Minimal information for studies of extracellular vesicles 2018 (MISEV2018): a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

Prevention of herpes simplex virus induced stromal keratitis by a glycoprotein B-specific monoclonal antibody.

The increasing incidence of acyclovir (ACV) and multidrug-resistant strains in patients with corneal HSV-1 infections leading to Herpetic Stromal Keratitis (HSK) is a major health problem in industrialized countries and often results in blindness. To overcome this obstacle, we have previously developed an HSV-gB-specific monoclonal antibody (mAb 2c) that proved to be highly protective in immunodeficient NOD/SCID-mice towards genital infections. In the present study, we examined the effectivity of mAb 2c in preventing the immunopathological disease HSK in the HSK BALB/c mouse model. Therefore, mice were inoculated with HSV-1 strain KOS on the scarified cornea to induce HSK and subsequently either systemically or topically treated with mAb 2c. Systemic treatment was performed by intravenous administration of mAb 2c 24 h prior to infection (pre-exposure prophylaxis) or 24, 40, and 56 hours after infection (post-exposure immunotherapy). Topical treatment was performed by periodical inoculations (5 times per day) of antibody-containing eye drops as control, starting at 24 h post infection. Systemic antibody treatment markedly reduced viral loads at the site of infection and completely protected mice from developing HSK. The administration of the antiviral antibody prior or post infection was equally effective. Topical treatment had no improving effect on the severity of HSK. In conclusion, our data demonstrate that mAb 2c proved to be an excellent drug for the treatment of corneal HSV-infections and for prevention of HSK and blindness. Moreover, the humanized counterpart (mAb hu2c) was equally effective in protecting mice from HSV-induced HSK when compared to the parental mouse antibody. These results warrant the future development of this antibody as a novel approach for the treatment of corneal HSV-infections in humans

An Exceptional Summer during the South Pole Race of 1911-1912

The race for the South Pole during the summer of 1911-1912 was marked by exceptionally high temperature and pressure anomalies experienced by both Amundsen and Scott. The meteorological conditions during the Amundsen and Scott South Pole expeditions in 1911-1912 are examined using a combination of observations collected during the expeditions as well as modern reanalysis and reconstructed pressure datasets. It is found that over much of this austral summer, pressures were exceptionally high (more than two standard deviations above the climatological mean) at both main bases, as well as along the sledging journeys, especially in December 1911. In conjunction with the anomalously high pressures, Amundsen and his crew experienced temperatures that peaked above -16°C on the polar plateau on December 6 1911, which is extremely warm for this region. While Scott also encountered unusually warm conditions at this time, the above average temperatures were accompanied by a wet snowstorm that slowed his progress across the Ross Ice Shelf. Although January 1912 was marked with slightly below average temperatures and pressure, high temperatures and good conditions were observed in early February 1912, when Scott and his companions were at the top of the Beardmore Glacier. When compared to the anomalously cold temperatures experienced by the Scott polar party in late February and March of 1912, the temperature change is in the top 3% based on more than 35 years of reanalysis data. Scott and his companions therefore faced an exceptional decrease in temperature when transiting to the Ross Ice Shelf in February/March 1912, which likely made the persistent cold spell they experienced on the Ross Ice Shelf be perceived as even more intense by comparison

Biallelic variants in YRDC cause a developmental disorder with progeroid features

The highly conserved YrdC domain-containing protein (YRDC) interacts with the well-described KEOPS complex, regulating specific tRNA modifications to ensure accurate protein synthesis. Previous studies have linked the KEOPS complex to a role in promoting telomere maintenance and controlling genome integrity. Here, we report on a newborn with a severe neonatal progeroid phenotype including generalized loss of subcutaneous fat, microcephaly, growth retardation, wrinkled skin, renal failure, and premature death at the age of 12 days. By trio whole-exome sequencing, we identified a novel homozygous missense mutation, c.662T > C, in YRDC affecting an evolutionary highly conserved amino acid (p.Ile221Thr). Functional characterization of patient-derived dermal fibroblasts revealed that this mutation impairs YRDC function and consequently results in reduced t(6)A modifications of tRNAs. Furthermore, we established and performed a novel and highly sensitive 3-D Q-FISH analysis based on single-telomere detection to investigate the impact of YRDC on telomere maintenance. This analysis revealed significant telomere shortening in YRDC-mutant cells. Moreover, single-cell RNA sequencing analysis of YRDC-mutant fibroblasts revealed significant transcriptome-wide changes in gene expression, specifically enriched for genes associated with processes involved in DNA repair. We next examined the DNA damage response of patient's dermal fibroblasts and detected an increased susceptibility to genotoxic agents and a global DNA double-strand break repair defect. Thus, our data suggest that YRDC may affect the maintenance of genomic stability. Together, our findings indicate that biallelic variants in YRDC result in a developmental disorder with progeroid features and might be linked to increased genomic instability and telomere shortening

Risks of less common cancers in proven mutation carriers with lynch syndrome

Item does not contain fulltextPURPOSE Patients with Lynch syndrome are at high risk for colon and endometrial cancer, but also at an elevated risk for other less common cancers. The purpose of this retrospective cohort study was to provide risk estimates for these less common cancers in proven carriers of pathogenic mutations in the mismatch repair (MMR) genes MLH1, MSH2, and MSH6. PATIENTS AND METHODS Data were pooled from the German and Dutch national Lynch syndrome registries. Seven different cancer types were analyzed: stomach, small bowel, urinary bladder, other urothelial, breast, ovarian, and prostate cancer. Age-, sex- and MMR gene-specific cumulative risks (CRs) were calculated using the Kaplan-Meier method. Sex-specific incidence rates were compared with general population incidence rates by calculating standardized incidence ratios (SIRs). Multivariate Cox regression analysis was used to estimate the impact of sex and mutated gene on cancer risk. Results The cohort comprised 2,118 MMR gene mutation carriers (MLH1, n = 806; MSH2, n = 1,004; MSH6, n = 308). All cancers were significantly more frequent than in the general population. The highest risks were found for male small bowel cancer (SIR, 251; 95% CI, 177 to 346; CR at 70 years, 12.0; 95% CI, 5.7 to 18.2). Breast cancer showed an SIR of 1.9 (95% CI, 1.4 to 2.4) and a CR of 14.4 (95% CI, 9.5 to 19.3). MSH2 mutation carriers had a considerably higher risk of developing urothelial cancer than MLH1 or MSH6 carriers. CONCLUSION The sex- and gene-specific differences of less common cancer risks should be taken into account in cancer surveillance and prevention programs for patients with Lynch syndrome

Effective virus neutralization in HSV-1 KOS infected eyes by mAb 2c.

<p>Representatively, six mice from each group were killed at day 5 post infection. Primary infected eyes were homogenized and inspected for viral loads using a standard plaque assay. Statistical analysis was undertaken with a nonparametric ANOVA test. Comparisons were considered significant at *<i>P</i> < 0.05. Error bars represent the SEM.</p

Influence of mAb 2c treatment on the cellular and humoral immune response to HSV-1 of corneally infected mice.

<p>The reduced virus titers correlate with reduced anti-HSV immune responses. The total numbers of cells in draining lymph nodes (DLN) <b>(A)</b> and spleens <b>(B)</b> and the relative antibody titers in 10 µl tear fluids <b>(C)</b> and 60 µl sera <b>(D)</b> of mice on day 14 post infection are shown. Each dot represents a single mouse. Differences between the groups were statistically significant by a nonparametric ANOVA one way test (*<i>P</i> < 0.05; **<i>P</i> < 0.01; ***<i>P</i> < 0.001). Error bars represent the SEM.</p

Prevention of corneal HSV-1 KOS infection in mice by the humanized antibody mAb hu2c.

<p>The clinical disease scores of infected mice for blepharitis, epithelial defects and corneal opacity (stromal keratitis) are shown as an average score of ten mice per group over a period of 14 days <b>(A)</b> or as dot plot <b>(B)</b> taken on day 14 after infection. Every dot represents a single mouse. Differences between the groups were statistically significant by a nonparametric ANOVA one way test (**<i>P</i> < 0.01; ***<i>P</i> < 0.001). Error bars represent the SEM. PBS-treated group showed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116800#pone.0116800.g003" target="_blank">Fig. 3</a> serves as control. Pictures and histological stainings representative for mice systemically treated with mAb hu2c are shown <b>(C)</b>. Haematoxylin-eosin staining. Magnification: 120x. Scale bars:100 μm.</p

MAbs 2c and hu2c restrict cell-to-neuron <b>(A-F)</b> and neuron-to-cell spread of HSV-1 <b>(G-L)</b>.

<p>For the investigation of cell-to-neuron spread, epithelial C127I cells (arrows) were infected with the reporter virus HSV-1(17⁺)Lox-Che. At 14 hpi cells were detached, treated with the indicated antibodies and co-cultured with uninfected DRG sensory neurons (arrowheads) <b>(A-E)</b>. For the investigation of neuron-to-cell transmission, DRG neurons were infected with HSV-1(17⁺)Lox-Che. At 24 hpi, GFP-transfected, uninfected C127I were detached, treated with the indicated antibodies and co-cultured with the infected neurons <b>(G-K)</b>. For both settings, cells were fixed as indicated at 7, 22 and 30 hpi with PHEMO and labeled with anti-β-tubulin-III. Images were acquired with a confocal microscope. For the quantification of the cell-to-neuron <b>(F)</b> or neuron-to-cell transmission <b>(L)</b>, the values of mCherry-fluorescence were determined in a defined area within neurons <b>(F)</b> or GFP-positive C127I cells (G). (A-E and G-K) Scale bar is 10 µm. <b>(F and L)</b>. Error bars show standard error of the mean (SEM) of one representative experiment. Differences between the groups were statistically significant by a nonparametric ANOVA one way test (***<i>P</i> < 0.001).</p