Equine herpesvirus 1 bridles T lymphocytes to reach its target organs

Equine herpesvirus 1 (EHV1) replicates in the respiratory epithelium and disseminates through the body via a cell-associated viremia in leukocytes, despite the presence of neutralizing antibodies. "Hijacked" leukocytes, previously identified as monocytic cells and T lymphocytes, transmit EHV1 to endothelial cells of the endometrium or central nervous system, causing reproductive (abortigenic variants) or neurological (neurological variants) disorders. In the present study, we questioned the potential route of EHV1 infection of T lymphocytes and how EHV1 misuses T lymphocytes as a vehicle to reach the endothelium of the target organs in the absence or presence of immune surveillance. Viral replication was evaluated in activated and quiescent primary T lymphocytes, and the results demonstrated increased infection of activated versus quiescent, CD4(+) versus CD8(+), and blood-versus lymph node-derived T cells. Moreover, primarily infected respiratory epithelial cells and circulating monocytic cells efficiently transferred virions to T lymphocytes in the presence of neutralizing antibodies. Albeit T-lymphocytes express all classes of viral proteins early in infection, the expression of viral glycoproteins on their cell surface was restricted. In addition, the release of viral progeny was hampered, resulting in the accumulation of viral nucleocapsids in the T cell nucleus. During contact of infected T lymphocytes with endothelial cells, a late viral protein(s) orchestrates T cell polarization and synapse formation, followed by anterograde dynein-mediated transport and transfer of viral progeny to the engaged cell. This represents a sophisticated but efficient immune evasion strategy to allow transfer of progeny virus from T lymphocytes to adjacent target cells. These results demonstrate that T lymphocytes are susceptible to EHV1 infection and that cell-cell contact transmits infectious virus to and from T lymphocytes. IMPORTANCE Equine herpesvirus 1 (EHV1) is an ancestral alphaherpesvirus that is related to herpes simplex virus 1 and causes respiratory, reproductive, and neurological disorders in Equidae. EHV1 is indisputably a master at exploiting leukocytes to reach its target organs, accordingly evading the host immunity. However, the role of T lymphocytes in cell-associated viremia remains poorly understood. Here we show that activated T lymphocytes efficiently become infected and support viral replication despite the presence of protective immunity. We demonstrate a restricted expression of viral proteins on the surfaces of infected T cells, which prevents immune recognition. In addition, we indicate a hampered release of progeny, which results in the accumulation of nucleocapsids in the T cell nucleus. Upon engagement with the target endothelium, late viral proteins orchestrate viral synapse formation and viral transfer to the contact cell. Our findings have significant implications for the understanding of EHV1 pathogenesis, which is essential for developing innovative therapies to prevent the devastating clinical symptoms of infection

PirABVP toxin binds to epithelial cells of the digestive tract and produce pathognomonic AHPND lesions in germ-free brine shrimp

Acute hepatopancreatic necrosis disease (AHPND), a newly emergent farmed penaeid shrimp bacterial disease originally known as early mortality syndrome (EMS), is causing havoc in the shrimp industry. The causative agent of AHPND was found to be a specific strain of bacteria, e.g., Vibrio and Shewanella sps., that contains pVA1 plasmid (63–70 kb) encoding the binary PirAVP and PirBVP toxins. The PirABVP and toxins are the primary virulence factors of AHPND-causing bacteria that mediates AHPND and mortality in shrimp. Hence, in this study using a germ-free brine shrimp model system, we evaluated the PirABVP toxin-mediated infection process at cellular level, including toxin attachment and subsequent toxin-induced damage to the digestive tract. The results showed that, PirABVP toxin binds to epithelial cells of the digestive tract of brine shrimp larvae and produces characteristic symptoms of AHPND. In the PirABVP-challenged brine shrimp larvae, shedding or sloughing of enterocytes in the midgut and hindgut regions was regularly visualized, and the intestinal lumen was filled with moderately electron-dense cells of variable shapes and sizes. In addition, the observed cellular debris in the intestinal lumen of the digestive tract was found to be of epithelial cell origin. The detailed morphology of the digestive tract demonstrates further that the PirABVP toxin challenge produces focal to extensive necrosis and damages epithelial cells in the midgut and hindgut regions, resulting in pyknosis, cell vacuolisation, and mitochondrial and rough endoplasmic reticulum (RER) damage to different degrees. Taken together, our study provides substantial evidence that PirABVP toxins bind to the digestive tract of brine shrimp larvae and seem to be responsible for generating characteristic AHPND lesions and damaging enterocytes in the midgut and hindgut regions

The separation and characterization of extracellular vesicles from medium conditioned by bovine embryos

Extracellular vesicles (EVs) have been identified as one of the communication mechanisms amongst embryos. They are secreted into the embryo culture medium and, as such, represent a source of novel biomarkers for identifying the quality of cells and embryos. However, only small amounts of embryo-conditioned medium are available, which represents a challenge for EV enrichment. Our aim is to assess the suitability of different EV separation methods to retrieve EVs with high specificity and sufficient efficiency. Bovine embryo-conditioned medium was subjected to differential ultracentrifugation (DU), OptiPrep(TM) density gradient (ODG) centrifugation, and size exclusion chromatography. Separated EVs were characterized by complementary characterization methods, including Western blot, electron microscopy, and nanoparticle tracking analysis, to assess the efficiency and specificity. OptiPrep(TM) density gradient centrifugation outperformed DU and SEC in terms of specificity by substantial removal of contaminating proteins such as ribonucleoprotein complexes (Argonaute-2 (AGO-2)) and lipoproteins (ApoA-I) from bovine embryo-derived EVs (density: 1.02-1.04, 1.20-1.23 g/mL, respectively). In conclusion, ODG centrifugation is the preferred method for identifying EV-enriched components and for improving our understanding of EV function in embryo quality and development

The predictive value of the cervical consistency index to predict spontaneous preterm birth in asymptomatic twin pregnancies at the second-trimester ultrasound scan: A prospective cohort study

Novel transvaginal ultrasound (TVU) markers have been proposed to improve spontaneous preterm birth (sPTB) prediction. Preliminary results of the cervical consistency index (CCI), uterocervical angle (UCA), and cervical texture (CTx) have been promising in singletons. However, in twin pregnancies, the results have been inconsistent. In this prospective cohort study of asymptomatic twin pregnancies assessed between 18+0-22+0 weeks, we evaluated TVU derived cervical length (CL), CCI, UCA, and the CTx to predict sPTB < 34+0 weeks. All iatrogenic PTB were excluded. In the final cohort of 63 pregnancies, the sPTB rate < 34+0 was 16.3%. The CCI, UCA, and CTx, including the CL was significantly different in the sPTB < 34+0 weeks group. The best area under the receiver operating characteristic curve (AUC) for sPTB < 34+0 weeks was achieved by the CCI 0.82 (95%CI, 0.72-0.93), followed by the UCA with AUC 0.72 (95%CI, 0.57-0.87). A logistic regression model incorporating parity, chorionicity, CCI, and UCA resulted in an AUC of 0.91 with a sensitivity of 55.3% and specificity of 88.1% for predicting sPTB < 34+0. The CCI performed better than other TVU markers to predict sPTB < 34+0 in twin gestations, and the best diagnostic accuracy was achieved by a combination of parity, chorionicity, CCI, and UCA

A study of carry-over and histopathological effects after chronic dietary intake of citrinin in pigs, broiler chickens and laying hens

Citrinin (CIT) is a polyketide mycotoxin occurring in a variety of food and feedstuff, among which cereal grains are the most important contaminated source. Pigs and poultry are important livestock animals frequently exposed to mycotoxins, including CIT. Concerns are rising related to the toxic, and especially the potential nephrotoxic, properties of CIT. The purpose of this study was to clarify the histopathological effects on kidneys, liver, jejunum and duodenum of pigs, broiler chickens and laying hens receiving CIT contaminated feed. During 3 weeks, pigs (n = 16) were exposed to feed containing 1 mg CIT/kg feed or to control feed (n = 4), while 2 groups of broiler chickens and laying hens (n = 8 per group) received 0.1 mg CIT/kg feed (lower dose group) and 3 or 3.5 mg CIT/kg feed (higher dose group), respectively, or control feed (n = 4). CIT concentrations were quantified in plasma, kidneys, liver, muscle and eggs using a validated ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. Kidneys, liver, duodenum and jejunum were evaluated histologically using light microscopy, while the kidneys were further examined using transmission electron microscopy (TEM). Histopathology did not reveal major abnormalities at the given contamination levels. However, a significant increase of swollen and degenerated mitochondria in renal cortical cells from all test groups were observed (p < 0.05). These observations could be related to oxidative stress, which is the major mechanism of CIT toxicity. Residues of CIT were detected in all collected tissues, except for muscle and egg white from layers in the lowest dose group, and egg white from layers in the highest dose group. CIT concentrations in plasma ranged between 0.1 (laying hens in lower dose group) and 20.8 ng/mL (pigs). In tissues, CIT concentrations ranged from 0.6 (muscle) to 20.3 µg/kg (liver) in pigs, while concentrations in chickens ranged from 0.1 (muscle) to 70.2 µg/kg (liver). Carry-over ratios from feed to edible tissues were between 0.1 and 2% in pigs, and between 0.1 and 6.9% in chickens, suggesting a low contribution of pig and poultry tissue-derived products towards the total dietary CIT intake for humans

Immunogenicity and protection efficacy of a naked self-replicating mRNA-based Zika virus vaccine

To combat emerging infectious diseases like Zika virus (ZIKV), synthetic messenger RNAs (mRNAs) encoding viral antigens are very attractive as they allow a rapid, generic, and flexible production of vaccines. In this work, we engineered a self-replicating mRNA (sr-mRNA) vaccine encoding the pre-membrane and envelope (prM-E) glycoproteins of ZIKV. Intradermal electroporation of as few as 1 µg of this mRNA-based ZIKV vaccine induced potent humoral and cellular immune responses in BALB/c and especially IFNAR1-/- C57BL/6 mice, resulting in a complete protection of the latter mice against ZIKV infection. In wild-type C57BL/6 mice, the vaccine resulted in very low seroconversion rates and antibody titers. The potency of the vaccine was inversely related to the dose of mRNA used in wild-type BALB/c or C57BL/6 mice, as robust type I interferon (IFN) response was determined in a reporter mice model (IFN-β+/Δβ-luc). We further investigated the inability of the sr-prM-E-mRNA ZIKV vaccine to raise antibodies in wild-type C57BL/6 mice and found indications that type I IFNs elicited by this naked sr-mRNA vaccine might directly impede the induction of a robust humoral response. Therefore, we assume that the efficacy of sr-mRNA vaccines after intradermal electroporation might be increased by strategies that temper their inherent innate immunogenicity

Isolation and characterization of functionally active extracellular vesicles from culture medium conditioned by bovine embryos in vitro

Extracellular vesicles (EVs) play a possible role in cell&ndash;cell communication and are found in various body fluids and cell conditioned culture media. The aim of this study was to isolate and characterize EVs in culture medium conditioned by bovine embryos in group and to verify if these EVs are functionally active. Initially, ultracentrifuged bovine serum albumin (BSA) containing medium was selected as suitable EV-free embryo culture medium. Next, EVs were isolated from embryo conditioned culture medium by OptiPrepTM density gradient ultracentrifugation. Isolated EVs were characterized by nanoparticle tracking analysis, western blotting, transmission, and immunoelectron microscopy. Bovine embryo-derived EVs were sizing between 25&ndash;230 nm with an average concentration of 236.5 &plusmn; 1.27 &times; 108 particles/mL. Moreover, PKH67 EV pre-labeling showed that embryo-secreted EVs were uptaken by zona-intact bovine embryos. Since BSA did not appear to be a contaminating EV source in culture medium, EV functionality was tested in BSA containing medium. Individual embryo culture in BSA medium enriched with EVs derived from conditioned embryo culture medium showed significantly higher blastocyst rates at day 7 and 8 together with a significantly lower apoptotic cell ratio. In conclusion, our study shows that EVs play an important role in inter embryo communication during bovine embryo culture in group

Arabin cervical pessary for prevention of preterm birth in cases of twin-to-twin transfusion syndrome treated by fetoscopic LASER coagulation: the PECEP LASER randomised controlled trial

Abstract Background Fetoscopic LASER coagulation of the placental anastomoses has changed the prognosis of twin-twin transfusion syndrome. However, the prematurity rate in this cohort remains very high. To date, strategies proposed to decrease the prematurity rate have shown inconclusive, if not unfavourable results. Methods This is a randomised controlled trial to investigate whether a prophylactic cervical pessary will lower the incidence of preterm delivery in cases of twin-twin transfusion syndrome requiring fetoscopic LASER coagulation. Women eligible for the study will be randomised after surgery and allocated to either pessary or expectant management. The pessary will be left in place until 37 completed weeks or earlier if delivery occurs. The primary outcome is delivery before 32 completed weeks. Secondary outcomes are a composite of adverse neonatal outcome, fetal and neonatal death, maternal complications, preterm rupture of membranes and hospitalisation for threatened preterm labour. 352 women will be included in order to decrease the rate of preterm delivery before 32 weeks’ gestation from 40% to 26% with an alpha-error of 0.05 and 80% power. Discussion The trial aims at clarifying whether the cervical pessary prolongs the pregnancy in cases of twin-twin transfusion syndrome regardless of cervical length at the time of fetoscopy. Trial registration ClinicalTrials.gov Identifier: NCT01334489 . Registered 04 December 2011

The Placenta in Twin-to-Twin Transfusion Syndrome and Twin Anemia Polycythemia Sequence

Twin-to-twin transfusion syndrome (TTTS) and twin anemia polycythemia sequence (TAPS) are complications unique to monochorionic twin pregnancies and their shared circulation. Both are the result of the transfusion imbalance in the intertwin circulation. TTTS is characterized by an amniotic fluid discordance, whereas in TAPS, there is a severe discordance in hemoglobin levels. The article gives an overview of the typical features of TTTS and TAPS placentas.status: publishe