DerSimonian, and Laird to calculate risk ratios and 95% confidence intervals. RESULTS: Six studies from 2014 to 2017 were included in this meta-analysis involving 2,516 subjects with STEMI who underwent PCI (888 fQRS and 1,628 non-fQRS). Fragmented QRS was associated with overall mortality in STEMI patients who underwent PCI (pooled risk ratio = 3.87; 95% CI 1.96-7.66, I2  = 43%). CONCLUSION: Fragmented QRS was associated with increased overall mortality up to threefold. Our study suggests that fQRS could be an important tool for risk assessment in STEMI patients who underwent PCI.

A cholesterol-lowering VLP vaccine that targets PCSK9.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a secretory protein that controls cholesterol homeostasis by enhancing endosomal and lysosomal degradation of the low-density lipoprotein receptor (LDL-R). Mutations that cause increased activity of PCSK9 are associated with hypercholesterolemia, atherosclerosis and early cardiovascular disease (CVD), whereas individuals with loss-of-function mutations in PCSK9 are apparently healthy but are hypocholesterolemic and have a dramatically decreased risk of CVD. In this study, we generated virus-like particle (VLP)-based vaccines targeting PCSK9. Mice and macaques vaccinated with bacteriophage VLPs displaying PCSK9-derived peptides developed high titer IgG antibodies that bound to circulating PCSK9. Vaccination was associated with significant reductions in total cholesterol, free cholesterol, phospholipids, and triglycerides. A vaccine targeting PCSK9 may, therefore, be an attractive alternative to monoclonal antibody-based therapies.

Identification of an Immunogenic Mimic of a Conserved Epitope on the Plasmodium falciparum Blood Stage Antigen AMA1 Using Virus-Like Particle (VLP) Peptide Display.

We have developed a peptide display platform based on VLPs of the RNA bacteriophage MS2 that combines the high immunogenicity of VLP display with affinity selection capabilities. Random peptides can be displayed on the VLP surface by genetically inserting sequences into a surface-exposed loop of the viral coat protein. VLP-displayed peptides can then be isolated by selection using antibodies, and the VLP selectants can then be used directly as immunogens. Here, we investigated the ability of this platform to identify mimotopes of a highly conserved conformational epitope present on the Plasmodium falciparum blood-stage protein AMA1. Using 4G2, a monoclonal antibody that binds to this epitope and is a potent inhibitor of erythrocyte invasion, we screened three different VLP-peptide libraries and identified specific VLPs that bound strongly to the selecting mAb. We then tested the ability of a handful of selected VLPs to elicit anti-AMA1 antibody responses in mice. Most of the selected VLPs failed to reliably elicit AMA1 specific antibodies. However, one VLP consistently induced antibodies that cross-reacted with AMA1. Surprisingly, this VLP bound to 4G2 more weakly than the other selectants we identified. Taken together, these data demonstrate that VLP-peptide display can identify immunogenic mimics of a complex conformational epitope and illustrate the promise and challenges of this approach.

Alcohol exposure decreases CREB binding protein expression and histone acetylation in the developing cerebellum.

BACKGROUND: Fetal alcohol exposure affects 1 in 100 children making it the leading cause of mental retardation in the US. It has long been known that alcohol affects cerebellum development and function. However, the underlying molecular mechanism is unclear. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate that CREB binding protein (CBP) is widely expressed in granule and Purkinje neurons of the developing cerebellar cortex of naïve rats. We also show that exposure to ethanol during the 3(rd) trimester-equivalent of human pregnancy reduces CBP levels. CBP is a histone acetyltransferase, a component of the epigenetic mechanism controlling neuronal gene expression. We further demonstrate that the acetylation of both histone H3 and H4 is reduced in the cerebellum of ethanol-treated rats. CONCLUSIONS/SIGNIFICANCE: These findings indicate that ethanol exposure decreases the expression and function of CBP in the developing cerebellum. This effect of ethanol may be responsible for the motor coordination deficits that characterize fetal alcohol spectrum disorders.