Innate immune response of rainbow trout erythrocytes to spinycterins expressing a downsized viral fragment of viral haemorrhagic septicaemia virus

Recent studies have reported on the importance of RBCs in fish responses to viral infections and DNA vaccines. Surface-displaying recombinant bacterins (spinycterins) are a safe and adaptable prototype for viral vaccination of fish and represent an alternative method of aquaculture prophylaxis, since have been reported to enhance fish immune response. We evaluated the innate immune response of rainbow trout (Oncorhynchus mykiss) red blood cells (RBCs), head kidney, and spleen to spinycterins expressing a fragment of the glycoprotein G of viral haemorrhagic septicemia virus (VHSV), one of the most devastating world-wide diseases in farmed salmonids. We first selected an immunorelevant downsized viral fragment of VHSV glycoprotein G (frg16252-450). Then, spinycterins expressing frg16252-450 fused to Nmistic anchor-motif (Nmistic+frg16252-450) were compared to spinycterins expressing frg16252-450 internally without the anchor motif. Nmistic+frg16252-450 spinycterins showed increased attachment to RBCs in vitro and modulated the expression of interferon- and antigen presentation-related genes in RBCs in vitro and in vivo, after intravenous injection. In contrast, the head kidney and spleen of fish injected with frg16252-450, but not Nmistic+frg16252-450, spinycterins demonstrated upregulation of interferon and antigen-presenting genes. Intravenous injection of Nmistic+frg16252-450 spinycterins resulted in a higher innate immune response in RBCs while frg16252-450 spinycterins increased the immune response in head kidney and spleen. Although more studies are required to evaluate the practicality of using spinycterins as fish viral vaccines, these results highlight the important contribution of RBCs to the fish innate immune response to antiviral prophylactics.

The CORBEL matrix on informed consent in clinical studies: a multidisciplinary approach of Research Infrastructures Building Enduring Life-science Services

BACKGROUND

Informed consent forms for clinical research are several and variable at international, national and local levels. According to the literature, they are often unclear and poorly understood by participants. Within the H2020 project CORBEL-Coordinated Research Infrastructures Building Enduring Life-science Services-clinical researchers, researchers in ethical, social, and legal issues, experts in planning and management of clinical studies, clinicians, researchers in citizen involvement and public engagement worked together to provide a minimum set of requirements for informed consent in clinical studies.

METHODS

The template was based on a literature review including systematic reviews and guidelines searched on PubMed, Embase, Cochrane Library, NICE, SIGN, GIN, and Clearinghouse databases, and on comparison of templates gathered through an extensive search on the websites of research institutes, national and international agencies, and international initiatives. We discussed the draft versions step-by-step and then we referred to it as the "matrix" to underline its modular character and indicate that it allows adaptation to the context in which it will be used. The matrix was revised by representatives of two international patient groups.

RESULTS

The matrix covers the process of ensuring that the appropriate information, context and setting are provided so that the participant can give truly informed consent. It addresses the key topics and proposes wording on how to clarify the meaning of placebo and of non-inferiority studies, the importance of individual participants' data sharing, and the impossibility of knowing in advance how the data might be used in future studies. Finally, it presents general suggestions on wording, format, and length of the information sheet.

CONCLUSIONS

The matrix underlines the importance of improving the process of communication, its proper conditions (space, time, setting), and addresses the participants' lack of knowledge on how clinical research is conducted. It can be easily applied to a specific setting and could be a useful tool to identify the appropriate informed consent format for any study. The matrix is mainly intended to support multicentre interventional randomized clinical studies, but several suggestions also apply to non-interventional research.

Reasonable expectations of privacy in non-disclosure of familial genetic risk: What is it reasonable to expect?

Where there is conflict between a patient's interests in non-disclosure of their genetic information to relatives and the relative's interest in knowing the information because it indicates their genetic risk, clinicians have customarily been able to protect themselves against legal action by maintaining confidence even if, professionally, they did not consider this to be the right thing to do. In ABC v St Georges Healthcare NHS Trust ([2017] EWCA Civ 336) the healthcare team recorded their concern about the wisdom of the patient's decision to withhold genetic risk information from his relative, but chose to respect what they considered to be an unwise choice. Even though professional guidance considers that clinicians have the discretion to breach confidence where they believe this to be justified, (Royal College of Physicians, Royal College of Pathologists and the British Society of Human Genetics, 2006; GMC, 2017) clinicians find it difficult to exercise this discretion in line with their convictions against the backdrop of the legal prioritisation of the duty to maintain confidence. Thus, the professional discretion is not being freely exercised because of doubts about the legal protection available in the event of disclosure. The reliance on consent as the legal basis for setting aside the duty of confidence often vetoes sharing information with relatives. This paper argues that an objective approach based on privacy, rather than a subjective consent-based approach, would give greater freedom to clinicians to exercise the discretion which their professional guidance affords.

The impact of the General Data Protection Regulation on health research

BACKGROUND

On the May 25, 2018 the General Data Protection Regulation (hereafter the GDPR or the Regulation) came into force, replacing the Data Protection Directive 95/46/EC (upon which the Data Protection Act 1998 is based), and imposing new responsibilities on organizations which process the data of European Union citizens.

SOURCES OF DATA

This piece examines the impact of the Regulation on health research.

AREAS OF AGREEMENT

The Regulation seeks to harmonize data privacy laws across Europe, to protect and empower all EU citizen's data privacy and to reshape the way that organizations approach data privacy (See the GDPR portal at: https://www.eugdpr.org/ (accessed 8 May 2018). As a Regulation the GDPR is directly applicable in all member states as opposed to a directive which requires national implementing measures (In the UK the Data Protection Act 1998 was the implementing legislation for the Data Protection Directive 95/46/EC.).

AREAS OF CONTROVERSY

The Regulation is sector wide, but its impact on organizations us sector specific. In some sectors, the Regulation inhibits the processing of personal data, whilst in others it enables that processing. The Regulation takes the position that the 'processing of data should be designed to serve mankind' (Recital 4). Whilst it does not spell out what exactly is meant by this, it indicates that a proportionate approach will be taken to the protection of personal data, where that data can be processed for common goods such as healthcare. Thus, the protection of personal data is not absolute, but considered in relation to its function in society and balance with other fundamental rights in accordance with the principle of proportionality (Recital 4). Differing interpretations of proportionality can detract from the harmonization objective of the Regulation.

GROWING POINTS

Reflecting the commitment to proportionality, scientific research holds a privileged position in the Regulation. Throughout the Regulation provision is made for organizations that process personal data for scientific research purposes to avoid restrictive measures which might impede the increase of knowledge. However, the application of the Regulation differs across health research sectors and across jurisdictions. Transparency and engagement across the health research sector is required to promote alignment.

AREAS TIMELY FOR DEVELOPING RESEARCH

Research which focuses on the particular problems which arise in the context of the regulation's application to health research would be welcome. Particularly in the context of the operation of the Regulation alongside the duty of confidentiality and the variation in approaches across Member States.

Using and Disclosing Confidential Patient Information and The English Common Law: What are the Information Requirements of a Valid Consent?

The National Health Service in England and Wales is dependent upon the flow of confidential patient data. In the context of consent to the use of patient health data, insistence on the requirements of an 'informed' consent that are difficult to achieve will drive reliance on alternatives to consent. Here we argue that one can obtain a valid consent to the disclosure of confidential patient data, such that this disclosure would not amount to a breach of the common law duty of confidentiality, having provided less information than would typically be associated with an 'informed consent'. This position protects consent as a practicable legal basis for disclosure from debilitating uncertainty or impracticability and, perhaps counter-intuitively, promotes patient autonomy.

Exploring the potential duty of care in clinical genomics under UK law

Genome-wide sequencing technologies are beginning to be used in projects that have both clinical diagnostic and research components. The clinical application of this technology, which generates a huge amount of information of varying diagnostic certainty, involves addressing a number of challenges to establish appropriate standards. In this article, we explore the way that UK law may respond to three of these key challenges and could establish new legal duties in relation to feedback of findings that are unrelated to the presenting condition (secondary, additional or incidental findings); duties towards genetic relatives as well as the patient and duties on the part of researchers and professionals who do not have direct contact with patients. When considering these issues, the courts will take account of European and international comparisons, developing guidance and relevant ethical, social and policy factors. The UK courts will also be strongly influenced by precedent set in case law.

Non-disclosure of genetic risks: The case for developing legal wrongs

In ABC v. St Georges Healthcare NHS Trust, the High Court of England and Wales rejected the argument that doctors have a legal duty to disclose actionable genetic risks to a patient’s relatives. This article reconsiders the concept of a duty to disclose actionable genetic risks in the context of widening perceptions of legal harm and developing professional and public perceptions of corresponding wrongs.

Development of new therapeutical/adjuvant molecules by pepscan mapping of autophagy and IFN inducing determinants of rhabdoviral G proteins

Surface glycoproteins of enveloped virus are potent elicitors of both innate and adaptive host immune responses. Therefore, the identification of viral glycoprotein determinants directly implicated in the induction of these responses might be of special interest for designing new therapeutical/adjuvant molecules. In this work we review the contribution of the "pepscan" approach to the screening of viral functions in the sequence of glycoprotein G (gpG) of the fish rhabdovirus of viral hemorrhagic septicemia (VHSV). Among others, by scanning gpG peptides, it has been possible to identify and validate minimal determinants for gpG directly implicated in initiating the fish type I Interferon-associated immune responses as well as in the antiviral autophagy program. Further fine-tunning of the identified peptides in the gpG of VHSV has allowed designing novel adjuvants that decrease DNA vaccine requirements and identify possible innovative antiviral molecules. In addition, these results have also contributed to improve our knowledge on how to stimulate the fish immune system.

Attitudes towards the sharing of genetic information with at-risk relatives: results of a quantitative survey

To investigate public attitudes towards receiving genetic information arising from a test on a relative, 955 University of Sheffield students and staff were surveyed using disease vignettes. Strength of attitude was measured on whether, in the event of relevant information being discovered, they, as an at-risk relative, would want to be informed, whether the at-risk relative's interest should override proband confidentiality, and, if they had been the proband, willingness to give up confidentiality to inform such relatives. Results indicated considerably more complexity to the decision-making than simple statistical risk. Desire for information only slightly increased with risk of disease manifestation [log odds 0.05 (0.04, 0.06) per percentage point increase in manifestation risk]. Condition preventability was the primary factor increasing desire [modifiable baseline, non-preventable log odds -1.74 (-2.04, -1.44); preventable 0.64 (0.34, 0.95)]. Disease seriousness also increased desire [serious baseline, non-serious log odds -0.89 (-1.19, -0.59); fatal 0.55 (0.25, 0.86)]. Individuals with lower education levels exhibited much greater desire to be informed [GCSE log odds 1.67 (0.64, 2.66)]. Age did not affect desire. Our findings suggest that attitudes were influenced more by disease characteristics than statistical risk. Respondents generally expressed strong attitudes demonstrating that this was not an issue which people felt ambivalent about. We provide estimates of the British population in favour/against disclosure for various disease scenarios.

VHSV G glycoprotein major determinants implicated in triggering the host type I IFN antiviral response as DNA vaccine molecular adjuvants

We have recently identified the two major determinants of the glycoprotein G of the viral hemorrhagic septicaemia rhabdovirus (gpGVHSV), peptides p31 and p33 implicated in triggering the host type I IFN antiviral response associated to these rhabdoviral antigens. With the aim to investigate the properties of these viral glycoprotein regions as DNA molecular adjuvants, their corresponding cDNA sequences were cloned into a plasmid (pMCV1.4) flanked by the signal peptide and transmembrane sequences of gpGVHSV. In addition, a plasmid construct encoding both sequences p31 and p33 (pMCV1.4-p31+p33) was also designed. In vitro transitory cell transfection assays showed that these VHSV gpG regions were able to induce the expression of type I IFN stimulated genes as well as to confer resistance to the infection with a different fish rhabdovirus, the spring viremia of carp virus (SVCV). In vivo, zebrafish intramuscular injection of only 1μg of the construct pMCV1.4-p31+p33 conferred fish protection against SVCV lethal challenge up to 45 days post-immunization. Moreover, pMCV1.4-p31+p33 construct was assayed for molecular adjuvantcity's for a DNA vaccine against SVCV based in the surface antigen of this virus (pAE6-GSVCV). The results showed that the co-injection of the SVCV DNA vaccine and the molecular adjuvant allowed (i) a ten-fold reduction in the dose of pAE6-Gsvcv without compromising its efficacy (ii) an increase in the duration of protection, and (iii) an increase in the survival rate. To our knowledge, this is the first report in which specific IFN-inducing regions from a viral gpG are used to design more-efficient and cost-effective viral vaccines, as well as to improve our knowledge on how to stimulate the innate immune system.

Ex vivo transfection of trout pronephros leukocytes, a model for cell culture screening of fish DNA vaccine candidates

DNA vaccination opened a new era in controlling and preventing viral diseases since DNA vaccines have shown to be very efficacious where some conventional vaccines have failed, as it occurs in the case of the vaccines against fish novirhabdoviruses. However, there is a big lack of in vitro model assays with immune-related cells for preliminary screening of in vivo DNA vaccine candidates. In an attempt to solve this problem, rainbow trout pronephros cells in early primary culture were transfected with two plasmid DNA constructions, one encoding the green fluorescent protein (GFP) and another encoding the viral haemorrhagic septicaemia virus (VHSV) glycoprotein G (G(VHSV)) - the only viral antigen which has conferred in vivo protection. After assessing the presence of GFP- and G(VHSV)-expressing cells, at transcription and protein levels, the immune response in transfected pronephros cells was evaluated. At 24h post-transfection, G(VHSV) up-regulated migm and tcr transcripts expression, suggesting activation of B and T cells, as well, a high up-regulation of tnfα gene was observed. Seventy-two hours post-transfection, we detected the up-regulation of mx and tnfα genes transcripts and Mx protein which correlated with the induction of an anti-VHSV state. All together we have gathered evidence for successful transfection of pronephros cells with pAE6G, which correlates with in vivo protection results, and is less time-consuming and more rapid than in vivo assays. Therefore, this outcome opens the possibility to use pronephros cells in early primary culture for preliminary screening fish DNA vaccines as well as to further investigate the function that these cells perform in fish immune response orchestration after DNA immunisation.

In vitro analysis of the factors contributing to the antiviral state induced by a plasmid encoding the viral haemorrhagic septicaemia virus glycoprotein G in transfected trout cells

We have found out that transfection of the RTG-2 cell line with the viral haemorrhagic septicaemia virus (VHSV) glycoprotein G (G(VHSV))-coding plasmid induces an anti-VHSV state, similar to that induced by poly I:C. Taking the advantage of the constitutive expression of toll-like receptor 9 gene (tlr9) in RTG-2 cells, we have investigated whether this antiviral state was induced by the cytosine-phosphodiester-guanine (CpG) motifs present in the plasmid DNA, by the endogenous expression of G(VHSV) protein or by both elements. For that, we have analysed the expression profile of the rainbow trout tlr9 and several genes related to TLR9-mediated immune response in the absence or presence of a lysosomotropic drug that specifically blocks TLR9-CpG DNA interaction. The results suggested that the high levels of cell protection conferred by a plasmid encoding G(VHSV) gene are due to G(VHSV) rather than to the CpG motifs within plasmid DNA. Therefore, plasmid DNA might not play a key role in the immune response elicited by DNA vaccines or perhaps other receptors instead TLR9 could be implicated in CpG motifs recognition and signalling. In addition, since RTG-2 cells express tlr9 gene, this cell line could be a good tool for screening TLR9 agonists, such as the immunomodulatory oligonucleotides (IMOs), as fish DNA vaccine adjuvants.

Antimicrobial peptides as model molecules for the development of novel antiviral agents in aquaculture

Antimicrobial peptides (AMPs) are one of the components of the non-specific immune system that operate first lines of protection in many animal species including fish. They exert broad-spectrum antimicrobial activity, apart from many other potential roles in innate immunity, and represent a promising class of antiviral agents. Recent advances in understanding the mechanisms of their antiviral action(s) indicate that they have a dual role in antiviral defence, acting not only directly on the virion but also on the host cell. Despite the acute problems of viral diseases and restrictions in using chemicals in aquaculture, few but successful attempts to assess the antiviral activities of fish AMPs have been reported. This review focuses on the antiviral activities and mechanisms of action of some AMPs, and their potential relevance in the aquaculture industry, one of the most important sources of fishery products in the near future. It is a matter of notable concern to understand whether the AMPs can be used as model molecules for designing antiviral drugs that might help to solve the problems with viruses in the fish farming industry worldwide. In addition, because fish rely more heavily on their innate immune defences than mammals, they might constitute a potential rich source of antiviral compounds for fighting against mammalian viral infections.

The rainbow trout TLR9 gene and its role in the immune responses elicited by a plasmid encoding the glycoprotein G of the viral haemorrhagic septicaemia rhabdovirus (VHSV)

The aim of this work was to improve the knowledge about the factors contributing to the immunogenicity of the DNA vaccines based on the viral haemorrhagic septicaemia virus glycoprotein G gene, through identifying the rainbow trout Toll-like receptor 9 (Omtlr9) gene that curiously contains an insertion of an incomplete transposon at the 5'-end of the third intron. Concerning the role played by this receptor in the fish innate defence, in response to the injection of a plasmid (pAE6) encoding or not the viral haemorrhagic septicaemia rhabdovirus (VHSV) glycoprotein G gene (pAE6-G), the presence of Omtlr9 transcripts remained unchanged in the fish secondary lymphoid organs while was highly increased at the injection site (muscle). The level of Omtlr9 transcripts correlated with those of cluster of differentiation 83 (cd83) and CXC chemokine receptor 4 (cxcr4), suggesting the recruitment of dendritic-like cells into the muscle as the source of Omtlr9 expressing cells. Transcription of tumour necrosis factor-alpha (tnf alpha) and interleukin-6 (il6) genes, two cytokines directly related to TLR9 induction with unmethylated CpG oligodeoxynucleotides (CpG ODNs), was solely observed in head kidney and spleen of the fish immunised with pAE6-G. Thus, the glycoprotein G of VHSV could be more implicated in triggering the pathways for TNF-alpha and IL6 production than the recognition of the unmethylated CpG motifs of the plasmid backbone by OmTLR9. Therefore, our results seem to indicate that OmTLR9-mediated recognition of plasmid DNA is not the key of the innate immune recognition of the adjuvant elements of fish DNA vaccines.

Expression and antiviral activity of a beta-defensin-like peptide identified in the rainbow trout (Oncorhynchus mykiss) EST sequences

The in silico identification of a beta-defensin-like peptide sequence (omBD-1) in the rainbow trout (Oncorhynchuss mykiss) database of salmonid EST is reported here. We have studied the transcript expression of this beta-defensin-like sequence in different organs and expressed the recombinant peptide in a fish cell line. Finally, we have demonstrated the in vitro antiviral activity of the recombinant trout beta-defensin-like peptide against viral haemorrhagic septicaemia rhabdovirus (VHSV), one of the most devastating viruses for worldwide aquaculture. Thus, the resistance to VHSV infection of EPC cells transfected with pMCV 1.4-omBD-1 has been shown. Since EPC cells transfected with omBD-1 produced acid and heat stable antiviral activity and up regulation of Mx, a type I IFN-mediated mechanism of antiviral action is suggested. To our knowledge, this is the first report showing biological activity of a beta-defensin-like peptide from any fish.

In vitro and in vivo differential expression of rainbow trout (Oncorhynchus mykiss) Mx isoforms in response to viral haemorrhagic septicaemia virus (VHSV) G gene, poly I:C and VHSV

Three different Mx isoforms are known to be present in rainbow trout, however, to date, neither their mechanism of action nor their regulation have been established. Because most previous studies have focused only on one Mx isoform of the three present in rainbow trout, the expression of all isoforms was simultaneously studied in this work in response to the viral haemorrhagic septicaemia virus (VHSV) G gene, poly I:C or VHSV. Thus, RT-PCR assays were specifically designed to amplify each of the Mx1, Mx2 and Mx3 transcripts induced both in vitro (RTG-2 cell line and head kidney leucocytes) and in vivo (muscle, head kidney, spleen and liver). Regardless of the inducer used, in vitro results showed that while in RTG-2 cells Mx3 was predominantly induced, all three isoforms were similarly induced in head kidney leukocytes. In vivo, regardless of the inducer used a predominant expression of Mx3 transcripts was also observed in muscle but expression of all three Mx isoforms or predominantly Mx1 and Mx2 was found in head kidney and spleen. Mx expression in the liver was however more dependent on the inducer used. In conclusion, the results obtained demonstrated, for the first time, that both in vitro and in vivo the expression of the different Mx genes is differentially regulated. Moreover, this is also the first report showing Mx induction after cell transfection with a plasmid coding for the VHSV-G protein.