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Our study demonstrates the first application of the salmonid alphavirus-based replicon vector system (pSAV) as a DNA vaccine in a non-salmonid fish species, in common carp (Cyprinus carpio) against spring viraemia of carp virus (SVCV). SAV replicon encoding the glycoprotein of the SVCV was used as a DNA-layered plasmid, and its efficacy was compared with a previously described conventional DNA vaccine construct (pcDNA3.1 based vector) and with a control group (pcDNA3.1-empty-plasmid) in an SVCV challenge at a water temperature of 14 ± 1 °C. Vaccine prototypes were administered intramuscularly at a dose of 0.1 µg/g of fish (n = 25 per group). The DNA-layered SAV replicon resulted in 88% survival, compared to around 50% in all other groups. The DNA-layered pSAV vaccination induced the innate immune genes at the injection site, and increased IgM upregulation was also observed. Our preliminary results show that the SAV-based replicon construct may serve as a potential vaccine candidate for the protection of non-salmonid fish in the future provided that further clinical and field trials confirm its efficiency.

The effectiveness of acyclovir, a selective anti-herpesvirus agent, was tested both in silico and in vitro against two ranaviruses, namely the European catfish virus (ECV) and Frog virus 3 (FV3). ECV can cause significant losses in catfish aquaculture, while FV3 poses a risk to vulnerable amphibian populations. The genome of ranaviruses encodes thymidine kinases (TKs) similar to those of herpesviruses. Molecular docking simulations demonstrated that the acyclovir molecule can bind to the active sites of both investigated viral TKs in an orientation conducive to phosphorylation. Subsequently, the antiviral effect of acyclovir was tested in vitro in Epithelioma Papulosum Cyprini (EPC) cells with endpoint titration and qPCR. Acyclovir was used at a concentration of 800 µM, which significantly reduced the viral loads and titers of the ranaviruses. A similar reduction rate was observed with Ictalurid herpesvirus 2, which was used as a positive control virus. These promising results indicate that acyclovir might have a wider range of uses; besides its effectiveness against herpesviruses, it could also be used against ranavirus infections.

ABSTRACT Unexpected mass mortality of black bullhead Ameiurus melas (Rafinesque, 1820) fingerlings occurred 1 week after their arrival at our animal facility. The specimens of the invasive fish species originated from Lake Balaton, the largest natural freshwater lake in Hungary. The mortality reached 100% within 3 days. Gross pathological examination detected inflammation in the inner organs, renomegaly, and a marble, pale pink liver. Two pathogenic bacteria strains, Vibrio cholerae Pacini, 1854, and Plesiomonas shigelloides (Bader 1954), were detected in the fish liver examined. The molecular virological examination showed the presence of the nucleic acid of two dsDNA viruses. One is the Ictalurid herpesvirus 2 (IcHV‐2), which is a well‐known pathogen of the black bullhead that has only been reported from Italian fish farms previously. This is the first report of IcHV‐2 from a natural freshwater habitat. The other viral DNA detected in fish belongs to an unidentified virus species. Sequence analysis of the partial DNA polymerase gene confirmed that the novel virus is a member of the subfamily Chordopoxvirinae within the family Poxviridae. Although the causative agent of this mass mortality could not be identified with certainty, the clinical signs suggest that the detected viruses are the most suspicious. Furthermore, our results highlight that the health monitoring of invasive species is also important for the timely detection of pathogens that threaten the native fish fauna. [ABSTRACT FROM AUTHOR]

The efficacy of silver nanoparticles (AgNPs) was tested in vitro against three different fish viruses, causing significant economic damage in aquaculture. These viruses were the spring viraemia of carp virus (SVCV), European catfish virus (ECV), and Ictalurid herpesvirus 2 (IcHV-2). The safe concentration of AgNPs that did not cause cytotoxic effects in EPC cells proved to be 25 ng/mL. This dose of AgNPs decreased significantly (5–330×) the viral load of all three viruses in three different types of treatments (virus pre-treatment, cell pre-treatment, and cell post-treatment with the AgNPs). In a higher concentration, the AgNPs proved to be efficient against ECV and IcHV-2 even in a delayed post-cell-treatment experiment (AgNP treatment was applied 24 h after the virus inoculation). These first in vitro results against three devastating fish viruses are encouraging to continue the study of the applicability of AgNPs in aquaculture in the future.

Simple Summary: Common carp is in the top three among the farmed fish species worldwide. Spring viraemia of carp is caused by a virus that is economically significant, causing devastating losses in common carp aquaculture. Hence, the development of new-generation vaccines against this virus is pivotal. Previously, a salmonid alphavirus-based replicon vector system was developed and tested against viruses infecting Atlantic salmon. In our study, we demonstrate the first application of this vector system in a non-salmonid fish species. The replicon system provided significant protection against the spring viraemia virus as early as three weeks post-vaccination. Our study demonstrates the first application of the salmonid alphavirus-based replicon vector system (pSAV) as a DNA vaccine in a non-salmonid fish species, in common carp (Cyprinus carpio) against spring viraemia of carp virus (SVCV). SAV replicon encoding the glycoprotein of the SVCV was used as a DNA-layered plasmid, and its efficacy was compared with a previously described conventional DNA vaccine construct (pcDNA3.1 based vector) and with a control group (pcDNA3.1-empty-plasmid) in an SVCV challenge at a water temperature of 14 ± 1 °C. Vaccine prototypes were administered intramuscularly at a dose of 0.1 µg/g of fish (n = 25 per group). The DNA-layered SAV replicon resulted in 88% survival, compared to around 50% in all other groups. The DNA-layered pSAV vaccination induced the innate immune genes at the injection site, and increased IgM upregulation was also observed. Our preliminary results show that the SAV-based replicon construct may serve as a potential vaccine candidate for the protection of non-salmonid fish in the future provided that further clinical and field trials confirm its efficiency. [ABSTRACT FROM AUTHOR]

The effectiveness of acyclovir, a selective anti-herpesvirus agent, was tested both in silico and in vitro against two ranaviruses, namely the European catfish virus (ECV) and Frog virus 3 (FV3). ECV can cause significant losses in catfish aquaculture, while FV3 poses a risk to vulnerable amphibian populations. The genome of ranaviruses encodes thymidine kinases (TKs) similar to those of herpesviruses. Molecular docking simulations demonstrated that the acyclovir molecule can bind to the active sites of both investigated viral TKs in an orientation conducive to phosphorylation. Subsequently, the antiviral effect of acyclovir was tested in vitro in Epithelioma Papulosum Cyprini (EPC) cells with endpoint titration and qPCR. Acyclovir was used at a concentration of 800 µM, which significantly reduced the viral loads and titers of the ranaviruses. A similar reduction rate was observed with Ictalurid herpesvirus 2, which was used as a positive control virus. These promising results indicate that acyclovir might have a wider range of uses; besides its effectiveness against herpesviruses, it could also be used against ranavirus infections. [ABSTRACT FROM AUTHOR]

Mucosal immunisation is important for initiating mucosal CD8+ T­cell responses but mucosal recruitment of protective CD8+ T cells can also be induced by skin immunisation. Here the authors examine the underlying mechanism and report a novel role for ILC1 recruiting CD8+ T cells to the mucosa after skin immunisation.

Kutatásaimat a kárpátaljai Izsnyétén 2012-ben kezdtem antropológiai kutatócsoporttal. Kezdetben a lokális település együttélési mechanizmusaira, az ott élő etnikumok kulturális sajátosságaira voltunk kíváncsiak, de a háborús helyzet miatt hamarabb abba kellett hagynunk empirikus kutatásainkat 2015 előtt. 2017-ben, doktoranduszként folytattam empirikus kutatásaimat Izsnyétén, ahol a magyarok abszolút többséget képviselnek az államalkotó ukrán etnikummal szemben. Az alapvető kutatási koncepció az volt, hogy olyan határhoz közel eső lokális települést válasszak, ahol kettő, vagy három eltérő etnikum él együtt évtizedek óta. Tanulmányomban az etnicitás termelődésének folyamatát vizsgálom, valamint a településen élő etnikumok egymásról alkotott képét és változásait, valamint egymáshoz való alkalmazkodási folyamatait korábbi kutatások adataival összehasonlítva, reflektálva a változásokra, főként az asszimiláció tükrében. Már a 2012-es kutatások eredményei is térbeli izolációt mutattak, sok esetben a disszimiláció volt tapasztalható az együtt élő etnikumok között, azonban számos más tényező és aspektus az elmúlt években eltérő, változatos folyamatokat idézett elő.

We have limited knowledge about the course of the European catfish virus (ECV) infection in different age groups of wels catfish (Silurus glanis). The results of this study demonstrate that an ECV strain isolated from the brown bullhead (Ameiurus nebulosus) in Hungary could cause devastating losses among juvenile wels catfish. Furthermore, the age-related mortality rate following ECV infection was investigated in three virus challenge experiments at two different virus dosages. Eight-week-old (ca. 3 g), ten-week-old (ca. 8 g), and sixteen-week-old (ca. 55 g) catfish were infected with ECV at 21°C. In the youngest age group, 96% (at a 106 TCID50/mL dosage) and 100% (at 105 TCID50/mL) mortality rates were observed, while these rates were reduced to 56% and 68% in the ten-week-old groups, respectively. The mortality was significantly higher in the virus-exposed groups than in the control ones. In the sixteen-week-old group, 23% mortality was detected at a 105 TCID50/mL concentration of ECV. Here, a significant difference was not found between the exposed and control groups. The performed experiments show that different age groups of wels catfish may have various susceptibility to ECV. These findings draw attention to the importance of the prevention of/protection against virus infections in juvenile (up to 3-month-old) wels catfish in aquaculture.

Student mobility is a common phenomenon in Luxembourg, as almost every student spends a period abroad before graduating. Based on material from this “hyper-mobile” academic context, we will focus on the first phase of going abroad. First, we will analyse how the idea to study abroad is related to different notions of forced or non-forced mobility. Second, we will turn to the choice of destination, focussing on geographical distance and language distance between the country of origin and the place of destination. Geographical distance is not a goal as such but is a proxy for other dimensions, e.g. greater distance can be equated with a wish to try out new things and start a new life phase while shorter distance emphasises strong embeddedness in pre-existing social ties and obligations. In terms of language, students mostly choose countries where one of Luxembourg’s official languages is spoken (either because they have mastered it or because they would like to improve it for professional reasons), and countries where an additional language can be learnt or practised. Our results show that studying abroad is not the decision of a moment, but rather a process embedded in students’ past, present and future as well as in their social surroundings.

Transition from study to work is considered as the end of youth. How do young people prepare to enter the labour market? What are the strategies young people utilise to become employed if it occurs in another country, as in the case of employment mobility? To answer these questions, the proposed article focuses on how young people move and enter the employment in other destination countries. Alongside with the literature on youth and transition we also observe that young people equally experience challenges of matching their skills in the destination countries. They relate to inequalities on the job market depending on their skills, their qualifications, the type of jobs, their working experiences, etc. The discussions in this paper thus first touch upon the topic of inequality with regard to the process of recruitment and becoming employed. Second, they draw attention to the inferior positioning that young people are prepared to put themselves into when entering the labour market for the first time and emphasise the fact that young people often experience discrimination and unequal treatment when they complete education and apply for jobs, on the grounds of being young and inexperienced. As a result, such a positioning often puts young people in a vulnerable situation, which they accept and endure as long as they are promised work. Furthermore, by focusing on how young people enter the labour market in the receiving country, the paper also explores strategies that young people apply for being employed, becoming integrated in the labour market, overcoming inequalities in employment and finding ways to cope with these challenges in the labour market, as well as their own social lives in the destination country.

Human adenovirus 5 (HAdV-5) is used as a vector in gene therapy clinical trials, hence its interactions with the host immune system have been widely studied. Previous studies have demonstrated that HAdV-5 binds specifically to murine coagulation factor X (mFX), inhibiting IgM and complement-mediated neutralization. Here, we examined the physical binding of immune components to HAdV-5 by nanoparticle tracking analysis, neutralization assays, mass spectrometry analysis and in vivo experiments. We observed that purified mouse Immunoglobulin M (IgM) antibodies bound to HAdV-5 only in the presence of complement components. Active serum components were demonstrated to bind to HAdV-5 in the presence or absence of mFX, indicating that immune molecules and mFX might bind to different sites. Since binding of mFX to HAdV-5 blocks the neutralization cascade, these findings suggested that not all complement-binding sites may be involved in virion neutralization. Furthermore, the data obtained from serum neutralization experiments suggested that immune molecules other than IgM and IgG may trigger activation of the complement cascade in vitro. In vivo experiments were conducted in immunocompetent C57BL/6 or immuno-deficient Rag2-/- mice. HAdV-5T* (a mutant HAdV-5 unable to bind to human or mFX) was neutralized to some extent in both mouse models, suggesting that murine immunoglobulins were not required for neutralization of HAdV-5 in vivo. Liquid Chromatography-Mass Spectrometry (LC-MS/MS) analysis of HAdV-5 and HAdV-5T* after exposure to murine sera showed stable binding of C3 and C4b in the absence of mFX. In summary, these results suggest that HAdV-5 neutralization can be mediated by both the classical and alternative pathways and that, in the absence of immunoglobulins, the complement cascade can be activated by direct binding of C3 to the virion.