Wildlife health surveillance: gaps, needs and opportunities.

Disease emergence represents a global threat to public health, economy and biological conservation. Most emerging zoonotic diseases have an animal origin, most commonly from wildlife. To prevent their spread and to support the implementation of control measures, disease surveillance and reporting systems are needed, and due to globalisation, these activities should be carried out at the global level. To define the main gaps affecting the performance of wildlife health surveillance and reporting systems globally, the authors analysed data from a questionnaire sent to National Focal Points of the World Organisation for Animal Health that inquired on structure and limits of wildlife surveillance and reporting systems in their territories. Responses from 103 Members, covering all areas of the globe, revealed that 54.4% have a wildlife disease surveillance programme and 66% have implemented a strategy to manage disease spread. The lack of dedicated budget affected the possibility of outbreak investigations, sample collection and diagnostic testing. Although most Members maintain records relating to wildlife mortality or morbidity events in centralised databases, data analysis and disease risk assessment are reported as priority needs. The authors' evaluation of surveillance capacity found an overall low level, with marked variability among Members that was not restricted to a specific geographical area. Increased wildlife disease surveillance globally would help in understanding and managing risks to animal and public health. Moreover, consideration of the influence of socio-economic, cultural and biodiversity aspects could improve disease surveillance under a One Health approach.

L'émergence de maladies représente une menace pour la santé publique, l'économie et la conservation de la biodiversité au niveau mondial. La plupart des maladies émergentes sont d'origine animale et proviennent de la faune sauvage. Afin de prévenir leur propagation et de soutenir la mise en oeuvre de mesures de contrôle, une surveillance des maladies et des systèmes de notification sont nécessaires - et ce à l'échelle internationale, en raison de la mondialisation. En vue de définir les lacunes principales affectant les performances de la surveillance et de la notification sanitaire relative à la faune sauvage au niveau mondial, les auteurs ont analysé les données d'un questionnaire envoyé aux Points focaux nationaux de l'Organisation mondiale de la santé animale et traitant de la structure et des limites des systèmes de surveillance et de notification applicables à la faune sauvage sur leur territoire. Selon les réponses des 103 Membres, qui représentaient toutes les régions du monde, 54,4 % disposent d'un programme de surveillance et 66 % ont mis en oeuvre une stratégie visant à gérer la propagation de maladies. L'absence de budgets dédiés affecte la possibilité d'enquêter sur l'apparition d'épidémies, de prélever des échantillons et d'effectuer des tests diagnostiques. Bien que la majorité des Membres consignent dans des bases de données centralisées les événements de mortalité et de morbidité affectant la faune sauvage, l'analyse des données et l'évaluation des risques sanitaires ont été mentionnées comme étant des besoins prioritaires. Les auteurs ont évalué les capacités de surveillance qui se situent, selon eux, à un niveau faible et se caractérisent par une grande variabilité entre les Membres, indépendamment des zones géographiques dont il s'agit. Une meilleure surveillance sanitaire de la faune sauvage au niveau mondial permettrait d'améliorer la compréhension et la gestion des risques pour la santé animale et publique. Par ailleurs, une réflexion sur l'influence des aspects socio-économiques, culturels et liés à la biodiversité améliorerait la surveillance sanitaire mise en place dans le cadre de l'approche Une seule santé.

La aparición de enfermedades representa una amenaza de dimensión mundial para la salud pública, la economía y la conservación de los recursos biológicos. La mayor parte de las enfermedades zoonóticas tienen un origen animal, por lo general localizado en la fauna silvestre. Para evitar que estas enfermedades se propaguen y apoyar la aplicación de medidas de lucha hacen falta sistemas de vigilancia y notificación de enfermedades, sistemas que, teniendo en cuenta las dinámicas de la mundialización, deben declinarse a escala planetaria. Con objeto de determinar las principales carencias que lastran el buen funcionamiento de los sistemas de vigilancia y notificación de enfermedades de la fauna silvestre a escala mundial, los autores analizaron datos extraídos de un cuestionario distribuido entre los puntos focales nacionales de la Organización Mundial de Sanidad Animal, en el cual se les preguntaba por la estructura y los límites que presentaban en su territorio dichos sistemas. Las respuestas recibidas de 103 Miembros de todas las zonas del globo pusieron de relieve que un 54,4% de ellos cuenta con un programa de vigilancia sanitaria de la fauna silvestre y que un 66% tiene implantada una estrategia para contener la propagación de enfermedades. La falta de un presupuesto asignado específicamente a estas tareas limita la posibilidad de investigar eventuales brotes, obtener muestras y practicar pruebas de diagnóstico. Aunque la mayoría de los Miembros lleva un registro de los episodios de mortalidad y morbilidad de animales salvajes en bases de datos centralizadas, el análisis de datos y la determinación del riesgo de enfermedad son dos de los aspectos mencionados como necesidad prioritaria. La evaluación de la capacidad de vigilancia realizada por los autores puso de manifiesto un nivel en general bajo, con una marcada heterogeneidad entre los Miembros que no se circunscribía a una zona geográfica en particular. Una mayor vigilancia de las enfermedades de la fauna silvestre a escala mundial ayudaría a aprehender y manejar mejor los riesgos que estas presentan para la sanidad animal y la salud pública. Además, el hecho de tener en cuenta la influencia de factores socioeconómicos, culturales y ligados a la diversidad biológica podría traducirse en una más eficaz vigilancia sanitaria en clave de Una sola salud.

Integration of wildlife and environmental health into a One Health approach.

Climate change, habitat fragmentation and pollution, and subsequent loss of biodiversity and degradation of natural environments, threaten the range of ecosystem services that support all life on this planet. These changes, among others, are also driving the emergence of infectious diseases, with negative health outcomes for humans, animals, and our shared environment. Historically, interventions aimed at human and agricultural health issues did not always integrate wildlife or environmental health as part of the solution, which has resulted in unintended consequences. One Health recognises the interdependence of humans, animals and their shared environment, and provides a conceptual framework for developing interventions that optimise outcomes for human, animal and environmental health. However, there is a need to clearly articulate the core values, goals, and objectives of One Health for all relevant sectors in order to maximise synergies for communication, coordination, collaboration and, ultimately, for joint actions on disease control and prevention. The application of systems and harm reduction approaches, focusing on the socio-economic and environmental determinants of health, and ensuring good governance and effective leadership will also maximise the opportunities to develop 'win-win-win' solutions to global health and environmental challenges. These solutions would help propel One Health forward to reach its full potential and truly optimise health outcomes for all.

Le changement climatique, la fragmentation et la pollution des habitats, parallèlement à la perte de biodiversité et à la dégradation du milieu naturel qui en résultent constituent une menace pour le large éventail de services écosystémiques dont dépend la vie sur cette planète. Ces changements, parmi d'autres, favorisent également l'émergence des maladies infectieuses, avec des effets négatifs sur la santé des humains, des animaux et de leur environnement commun. Par le passé, les interventions en matière de santé humaine, végétale et animale (ces deux dernières dans le cadre des productions agricoles) ne prenaient pas toujours en compte la santé de la faune sauvage ni celle de l'environnement, ni leur rôle en tant qu'elles font partie des solutions recherchées, omission qui a vite entraîné d'importants effets indésirables. La méthode Une seule santé tient compte de l'interdépendance entre les humains, les animaux et leur environnement commun et fournit un cadre conceptuel pour la conception d'interventions dont les résultats seront ainsi les meilleurs possibles pour la santé tant humaine qu'animale et environnementale. Toutefois, il est nécessaire d'articuler clairement les valeurs, les objectifs et les résultats essentiels recherchés via Une seule santé par chacun des secteurs concernés, afin de maximiser les synergies en termes de communication, de coordination, de collaboration et, en définitive, d'activités communes pour le contrôle et la prévention des maladies. L'application de systèmes et d'approches d'atténuation des risques, axés sur les déterminants socio-économiques et environnementaux de la santé, ainsi que l'exercice d'une bonne gouvernance et d'un leadership efficace sont également des facteurs qui contribueront favorablement à la conception de solutions « gagnant-gagnant ¼ afin de résoudre les défis sanitaires et environnementaux mondiaux. Ces solutions pourraient donner une forte impulsion à la démarche Une seule santé, lui permettant de réaliser tout son potentiel et d'optimiser les bénéfices pour la santé de tous.

El cambio climático, la fragmentación y contaminación de los hábitats y su corolario, la pérdida de diversidad biológica y la degradación del medio natural, ponen en peligro toda la panoplia de servicios ecosistémicos que sostienen la vida en nuestro planeta. Estos cambios, entre otros, también están induciendo la aparición de enfermedades infecciosas que repercuten negativamente en la salud de personas, animales y el medio ambiente común a todos. Tradicionalmente, las intervenciones destinadas a abordar problemas sanitarios o agrícolas no siempre integraban la sanidad de la fauna silvestre y la salud ambiental como parte de la solución, lo que a veces tenía consecuencias imprevistas. La noción de Una sola salud, fundada en la realidad de la dependencia recíproca entre personas, animales y el medio ambiente común a todos ellos, ofrece un marco teórico desde el cual definir intervenciones que optimicen los resultados para la salud humana, animal y ambiental. No obstante, es necesario formular claramente los valores, fines y objetivos fundamentales de Una sola salud para todos los sectores afectados con objeto de lograr la máxima sinergia posible en materia de comunicación, coordinación, colaboración y, a la postre, acción conjunta de control y prevención de enfermedades. La aplicación de métodos sistémicos y de reducción de daños, que estén centrados en los determinantes socioeconómicos y ambientales de la salud y aseguren una gobernanza adecuada y un liderazgo eficaz, también ofrecerá un máximo de posibilidades de dar con soluciones que sean beneficiosas en las tres vertientes a la vez para responder a los problemas sanitarios y ambientales del mundo. Estas soluciones ayudarían a conferir impulso a la noción de Una sola salud para así poder extraer de ella el máximo provecho y optimizar realmente los resultados sanitarios en todos los frentes.

Proposed attributes of national wildlife health programmes.

Wildlife health is important for conservation, healthy ecosystems, sustainable development and biosecurity. It presents unique challenges for national programme governance and delivery because wildlife health not only crosses jurisdictional responsibilities and authorities but also inherently spans multiple sectors of expertise. The World Organisation for Animal Health (OIE) encourages its Members to have wildlife disease monitoring and notification systems. Where national wildlife health surveillance programmes do exist, they vary in scope and size. Evidence-based guidance is lacking on the critical functions and roles needed to meet the OIE's recommendations and other expectations of a national programme. A literature review and consultation with national wildlife health programme leaders identified five key attributes of national programmes: 1) being knowledge and science based; 2) fostering cross-nation equivalence and harmonisation; 3) developing partnerships and national coordination; 4) providing leadership and administration of national efforts; and 5) capacity development. Proposed core purposes include: 1) establishment and communication of the national wildlife health status; 2) leading national planning; 3) centralising information and expertise; 4) developing national networks leading to harmonisation and collaborations; 5) developing wildlife health workforces; and 6) centralising administration and management of national programmes. A national wildlife health programme should aim to identify, effectively communicate and manage the risk to or from a country's wildlife populations. It should generate the appropriate knowledge required to improve the effectiveness of wildlife policies and systems, including identifying and assessing emerging priorities, thus facilitating early warning, preparedness and preventive actions.

La santé de la faune sauvage a un impact important sur la préservation des espèces et d'écosystèmes sains, sur le développement durable et sur la biosécurité. Les défis sont nombreux et complexes pour les programmes nationaux de gouvernance et de mise en oeuvre car les responsabilités et les compétences juridictionnelles sont croisées et les secteurs d'expertise sont multiples. L'Organisation mondiale de la santé animale (OIE) encourage ses Membres à mettre en place des systèmes de notification et de surveillance des maladies de la faune sauvage. Les programmes existants sont de tailles et de compétences variables et les orientations prises concernant les fonctions indispensables pour répondre aux recommandations de l'OIE et à ce qui est attendu d'un programme national ne sont pas toujours déterminées sur une base scientifique. Une revue de la littérature et des consultations auprès de responsables des programmes nationaux de santé de la faune sauvage ont permis d'identifier cinq attributs à proposer pour ces programmes nationaux. Ces programmes doivent :1) fonctionner sur la base de données scientifiques ; 2) favoriser l'équivalence et l'harmonisation transnationales ; 3) développer des partenariats et une coordination à l'échelle nationale ; 4) encadrer et administrer les efforts nationaux ; et 5) assurer le renforcement des capacités. Les missions essentielles sont : 1) déterminer et rendre publique la situation sanitaire de la faune sauvage dans le pays ; 2) encadrer le plan national ; 3) centraliser l'information et l'expertise ; 4) développer les réseaux nationaux d'harmonisation et de collaboration ; 5) former des personnels compétents dans le domaine de la faune sauvage ; et 6) centraliser l'administration et la gestion des programmes nationaux. Les objectifs d'un programme national de santé de la faune sauvage sont d'identifier, de rendre publics et de gérer les risques pour les populations d'animaux sauvages ainsi que les risques générés par ces mêmes populations. Ces programmes doivent promouvoir les connaissances nécessaires pour améliorer l'efficacité des politiques et des systèmes applicables à la faune sauvage, en particulier l'identification et l'évaluation des nouvelles priorités afin de faciliter la mise en oeuvre de systèmes d'alerte précoce, de préparation aux urgences et d'action préventive.

La salud de los animales silvestres, tan importante para la conservación del medio, el buen funcionamiento de los ecosistemas, el desarrollo sostenible y la seguridad biológica, presenta singulares dificultades desde el punto de vista de la gobernanza y aplicación de programas nacionales, dado que la fauna silvestre no solo toca a múltiples responsabilidades y atribuciones jurisdiccionales sino que, por su propia naturaleza, convoca a una plétora de especialidades técnicas. La Organización Mundial de Sanidad Animal (OIE) alienta a sus Miembros a que se doten de sistemas de vigilancia y notificación de enfermedades de la fauna silvestre. Allí donde existen, los programas nacionales en la materia son muy variopintos en cuanto a sus dimensiones y alcance. Faltan pautas científicamente sólidas sobre las funciones y atribuciones básicas que se requieren para cumplir las recomendaciones de la OIE y otras expectativas a las que pueda responder un programa nacional. Tras efectuar un estudio bibliográfico y consultar a los directivos de programas nacionales en la materia, los autores determinaron cinco atributos clave que debe reunir todo programa nacional: 1) estar basado en el saber y la ciencia; 2) favorecer la equivalencia y la armonización entre naciones; 3) crear alianzas y mecanismos de coordinación nacional; 4) encabezar y administrar las actividades a escala nacional; y 5) desarrollar los medios de acción del país. Los objetivos básicos propuestos son: 1) determinar y dar a conocer la situación sanitaria de la fauna silvestre del país; 2) dirigir las labores de planificación a escala nacional; 3) centralizar la información y las competencias especializadas; 4) instituir redes nacionales que propicien la armonización y las iniciativas de colaboración; 5) desarrollar los recursos humanos dedicados a la sanidad de la fauna silvestre; y 6) centralizar la gestión y administración de los programas nacionales. Todo programa nacional de sanidad de la fauna silvestre debe responder a la finalidad de detectar, comunicar eficazmente y gestionar los riesgos que amenacen a las poblaciones de animales silvestres del país o que provengan de ellas. A tal efecto debe generar el conocimiento adecuado y necesario para conferir más eficacia a las políticas y sistemas tocantes a la fauna silvestre, lo que supone, entre otras cosas, determinar y evaluar las nuevas prioridades, facilitando con ello la alerta anticipada y las labores de preparación y prevención.

Accumulation of small hyaluronan oligosaccharides in tumour interstitial fluid correlates with lymphatic invasion and lymph node metastasis.

BACKGROUND: Association studies have implicated the glycosaminoglycan hyaluronan (hyaluronic acid, HA) and its degrading enzymes the hyaluronidases in tumour progression and metastasis. Oligosaccharides of degraded HA have been ascribed a number of biological functions that are not exerted by high-molecular-weight HA (HMW-HA). However, whether these small HA oligosaccharides (sHA) have a role in tumour progression currently remains uncertain due to an inability to analyse their concentration in tumours. METHODS: We report a novel method to determine the concentration of sHA ranging from 6 to 25 disaccharides in tumour interstitial fluid (TIF). Levels of sHA were measured in TIF from experimental rat tumours and human colorectal tumours. RESULTS: While the majority of HA in TIF is HMW-HA, concentrations of sHA up to 6 µg ml(-1) were detected in a subset of tumours, but not in interstitial fluid from healthy tissues. In a cohort of 72 colorectal cancer patients we found that increased sHA concentrations in TIF are associated with lymphatic vessel invasion by tumour cells and the formation of lymph node metastasis. CONCLUSIONS: These data document for the first time the pathophysiological concentration of sHA in tumours, and provide evidence of a role for sHA in tumour progression.

Flow cytometry-based isolation of dermal lymphatic endothelial cells from newborn rats.

The lymphatic system plays a key role in tissue homeostasis, fatty acid transport, and immune surveillance. Pathologically, dysfunction of the lymphatic system results in edema, and increased lymphangiogenesis can contribute to tumor metastasis. Lymphatic vessels are composed of lymphatic endothelial cells (LECs) that can be identified by distinct marker molecules such as Prox-1, podoplanin, VEGFR-3 and LYVE-1. Primary LECs represent a valuable tool for the study of basic functions of the lymphatic system. However, their isolation remains a challenge, particularly if rodent tissues are used as a source. We developed a method for the isolation of rat dermal LECs from the skin of newborn rats based on sequential enzymatic digestion with trypsin and Liberase followed by flow cytometric sorting using LYVE-1 specific antibodies. Cells isolated according to this protocol expressed the lymphatic markers Prox-1, podoplanin, LYVE-1 and VEGFR-3, and displayed an endothelial-like morphology when taken into culture. These primary cells can be used for studying lymphatic biology in rat models, and the protocol we describe here therefore represents an important extension of the experimental repertoire available for rats and for modeling the human lymphatic system.

Mass spectrometry and EST-database searching allows characterization of the multi-protein spliceosome complex.

Many important cell mechanisms are carried out and regulated by multi-protein complexes, for example, transcription and RNA processing machinery, receptor complexes and cytoskeletal structures. Most of these complexes remain only partially characterized due to the difficulty of conventional protein analysis methods. The rapid expansion of DNA sequence databases now provides whole or partial gene sequences of model organisms, and recent advances in protein microcharacterization via mass spectrometry allow the possibility of linking these DNA sequences to the proteins in functional complexes. This approach has been demonstrated in organisms whose genomes have been sequenced, such as budding yeast. Here we report the first characterization of an entire mammalian multi-protein complex using these methods. The machinery that removes introns from mRNA precursors--the spliceosome--is a large multi-protein complex. Approximately half of the components excised from a two-dimensional gel separation of the spliceosome were found in protein sequence databases. Using nanoelectrospray mass spectrometry, the remainder were identified and cloned using public expressed sequence tag (EST) databases. Existing EST databases are thus already sufficiently complete to allow rapid characterization of large mammalian protein complexes via mass spectrometry.

Hyaluronate receptors: key players in growth, differentiation, migration and tumor progression.

Hyaluronate (HA) is an abundant component of extracellular matrix that is believed to be crucial in many cellular processes, including tissue remodeling, the creation of cell-free spaces, inflammation and tumorigenesis. Although several well characterized proteins within the extracellular matrix associate with HA, it is now clear that cells can also bind and respond to HA directly, via cell-surface HA-binding proteins. The cDNAs coding for two families of such proteins, CD44 and RHAMM, have been cloned and characterized. These proteins have been implicated in a number of physiological processes, including cell migration, lymphocyte activation and tumor progression. Although many of these processes depend on an association with HA, some are apparently HA-independent, suggesting that other ligands for these receptors may be involved.

Nuclear organization of pre-mRNA splicing factors.

The splicing of mRNA precursors (pre-mRNA) in the nucleus is catalyzed by a complex machinery termed the spliceosome. In order to understand how it functions in vivo, it is essential to complement biochemical analyses with a detailed study of how spliceosome components are organized within the nucleus.

Regulated clustering of variant CD44 proteins increases their hyaluronate binding capacity.

Cell contact with the extracellular matrix component hyaluronic acid (HA) plays an important role in many developmental, physiological, and pathological processes, although the regulation of this contact is poorly understood. CD44 proteins carry an amino acid motif that mediates affinity to HA. Artificial clustering of the smallest 85-kD isoform of CD44 (CD44s) has previously been shown to promote binding of the protein to soluble HA (Lesley, J., R. Hyman, and P.W. Kincade. 1993. Adv. Immunol. 54:271-335; Persche, A., J. Lesley, N. English, I. Trowbridge, and R. Hyman. 1995. Eur. J. Immunol. 25:495-501). Here we show that in rat pancreatic carcinoma cells, splice variants of CD44 (CD44v), but not CD44s, form molecular aggregates in the plasma membrane. We demonstrate that reduction-sensitive dimerization of CD44v occurs, and also that larger aggregations of the protein can be stabilized by chemical cross-linking. Different CD44v proteins present on the same cell exclusively form homoaggregates. Molecular clustering does not require an intact cytoplasmic domain of the protein. The ability of cells to bind to soluble HA is upregulated more than one magnitude by the ectopic expression of CD44v4-v7, but only when the CD44v4-v7 protein forms intermolecular aggregates. Tunicamycin treatment inhibits HA binding by CD44v and at the same time destroys oligomerization. We propose that the regulation of clustering of CD44, mediated by factors including the presence of variant exons and glycosylation, allows cells in turn to regulate their HA binding properties.

An essential role for CD44 variant isoforms in epidermal Langerhans cell and blood dendritic cell function.

Upon antigen contact, epidermal Langerhans cells (LC) and dendritic cells (DC) leave peripheral organs and home to lymph nodes via the afferent lymphatic vessels and then assemble in the paracortical T cell zone and present antigen to T lymphocytes. Since splice variants of CD44 promote metastasis of certain tumors to lymph nodes, we explored the expression of CD44 proteins on migrating LC and DC. We show that upon antigen contact, LC and DC upregulate pan CD44 epitopes and epitopes encoded by variant exons v4, v5, v6, and v9. Antibodies against CD44 epitopes inhibit the emigration of LC from the epidermis, prevent binding of activated LC and DC to the T cell zones of lymph nodes, and severely inhibit their capacity to induce a delayed type hypersensitivity reaction to a skin hapten in vivo. Our results demonstrate that CD44 splice variant expression is obligatory for the migration and function of LC and DC.

Experimental infection of highly pathogenic avian influenza viruses, Clade 2.3.4.4 H5N6 and H5N8, in Mandarin ducks from South Korea.

Outbreaks of highly pathogenic avian influenza (HPAI) have been reported worldwide. Wild waterfowl play a major role in the maintenance and transmission of HPAI. Highly pathogenic avian influenza subtype H5N6 and H5N8 viruses simultaneously emerged in South Korea. In this study, the comparative pathogenicity and infectivity of Clade 2.3.4.4 Group B H5N8 and Group C H5N6 viruses were evaluated in Mandarin duck (Aix galericulata). None of the ducks infected with H5N6 or H5N8 viruses showed clinical signs or mortality. Serological assays revealed that the HA antigenicity of H5N8 and H5N6 viruses was similar to each other. Moreover, both the viruses did not replicate after cross-challenging with H5N8 and H5N6 viruses, respectively, as the second infection. Although both the viruses replicated in most of the internal organs of the ducks, viral replication and shedding through cloaca were higher in H5N8-infected ducks than in H5N6-infected ducks. The findings of this study provide preliminary information to help estimate the risks involved in further evolution and dissemination of Clade 2.3.4.4 HPAI viruses among wild birds.

Semi-quantitative assessment of disease risks at the human, livestock, wildlife interface for the Republic of Korea using a nationwide survey of experts: A model for other countries.

Wildlife-associated diseases and pathogens have increased in importance; however, management of a large number of diseases and diversity of hosts is prohibitively expensive. Thus, the determination of priority wildlife pathogens and risk factors for disease emergence is warranted. We used an online questionnaire survey to assess release and exposure risks, and consequences of wildlife-associated diseases and pathogens in the Republic of Korea (ROK). We also surveyed opinions on pathways for disease exposure, and risk factors for disease emergence and spread. For the assessment of risk, we employed a two-tiered, statistical K-means clustering algorithm to group diseases into three levels (high, medium and low) of perceived risk based on release and exposure risks, societal consequences and the level of uncertainty of the experts' opinions. To examine the experts' perceived risk of routes of introduction of pathogens and disease amplification and spread, we used a Bayesian, multivariate normal order-statistics model. Six diseases or pathogens, including four livestock and two wildlife diseases, were identified as having high risk with low uncertainty. Similarly, 13 diseases were characterized as having high risk with medium uncertainty with three of these attributed to livestock, six associated with human disease, and the remainder having the potential to affect human, livestock and wildlife (i.e., One Health). Lastly, four diseases were described as high risk with high certainty, and were associated solely with fish diseases. Experts identified migration of wildlife, international human movement and illegal importation of wildlife as the three routes posing the greatest risk of pathogen introduction into ROK. Proximity of humans, livestock and wildlife was the most significant risk factor for promoting the spread of wildlife-associated diseases and pathogens, followed by high density of livestock populations, habitat loss and environmental degradation, and climate change. This study provides useful information to decision makers responsible for allocating resources to address disease risks. This approach provided a rapid, cost-effective method of risk assessment of wildlife-associated diseases and pathogens for which the published literature is sparse.

Newly assembled snRNPs associate with coiled bodies before speckles, suggesting a nuclear snRNP maturation pathway.

BACKGROUND: Small nuclear ribonucleoproteins (snRNPs), which are essential components of the mRNA splicing machinery, comprise small nuclear RNAs, each complexed with a set of proteins. An early event in the maturation of snRNPs is the binding of the core proteins - the Sm proteins - to snRNAs in the cytoplasm followed by nuclear import. Immunolabelling with antibodies against Sm proteins shows that splicing snRNPs have a complex steady-state localisation within the nucleus, the result of the association of snRNPs with several distinct subnuclear structures. These include speckles, coiled bodies and nucleoli, in addition to a diffuse nucleoplasmic compartment. The reasons for snRNP accumulation in these different structures are unclear. RESULTS: When mammalian cells were microinjected with plasmids encoding the Sm proteins B, D1 and E, each tagged with either the green fluorescent protein (GFP) or yellow-shifted GFP (YFP), a pulse of expression of the tagged proteins was observed. In each case, the newly synthesised GFP/YFP-labelled snRNPs accumulated first in coiled bodies and nucleoli, and later in nuclear speckles. Mature snRNPs localised immediately to speckles upon entering the nucleus after cell division. CONCLUSIONS: The complex nuclear localisation of splicing snRNPs results, at least in part, from a specific pathway for newly assembled snRNPs. The data demonstrate that the distribution of snRNPs between coiled bodies and speckles is directed and not random.

Two different functions for CD44 proteins in human myelopoiesis.

CD44 is important during myelopoiesis, although the contributions of variant CD44 proteins are unclear. We show here that in human long-term bone marrow culture antibodies recognizing a CD44 NH2-terminal epitope (mab 25-32) or a CD44v6 epitope (mab VFF18) inhibit myelopoiesis. However, mab 25-32 but not mab VFF18 affects myeloid colony formation. These data suggest that an early precursor cell compartment is the target for the 25-32 antibody, whereas the mab VFF18 targets later stages in myelopoiesis. Since the bulk of hemopoietic precursor cells are negative for the v6 epitope and only a minor subset of myeloid cells express the v6 epitope, we have used several human myeloid progenitor cell lines to unravel the function of different CD44 proteins. These cell lines produce variant CD44 proteins, predominantly a new variant CD44v4-v10, when stimulated towards myeloid differentiation. Features that can be acquired by the expression of CD44v4-v10 are an increased hyaluronate (HA) and a de novo chondroitin sulphate A (CS-A) binding. Although, the expression of CD44v4-v10 per se is necessary for HA and CS-A binding, the protein backbone seems to require appropriate glycosylation. HA binding results in CD44-mediated cellular self-aggregation and adhesion to the stromal cell line MS-5. In summary, our data suggest that different CD44 proteins are important for at least two different steps in myelopoiesis.

EACR-MRS conference on Seed and Soil: In Vivo Models of Metastasis.

New experimental tools are urgently required to better understand the metastatic process. The importance of such tools is underscored by the fact that many anti-cancer therapies are generally ineffective against established metastases. This makes a major contribution to the fact that metastatic spread is responsible for over 90% of cancer patient deaths. It was therefore timely that the recent "Seed and Soil: In Vivo Models of Metastasis" conference held in Berlin, Germany (27-29 of November 2017) aimed to give an in-depth overview of the latest research models and tools for studying metastasis, and to showcase recent findings from world-leading metastasis researchers. This Meeting Report summarises the major themes of this ground-breaking conference.

The relationship between tumors and the lymphatics: what more is there to know?

Ten years ago the relationship between tumors and the lymphatic system was perceived to be rather passive. Since then, the dramatic increase in our understanding of the molecular biology of lymphatic endothelial cells and the regulation of lymphangiogenesis has revealed that tumors can actively interact with the lymphatics by inducing lymphangiogenesis. In turn, this interaction promotes the entry of tumor cells into the lymphatic vasculature and their subsequent transport to regional lymph nodes, a process that stimulates the formation of metastases. Tumor-induced lymphangiogenesis has thus emerged as an important new target in the fight against metastatic cancer. Nevertheless, there is still much to be learned about the relationship between tumors and the lymphatics that will have important ramifications for the design of clinical trials aimed at the application of anti-lymphangiogenesis therapies in the management of cancer. This Lymphangiogenesis Review focuses on these issues.

Metastasis suppression by the standard CD44 isoform does not require the binding of prostate cancer cells to hyaluronate.

Previous studies from this laboratory have demonstrated that down-regulation of the standard CD44 isoform at the mRNA and protein level is associated with the acquisition of high metastatic ability within the Dunning R-3327 system of rat prostate cancers. Additional studies demonstrated that transfection-induced enhanced expression of the standard CD44 isoform suppresses the metastatic ability of the AT3.1 Dunning subline without suppressing tumorigenicity. The standard CD44 isoform is a major cell surface receptor for the extracellular matrix glycosaminoglycan hyaluronate. In this study, an investigation was made to resolve whether the ability of the standard CD44 isoform to suppress metastasis of the AT3.1 prostate cancer cells critically requires enhanced hyaluronate binding. Highly metastatic Dunning AT3.1 rat prostate cancer cells were transfected with expression plasmids encoding either the wild-type or mutant standard CD44 isoform. The mutant standard CD44 isoform construct encoded a protein unable to bind to hyaluronate. Transfectants were isolated and characterized with regard to their level of standard CD44 isoform expression, hyaluronate binding, tumorigenicity, and metastatic ability. Expression of the wild-type standard CD44 isoform increased the hyaluronate binding of prostate cancer cells and suppressed their metastatic ability without suppressing their tumorigenicity. Expression of the mutant CD44 standard isoform did not increase hyaluronate binding; however, it equally suppressed the metastatic ability of the AT3.1 prostate cancer cells. These results demonstrate that the metastasis suppression by the standard CD44 isoform is independent of its ability to bind to hyaluronate.

Gene expression patterns associated with the metastatic phenotype in rodent and human tumors.

Using subtractive technology, we have generated metastasis-associated gene expression profiles for rat mammary and pancreatic adenocarcinomas. Several genes whose expression is thought to be related to tumor progression such as c-Met, urokinase-type plasminogen activator receptor, ezrin, HMG-1, oncomodulin, cathepsin, and caveolin were thereby isolated. Half of the metastasis-associated clones showed no significant homology to genes with known function. Notably, several of the metastasis-associated clones were also expressed in metastatic lines but not in nonmetastatic lines of other tumor models. Furthermore, in situ hybridization using selected clones documents the relevance of these results for human cancer because strong expression in tumor cells including metastases was detected in human colorectal cancer samples and, to a lesser extent, in mammary cancer samples. These data support the concept that tumors express a "metastatic program" of genes.

Hyaluronate-independent metastatic behavior of CD44 variant-expressing pancreatic carcinoma cells.

Several studies have demonstrated a correlation between the expression of CD44 variant isoforms and the ability of tumor cells to metastasize. The CD44 proteins carry amino acid sequence motifs that confer the ability to bind to the extracellular matrix component hyaluronate (HA). In this study, we investigated whether a CD44 variant previously shown to stimulate metastasis in a rat pancreatic carcinoma model (BSp73AS) is capable of binding to HA, and whether such binding is critical for metastasis. We show that transfection of this CD44 variant into BSp73AS cells increases the HA-binding capacity of the cells in a dose-dependent manner. Transfection of the same CD44 variant isoform into BDX2 cells also conferred strong HA-binding properties on these cells, but was insufficient to cause them to metastasize. Transfection of a surface-bound hyaluronidase into metastasizing BSp73AS cells bearing variant CD44 efficiently ablated the ability of these cells to bind to HA. However, in metastasis assays, these hyaluronidase-transfected cells showed patterns of metastasis similar to those of the parental cell line. We also show that the HA-binding capacity of a variety of tumor cells is not correlated with their metastatic proclivity, and that an antibody previously shown to block metastasis of the pancreatic carcinoma cells does not interfere with their ability to bind to HA. We conclude that although CD44 variant expression does promote metastasis formation, HA binding by tumor cells is not rate limiting for metastasis in the BSp73AS system and probably also in other metastasizing tumors. Furthermore, for metastasis by CD44 variant-expressing BSp73AS cells to occur, contact of the CD44 variant protein with a ligand other than HA Is required.

CD44 variants but not CD44s cooperate with beta1-containing integrins to permit cells to bind to osteopontin independently of arginine-glycine-aspartic acid, thereby stimulating cell motility and chemotaxis.

The expression of osteopontin (OPN), CD44 variants, and integrins has been correlated with tumorigenesis and metastasis. Here we show that these proteins cooperate to enhance cell motility. First, we demonstrate that several different CD44 variants bind to OPN in an arginine-glycineaspartic acid-independent manner, but that the standard form of CD44 does not. These CD44 variants bind to both the amino- and COOH-terminal portions of OPN independently of the arginine-glycine-aspartic acid sequence, suggesting that multiple domains on OPN can be bound by the CD44 variants. Antibodies directed against the integrin beta1 subunit are able to inhibit this binding. The binding of CD44 variants to OPN is significantly augmented by both anti-CD44s and anti-CD44v antibodies. This augmentation by anti-CD44 antibodies is OPN specific and, again, can be blocked by anti-beta1 antibodies. Finally, we show that OPN binding by CD44 variants/beta1-containing integrins promotes cell spreading, motility, and chemotactic behavior.