RESUMEN
The Global Burden of Animal Diseases provides an analytical framework to measure the overall health of various farmed animal populations, to estimate the farm-level burden of different diseases, incorporating production losses due to morbidity and mortality as well as health expenditure, and to identify the wider economic and human health impacts of animal disease. Attributing the burden of animal diseases to specific causes or groups of causes requires methodological choices, including the classification of diseases and the resulting health states that manifest in loss of production. The aim of this article is to address the key challenges in the process of estimating farm-level disease burden, including ambiguity in terminology, data availability and collation, and adjustments for comorbidity. Using infection with zoonotic Brucella spp. in small ruminants as an aetiological cause of disease and abortion as a sequela of multiple diseases, practical examples of the framework are provided. Cause-specific attribution of the burden of animal disease captures temporal and spatial trends, an understanding of which is essential for planning, monitoring and evaluating animal health programmes and disease interventions.
Le programme " Impact mondial des maladies animales " fournit un cadre analytique pour mesurer l'état de santé général de diverses populations d'animaux d'élevage, estimer la charge de morbidité associée à certaines maladies à l'échelle d'une exploitation, prendre en compte aussi bien les pertes de production dues à la morbidité et à la mortalité que les dépenses de santé, et mettre en lumière les effets plus larges des maladies animales sur l'économie et la santé humaine. Des choix méthodologiques doivent être faits pour attribuer l'impact des maladies animales à des facteurs spécifiques ou à des séries de facteurs, en classant les maladies et en définissant les profils sanitaires qui en résultent et qui induisent des pertes de production. L'objectif de cet article est d'aborder les principales difficultés rencontrées lors de l'estimation de la charge de morbidité à l'échelle des exploitations, en particulier celles relevant d'une terminologie ambiguë, de la disponibilité et modalités de collecte des données, et des ajustements à effectuer en cas de comorbidité. Les auteurs donnent des exemples concrets du cadre proposé, en prenant d'une part l'infection zoonotique par des Brucella spp. chez les petits ruminants comme cause étiologique de la maladie, et d'autre part les avortements comme séquelles de plusieurs maladies. L'attribution de l'impact des maladies animales à des facteurs spécifiques permet de saisir les tendances aussi bien dans le temps que dans l'espace, dont la connaissance se révèle indispensable pour assurer la planification, le suivi et l'évaluation des programmes de santé animale et des interventions liées aux maladies.
El impacto global de las enfermedades animales proporciona un marco analítico para medir la sanidad general de diversas poblaciones de animales de granja, estimar el impacto de las distintas enfermedades en las explotaciones, incorporando las pérdidas de producción debidas a la morbilidad y a la mortalidad, así como los gastos sanitarios, y determinar las repercusiones más amplias de las enfermedades animales en la economía y la salud humana. Para atribuir el impacto de las enfermedades animales a causas o grupos de causas específicos es necesario tomar decisiones metodológicas, incluida la clasificación de las enfermedades y de los estados sanitarios resultantes, que se traducen en pérdidas de producción. El objetivo de este artículo es abordar las principales dificultades que se plantean en el proceso de la estimación del impacto de las enfermedades en las explotaciones, entre ellas la ambigûedad terminológica, la disponibilidad y el cotejo de datos, y los ajustes por comorbilidad. Utilizando la infección zoonótica por Brucella spp. en pequeños rumiantes como causa etiológica de enfermedad y el aborto como secuela de múltiples enfermedades, se ofrecen ejemplos prácticos del marco. La atribución del impacto de las enfermedades animales a causas específicas permite captar tendencias temporales y espaciales cuya comprensión es esencial para planificar, supervisar y evaluar programas de sanidad animal e intervenciones relacionadas con enfermedades.
Asunto(s)
Enfermedades de los Animales , Animales , Enfermedades de los Animales/epidemiología , Costo de Enfermedad , ZoonosisRESUMEN
The Global Burden of Animal Diseases (GBADs) programme aims to assess the impact of animal health on agricultural animals, livestock production systems and associated communities worldwide. As part of the objectives of GBADs'Animal Health Ontology theme, the programme reviewed conceptual frameworks, ontologies and classification systems in biomedical science. The focus was on data requirements in animal health and the connections between animal health and human and environmental health. In May 2023, the team conducted searches of recognised repositories of biomedical ontologies, including BioPortal, Open Biological and Biomedical Ontology Foundry, and Ontology Lookup Service, to identify animal and livestock ontologies and those containing relevant concepts. Sixteen ontologies were found, covering topics such as surveillance, anatomy and genetics. Notable examples include the Animal Trait Ontology for Livestock, the Animal Health Surveillance Ontology, the National Center for Biotechnology Information Taxonomy and the Uberon Multi-Species Anatomy Ontology. However, some ontologies lacked class definitions for a significant portion of their classes. The review highlights the need for domain evidence to support proposed models, critical appraisal of external ontologies before reuse, and external expert reviews along with statistical tests of agreements. The findings from this review informed the structural framework, concepts and rationales of the animal health ontology for GBADs. This animal health ontology aims to increase the interoperability and transparency of GBADs data, thereby enabling estimates of the impacts of animal diseases on agriculture, livestock production systems and associated communities globally.
Le programme " Impact mondial des maladies animales " (GBADs) vise à évaluer l'impact de la santé animale sur les animaux d'élevage, les systèmes de production animale et les communautés liées à ce secteur d'activités dans le monde. Afin de définir une ontologie de la santé animale répondant aux objectifs du GBADs, le programme a procédé à un examen des cadres conceptuels, des ontologies et des systèmes de classification actuellement appliqués en sciences biomédicales. Il s'agissait de définir les besoins en données dans le domaine de la santé animale ainsi que les connexions entre la santé animale, la santé publique et la santé environnementale. En mai 2023, l'équipe a procédé à des recherches dans des référentiels reconnus d'ontologies biomédicales, notamment BioPortal, Open Biological and Biomedical Ontology Foundry et Ontology Lookup Service, afin de recenser les ontologies relatives aux animaux et au bétail ainsi que celles contenant des concepts pertinents. Seize ontologies ont été relevées, couvrant des thèmes tels que la surveillance, l'anatomie et la génétique. Parmi les exemples notables on peut citer : Animal Trait Ontology for Livestock (ontologie dédiée aux caractères phénotypiques des animaux d'élevage), Animal Health Surveillance Ontology (ontologie dédiée à la surveillance de la santé animale), National Center for Biotechnology Information Taxonomy (la base de données Taxonomie du Centre américain pour les informations biotechnologiques), et Uberon Multi-Species Anatomy Ontology (ontologie anatomique représentant diverses espèces animales). Il a cependant été constaté que certaines ontologies ne disposent pas de définitions de classes pour une grande partie des classes qui les composent. L'examen a souligné l'importance d'étayer les modèles proposés par des données issues des spécialités en question, de procéder à une évaluation critique des ontologies externes avant de les réutiliser et de faire effectuer des examens complémentaires par des experts externes ainsi que des tests statistiques de concordance. Les résultats de cette étude ont apporté des éléments permettant de définir le cadre structurel, les concepts et les principes de l'ontologie relative à la santé animale destinée au GBADs. Cette ontologie de la santé animale vise à accroître l'interopérabilité et la transparence des données du GBADs, ce qui permet d'effectuer des estimations de l'impact des maladies animales sur l'agriculture, les systèmes de production animale et les communautés associées à ce secteur d'activités à l'échelle mondiale.
El programa sobre el impacto global de las enfermedades animales (GBADs) tiene como objetivo evaluar el impacto de la sanidad animal en los animales de granja, los sistemas de producción ganadera y las comunidades conexas en todo el mundo. Como parte de los objetivos en torno al tema de la ontología de la sanidad animal del GBADs, el programa revisó marcos conceptuales, ontologías y sistemas de clasificación en el ámbito de la ciencia biomédica. Se hizo hincapié en los requisitos de datos sobre la sanidad animal y en las conexiones entre la sanidad animal y la salud humana y ambiental. En mayo de 2023, el equipo realizó búsquedas en repositorios reconocidos de ontologías biomédicas, como BioPortal, Open Biological and Biomedical Ontology Foundry y Ontology Lookup Service, para identificar no solo ontologías animales y ganaderas, sino también aquellas que incluyeran conceptos relevantes. En este sentido, se encontraron dieciséis ontologías, que abarcan temas como vigilancia, anatomía y genética. Entre los ejemplos más destacados figuran Animal Trait Ontology for Livestock (Ontología de Características Animales para el Ganado), Animal Health Surveillance Ontology (Ontología de Vigilancia de la Sanidad Animal), National Center for Biotechnology Information Taxonomy (la base de datos Taxonomía del Centro Nacional para la Información Biotecnológica) y Uberon Multi-Species Anatomy Ontology (Ontología Anatómica de Especies Múltiples). Sin embargo, algunas ontologías carecían de definiciones para una parte significativa de sus clases. La revisión pone de relieve la necesidad de contar con datos probatorios del ámbito en cuestión que respalden los modelos propuestos, una evaluación crítica de las ontologías externas antes de su reutilización y revisiones de expertos externos junto con pruebas estadísticas de los acuerdos. Los resultados de esta revisión han servido de base para el marco estructural, los conceptos y los fundamentos de la ontología de la sanidad animal para el GBADs. Esta ontología pretende aumentar la interoperabilidad y la transparencia de los datos del GBADs, permitiendo así estimar el impacto de las enfermedades animales en la agricultura, los sistemas de producción ganadera y las comunidades conexas en todo el mundo.
Asunto(s)
Enfermedades de los Animales , Ontologías Biológicas , Ganado , Animales , Enfermedades de los Animales/epidemiología , Salud Global , HumanosRESUMEN
We quantified the sensitivity of surveillance for lumpy skin disease (LSD) and foot and mouth disease (FMD) in cattle in the Kimberley region of Western Australia. We monitored producer and veterinary activity with cattle for 3 years commencing January 2020. Each year, ~274,000 cattle of 685,540 present on 92 pastoral leases (stations) were consigned to other stations, live export or slaughter. Veterinarians examined 103,000 cattle on the stations, 177,000 prior to live export, and 10,000 prior to slaughter. Detection probabilities for the disease prior to transport or during veterinary procedures and inspections were elicited by survey of 17 veterinarians working in Northern Australia. The veterinarians estimated the probabilities that they would notice, recognise, and submit samples from clinical cases of LSD and FMD, given a 5% prevalence of clinical signs in the herd. We used scenario tree methodology to estimate monthly surveillance sensitivity of observations made by producers and by veterinarians during herd management visits, pre-export inspections, and ante-mortem inspections. Average monthly combined sensitivities were 0.49 for FMD and 0.37 for LSD. Sensitivity was high for both diseases during the dry season and low in the wet season. We estimated the confidence in freedom from the estimated surveillance sensitivity given one hypothetically infected herd, estimated probability of introduction, and prior confidence in freedom. This study provided assurance that the Kimberley is free of these diseases and that routine producer and veterinary interactions with cattle are adequate for the timely detection of the disease should they be introduced.
Asunto(s)
Enfermedades de los Bovinos , Fiebre Aftosa , Dermatosis Nodular Contagiosa , Animales , Bovinos , Fiebre Aftosa/diagnóstico , Fiebre Aftosa/epidemiología , Australia Occidental/epidemiología , Dermatosis Nodular Contagiosa/diagnóstico , Dermatosis Nodular Contagiosa/epidemiología , Brotes de Enfermedades/veterinaria , Australia/epidemiología , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/epidemiologíaRESUMEN
A global strategic plan for the elimination of dog-mediated human rabies deaths by 2030 was announced in 2018. The cost-effectiveness of annual mass dog vaccination programmes, as a control and elimination method, has been advocated on many occasions. Complementary methods, such as animal birth control (ABC) activities, have received less attention. This paper provides a case-study of a programme operated by Help in Suffering (HIS) in Jaipur, India from 1994/95 until 2016/17 comprising both ABC and additional vaccination-only activities. The availability of cost data alongside information on dog numbers, dog bites and human rabies cases provided an exceptionally detailed and unique retrospective dataset recording actual events and expenditures. Updated to 2016/17 prices, the total cost of the programme was 658,744 USD. Since 2007/2008, activity costs have been separated and returned costs of 10.78 USD per dog, both sterilised and vaccinated, and 1.86 USD per dog, vaccinated only. Over the course of the programme, the number of disability-adjusted life years (DALYs) due to premature death and the distress associated with dog bites was estimated to be 36,246 fewer than would have been expected if HIS had not been operating, based on a counterfactual scenario using pre-intervention values. Linking the DALY figure to the cost of the activities undertaken by HIS yields a cost of 26 USD per DALY averted. Discounted at 3%, the DALYs averted equate to 16,587 at a cost of 40 USD per DALY averted. Both cases make it a very cost-effective intervention, in relation to the threshold of investing one year's gross domestic product (GDP) per DALY averted (1981 USD in 2016/17). The monetary benefit from fewer dog bites and clinical human rabies cases requiring treatment amounted to 5.62 million USD after discounting, which, if attributed to Help in Suffering, yields a monetary benefit-cost ratio of 8.5. Thus, the potential monetary benefits greatly outweigh the programme costs, even without considering the DALYs averted. If a modest notional monetary value of one year's GDP is assigned to represent the human capital or production value of DALYs averted, the discounted societal economic benefit reaches 38.48 million USD and implies a benefit-cost ratio of 58.4. These economic analyses demonstrate that ABC activities in combination with additional vaccination efforts can be a cost-effective control measure for dog-mediated human rabies.
Asunto(s)
Mordeduras y Picaduras/veterinaria , Análisis Costo-Beneficio , Enfermedades de los Perros/prevención & control , Vacunación Masiva/veterinaria , Rabia/veterinaria , Animales , Mordeduras y Picaduras/prevención & control , Perros , India , Vacunación Masiva/economía , Años de Vida Ajustados por Calidad de Vida , Rabia/prevención & control , Estudios RetrospectivosRESUMEN
This report demonstrates that using interferon gamma release assays to screen for latent tuberculosis infection in female commercial sex workers in an outreach sexual health clinic is feasible and acceptable. Routine interferon gamma release assay use successfully identified high numbers of latent tuberculosis infection. Innovative approaches to treatment and follow up were required to improve treatment adherence in this group. Direct observation of therapy within the sexual health clinic was also feasible. Successful follow up was dependent on the support of outreach workers, interpreters and tuberculosis nurses.
Asunto(s)
Ensayos de Liberación de Interferón gamma/métodos , Interferón gamma/análisis , Tuberculosis Latente/diagnóstico , Tamizaje Masivo/métodos , Mycobacterium tuberculosis/inmunología , Aceptación de la Atención de Salud , Trabajadores Sexuales , Adolescente , Adulto , Estudios de Factibilidad , Humanos , Incidencia , Tuberculosis Latente/epidemiología , Tuberculosis Latente/inmunología , Tuberculosis Latente/metabolismo , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis/aislamiento & purificación , Evaluación de Procesos y Resultados en Atención de Salud , Prevalencia , Adulto JovenRESUMEN
In common with other mammalian species, the laboratory rat (Rattus norvegicus) expresses MHC class I molecules that have been categorized as either classical (class Ia) or nonclassical (class Ib). This distinction separates the class Ia molecules that play a conventional role in peptide Ag presentation to CD8 T cells from the others, whose function is unconventional or undefined. The class Ia molecules are encoded by the RT1-A region of the rat MHC, while the RT1-C/E/M region encodes up to 60 other class I genes or gene fragments, a number of which are known to be expressed (or to be expressible). Here we report upon novel MHC class Ib genes of the rat that we have expression cloned using new monoclonal alloantibodies and which we term RT1-U. The products detected by these Abs were readily identifiable by two-dimensional analysis of immunoprecipitates and were shown to be distinct from the class Ia products. Cellular studies of these molecules indicate that they function efficiently as targets for cytotoxic killing by appropriately raised polyclonal alloreactive CTL populations. The sequences of these class Ib genes group together in phylogenetic analysis, suggesting a unique locus or family. The combined serological, CTL, and sequence data all indicate that these products are genetically polymorphic.
Asunto(s)
Antígenos de Histocompatibilidad/genética , Antígenos de Histocompatibilidad/aislamiento & purificación , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/metabolismo , Presentación de Antígeno , Reacciones Antígeno-Anticuerpo , Secuencia de Bases , Clonación Molecular , ADN Complementario/aislamiento & purificación , Femenino , Haplotipos , Antígenos de Histocompatibilidad/inmunología , Antígenos de Histocompatibilidad/metabolismo , Células L , Ratones , Datos de Secuencia Molecular , Familia de Multigenes/inmunología , Polimorfismo Genético , Pruebas de Precipitina , Ratas , Ratas Endogámicas , Homología de Secuencia de Ácido Nucleico , Linfocitos T/inmunología , Linfocitos T/metabolismoRESUMEN
Helicobacter pylori is recognised as an important factor in gastroduodenal pathology. The 128 kDa CagA protein has been established as a useful marker of H. pylori strains associated with more severe forms of disease. A mouse monoclonal antibody raised against the CagA protein has been produced and characterised as belonging to the IgG1 subtype. It identified the protein in all clinical isolates (10/10) from this laboratory and in two NCTC reference strains (NCTC 11637 and NCTC 11961). No cross-reacting proteins were detected in H. pylori L2, a well characterised strain known not to contain the cagA gene, or in four Helicobacter sp. from non-human sources (H. canis, H. mustelidae, H. muridarum and H. acinonyx). The monoclonal antibody was used to develop an antigen capture ELISA system for detecting the presence of antibodies to the CagA protein in human serum samples.
Asunto(s)
Anticuerpos Antibacterianos/biosíntesis , Anticuerpos Antibacterianos/sangre , Anticuerpos Monoclonales/biosíntesis , Proteínas Bacterianas/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Infecciones por Helicobacter/inmunología , Helicobacter pylori/inmunología , Animales , Antígenos Bacterianos/química , Antígenos Bacterianos/genética , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Secuencia de Bases , Biomarcadores , Cartilla de ADN/genética , ADN Bacteriano/genética , Genes Bacterianos , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Helicobacter pylori/patogenicidad , Humanos , Inmunoglobulina G/biosíntesis , Ratones , Datos de Secuencia Molecular , Peso Molecular , Reacción en Cadena de la Polimerasa , Virulencia/genética , Virulencia/inmunologíaRESUMEN
Cholera toxin and the related Escherichia coli heat-labile enterotoxin are hexameric proteins comprising one A-subunit and five B-subunits. In this paper we report the generation and characterization of a monoclonal antibody, designated LDS47, that recognizes and precipitates in vivo assembly intermediates of the B-subunit (EtxB) of E. coli heat-labile enterotoxin. The monoclonal antibody is unable to precipitate native B-subunit pentamers, thus making LDS47 a useful probe for studying the early stages of enterotoxin biogenesis. The use of LDS47 to monitor the in vivo turnover of newly synthesized B-subunits in the periplasm of E. coli demonstrated that (i) the turnover of unassembled B-subunits followed an apparent first order process and (ii) it occurred concomitantly with the assembly of native B-pentamers (k = 0.317 +/- 0.170 min-1; t1/2 = 2.2 min). No other proteins were co-precipitated with the newly synthesized B-subunits; a finding that implies that unassembled B-subunits do not stably associate with other periplasmic proteins prior to their assembly into a macromolecular complex. The use of overlapping synthetic peptides corresponding to the entire EtxB polypeptide demonstrated that the epitope recognized by LDS47 is located within the amino-terminal decapeptide of the B-subunit. From the x-ray structural analysis of the toxin (Sixma, T., Kalk, K., van Zanten, B., Dauter, Z., Kingma, J., Witholt, B., and Hol, W. G. J. (1993) J. Mol. Biol. 230, 890-918), this region appears to resemble a curved finger that clasps the adjacent B-subunit. Thus, this region might be expected to be exposed in the unfolded or unassembled subunit, but to become partially buried upon assembly and thus inaccessible to recognition by the monoclonal antibody.
Asunto(s)
Anticuerpos Monoclonales , Toxinas Bacterianas/química , Toxinas Bacterianas/inmunología , Enterotoxinas/química , Enterotoxinas/inmunología , Proteínas de Escherichia coli , Secuencia de Aminoácidos , Anticuerpos Antibacterianos , Especificidad de Anticuerpos , Toxinas Bacterianas/genética , Reacciones Cruzadas , Enterotoxinas/genética , Mapeo Epitopo , Epítopos/química , Epítopos/genética , Escherichia coli/genética , Modelos Moleculares , Sondas Moleculares , Datos de Secuencia Molecular , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/inmunología , Conformación Proteica , Desnaturalización Proteica , Pliegue de ProteínaRESUMEN
Monoclonal antibodies were produced from fusions between splenocytes from BALB/c mice immunised with purified human islets and the mouse myeloma cell line NS-0/Uncl. Supernatants from uncloned hybrids were screened by immunohistology on frozen sections of human pancreas. The range of specificities appeared to reflect the relative purity of the human islet preparations used. Eight monoclonal antibodies were investigated further, four of these bound to islet cells, two to acinar cells, one to ductal cells and one to occasional cells. The antigens recognised by these antibodies were characterised by immunohistology using a number of different tissues, as well as haemagglutination, immunoblotting and radioimmunoassay for insulin. Seven of the eight antibodies studied were IgM. One acinar cell antibody (IgG2a) precipitated proteins of 200Kd and 11OKd molecular weight. None of the antibodies bound directly to insulin. Seven of the antibodies appear to have defined previously unreported epitopes in the pancreas and will prove useful in further studies of human pancreatic cells.
Asunto(s)
Anticuerpos Monoclonales , Islotes Pancreáticos/citología , Islotes Pancreáticos/inmunología , Páncreas/citología , Animales , Especificidad de Anticuerpos , Línea Celular , Separación Celular/métodos , Reacciones Cruzadas , Humanos , Inmunoglobulina G/clasificación , Inmunoglobulina M , Inmunohistoquímica , Linfocitos/inmunología , Ratones , Ratones Endogámicos BALB C/inmunología , Mieloma MúltipleRESUMEN
Thick and thin filaments in asynchronous flight muscle overlap nearly completely and thick filaments are attached to the Z-disc by connecting filaments. We have raised antibodies against a fraction of Lethocerus flight muscle myofibrils containing Z-discs and associated filaments and also against a low ionic strength extract of myofibrils. Monoclonal antibodies were obtained to proteins of 800 kd (p800), 700 kd (p700), 400 kd (p400) and alpha-actinin. The positions of the proteins in Lethocerus flight and leg myofibrils were determined by immunofluorescence and electron microscopy. p800 is in connecting filaments of flight myofibrils and in A-bands of leg myofibrils. p700 is in Z-discs of flight myofibrils and an immunologically related protein, p500, is in leg muscle Z-discs. p400 is in M-lines of both flight and leg myofibrils. Preliminary DNA sequencing shows that p800 is related to vertebrate titin and nematode twitchin. Molecules of p800 could extend from the Z-disc a short way along thick filaments, forming a mechanical link between the two structures. All three high molecular weight proteins probably stabilize the structure of the myofibril.
Asunto(s)
Insectos/ultraestructura , Proteínas Musculares/inmunología , Músculos/ultraestructura , Proteínas Quinasas , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/inmunología , Conectina , Extremidades , Vuelo Animal , Técnica del Anticuerpo Fluorescente , Inmunohistoquímica , Insectos/anatomía & histología , Datos de Secuencia Molecular , Peso Molecular , Proteínas Musculares/química , Proteínas Musculares/metabolismoRESUMEN
A new method is described for the large-scale purification of human pancreatic islets with a discontinuous gradient of bovine serum albumin formed on an IBM 2991 cell separator. Fifteen human pancreases were processed, and after density-gradient centrifugation, a mean of 2643 islets/ml pancreatic digest were recovered with a mean purity of 63% and contained in 430 microliter mean vol. Viability of gradient-isolated islets was compared with that of non-density-gradient islets (handpicked) and showed no difference in function. This technique allows isolation of intact, viable human islets of Langerhans of sufficient purity for potential human transplantation.
Asunto(s)
Separación Celular/instrumentación , Islotes Pancreáticos/citología , Adulto , Animales , Separación Celular/métodos , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/cirugía , Humanos , Ratas , Ratas DesnudasRESUMEN
Troponin has been prepared from the asynchronous flight muscle of Lethocerus (water bug) taking special care to prevent proteolysis. The regulatory complex contained tropomyosin and troponin components. The troponin components were Tn-C (18,000 Mr), Tn-T (apparent Mr 53,000) and a heavy component, Tn-H (apparent Mr 80,000). The troponin was tightly bound to tropomyosin and could not be dissociated from it in non-denaturing conditions. A complex of Tn-T, Tn-H and tropomyosin inhibited actomyosin ATPase activity and the inhibition was relieved by Tn-C from vertebrate striated muscle in the presence of Ca2+. However, unlike vertebrate Tn-I, Tn-H by itself was not inhibitory. Monoclonal antibodies were obtained to Tn-T and Tn-H. Antibody to Tn-T was used to screen an expression library of Drosophila cDNA cloned in lambda phage. The sequence of cDNA coding for the protein was determined and hence the amino acid sequence. The Drosophila protein has a sequence similar to that of vertebrate skeletal and cardiac Tn-T. The sequence extends beyond the carboxyl end of the vertebrate sequences, and the last 40 residues are acidic. Part of the sequence of Drosophila Tn-T is homologous to the carboxyl end of the Drosophila myosin light chain MLC-2 and one anti-Tn-T antibody cross-reacted with the light chain. Lethocerus Tn-H is related to the large tropomyosins of Drosophila flight muscle, for which the amino acid sequence is known, since antibodies that recognize this component also recognize the large tropomyosins. Tn-H is easily digested by calpain, suggesting that part of the molecule has an extended configuration. Electron micrographs of negatively stained specimens showed that Lethocerus thin filaments have projections at about 39 nm intervals, which are not seen on thin filaments from vertebrate striated muscle and are probably due to the relatively large troponin complex. Decoration of the thin filaments with myosin subfragment-1 in rigor conditions appeared not to be affected by the troponin. The troponin of asynchronous flight muscle lacks the Tn-I component of vertebrate striated muscle. Tn-H occurs only in the flight muscle and may be involved in the activation of this muscle by stretch.
Asunto(s)
Vuelo Animal , Hemípteros/metabolismo , Músculos/metabolismo , Troponina/metabolismo , Secuencia de Aminoácidos , Animales , Calpaína/metabolismo , Citoesqueleto/metabolismo , Citoesqueleto/ultraestructura , Drosophila melanogaster/metabolismo , Moscas Domésticas/metabolismo , Microscopía Electrónica , Datos de Secuencia Molecular , Tropomiosina/metabolismoRESUMEN
Plant and bacterial antigens contributing to nodule development and symbiosis in pea (Pisum sativum L.) roots were identified after isolation of a set of monoclonal antibody (McAb)-producing hybridoma lines. Rats were immunised with the peribacteriod material released by mild osmotic shock treatment from membrane-enclosed bacteroids of Rhizobium leguminosarum bv. viceae. In order to diversify the range of McAb specificities, this material was either used as immunogen directly (method 1), or after immunodepletion of a set of glycoprotein and lipopolysaccharide antigens (method 2), or after deglycosylation (method 3). After fusion and screening of cloned hybridoma lines, these three immunisation methods gave respectively 4, 2 and 1 classes of McAb with unique antigen specificities. Ultrastructural immunogold localisation studies showed four different antigens to be present on peribacteriod and plasma membranes (identified by MAC 64, 202, 206 or 209); in addition, a glycoprotein of plant origin but present in the infection-thread matrix was identified by MAC 204. Although none of the epitopes recognised by these McAb was nodule-specific, several were found to be more abundant in extracts of nodule tissue than in uninfected roots (MAC 64, 202, 204, 206). Two McAb reacted with new bacterial antigens: MAC 203 identified a bacterial antigen expressed upon infection but not in free-living cultures of Rhizobium, and MAC 115 identified a bacterial polypeptide (55 kdaltons) that was present in both free-living and bacteroid forms. There were also some McAb of broader specificity that react with antigens present in both plant and bacterial cytoplasms.
RESUMEN
Evidence is accumulating that the development of insulin-dependent diabetes mellitus involves autoimmune phenomena, both in the human and in the BB rat model. A strong association is observed in both cases with alleles of the class II major histocompatibility complex (MHC). Results of the present study show that autoimmune phenomena, as assessed by the presence of clinical diabetes or histological thyroiditis, are prevented by the injection of monoclonal antibodies to class II gene products in the BB rat. Immunosuppression was specifically obtained with a monoclonal antibody to the murine I-E equivalent, as opposed to the murine I-A equivalent, of the rat major histocompatibility complex. This represents indirect evidence for I-E subregion control of immune responses to islet cell and thyroid antigens in the BB rat model. The frequent occurrence of anaphylactic type deaths in young (1 month old) animals receiving more than six weekly injections of partially purified homologous (rat) monoclonal antibodies to rat class II gene products underscores the potential risks of this type of immunotherapy. The presumed immunologic mechanism (IgE antibody) and its specificity (anti-allotype, anti-idiotype, or anti-impurity) must be clarified to assess the risks and feasibility of this type of therapy.
Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Enfermedades Autoinmunes/prevención & control , Diabetes Mellitus Experimental/prevención & control , Modelos Animales de Enfermedad/prevención & control , Antígenos de Histocompatibilidad Clase II , Antígenos de Histocompatibilidad/inmunología , Inmunoterapia , Ratas Endogámicas BB/inmunología , Ratas Endogámicas/inmunología , Tiroiditis/prevención & control , Anafilaxia/etiología , Animales , Anticuerpos Antiidiotipos/uso terapéutico , Enfermedades Autoinmunes/inmunología , Glucemia/análisis , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/inmunología , Modelos Animales de Enfermedad/genética , Modelos Animales de Enfermedad/inmunología , Inmunoglobulina E/inmunología , Inmunoterapia/efectos adversos , Islotes Pancreáticos/inmunología , Ratas , Glándula Tiroides/inmunología , Tiroiditis/genética , Tiroiditis/inmunologíaRESUMEN
Three rat hybridoma lines that produced monoclonal antibodies reacting with the peribacteroid membrane from Pisum sativum were isolated, and these all appeared to recognize the same antigenic structure. Using one of these monoclonal antibodies, AFRC MAC 64, electron microscopy of immunogold-stained thin sections of nodule tissue revealed that the antigen, present in the peribacteroid membrane, was also found in the plant plasma membranes and in the Golgi bodies, but not in the endoplasmic reticulum. When peribacteroid membrane proteins were separated by SDS-polyacrylamide gel electrophoresis and transferred to nitrocellulose by electro-blotting, it was found that MAC 64 bound to a series of protease-sensitive bands that migrated in the mol. wt. range 50-85 K. The epitope was sensitive to periodate oxidation and its structure may therefore involve the carbohydrate component of a membrane glycoprotein. We suggest that this structure originates in the Golgi apparatus and is subsequently transferred to the peribacteroid membranes and plasma membranes. The monoclonal antibody also reacted with peribacteroid membranes from nodules of Vicia and lupin, and with plasma membranes and Golgi membranes from uninfected plant cells, including root tip cells from onion (Allium cepa), indicating that the antigen is highly conserved in the plasma membranes of plant cells.
Asunto(s)
Membrana Celular/inmunología , Aparato de Golgi/inmunología , Pisum sativum/inmunología , Raíces de Plantas/inmunología , Rhizobium/inmunología , Anticuerpos Monoclonales/inmunología , Reacciones Cruzadas/inmunología , Pisum sativum/microbiología , Raíces de Plantas/microbiologíaRESUMEN
Over 300 monoclonal IgG alloantibodies have been prepared against RT1Aa , the class I major histocompatibility complex molecule of the DA rat. In this study a combination of techniques is exploited to show that all these antibodies can be allocated to 9 antigenic sites which form a continuous antigenic surface, that is, no site is completely isolated from the rest. The results suggest that techniques for the identification of antigenic sites using competitive inhibition of monoclonal antibody binding are generally valid, in the sense that competition between antibodies appears most commonly to represent competition between combining sites for a structural feature of the antigenic surface. From the distribution of antibodies between sites, it is clear that the RT1Aa molecule has three immunogenic areas against which nearly all the antibodies studied were directed. Of these areas one is both antigenically complex, consisting of four closely spaced sites, and remarkably immunodominant. Antibodies directed at sites between the major areas are extremely rare.