Contribution of the genetic background to the immune response of broilers vaccinated or challenged with LPAI H9N2

<p>Abstract</p> <p>Background</p> <p>The knowledge on the immune responses to LPAI is limited. The purpose of this study was to investigate the immune responses of two divergently selected lines of broilers, a line responding with high antibody response to antigens (HH), and a line responding with low antibody titers (LL) to antigen.</p> <p>Methods</p> <p>Day old chicks from each line were divided in two groups, one vaccinated with inactivated H9N2 vaccine and one non-vaccinated. At 21 days of age all the chicks were challenged with field isolate of H9N2, 1X10^6.5 ELD₅₀ per chick by drops to the eye, nose and beak. Twenty four hours and 14 days post challenge (PC), the chickens were weighed blood spleen and lungs were taken and leukocytes were isolated. The leukocytes were stained with monoclonal antibodies for surface markers and analyzed by flow cytometry. We used Elispot assay to identify the number of antibody producing cells in each of the organs. mRNA was extracted using TRIsol reagent in order to assess the cytokine production level by qRT-PCR using the SYBR green methods.</p> <p>Results</p> <p>Our results showed that LL-vaccinated group gained more weight than any of the other group. Using IDEXX kit, no antibody titers could be identified in vaccinated chicks 21 days post vaccination while 14 days PC vaccinated HH chickens demonstrated the highest average antibody titers. LL vaccinated chickens demonstrated higher average antibody titer than non-vaccinated LL. Using the Elispot assay no difference were found between the groups either cells producing IgA, IgM or IgY beside of a high number of IgY producing cells in the lungs of vaccinated HH birds.</p> <p>Conclusions</p> <p>Further data on leukocytes subpopulations using flow cytometry, cytokines production (IFNγ, IL-6, IL-18, IL-2 and IL-4) isotype specific antibody responses and number and functionality of NK cells are in process.</p

The FLY-project: study protocol for mixed methods research to explore the complex social dynamics of sustainable food-related lifestyles in youth in practical education

Background: The present-day food system is a key driver of climate change and biodiversity loss, making it imperative for populations to shift towards more sustainable diets. The involvement of youth in this transition is vital because they are in a formative period where their identities, values, and norms, including their food behaviours, are being shaped. Special attention should be paid to youth in practical education because they are often overlooked in existing studies, yet evidence suggests they may lack the necessary resources to support dietary changes, resulting in lower levels of pro-environmental food-related behaviours. The aim of the FLY (Food-related Lifestyles in Youth) project is to study how sustainable food-related lifestyles and underlying factors develop in early adolescence, particularly in Dutch youth in practical education, how these spread in social networks, and to develop community-level intervention strategies to support youths’ transition to sustainable food-related behaviours. Methods/design: The FLY-project adopts a mixed-method approach. First, two literature reviews are conducted. A systematic review assesses how capabilities, opportunities and motivation are associated with sustainable food behaviours in youth, and how these elements interrelate in determining sustainable food-related lifestyles. A scoping review studies community-level interventions that target sustainable and healthy food-related behaviours. Second, focus groups are conducted to explore the barriers and facilitating factors concerning capabilities, opportunities, and motivations that Dutch youth in practical-level education experience to transition to more sustainable food-related lifestyles. Third, a cohort survey study is conducted to track the dynamic interplay between capabilities, opportunities, motivation, and changes in specific sustainable food behaviours over time, and to assess the diffusion of sustainable food-related lifestyles via social (media) networks. Fourth, an experimental research programme tests promising intervention approaches, some of which are co-created with youth, targeting relevant underlying factors. Discussion: This paper describes the rationale, conceptual framework, design and methods of the FLY-project. The FLY-project contributes to an understanding of underlying factors of sustainable food-related behaviours in adolescence and results in a multi-component intervention toolkit, with a particular focus on youth in practical education programmes

Reduced immune reaction prevents immunopathology after challenge with avian influenza virus: A transcriptomics analysis of adjuvanted vaccines

To gain more insight in underlying mechanisms correlating to protection against avian influenza virus (AIV) infection, we investigated correlates of protection after AIV H9N2 infection and studied the contribution of different adjuvants to a protective response at host transcriptional level. One-day-old chickens were immunised with inactivated H9N2 supplemented with w/o, Al(OH)3, CpG or without adjuvant. Two weeks later, birds were homologously challenged and at 1-4 days post challenge (d.p.c.) trachea and lung were collected. Birds immunised with H9N2+w/o or H9N2+Al(OH)3 were protected against challenge infection and had lower viral RNA expression, less immune related genes induced after challenge, a lower amplitude of change of gene expression and smaller cellular influxes compared to the higher and prolonged gene expression in unprotected birds. We show that a limited number of differentially expressed genes correlates with reduced immune activation and subsequently reduced immunopathology after challenge with AIV

Identification of new populations of chicken natural killer (NK) cells

Natural killer (NK) cell activity is conserved throughout vertebrate development, but characterization of non-mammalian NK-cells has been hampered by the absence of specific mAbs for these cells.Monoclonal antibodies were generated against in vitro IL-2 expanded sorted CD3-CD8α+ peripheral blood lymphocytes, previously described to contain chicken NK-cells. Screening of embryonic and adult splenocytes with hybridoma supernatants resulted in five candidate NK markers.Activation of chicken NK-cells with PMA/Ionomycin or with the NK target cell-line LSCC-RP9 resulted in increased expression of CD107 (LAMP-1) and a newly developed flow cytometry based cytotoxicity assay showed that NK-cells were able to kill target cells. Combining NK markers with functional assays indicated that marker positive cells showed NK-cell function.In conclusion, we generated new monoclonal antibodies and developed two functional assays which will enhance our understanding of the role of NK-cells in healthy and diseased chickens

The Price of Land and the Process of Expropriation

This paper applies a game theoretic model to situations in which the Dutch government expropriates land from some farmers in order to create a new public project. The model is a version of a finite period bargaining model with asymmetric information and one-sided offers. It is shown that the model can explain some casual observations as the fact that usually, but not always, the government and the farmers settle by agreement

Role of eHealth application Oncokompas in supporting self-management of symptoms and health-related quality of life in cancer survivors:a randomised, controlled trial

Background Knowledge about the efficacy of behavioural intervention technologies that can be used by cancer survivors independently from a health-care provider is scarce. We aimed to assess the efficacy, reach, and usage of Oncokompas, a web-based eHealth application that supports survivors in self-management by monitoring health-related quality of life (HRQOL) and cancer-generic and tumour-specific symptoms and obtaining tailored feedback with a personalised overview of supportive care options. Methods In this non-blinded, randomised, controlled trial, we recruited patients treated at 14 hospitals in the Netherlands for head and neck cancer, colorectal cancer, breast cancer, Hodgkin lymphoma, or non-Hodgkin lymphoma. Adult survivors (aged ≥18 years) were recruited through the Netherlands Cancer Registry (NCR) and invited by their treating physician through the Patient Reported Outcomes Following Initial Treatment and Long term Evaluation of Survivorship (PROFILES) registry. Participants were randomly assigned (1:1) by an independent researcher to the intervention group (access to Oncokompas) or control group (access to Oncokompas after 6 months), by use of block randomisation (block length of 68), stratified by tumour type. The primary outcome was patient activation (knowledge, skills, and confidence for self-management), assessed at baseline, post-intervention, and 3-month and 6-month follow-up. Linear mixed models (intention-to-treat) were used to assess group differences over time from baseline to 6-month follow-up. The trial is registered in the Netherlands Trial Register, NTR5774 and is completed. Findings Between Oct 12, 2016, and May 24, 2018, 625 (21%) of 2953 survivors assessed for eligibility were recruited and randomly assigned to the intervention (320) or control group (305). Median follow-up was 6 months (IQR 6−6). Patient activation was not significantly different between intervention and control group over time (difference at 6-month follow-up 1·7 [95% CI −0·8–4·1], p=0·41). Interpretation Oncokompas did not improve the amount of knowledge, skills, and confidence for self-management in cancer survivors. This study contributes to the evidence for the development of tailored strategies for development and implementation of behavioural intervention technologies among cancer survivors

Highly pathogenic avian influenza virus infection in chickens but not ducks is associated with elevated host immune and pro-inflammatory responses

Highly pathogenic avian influenza (HPAI) H5N1 viruses cause severe infection in chickens at near complete mortality, but corresponding infection in ducks is typically mild or asymptomatic. To understand the underlying molecular differences in host response, primary chicken and duck lung cells, infected with two HPAI H5N1 viruses and a low pathogenicity avian influenza (LPAI) H2N3 virus, were subjected to RNA expression profiling. Chicken cells but not duck cells showed highly elevated immune and pro-inflammatory responses following HPAI virus infection. HPAI H5N1 virus challenge studies in chickens and ducks corroborated the in vitro findings. To try to determine the underlying mechanisms, we investigated the role of signal transducer and activator of transcription-3 (STAT-3) in mediating pro-inflammatory response to HPAIV infection in chicken and duck cells. We found that STAT-3 expression was down-regulated in chickens but was up-regulated or unaffected in ducks in vitro and in vivo following H5N1 virus infection. Low basal STAT-3 expression in chicken cells was completely inhibited by H5N1 virus infection. By contrast, constitutively active STAT-3 detected in duck cells was unaffected by H5N1 virus infection. Transient constitutively-active STAT-3 transfection in chicken cells significantly reduced pro-inflammatory response to H5N1 virus infection; on the other hand, chemical inhibition of STAT-3 activation in duck cells increased pro-inflammatory gene expression following H5N1 virus infection. Collectively, we propose that elevated pro-inflammatory response in chickens is a major pathogenicity factor of HPAI H5N1 virus infection, mediated in part by the inhibition of STAT-3

Identification of Novel Avian Influenza Virus Derived CD8+ T-Cell Epitopes

Avian influenza virus (AIV) infection is a continuing threat to both humans and poultry. Influenza virus specific CD8+ T cells are associated with protection against homologous and heterologous influenza strains. In contrast to what has been described for humans and mice, knowledge on epitope-specific CD8+ T cells in chickens is limited. Therefore, we set out to identify AIV-specific CD8+ T-cell epitopes. Epitope predictions based on anchor residues resulted in 33 candidate epitopes. MHC I inbred chickens were infected with a low pathogenic AIV strain and sacrificed at 5, 7, 10 and 14 days post infection (dpi). Lymphocytes isolated from lung, spleen and blood were stimulated ex vivo with AIV-specific pooled or individual peptides and the production of IFNγ was determined by ELIspot. This resulted in the identification of 12 MHC B12-restricted, 3 B4-restricted and 1 B19-restricted AIV- specific CD8+ T-cell epitopes. In conclusion, we have identified novel AIV-derived CD8+ T-cell epitopes for several inbred chicken strains. This knowledge can be used to study the role of CD8+ T cells against AIV infection in a natural host for influenza, and may be important for vaccine development

Thrombus Migration Paradox in Patients With Acute Ischemic Stroke

Background and Purpose- The location of the thrombus as observed on first digital subtraction angiography during endovascular treatment may differ from the initial observation on initial noninvasive imaging. We studied the incidence of thrombus dynamics, its impact on patient outcomes, and its association with intravenous thrombolytics. Methods- We included patients from the MR CLEAN registry (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke) with an initial target occlusion on computed tomography angiography located in the intracranial internal carotid artery, M1, or M2. The conventional angiography target occlusion was defined during endovascular treatment. Thrombus dynamics were classified as growth, stability, migration, and resolution. The primary outcome was functional outcome at 90 days (modified Rankin Scale). The secondary outcomes were successful and complete reperfusion (extended treatment in cerebral infarction scores of 2b-3 and 3, respectively). Results- The analysis included 1349 patients. Thrombus migration occurred in 302 (22%) patients, thrombus growth in 87 (6%), and thrombus resolution in 39 (3%). Intravenous treatment with alteplase was associated with more thrombus migration (adjusted odds ratio, 2.01; CI, 1.29-3.11) and thrombus resolution (adjusted odds ratio, 1.85; CI, 1.22-2.80). Thrombus migration was associated with a lower chance of complete reperfusion (adjusted odds ratio, 0.57; CI, 0.42-0.78) and successful reperfusion (adjusted odds ratio, 0.74; CI, 0.55-0.99). In the subgroup of patients with M1 initial target occlusion, thrombus migration was associated with better functional outcome (adjusted common odds ratio, 1.49; CI, 1.02-2.17), and there was a trend towards better functional outcome in patients with thrombus resolution (adjusted common odds ratio, 2.23; CI, 0.93-5.37). Conclusions- In patients with acute ischemic stroke, thrombus location regularly changes between computed tomography angiography and digital subtraction angiography. Administration of intravenous alteplase increases the chance of thrombus migration and resolution. Thrombus migration is associated with better functional outcome but reduces the rate of complete reperfusion

The role of type I interferons (IFNs) in the regulation of chicken macrophage inflammatory response to bacterial challenge

International audienceMammalian type I interferons (IFNα/β) are known to modulate inflammatory processes in addition to their antiviral properties. Indeed, virus-induced type I interferons regulate the mammalian phagocyte immune response to bacteria during superinfections. However, it remains unresolved whether type I IFNs similarly impact the chicken macrophage immune response. We first evidenced that IFNα and IFNβ act differently in terms of gene expression stimulation and activation of intracellular signaling pathways in chicken macrophages. Next, we showed that priming of chicken macrophages with IFNα increased bacteria uptake, boosted bacterial-induced ROS/NO production and led to an increased transcriptional expression or production of NOS2/NO, IL1B/IL-1β and notably IFNB/IFNβ. Neutralization of IFNβ during bacterial challenge limited IFNα-induced augmentation of the pro-inflammatory response. In conclusion, we demonstrated that type I IFNs differently regulate chicken macrophage functions and drive a pro-inflammatory response to bacterial challenge. These findings shed light on the diverse functions of type I IFNs in chicken macrophages