transforming-growth-factor-beta and Poultry-Diseases

Campylobacteriosis is mainly caused by infection with Campylobacter jejuni following consumption or handling of Campylobacter-contaminated poultry meat. The aim of this study was to investigate the effect of probiotic Enterococcus faecium AL41 on TGF-β4 and IL-17 expression and on immunocompetent cell distribution after C. jejuni infection in broiler chicken, as a second part of the previous study of Karaffová et al. (2017). Accordingly, day-old chicks were randomly divided into four experimental groups of 10 chicks each (n = 10): control (C), E. faecium AL41 (EFAL41), C. jejuni CCM6191 (CJ), and combined E. faecium AL41 + C. jejuni CCM6191 (EFAL41 + CJ). Samples from the caecum were collected on days 4 and 7 post Campylobacter infection (dpi), for the isolation of mRNA of TGF-β4, IL-17 and for immunohistochemistry. The relative mRNA expression of TGF-β4 was upregulated in the combined (EFAL41 + CJ) group compared to other groups during both samplings, but the expression of IL-17 was downregulated. Similarly, the highest density of CD3+ was detected in the combined group at 7 dpi, but the number of IgA+ cells was increased in both groups with EFAL41. It was concluded that the EFAL41 probiotic E. faecium strain can modulate the expression of selected cytokines (upregulation of TGF-β4 but downregulation of IL-17 relative expression), and activate IgA-producing cells in the caeca of chicks infected with C. jejuni CCM6191.

Topics: Animals; Campylobacter Infections; Campylobacter jejuni; Chickens; Enterococcus faecium; Gene Expression Regulation; Interleukin-17; Poultry Diseases; Probiotics; Transforming Growth Factor beta

Avian pathogenic

Topics: Animals; Chickens; Escherichia coli; Escherichia coli Infections; Macrophages; MicroRNAs; Poultry Diseases; Transforming Growth Factor beta

Fibrosis has also been recorded as a prominent pathological feature within wooden breast (WB) myopathy of broiler chickens. This study was conducted to evaluate the accumulation of fibril collagen, deposition of the extracellular matrix (ECM) components, and the underlying mechanism mediating the pathogenic fibrotic process in the pectoralis major (PM) muscle of WB-affected birds. Broiler chickens were categorized into the control and WB groups based on the evaluation of myopathic lesions. Results indicated that the total content and area of collagen in cross-sections of the PM muscle, as well as the augmented expression of collagen-I and fibronectin in the ECM, were greatly increased in birds with WB. Wooden breast myopathy upregulated expressions of transforming growth factor-beta (TGF-β) and the phosphorylation of Smad 2 and 3, thereby activating TGF-β-mediated Smad signaling pathway, which further enhanced the transcription of profibrotic mediators. In addition, regulators involved in collagen biosynthesis and cross-linking including prolyl 4-hydroxylase, lysyl oxidase, lysyl hydroxylase, and decorin were increased in the WB muscle. Finally, the expressions of both matrix metalloproteinases (MMP) and tissue inhibitor of metalloproteinases (TIMP) were increased in the WB muscle, which might be related with reduced ECM remodeling. Overall, WB myopathy induces severe fibrosis by enhancing ECM deposition and collagen cross-linking in the PM muscle of broiler chickens, possibly via the activation of TGF-β signaling and the dysregulation of the MMP and TIMP system.

Topics: Animals; Chickens; Fibrosis; Muscular Diseases; Pectoralis Muscles; Poultry Diseases; Signal Transduction; Transforming Growth Factor beta

Adjuvant enhancing mucosal immune response is preferred in controlling many pathogens at the portal of entry. Earlier, we reported that a toll-like-receptor 7 (TLR7) agonist, resiquimod (R-848), stimulated the systemic immunity when adjuvanted with the inactivated Newcastle disease virus vaccine in the chicken. Here, we report the effect of R-848 when adjuvanted with live or inactivated avian infectious bronchitis virus (IBV) vaccines with special emphasis on mucosal immunity. Specific pathogen free (SPF) chicks (n = 60) were equally divided into six groups at two weeks of age and immunized with either inactivated or live IBV vaccine adjuvanted with or without R-848. Groups that received either PBS or R-848 served as control. A booster was given on 14 days post-immunization (dpi). R-848 enhanced the antigen specific humoral and cellular immune responses when co-administered with the vaccines as evidenced by an increase in the antibody titre in ELISA and stimulation index in lymphocyte transformation test (LTT) till 35 dpi and increased proportion of CD4

Topics: Adjuvants, Immunologic; Animals; Antibodies, Viral; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Chickens; Coronavirus Infections; Disease Models, Animal; Imidazoles; Immunity; Immunity, Cellular; Immunity, Humoral; Immunity, Mucosal; Immunization; Immunoglobulin A; Infectious bronchitis virus; Leukocytes, Mononuclear; Poultry Diseases; Specific Pathogen-Free Organisms; Transforming Growth Factor beta; Vaccination; Vaccines, Attenuated; Vaccines, Inactivated; Viral Vaccines

Both CCR5 and CXCR4 are important chemokine receptors and take vital role in migration, development and distribution of T cells, however, whether they will influence the process of T cell infiltration into bursa of Fabricius during infectious bursal disease virus (IBDV) infection is unclear. In the current study, CCR5 and CXCR4 antagonists, Maraviroc and AMD3100, were administrated into chickens inoculated with IBDV, and the gene levels of IBDV VP2, CCR5, CXCR4 and related cytokines were determined by real-time PCR. The results showed that large number of T cells began to migrate into the bursae on Day 3 post infection with IBDV and the mRNA of chemokine receptors CCR5 and CXCR4 began to increase on Day 1. Moreover, antagonist treatments have increased the VP2, CCR5 and CXCR4 gene transcriptions and influenced on the gene levels of IL-2, IL-6, IL-8, IFN-γ, TGF-β4, MHC-I and MDA5. In conclusion, the chemokine receptors CCR5 and CXCR4 might influence virus replication during IBDV infection and further study would focus on the interaction between chemokine receptors and their ligands.

Topics: Animals; Benzylamines; Bursa of Fabricius; CCR5 Receptor Antagonists; Cell Movement; Chickens; Cyclams; Cyclohexanes; Cytokines; Heterocyclic Compounds; Infectious bursal disease virus; Interferon-gamma; Interleukin-2; Interleukin-6; Interleukin-8; Maraviroc; Poultry Diseases; Real-Time Polymerase Chain Reaction; Receptors, CCR5; Receptors, Chemokine; Receptors, CXCR4; RNA, Messenger; T-Lymphocytes; Transcription, Genetic; Transforming Growth Factor beta; Triazoles; Viral Structural Proteins; Virus Replication

The relative mRNA expression of IgA, TGF-β4, IL-17, and concentration of secretory IgA (sIgA) in small intestine of chickens pretreated with Enterococcus faecium AL41 and challenged with Salmonella Enteritidis PT4 were studied. Salmonella-free day-old chicks (40) Cobb 500 breed, were divided into four groups of 10 chicks each (n = 10): control (C), treated with E. faecium AL41 strain (EFAL41), challenged with Salmonella Enteritidis PT4 (SE), and combined (EFAL41+SE). Expression of IgA and sIgA concentration was upregulated in EFAL41 group in jejunum and ileum on 4 days post-Salmonella infection (dpi). Chicks in combined group demonstrated upregulation of cytokines and IgA expression, and increased sIgA concentration in the intestine flush on 7 dpi. The experiment demonstrated beneficial effect of E. faecium AL41 on IgA production and secretion in intestine. Findings also indicated that IgA played important role in decrease of S. Enteritidis in the intestine, and cytokines TGF-β4 and IL-17 contributed to the increased IgA secretion.

Topics: Animal Feed; Animals; Avian Proteins; Chickens; Cytokines; Diet; Enterococcus faecium; Enzyme-Linked Immunosorbent Assay; Immunoglobulin A; Interleukin-17; Intestine, Small; Poultry Diseases; Probiotics; Random Allocation; Real-Time Polymerase Chain Reaction; RNA, Messenger; Salmonella enteritidis; Salmonella Infections, Animal; Transforming Growth Factor beta; Up-Regulation

Potent vaccine efficiency is crucial for disease control in both human and livestock vaccination programmes. Free range chickens and chickens with access to outdoor areas have a high risk of infection with parasites including Ascaridia galli, a gastrointestinal nematode with a potential influence on the immunological response to vaccination against other infectious diseases. The purpose of this study was to investigate whether A. galli infection influences vaccine-induced immunity to Newcastle Disease (ND) in chickens from an MHC-characterized inbred line. Chickens were experimentally infected with A. galli at 4 weeks of age or left as non-parasitized controls. At 10 and 13 weeks of age half of the chickens were ND-vaccinated and at 16 weeks of age, all chickens were challenged with a lentogenic strain of Newcastle disease virus (NDV). A. galli infection influenced both humoral and cell-mediated immune responses after ND vaccination. Thus, significantly lower NDV serum titres were found in the A. galli-infected group as compared to the non-parasitized group early after vaccination. In addition, the A. galli-infected chickens showed significantly lower frequencies of NDV-specific T cells in peripheral blood three weeks after the first ND vaccination as compared to non-parasitized chickens. Finally, A. galli significantly increased local mRNA expression of IL-4 and IL-13 and significantly decreased TGF-ß4 expression in the jejunum two weeks after infection with A. galli. At the time of vaccination (six and nine weeks after A. galli infection) the local expression in the jejunum of both IFN-? and IL-10 was significantly decreased in A. galli-infected chickens. Upon challenge with the NDV LaSota strain, viral genomes persisted in the oral cavity for a slightly longer period of time in A. galli-infected vaccinees as compared to non-parasitized vaccinees. However, more work is needed in order to determine if vaccine-induced protective immunity is impaired in A. galli-infected chickens.

Topics: Animals; Antibodies, Viral; Ascaridia; Ascaridiasis; Chickens; Gene Expression Profiling; Immune Tolerance; Interleukin-13; Interleukin-4; Jejunum; Leukocytes, Mononuclear; Newcastle Disease; Newcastle disease virus; Poultry Diseases; Transforming Growth Factor beta; Viral Vaccines

Infection of chicken with Salmonella may lead to a carrier-state characterized by the persistence of bacteria in the ceca for a long period of time and result in their excretion in feces. This excretion is the source of contamination of their congeners and food. During infection, enterocytes are the primary target cells for Salmonella, the producers of soluble factors which launch immune response and cells which are reciprocally responsive to surrounding immune cells. This study used microarrays to compare the gene expression profile during carrier-state of enterocytes purified from infected and control chicks which are either resistant or susceptible to Salmonella Enteritidis carrier-state. In total, we identified 271 genes significantly differentially expressed with an absolute fold change greater than 1.5. A global analysis determined interaction networks between differentially regulated genes. Using an a priori approach, our analyses focused on differentially expressed genes which were transcriptionally linked to cytokines playing a major role in the fate of the immune response. The expression of genes transcriptionally linked to type I interferon and TGF-β was down-regulated in infected chicks from both lines. Gene expression linked to the Th1 axis suggests the latter is inhibited in both lines. Finally, the expression of genes linked to IL-4, IL-5 and IL-13 indicates that susceptibility to carrier-state could be associated with a Th2 bias. Overall, these results highlight that the response to Salmonella during the acute phase and carrier-state is different and that enterocytes play a central role in this response.

Topics: Animals; Carrier State; Chickens; Disease Susceptibility; Enterocytes; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Interferon Type I; Oligonucleotide Array Sequence Analysis; Poultry Diseases; Real-Time Polymerase Chain Reaction; Salmonella enteritidis; Salmonella Infections, Animal; Specific Pathogen-Free Organisms; Transforming Growth Factor beta

Transforming growth factor beta (TGF β ) is a family of genes that play a key role in mediating tissue remodeling in various forms of acute and chronic lung disease. In order to assess their role on pulmonary hypertension in broilers, we determined mRNA expression of genes of the TGF β family and endothelin 1 in lung samples from 4-week-old chickens raised either under normal or cold temperature conditions. Both in control and cold-treated groups of broilers, endothelin 1 mRNA expression levels in lungs from ascitic chickens were higher than levels from healthy birds (P < 0.05), whereas levels in animals with cardiac failure were intermediate. Conversely, TGF β 2 and TGF β 3 gene expression in lungs were higher in healthy animals than in ascitic animals in both groups (P < 0.05). TGF β 1, T β RI, and T β RII mRNA gene expression among healthy, ascitic, and chickens with cardiac failure showed no differences (P > 0.05). BAMBI mRNA gene expression was lowest in birds with ascites only in the control group as compared with the values from healthy birds (P < 0.05).

Topics: Animals; Chickens; Endothelin-1; Gene Expression Regulation; Hypertension, Pulmonary; Ligands; Lung; Male; Poultry Diseases; Receptors, Transforming Growth Factor beta; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta

Although IL-17 is a key factor in Th17 lineage host responses and plays critical roles in immunological control of a variety of infectious diseases, the contribution of IL-17 to immune function during Eimeria tenella infection is unknown. In the present study, we used an experimental E. tenella infection model to clarify the role of Th17-associated response in the resulting immune response by quantitative real-time PCR assays. We observed robust production of STAT-3 (the transcription factors), IL-1β, IL-6 and IL-17 in cecal intraepithelial lymphocytes during the early infection, peaking at 6h p.i. and declining thereafter. The expression of TGF-β was moderately upregulated and had 2 peaks at 6 and 72h p.i. during the early infection. To further investigate the role of chIL-17 during the infection, we treated the infected chickens with IL-17 and its neutralized antibody. As a result, the reduced fecal oocyst shedding and cecal lesion scores, but enhanced body weight gains were observed in IL-17 neutralized chickens. The results of histopathology showed that the neutrophils recruitment diminished and the parasite burden in IL-17 neutralized chickens decreased. These results may be due to the significant decrease in the production of IL-17, IL-6 and TGF-β, but enhanced IL-12 and IFN-γ expression in IL-17 neutralized chickens. The converse results were shown in IL-17 treated infected-chickens in which chickens showed increased fecal oocyst shedding, exacerbated lesion scores, and reduced body weight gains. These results suggested that chicken IL-17 might mediate E. tenella - induced immunopathology during the infection.

Topics: Animals; Antibodies, Protozoan; Cecum; Chickens; Cloning, Molecular; Coccidiosis; Eimeria tenella; Feces; Gene Expression Regulation; Interferon-gamma; Interleukin-12; Interleukin-17; Interleukin-1beta; Interleukin-6; Neutrophils; Polymerase Chain Reaction; Poultry Diseases; Rabbits; Recombinant Proteins; Specific Pathogen-Free Organisms; STAT3 Transcription Factor; Th17 Cells; Transforming Growth Factor beta; Weight Gain

Resistance to pathogens such as Salmonella enteritidis (SE) is a heritable trait important in maintaining the health of chickens and reducing bacterial contamination of poultry products. In chickens, heterophils act as the first responders to bacterial infections and are, therefore, responsible for initiating the immune response against SE challenge. This study measured mRNA expression of several immune response genes [interleukin-6 (IL-6), IL-10, transforming growth factor-beta4 (TGF-beta4), granulocyte macrophage-colony stimulating factor (GM-CSF), and Toll-like receptor-4 (TLR-4)] by heterophils from broiler, Leghorn, and Fayoumi chickens, either non-stimulated or stimulated in vitro with SE using quantitative reverse-transcriptase PCR. We found that heterophils of commercially selected broiler and Leghorn birds had differing early heterophil responses to SE in comparison with the native Fayoumi line. Heterophil stimulation with SE in vitro increased expression of pro- (IL-6 and GM-CSF) and anti-inflammatory cytokine mRNA (IL-10 and TGF-beta4) in the Fayoumi line, while the broiler and Leghorn line heterophils had decreased or no changes in the cytokine gene expression levels. The unique response of the Fayoumi line is in contrast to the lines with a history of genetic selection to increase growth or reproduction, a process which may favor reduced or suppressed inflammatory responses. The findings illustrate the potential value of native lines to provide biodiversity to enhance innate health in commercially selected poultry.

Topics: Animals; Chickens; Cytokines; Gene Expression; Granulocyte-Macrophage Colony-Stimulating Factor; Granulocytes; In Vitro Techniques; Interleukin-10; Interleukin-6; Poultry Diseases; Quantitative Trait, Heritable; RNA, Messenger; Salmonella enteritidis; Salmonella Infections, Animal; Species Specificity; Toll-Like Receptor 4; Transforming Growth Factor beta

Myoblast-extracellular matrix interactions play a pivotal role in skeletal muscle development. Transforming growth factor-beta (TGF-beta) is a key regulator of muscle cell proliferation and differentiation. The level of TGF-beta expressed will affect the concentration of the extracellular matrix proteoglycan decorin and the cell surface beta1 integrin subunit. The decorin proteoglycan is a regulator of cell growth as well as the organization of the extracellular matrix. The beta1 integrin plays a role in muscle cell attachment, migration, and the formation of multinucleated myotubes. In the current study, chicken myogenic satellite cells isolated from the pectoralis major muscle from the chicken genetic muscle weakness, low score normal (LSN), and normal pectoralis major muscle were used to investigate TGF-beta expression as it relates to decorin and beta1 integrin mRNA expression. The LSN muscle defect is characterized by altered myotube formation and sarcomere structure, and the satellite cells have reduced proliferation and differentiation. The mRNA expression was measured by real-time quantitative reverse transcription PCR. The LSN condition has elevated expression of TGF-beta2 and TGF-beta4 with increased expression of decorin and decreased beta1 integrin during myogenic satellite cell proliferation and differentiation. Normal satellite cell cultures were treated with the addition of exogenous TGF-beta during differentiation to determine if the altered expression of LSN decorin and beta1 integrin was associated with TGF-beta expression. The addition of exogenous TGF-beta decreased decorin expression during differentiation and reduced beta1 integrin expression at 24 and 48 h of differentiation. These results suggested that alteration of decorin expression in the LSN myogenic satellite cells may occur by a mechanism involving factors in addition to TGF-beta, but the addition of exogenous TGF-beta did affect both decorin and beta1 integrin expression. These data, therefore, suggested that TGF-beta might play a pivotal role in chicken skeletal muscle formation through modulation of the expression of both extracellular matrix molecules and cellular receptors important in the control of cell migration and growth regulation.

Topics: Animals; Cell Differentiation; Cell Division; Chickens; Decorin; Extracellular Matrix Proteins; Gene Expression; Integrin beta1; Muscle Weakness; Muscle, Skeletal; Polymerase Chain Reaction; Poultry Diseases; Proteins; Proteoglycans; RNA, Messenger; Satellite Cells, Skeletal Muscle; Transforming Growth Factor beta; Transforming Growth Factor beta2

To identify cell types and genes that are differentially expressed during immunopathogenesis of avian reovirus (ARV)-induced viral arthritis (VA), we inoculated arthrotropic strain S1133 of ARV into 1-day-old broilers, and examined tissue histology as well as RNA expression at different days post-inoculation (PI). Using immunohistochemical staining, we detected many CD68 expressing macrophages in and around the blood vessels of the arthritic joints. By RT-PCR, we found that expression of matrix metalloproteinase-2 (MMP-2) and bone morphogenetic protein-2 (BMP-2) was induced earlier in footpads and hock joints of ARV-infected chickens. By employing suppression subtractive hybridization (SSH) technique and RT-PCR, we further identified that small subunit of U2 snRNP auxiliary factor (U2AF35 or U2AF1) mRNA was differentially induced in the joint of ARV-infected chickens. By in situ hybridization (ISH), mRNA signals of U2AF35 and BMP-2 were located in chondrocytes within/near the epiphyseal plate and secondary center of ossification, and in epidermal cells and dermal fibroblast-like cells of arthritic joints. In addition, U2AF35 mRNA was expressed in the inflammatory infiltrates of the bone marrow of ARV-infected arthritic joints, while MMP-2 was mainly detected in chondrocytes. Interestingly, among U2AF35, MMP-2, and BMP-2 that were differentially expressed in the joint of ARV-infected chickens, only U2AF35 induction correlated well with arthritic manifestation. Because U2AF35 may assist in mRNA splicing of proinflammatory chemokines and cytokines, our results indicated that U2AF35 induction might play an immunopathological role in ARV-induced arthritis. This study has first associated U2AF35 to viral arthritis.

Topics: Animals; Antibodies, Viral; Arthritis, Infectious; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; Chickens; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Immunohistochemistry; In Situ Hybridization; Joints; Matrix Metalloproteinase 2; Nuclear Proteins; Orthoreovirus, Avian; Poultry Diseases; Reoviridae Infections; Reverse Transcriptase Polymerase Chain Reaction; Ribonucleoproteins; RNA, Messenger; Specific Pathogen-Free Organisms; Splicing Factor U2AF; Transforming Growth Factor beta

We recently showed that increased in vitro heterophil functional efficiency translates to increased in vivo resistance to a systemic Salmonella enteritidis (SE) infection utilizing a parental pair of broiler chickens (lines A and B) and the F1 reciprocal crosses (C and D). Heterophils produce cytokines and modulate acute protection against Salmonella in young poultry. Therefore, we hypothesize that heterophils from SE-resistant chickens (A and D) have the ability to produce an up-regulated pro-inflammatory cytokine response compared to that of heterophils from SE-susceptible chickens (B and C). In this study, heterophils were isolated from day-old chickens and treated with either RPMI-1640 (as the control), or phagocytic agonists (SE, or SE opsonized with either normal chicken serum or immune serum against SE) and cytokine mRNA expression assessed using real-time quantitative reverse transcription-polymerase chain reaction. Heterophils from SE-resistant chickens (A and D) had significantly higher levels of pro-inflammatory cytokine (interleukin (IL)-6, IL-8, and IL-18) mRNA expression upon treatment with all agonists compared to heterophils from SE-susceptible lines (B and C). Further, heterophils from SE-resistant chickens had significantly decreased mRNA expression levels of transforming growth factor-beta4, an anti-inflammatory cytokine, when compared to heterophils from SE-susceptible chickens. These data indicate cytokine gene expression in heterophils may be a useful parameter in determining resistance to Salmonella, as indicated by our previous in vivo SE studies. Therefore, heterophil functional efficiency and cytokine production may be useful biomarkers for poultry breeders to consider when developing new immunocompetent lines of birds.

Topics: Animals; Chickens; Cytokines; Disease Susceptibility; Gene Expression; Immunocompetence; Interleukin-18; Interleukin-6; Interleukin-8; Neutrophils; Poultry Diseases; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Salmonella Infections, Animal; Transforming Growth Factor beta

A linkage disequilibrium approach with microsatellites was employed to investigate QTL affecting immune response. Highly inbred males of two MHC-congenic Fayoumi chicken lines were mated with highly inbred G-B1 Leghorn hens. Adult F2 hens (n = 158) were injected twice with SRBC and fixed Brucella abortus (BA). Agglutinating antibody titers were measured. Secondary phase parameters of maximum titers (Ymax) and time (Tmax) needed to achieve Ymax were estimated from postsecondary titers by using a nonlinear regression model. A three-step genotype strategy (DNA pooling, selective genotyping, and whole population genotyping) was used to identify microsatellite markers that are associated with immune response to SRBC and BA. The linkage distances between adjacent markers in the F2 population were estimated by Crimap. The QTL affecting immune response to SRBC and BA were detected based on F statistic by interval mapping. A total of five significant QTL, as determined by a permutation test, were detected at the 5% chromosome-wise level on Chromosomes 3, 5, 6, and Z. Two (Chromosome 3 and 6) of five QTL were significant at the 1% chromosome-wise level. The variance explained by the QTL ranged from 6.46 to 7.50%. The results suggest that regions on Chromosomes 3, 5, 6, and Z contain QTL that affect antibody kinetics in the hen.

Topics: Agglutination Tests; Animals; Antibodies, Bacterial; Antibody Formation; Brucella abortus; Brucellosis; Chickens; Chromosome Mapping; Female; Gene Frequency; Genotype; Kinetics; Linkage Disequilibrium; Male; Microsatellite Repeats; Poultry Diseases; Quantitative Trait Loci; Transforming Growth Factor beta

Astroviruses are a leading cause of infantile viral gastroenteritis worldwide. Very little is known about the mechanisms of astrovirus-induced diarrhea. One reason for this is the lack of a small-animal model. Recently, we isolated a novel strain of astrovirus (TAstV-2) from turkeys with the emerging infectious disease poult enteritis mortality syndrome. In the present studies, we demonstrate that TAstV-2 causes growth depression, decreased thymus size, and enteric infection in infected turkeys. Infectious TAstV-2 can be recovered from multiple tissues, including the blood, suggesting that there is a viremic stage during infection. In spite of the severe diarrhea, histopathologic changes in the intestine were mild and there was a surprising lack of inflammation. This may be due to the increased activation of the potent immunosuppressive cytokine transforming growth factor beta during astrovirus infection. These studies suggest that the turkey will be a useful small-animal model with which to study astrovirus pathogenesis and immunity.

Topics: Animals; Astroviridae Infections; Cell Death; Cell Line; Diarrhea; Female; Humans; Inflammation; Male; Mamastrovirus; Poult Enteritis Mortality Syndrome; Poultry Diseases; Transforming Growth Factor beta; Turkeys

Eight chicken cytokine genes (IL-1beta, IL-2, IL-8, IL-15, IFN-alpha, IFN-gamma, TGF-beta4, lymphotactin) were evaluated for their adjuvant effect on a suboptimal dose of an Eimeria DNA vaccine carrying the 3-1E parasite gene (pcDNA3-1E). Chickens were given two subcutaneous injections with 50 microg of the pcDNA3-1E vaccine plus a cytokine expression plasmid 2 weeks apart and challenged with Eimeria acervulina 1 week later. IFN-alpha (1 microg) or 10 microg of lymphotactin expressing plasmids, when given simultaneously with the pcDNA3-1E vaccine, significantly protected against body weight loss induced by E. acervulina. Parasite replication was significantly reduced in chickens given the pcDNA3-1E vaccine along with 10 microg of the IL-8, lymphotactin, IFN-gamma, IL-15, TGF-beta4, or IL-1beta plasmids compared with chickens given the pcDNA3-1E vaccine alone. Flow cytometric analysis of duodenum intraepithelial lymphocytes showed chickens that received the pcDNA3-1E vaccine simultaneously with the IL-8 or IL-15 genes had significantly increased CD3+ cells compared with vaccination using pcDNA3-1E alone or in combination with the other cytokine genes tested. These results indicate that the type and the dose of cytokine genes injected into chickens influence the quality of the local immune response to DNA vaccination against coccidiosis.

Topics: Adjuvants, Immunologic; Animals; Chickens; Coccidiosis; Drug Evaluation, Preclinical; Duodenum; Eimeria; Genetic Vectors; Interferon-alpha; Interferon-gamma; Interferons; Interleukin-1; Interleukin-15; Interleukin-2; Interleukin-8; Interleukins; Lymphokines; Parasite Egg Count; Poultry Diseases; Sialoglycoproteins; Specific Pathogen-Free Organisms; Transforming Growth Factor beta; Vaccination; Vaccines, DNA; Weight Gain

Since the outbreak in humans of an H5N1 avian influenza virus in Hong Kong in 1997, poultry entering the live-bird markets of Hong Kong have been closely monitored for infection with avian influenza. In March 1999, this monitoring system detected geese that were serologically positive for H5N1 avian influenza virus, but the birds were marketed before they could be sampled for virus. However, viral isolates were obtained by swabbing the cages that housed the geese. These samples, known collectively as A/Environment/Hong Kong/437/99 (A/Env/HK/437/99), contained four viral isolates, which were compared to the 1997 H5N1 Hong Kong isolates. Analysis of A/Env/HK/437/99 viruses revealed that the four isolates are nearly identical genetically and are most closely related to A/Goose/Guangdong/1/96. These isolates and the 1997 H5N1 Hong Kong viruses encode common hemagglutinin (H5) genes that have identical hemagglutinin cleavage sites. Thus, the pathogenicity of the A/Env/HK/437/99 viruses was compared in chickens and in mice to evaluate the potential for disease outbreaks in poultry and humans. The A/Env/HK/437/99 isolates were highly pathogenic in chickens but caused a longer mean death time and had altered cell tropism compared to A/Hong Kong/156/97 (A/HK/156/97). Like A/HK/156/97, the A/Env/HK/437/99 viruses replicated in mice and remained localized to the respiratory tract. However, the A/Env/HK/437/99 isolates caused only mild pathological lesions in these tissues and no clinical signs of disease or death. As a measure of the immune response to these viruses, transforming growth factor beta levels were determined in the serum of infected mice and showed elevated levels for the A/Env/HK/437/99 viruses compared to the A/HK/156/97 viruses. This study is the first to characterize the A/Env/HK/437/99 viruses in both avian and mammalian species, evaluating the H5 gene from the 1997 Hong Kong H5N1 isolates in a different genetic background. Our findings reveal that at least one of the avian influenza virus genes encoded by the 1997 H5N1 Hong Kong viruses continues to circulate in mainland China and that this gene is important for pathogenesis in chickens but is not the sole determinant of pathogenicity in mice. There is evidence that H9N2 viruses, which have internal genes in common with the 1997 H5N1 Hong Kong isolates, are still circulating in Hong Kong and China as well, providing a heterogeneous gene pool for viral reassortment. The implications of these findin

Topics: Animals; Chickens; China; Disease Outbreaks; Hemagglutinin Glycoproteins, Influenza Virus; Hong Kong; Humans; Immunohistochemistry; Influenza A virus; Influenza A Virus, H5N1 Subtype; Influenza in Birds; Male; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Phylogeny; Poultry Diseases; Sequence Homology, Nucleic Acid; Transforming Growth Factor beta

Immunolocalization of transforming growth factor-beta1 (TGF-beta1) was determined in growth plates of two lines of broiler chickens with low and high incidences of tibial dyschondroplasia (TD). Ultrathin sections of growth plates from each line were treated with a polyclonal antibody specific for TGF-beta1, followed by colloidal gold-labeled protein A. Immunolocalization for TGF-beta1 was observed in chondrocytes of all zones of growth plates of low and high TD incidence lines. However, immunolocalization in extracellular matrix was restricted to the hypertrophic zones of both lines. In the hypertrophic zone of low TD incidence line, immunolocalization of TGF-beta1 in the extracellular matrix adjacent to collapsed cartilage canals (matrix streaks) was significantly greater than immunolocalization between patent cartilage canals. A similar increase was not observed in the high TD incidence line. Results indicate that chondrocytes of all zones of the growth plate contain TGF-beta1 but do not release it into extracellular matrix until hypertrophy has occurred. Greater concentrations of TGF-beta1 adjacent to collapsed cartilage canals may play a role in controlling angiogenesis and directing invasion of mineralized hypertrophic cartilage by metaphyseal blood vessels. A low concentration of TGF-beta1 in the extracellular matrix adjacent to collapsed cartilage canals of the high TD incidence line may be a factor in limiting vascular invasion of dyschondroplastic cartilage of TD lesions.

Topics: Animals; Chickens; Chondrocytes; Growth Plate; Immunohistochemistry; Osteochondrodysplasias; Poultry Diseases; Tibia; Transforming Growth Factor beta

The avian Low Score Normal (LSN) genetic muscle weakness is phenotypically characterized by a reduction in the ability of birds to right themselves from a supine position. In previous studies, LSN birds exhibited elevated levels of decorin transcript and protein at embryonic Day 20 and a large increase in collagen crosslinking at 6 wk posthatch. Transforming growth factor-beta (TGF-beta) expression has been reported to control decorin expression. Steady state levels of TGF-beta1 and TGF-beta2 transcripts were determined in ovo and posthatch in order to initiate an investigation of the mechanism underlying decorin expression. On embryonic Day 20 through 1 wk posthatch, TGF-beta2 transcript levels were elevated, whereas an increase in TGF-beta1 was only noted at 1 d posthatch. These data suggest that the increase in decorin expression may be associated with a modification in a TGF-beta signal transduction pathway.

Topics: Aging; Animals; Chick Embryo; Chickens; Decorin; Extracellular Matrix Proteins; Gene Expression Regulation, Developmental; Muscle Development; Muscle, Skeletal; Muscular Dystrophy, Animal; Poultry Diseases; Proteoglycans; Transcription, Genetic; Transforming Growth Factor beta

Immunoreactive growth factors were identified in chick embryonic cartilage and bone, and in the growth plate of normal tibiotarsi and tibiotarsi affected with tibial dyschondroplasia (TD). A specific pattern of temporal and spatial expression was observed for each growth factor. Transforming growth factor beta and alpha (TGF beta and TGF alpha) and epidermal growth factor (EGF) were briefly expressed in chondrocytes of early chick embryos. Immunolabelling for TGF beta then gradually shifted into cartilaginous matrix and was not observed in cytoplasm of hypertrophic chondrocytes until the late embryonic and post-hatch stages. The distribution and intensity of TGF beta labelling was the same in chondrocytes of the TD and normal growth plate. Insulin-like growth factor I (IGF-I) labelling persisted from the early embryonic stage to the end of the mid-stage and then disappeared from chondrocytes. IGF-I appeared again in chondrocytes 1-2 days before hatching. After hatching, the labelling intensified in prehypertrophic and hypertrophic chondrocytes. TD lesions displayed IGF-I in the distal region, mainly in chondrocytes around small blood vessels. EGF reappeared in proliferative and hypertrophic chondrocytes of the mid-embryonic stage. By day 18 after hatching, EGF was present mainly in prehypertrophic and hypertrophic chondrocytes. EGF was demonstrated only in distal proliferative and early prehypertrophic chondrocytes of the dyschondroplastic growth plate. TGF alpha was identified in hypertrophic chondrocytes adjacent to the periosteum and in the distal tip of the mid-embryonic growth plate. With progressing ossification, TGF alpha labeling intensified in the embryonic hypertrophic chondrocytes. In the TD growth plate at day 18 after hatching, TGF alpha expression was limited to 1-3 concentric layers of chondrocytes surrounding blood vessels.

Topics: Animals; Chick Embryo; Chickens; Epidermal Growth Factor; Growth Plate; Growth Substances; Immunohistochemistry; Insulin-Like Growth Factor I; Osteochondrodysplasias; Poultry Diseases; Tibia; Time Factors; Transforming Growth Factor alpha; Transforming Growth Factor beta

Previous immunolocalisation studies of dyschondroplasia have indicated that there is a reduction in the number of growth plate chondrocytes containing the protein transforming growth factor beta 3 (TGF-beta 3). The reduction in TGF-beta 3 in dyschondroplasia is likely to be a direct result of a reduction in the expression of the TGF-beta 3 gene. mRNA was extracted from small (0.09 g) samples of growth cartilage from the proximal tibiotarsus of three-week-old broiler chicks. The cartilage samples contained cells from all three zones of the growth plate (proliferative, transitional and upper hypertrophic) and were collected from normal and dyschondroplastic growth plates. The dyschondroplastic growth plates were identified by an accumulation of transitional chondrocytes which were considered to be a result of a failure to differentiate to the hypertrophic phenotype. A semi-quantitative polymerase chain reaction (PCR) was used to estimate the quantity of mRNA specific for glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and for each of the three isoforms of TGF beta (TGF-beta 1, TGF-beta 2 and TGF-beta 3) in each of the cartilage samples. The levels of expression of mRNA for GAPDH, TGF-beta 1 and TGF-beta 2 were similar in the two groups, but the expression of TGF-beta 3 mRNA was significantly reduced in the samples from the dyschondroplastic growth plates. The reduction in TGF-beta 3 levels is thought to be associated with the failure of chondrocyte hypertrophy in dyschondroplasia, and provides in vivo evidence that TGF-beta 3 is part of the cascade of events associated with the differentiation of chondrocytes during endochondral ossification in the chick.

Topics: Animals; Cartilage; Chickens; Immunohistochemistry; Osteochondrodysplasias; Poultry Diseases; Reference Values; RNA, Messenger; Tibia; Transcription, Genetic; Transforming Growth Factor beta