Amino acid substitutions in the H5N1 avian influenza haemagglutinin alter pH of fusion and receptor binding to promote a highly pathogenic phenotype in chickens

Highly pathogenic H5N1 avian influenza viruses cause devastating outbreaks in farmed poultry with serious consequences for animal welfare and economic losses. Zoonotic infection of humans through close contact with H5N1 infected birds is often severe and fatal. England experienced an outbreak of H5N1 in turkeys in 1991 that led to thousands of farmed bird mortalities. Isolation of clonal populations of one such virus from this outbreak uncovered amino acid differences in the virus haemagglutinin (HA) gene whereby the different genotypes could be associated with distinct pathogenic outcomes in chickens; both low pathogenic (LP) and high pathogenic (HP) phenotypes could be observed despite all containing a multi-basic cleavage site (MBCS) in the HA gene. Using reverse genetics, three amino acid substitutions in HA were examined for their ability to affect pathogenesis in the chicken. Restoration of amino acid polymorphisms close to the receptor binding site that are commonly found in H5 viruses only partially improved viral fitness in vitro and in vivo. A third novel substitution in the fusion peptide, HA2G4R, enabled the HP phenotype. HA2G4R decreased the pH stability of HA and increased the pH of HA fusion. The substitutions close to the receptor binding site optimised receptor binding while modulating the pH of HA fusion. Importantly, this study revealed pathogenic determinants beyond the MBCS

Cooperation in wild Barbary macaques: factors affecting free partner choice

A key aspect of cooperation is partner choice: choosing the best available partner improves the chances of a successful cooperative interaction and decreases the likelihood of being exploited. However, in studies on cooperation subjects are rarely allowed to freely choose their partners. Group-living animals live in a complex social environment where they can choose among several social partners differing in, for example, sex, age, temperament, or dominance status. Our study investigated whether wild Barbary macaques succeed to cooperate using an experimental apparatus, and whether individual and social factors affect their choice of partners and the degree of cooperation. We used the string pulling task that requires two monkeys to manipulate simultaneously a rope in order to receive a food reward. The monkeys were free to interact with the apparatus or not and to choose their partner. The results showed that Barbary macaques are able to pair up with a partner to cooperate using the apparatus. High level of tolerance between monkeys was necessary for the initiation of successful cooperation, while strong social bond positively affected the maintenance of cooperative interactions. Dominance status, sex, age, and temperament of the subjects also affected their choice and performance. These factors thus need to be taken into account in cooperative experiment on animals. Tolerance between social partners is likely to be a prerequisite for the evolution of cooperation

Induction of broad immunity by thermostabilised vaccines incorporated in dissolvable microneedles using novel fabrication methods

Dissolvable microneedle (DMN) patches for immunization have multiple benefits, including vaccine stability and ease-of-use. However, conventional DMN fabrication methods have several drawbacks. Here we describe a novel, microfluidic, drop dispensing-based dissolvable microneedle production method that overcomes these issues. Uniquely, heterogeneous arrays, consisting of microneedles of diverse composition, can be easily produced on the same patch. Robustness of the process was demonstrated by incorporating and stabilizing adenovirus and MVA vaccines. Clinically-available trivalent inactivated influenza vaccine (TIV) in DMN patches is fully stable for greater than 6months at 40°C. Immunization using low dose TIV-loaded DMN patches induced significantly higher antibody responses compared to intramuscular-based immunization in mice. TIV-loaded patches also induced a broader, heterosubtypic neutralizing antibody response. By addressing issues that will be faced in large-scale fill-finish DMN fabrication processes and demonstrating superior thermostable characteristics and immunogenicity, this study progresses the translation of this microneedle platform to eventual clinical deployment

Improved adjuvanting of seasonal influenza vaccines: Pre-clinical studies of MVA-NP+M1 co-administration with inactivated influenza vaccine.

Licensed seasonal influenza vaccines induce antibody responses against influenza hemagglutinin that are limited in their ability to protect against different strains of influenza. Cytotoxic T lymphocytes (CTLs) recognizing the conserved internal nucleoprotein (NP) and matrix protein (M1) are capable of mediating a cross-subtype immune response against influenza. Modified vaccinia virus Ankara encoding NP and M1 (MVA-NP+M1) is designed to boost pre-existing T-cell responses in adults in order to elicit a cross-protective immune response. We examined the co-administration of hemagglutinin (HA) protein formulations and candidate MVA-NP+M1 influenza vaccines in murine, avian, and swine models. Antibody responses post-immunization were measured by ELISA and pseudotype neutralization assays. Here we demonstrate that MVA-NP+M1 can act as an adjuvant enhancing antibody (Ab) responses to HA while simultaneously inducing potent T-cell responses to conserved internal antigens. We show that this regimen leads to the induction of cytophilic Ab isotypes that are capable of inhibiting hemagglutination and in the context of H5 exhibit cross-clade neutralization. The simultaneous induction of T cells and antibody responses has the potential to improve seasonal vaccine performance and could be employed in pandemic situations

An Exploratory Study of Emotional Dysregulation Dimensions in Youth With Attention Deficit Hyperactivity Disorder and/or Bipolar Spectrum Disorders

Emotional dysregulation (ED) is currently the most frequently used term to describe children with an impaired regulation of emotional states. Recent research studies speculate whether ED may be a neurodevelopmental disorder itself, a shared risk factor, or a common key feature of several psychiatric disorders, including, among others, attention deficit hyperactivity disorder (ADHD), and bipolar spectrum disorders (BSD). The association between ADHD and ED is one of the main reasons of misconceptions in the definition of boundaries between ADHD and BSD, leading to the frequent misdiagnosis of ADHD as BSD. Since ED is a multidimensional concept, a novel instrument—the Reactivity, Intensity, Polarity and Stability (RIPoSt) scale—was recently developed to assess the different dimensions of ED, which could help in detecting specific ED profiles in clinical youths. Our study included 154 patients, aged 13.8 ± 2.3 years, diagnosed with either ADHD, BSD, or comorbid condition, and a school-based sample of 40 healthy control (HC) adolescents, aged 12.5 ± 1.2 years. The RIPoSt scale and the Child Behavior Checklist were administered to both groups. Our results indicate that affective instability and negative emotionality subscales, as well as negative emotional dysregulation, are higher in BSD, both pure and comorbid with ADHD, while emotional impulsivity is higher in the comorbid condition and similar in the ADHD and BSD alone group; all clinical groups scored higher than HC. Conversely, positive emotionality is similar among clinical groups and within them and HC. Our findings also support the validity of the RIPoSt questionnaire, since the instrument proved to have good-to-excellent internal consistency, and strongly significant positive correlations were found with the CBCL-Dysregulation Profile, which is a commonly used, indirect measure of ED. Hence, the five subscales of the RIPoSt can be reliably used as an effective tool to study the emotional dysregulation in different clinical conditions, to help disentangle the complex relationship between ADHD and juvenile BSD and to provide clinicians with crucial evidence for better diagnostic characterization and therapeutic indications

Adjuvant-free immunization with hemagglutinin-Fc fusion proteins as an approach to influenza vaccines

The hemagglutinins (HAs) of human H1 and H3 influenza viruses and avian H5 influenza virus were produced as recombinant fusion proteins with the human immunoglobulin Fc domain. Recombinant HA-human immunoglobulin Fc domain (HA-HuFc) proteins were secreted from baculovirus-infected insect cells as glycosylated oligomer HAs of the anticipated molecular mass, agglutinated red blood cells, were purified on protein A, and were used to immunize mice in the absence of adjuvant. Immunogenicity was demonstrated for all subtypes, with the serum samples demonstrating subtype-specific hemagglutination inhibition, epitope specificity similar to that seen with virus infection, and neutralization. HuFc-tagged HAs are potential candidates for gene-to-vaccine approaches to influenza vaccination

The application of pseudotypes to Influenza pandemic preparedness

Human and animal populations are constantly exposed to multiple influenza strains due to zoonotic spillover and rapid viral evolution driven by intrinsic error­prone replication and immunological pressure. In this context, antibody responses directed against the haemagglutinin protein on the surface of the virus are of importance since they have been shown to correlate with protective immunity. Serological techniques, detecting these responses, play a critical role in influenza pandemic preparedness in particular with regards to the measurement of vaccine immunogenicity. As the recent human pandemics (H1N1) and avian influenza outbreaks (H5 and H7) have demonstrated, there is an urgent need to be better prepared to assess the contribution of the antibody response to protection against newly emerged viruses and to evaluate the extent of pre-existing hetero-subtypic immunity in populations. This review compares pseudotype-based assays with wildtype and VLP virus assays and discusses their place in the pandemic preparedness against the influenza virus. It additionally addresses the state of the art developments of pseudotype-based assays (chimeric haemagglutinins, multiplex and post-attachment) including the development and future deployment of assay kits and approaches towards standardization to both pre-clinical and clinical endpoints. Progress towards the development of an influenza pseudotype library for the purposes of pandemic preparedness is also outlined and discussed