1. Preparação da emulsão <ol><li> A emulsão é uma mistura 1:1 do antígeno (DTH pode ser induzida a vários antígenos: ovalbumina, toxóide tetânico, limpet keyhole hemocianina ....) em solução aquosa adicionado ao adjuvante completo de Freund. É muito importante adicionar o antígeno ao adjuvante e não o contrário! </li><li> Há uma grande quantidade de resíduos ao fazer e injetando uma emulsão, por isso sempre preparar 1,5 ou 2 vezes mais do que o que você precisa. </li><li> Dissolver antígeno em solução salina para preparar uma solução de 2 mg / ml. Não filtro, que você não quer perder os agregados! </li><li> Coloque completa adjuvante de Freund H37Ra (Difco, catalogo 231.131) em um tubo de vórtice e em alta velocidade. Adicionar a gota a gota, enquanto o antígeno vórtex. Quando todos o antígeno é adicionada vórtice, por mais 5 minutos. A mistura deve ficar branco. </li><li> Coloque a emulsão em uma seringa de vidro e vinculá-lo a outra seringa de vidro usando uma ponte de 18G (Fisher catálogo # 14-825-17L). Enviar a emulsão de uma seringa para o outro até que se torne rígido (5-10 min). É melhor usar duas seringas 5 ml. Se mais de 5 ml de emulsão são necessários, use vários conjuntos de 5 ml seringas. </li><li> A emulsão pode ser armazenada nas seringas a 4 ° C por 3 semanas. </li></ol> 2. Imunização dos ratos <ol><li> Misture a emulsão nas seringas por alguns minutos e transfira para a seringa utilizada para a injeção. Injetar 200 ml por via subcutânea em 1-2 locais na base da cauda usando agulhas 23G e uma ponta Luer-Lok seringa de 3 ml. </li></ol> 3. Desafio com o antígeno na parte de trás <ol><li> Sete dias após a imunização, a barba duas manchas nas costas dos ratos e injetar por via intradérmica de 20 ml de uma solução de antígeno 1 mg / ml em um ponto e salina (ou antígeno irrelevante) no outro ponto. Não filtrar a solução de antígeno, como você pode perder agregados que aumentam a reação inflamatória. </li><li> Os ratos devem ser anestesiado para evitar movimentos. Injectar a solução por via intradérmica, utilizando 27G ½ agulhas e seringas de 1 ml. Mudança de agulhas entre as injecções. Nota: o desafio pode ser feito no pavilhão das orelhas, em vez de as costas para as medições mais precisas. Veja vídeo em <a href="/index/Details.stp?ID=325">https://www.jove.com/index/Details.stp?ID=325</a> </li></ol> 4. Medição de DTH <ol><li> O local da injecção irão começar a transformar vermelhas e inchaço como um sinal de inflamação. Medir o diâmetro da área inflamada usando uma régua ou, melhor ainda, um paquímetro. O inchaço máxima deve ocorrer entre 24 e 72 horas. </li></ol>

<ol>
	<li>Beeton, C., Chandy, K. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+and+monitoring+of+adoptive+delayed-type+hypersensitivity+in+rats.">Induction and monitoring of adoptive delayed-type hypersensitivity in rats.</a> Journal of Visualized Experiments. 8, (2007).</li></ol>

Os autores são co-fundadores e consultores para Airmid Inc.

Para uma medição mais precisa da reação DTH recomendamos desafiando os ratos com o antígeno no pavilhão da orelha. A reação pode ser medido como uma diferença no ouvido inchaço entre o ouvido antígeno desafiou relevantes eo ouvido desafiados com solução salina, sozinho ou com o antígeno irrelevante. Uma demonstração do desafio no ouvido é mostrado na 1.

Usar reagentes estéreis soluções e seringas. As seringas de vidro e pontes 18G pode ser autoclavado. Leia folha de dados do material antes de manusear um reagente para a primeira vez e usar equipamentos de proteção adequados.

induction and monitoring of active delayed type hypersensitivity (dth) in rats

De hipersensibilidade do tipo retardado (DTH) é uma reação inflamatória mediada por linfócitos efetores CCR7-T de memória que infiltram o local da injeção de um antígeno contra o qual o sistema imunológico tem sido preparado. A reação inflamatória é caracterizada por vermelhidão e inchaço do local de desafio antigênico. É um modelo conveniente para determinar a eficácia in vivo de imunossupressores. DTH cutânea pode ser induzida ou por transferência adotiva de linfócitos T antígeno-específicos ou por imunização ativa com um antígeno e subseqüente desafio intradérmico com o antígeno para induzir a reação inflamatória da pele em uma área determinada. Respostas DTH pode ser induzida a vários antígenos, por exemplo ovalbumina, tuberculina, toxóide tetânico, ou limpet keyhole hemocianina (KLH). Aqui demonstramos como para induzir uma reação ativa DTH em ratos Lewis. Vamos primeiro preparar uma emulsão de água em óleo de KLH, nosso antígeno de interesse, em completa adjuvante de Freund e injetar este emulsão por via subcutânea a ratos. Isso vai preparar o sistema imunológico para desenvolver células de memória T direcionado para KLH. Sete dias mais tarde, vai desafiar os ratos por via intradérmica na parte traseira com KLH de um lado e com ovalbumina, um antígeno irrelevante, do outro lado. A reação inflamatória será visível 16-72 horas mais tarde, a área vermelha e inchada será medida como uma indicação da gravidade da DTH.

Watch this Scientific Journal Video about Induction and Monitoring of Active Delayed Type Hypersensitivity DTH in Rats at JoVE.com

Induction and Monitoring of Active Delayed Type Hypersensitivity DTH in Rats

De hipersensibilidade do tipo retardado (DTH) é uma reação inflamatória mediada por CCR7 efetuador linfócitos T de memória. Aqui demonstramos como induzir DTH ativa em ratos Lewis e monitorar a resposta inflamatória.

Indução e Monitoramento de hipersensibilidade do tipo retardada Ativa (DTH) em ratos

Delayed type hypersensitivity (DTH) is an inflammatory reaction mediated by CCR7- effector memory T lymphocytes that infiltrate the site of injection of ...

induction-monitoring-active-delayed-type-hypersensitivity-dth

Research

JoVE Journal

Biology

Induction and Monitoring of Active Delayed Type Hypersensitivity (DTH) in Rats

17.6K visualizações.  University of California, Irvine (UCI). De hipersensibilidade do tipo retardado (DTH) é uma reação inflamatória mediada por CCR7 efetuador linfócitos T de memória. Aqui demonstramos como induzir DTH ativa em ratos Lewis e monitorar a resposta inflamatória.

Vídeo: Induction and Monitoring of Active Delayed Type Hypersensitivity DTH in Rats

Induction and Monitoring of Adoptive Delayed-Type Hypersensitivity in Rats

Delayed type hypersensitivity (DTH) is an inflammatory reaction mediated by CCR7- effector memory T lymphocytes that infiltrate the site of injection of an antigen against which the immune system has been primed. The inflammatory reaction is characterized by redness and swelling of the site of antigenic challenge. It is a convenient model to determine the in vivo efficacy of immunosuppressants. Cutaneous DTH can be induced either by adoptive transfer of antigen-specific T lymphocytes or by active immunization with an antigen, and subsequent intradermal challenge with the antigen to induce the inflammatory reaction in a given skin area. DTH responses can be induced to various antigens, for example ovalbumin, tuberculin, tetanus toxoid, or keyhole limpet hemocyanin. Such reactions can also be induced against autoantigen, for example to myelin basic protein (MBP) in rats with experimental autoimmune encephalomyelitis induced with MBP, an animal model for multiple sclerosis (1).
Here we demonstrate how to induce an adoptive DTH reaction in Lewis rats. We will first stimulate ovalbumin-specific T cells in vitro and inject these activated cells intraperitoneally to naive rats. After allowing the cells to equilibrate in vivo for 2 days, we will challenge the rats with ovalbumin in the pinna of one ear, while the other ear wil receive saline. The inflammatory reaction will be visible 3-72 hours later and ear thickness will be measured as an indication of DTH severity.

Delayed type hypersensitivity (DTH) is an inflammatory reaction mediated by CCR7- effector memory T (TEM) lymphocytes. Here we demonstrate how to activate antigen-specific TEM cells, induce adoptive DTH in Lewis rats and monitor the inflammatory response.

Indução e Monitoramento de hipersensibilidade tardia-Type Adoptive em Ratos

Biologia

Imaging Effector Memory T cells in the Ear After Induction of Adoptive DTH

Delayed type hypersensitivity (DTH) is an immune reaction in which the main players are CCR7- effector / memory T lymphocytes. Here, we demonstrate a method for inducing and recording the progress of a DTH reaction in the rat ear. This is followed by a demonstration of the preparation of rat ear tissue for two-photon imaging of the CCR7- effector / memory T cell response.
An adoptive DTH is induced by the intraperitoneal injection of GFP-labeled Ova-specific CCR7- effector / memory T cell line (Beeton, C J. Visualized Experiments, Issue 8). Cells are then allowed to equilibrate in the rat for 48 hours before challenge by injecting one ear with saline (control ear) and the other with a 1:1 mix of Ova and Ova conjugated to Texas-Red (Ova-TR) to allow visualization of resident antigen-presenting cells.
We describe a method of tissue preparation useful for imaging the motility of cells within the deep dermal layer during an immune response, in conjunction with visualization of collagen fibers by second harmonic generation. Ear tissue is cut into 5 x 5 mm squares (slightly larger is better) and mounted onto plastic cover slips using Vetbond&trade;, which are then secured using silicone grease in an imaging chamber and superfused by oxygen-bubbled tissue culture medium at 37&deg;C.

Here we demonstrate a method for inducing and recording the progress of a delayed type-hypersensitivity (DTH) reaction in the rat ear. This is followed by a demonstration of the preparation of rat ear tissue for two-photon imaging of the effector / memory T cell response.

As células de memória efetoras T imagem no ouvido após a indução de DTH Adoptive

Delayed type hypersensitivity (DTH) is an immune reaction in which the main players are CCR7- effector / memory T lymphocytes. Here, we demonstrate a ...

Assay for Neural Induction in the Chick Embryo

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying the formation and initial patterning of the nervous system. This video demonstrates how to graft organizer tissue into a host, a method by which Hensen s node (the organizer in the chick embryo) is grafted to a host competent ectoderm. The organizer graft instructs overlying na ve tissue to adopt a neural fate via neural inducing signals. This mechanism is referred to as neural induction, and constitutes the initial step in the formation of brain and spinal cord in amniotes. This method is essentially used for the characterization of putative neural inducing molecules in chick. This video demonstrates the different steps in the assay for neural induction; First, the donnor embryo is explanted and pinned on a dish. Then, the host embryo is prepared for New culture. The graft is excised and transplanted to the host area pellucida margin. The host is cultured for 18-22 hrs. The assembly is fixed and processed for further applications (e.g. in situ hybridization). This method was originally devised by Waddington 1,2 and Gallera 3,4.

Neural induction is the first step in the formation of the brain. It is a mechanism by which Hensen's node (organizer), instructs adjacent tissue to adopt a neural fate, i.e. to give rise to the nervous system. This video demonstrates an assay for neural induction in chick embryo.

Ensaio para Indução Neural no embrião de galinha

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ...

In vitro Reconstitution of the Active T. castaneum Telomerase

Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more than a decade. Here, we present methods for the isolation of the recombinant Tribolium castaneum TERT (TcTERT) and the reconstitution of the active T. castaneum telomerase ribonucleoprotein (RNP) complex in vitro.
Telomerase is a specialized reverse transcriptase1 that adds short DNA repeats, called telomeres, to the 3' end of linear chromosomes2 that serve to protect them from end-to-end fusion and degradation. Following DNA replication, a short segment is lost at the end of the chromosome3 and without telomerase, cells continue dividing until eventually reaching their Hayflick Limit4. Additionally, telomerase is dormant in most somatic cells5 in adults, but is active in cancer cells6 where it promotes cell immortality7.
The minimal telomerase enzyme consists of two core components: the protein subunit (TERT), which comprises the catalytic subunit of the enzyme and an integral RNA component (TER), which contains the template TERT uses to synthesize telomeres8,9. Prior to 2008, only structures for individual telomerase domains had been solved10,11. A major breakthrough in this field came from the determination of the crystal structure of the active12, catalytic subunit of T. castaneum telomerase, TcTERT1.
Here, we present methods for producing large quantities of the active, soluble TcTERT for structural and biochemical studies, and the reconstitution of the telomerase RNP complex in vitro for telomerase activity assays. An overview of the experimental methods used is shown in Figure 1.

In vitro Reconstitution of the Active T. castaneum Telomerase

Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more than a decade. Here, we present methods for the isolation of the recombinant Tribolium castaneum TERT (TcTERT) and the reconstitution of the active T. castaneum telomerase ribonucleoprotein (RNP) complex in vitro.

Na reconstituição in vitro da atividade T. Telomerase castaneum

Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more ...

Induction and Testing of Hypoxia in Cell Culture

Hypoxia is defined as the reduction or lack of oxygen in organs, tissues, or cells. This decrease of oxygen tension can be due to a reduced supply in oxygen (causes include insufficient blood vessel network, defective blood vessel, and anemia) or to an increased consumption of oxygen relative to the supply (caused by a sudden higher cell proliferation rate). Hypoxia can be physiologic or pathologic such as in solid cancers 1-3, rheumatoid arthritis, atherosclerosis etc&#x2026; Each tissues and cells have a different ability to adapt to this new condition. During hypoxia, hypoxia inducible factor alpha (HIF) is stabilized and regulates various genes such as those involved in angiogenesis or transport of oxygen 4. The stabilization of this protein is a hallmark of hypoxia, therefore detecting HIF is routinely used to screen for hypoxia 5-7. 
In this article, we propose two simple methods to induce hypoxia in mammalian cell cultures and simple tests to evaluate the hypoxic status of these cells.

Here we propose simple methods to induce hypoxia in cell cultures and simple tests to evaluate the hypoxic status of the cultures.

Indução de hipóxia e Testes em Cultura de Células

Hypoxia is defined as the reduction or lack of oxygen in organs, tissues, or cells.  This decrease of oxygen tension can be due to a reduced supply in ...

Chromatographic Purification of Highly Active Yeast Ribosomes

Eukaryotic ribosomes are much more labile as compared to their eubacterial and archael counterparts, thus posing a significant challenge to researchers. Particularly troublesome is the fact that lysis of cells releases a large number of proteases and nucleases which can degrade ribosomes. Thus, it is important to separate ribosomes from these enzymes as quickly as possible. Unfortunately, conventional differential ultracentrifugation methods leaves ribosomes exposed to these enzymes for unacceptably long periods of time, impacting their structural integrity and functionality. To address this problem, we utilize a chromatographic method using a cysteine charged Sulfolink resin. This simple and rapid application significantly reduces co-purifying proteolytic and nucleolytic activities, producing high yields of intact, highly biochemically active yeast ribosomes. We suggest that this method should also be applicable to mammalian ribosomes. The simplicity of the method, and the enhanced purity and activity of chromatographically purified ribosome represents a significant technical advancement for the study of eukaryotic ribosomes.

Contamination of preparations of eukaryotic ribosomes purified by traditional methods by co-purifying nucleases and proteases negatively impacts on downstream biochemical and structural analyses. A rapid and simple chromatographic purification method is used to solve this problem using yeast ribosomes as a model system.

Purificação cromatográfica de Ribossomos Yeast Highly Active

Eukaryotic ribosomes are much more labile as compared to their eubacterial and archael counterparts, thus posing a significant challenge to researchers.  ...

Efficient Derivation of Human Cardiac Precursors and Cardiomyocytes from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based transplantation or by cardiac tissue engineering1-3. Cardiomyocytes become terminally-differentiated soon after birth and lose their ability to proliferate. There is no evidence that stem/progenitor cells derived from other sources, such as the bone marrow or the cord blood, are able to give rise to the contractile heart muscle cells following transplantation into the heart1-3. The need to regenerate or repair the damaged heart muscle has not been met by adult stem cell therapy, either endogenous or via cell delivery1-3. The genetically stable human embryonic stem cells (hESCs) have unlimited expansion ability and unrestricted plasticity, proffering a pluripotent reservoir for in vitro derivation of large supplies of human somatic cells that are restricted to the lineage in need of repair and regeneration4,5. Due to the prevalence of cardiovascular disease worldwide and acute shortage of donor organs, there is intense interest in developing hESC-based therapies as an alternative approach. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity6-8 (see a schematic in Fig. 1A). In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic9-11. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules12 (see a schematic in Fig. 1B). After screening a variety of small molecules and growth factors, we found that such defined conditions rendered nicotinamide (NAM) sufficient to induce the specification of cardiomesoderm direct from pluripotent hESCs that further progressed to cardioblasts that generated human beating cardiomyocytes with high efficiency (Fig. 2). We defined conditions for induction of cardioblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human cardiac cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of cardioblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human cardiac progenitors and functional cardiomyocytes for cardiovascular repair.

Derivação eficiente dos recursos humanos Precursores cardíaca e Cardiomyocytes pluripotentes a partir de células estaminais embrionárias humanas com a indução de moléculas pequenas

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based ...

Long-term Lethal Toxicity Test with the Crustacean Artemia franciscana

Our research activities target the use of biological methods for the evaluation of environmental quality, with particular reference to saltwater/brackish water and sediment. The choice of biological indicators must be based on reliable scientific knowledge and, possibly, on the availability of standardized procedures. In this article, we present a standardized protocol that used the marine crustacean Artemia to evaluate the toxicity of chemicals and/or of marine environmental matrices. Scientists propose that the brine shrimp (Artemia) is a suitable candidate for the development of a standard bioassay for worldwide utilization. A number of papers have been published on the toxic effects of various chemicals and toxicants on brine shrimp (Artemia). The major advantage of this crustacean for toxicity studies is the overall availability of the dry cysts; these can be immediately used in testing and difficult cultivation is not demanded1,2. Cyst-based toxicity assays are cheap, continuously available, simple and reliable and are thus an important answer to routine needs of toxicity screening, for industrial monitoring requirements or for regulatory purposes3. The proposed method involves the mortality as an endpoint. The numbers of survivors were counted and percentage of deaths were calculated. Larvae were considered dead if they did not exhibit any internal or external movement during several seconds of observation4. This procedure was standardized testing a reference substance (Sodium Dodecyl Sulfate); some results are reported in this work. This article accompanies a video that describes the performance of procedural toxicity testing, showing all the steps related to the protocol.

Long-term Lethal Toxicity Test with the Crustacean Artemia franciscana

This study concerns the development and standardization of a valuable methodological protocol to determine long-term (14 days) lethal toxicity exerted by chemical substances, industrial wastewater or sewage and liquid environmental samples on the saltwater crustacean, Artemia franciscana.

A longo prazo de Teste de toxicidade letal com o crustáceo Artemia franciscana</em

Our research activities target the use of biological methods for the evaluation of environmental quality, with particular reference to saltwater/brackish ...

In Vitro Synthesis of Modified mRNA for Induction of Protein Expression in Human Cells

The exogenous delivery of coding synthetic messenger RNA (mRNA) for induction of protein synthesis in desired cells has enormous potential in the fields of regenerative medicine, basic cell biology, treatment of diseases, and reprogramming of cells. Here, we describe a step by step protocol for generation of modified mRNA with reduced immune activation potential and increased stability, quality control of produced mRNA, transfection of cells with mRNA and verification of the induced protein expression by flow cytometry. Up to 3 days after a single transfection with eGFP mRNA, the transfected HEK293 cells produce eGFP. In this video article, the synthesis of eGFP mRNA is described as an example. However, the procedure can be applied for production of other desired mRNA. Using the synthetic modified mRNA, cells can be induced to transiently express the desired proteins, which they normally would not express.

In Vitro Synthesis of Modified mRNA for Induction of Protein Expression in Human Cells

In this video article, we describe the in vitro synthesis of modified mRNA for induction of protein expression in cells.

In Vitro Síntese de ARNm de modificação para indução da expressão da proteína em células humanas

The exogenous delivery of coding synthetic messenger RNA (mRNA) for induction of protein synthesis in desired cells has enormous potential in the fields ...

Experimental Protocol for Using Drosophila As an Invertebrate Model System for Toxicity Testing in the Laboratory

Emergent properties and external factors (population-level and ecosystem-level interactions, in particular) play important roles in mediating ecologically-important endpoints, though they are rarely considered in toxicological studies. D. melanogaster is emerging as a toxicology model for the behavioral, neurological, and genetic impacts of toxicants, to name a few. More importantly, species in the genus Drosophila can be utilized as a model system for an integrative framework approach to incorporate emergent properties and answer ecologically-relevant questions in&#160;toxicology research. The aim of this paper is to provide a protocol for exposing species in the genus Drosophila to pollutants to be used as a model system for a range of phenotypic outputs and ecologically-relevant questions. More specifically, this protocol can be used to 1) link multiple biological levels of organization and understand the impact of toxicants on both individual- and population-level fitness; 2) test the impact of toxicants at different stages of developmental exposure; 3) test multigenerational and evolutionary implications of pollutants; and 4) test multiple contaminants and stressors simultaneously.

Experimental Protocol for Using Drosophila As an Invertebrate Model System for Toxicity Testing in the Laboratory

In this paper, we provide a detailed protocol for exposing species in the genus Drosophila to pollutants with the goal of studying the impact of exposure on a range of phenotypic outputs at different developmental stages and for more than one generation.