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1.
J Neuroinflammation ; 7: 7, 2010 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-20109187

RESUMEN

BACKGROUND: Sudden limb paresis is a common problem in White Leghorn flocks, affecting about 1% of the chicken population before achievement of sexual maturity. Previously, a similar clinical syndrome has been reported as being caused by inflammatory demyelination of peripheral nerve fibres. Here, we investigated in detail the immunopathology of this paretic syndrome and its possible resemblance to human neuropathies. METHODS: Neurologically affected chickens and control animals from one single flock underwent clinical and neuropathological examination. Peripheral nervous system (PNS) alterations were characterised using standard morphological techniques, including nerve fibre teasing and transmission electron microscopy. Infiltrating cells were phenotyped immunohistologically and quantified by flow cytometry. The cytokine expression pattern was assessed by quantitative real-time PCR (qRT-PCR). These investigations were accomplished by MHC genotyping and a PCR screen for Marek's disease virus (MDV). RESULTS: Spontaneous paresis of White Leghorns is caused by cell-mediated, inflammatory demyelination affecting multiple cranial and spinal nerves and nerve roots with a proximodistal tapering. Clinical manifestation coincides with the employment of humoral immune mechanisms, enrolling plasma cell recruitment, deposition of myelin-bound IgG and antibody-dependent macrophageal myelin-stripping. Disease development was significantly linked to a 539 bp microsatellite in MHC locus LEI0258. An aetiological role for MDV was excluded. CONCLUSIONS: The paretic phase of avian inflammatory demyelinating polyradiculoneuritis immunobiologically resembles the late-acute disease stages of human acute inflammatory demyelinating polyneuropathy, and is characterised by a Th1-to-Th2 shift.


Asunto(s)
Modelos Animales de Enfermedad , Síndrome de Guillain-Barré/patología , Síndrome de Guillain-Barré/fisiopatología , Síndrome de Guillain-Barré/veterinaria , Animales , Antígenos CD/metabolismo , Pollos , Femenino , Citometría de Flujo , Ganglios Espinales/patología , Ganglios Espinales/ultraestructura , Genotipo , Síndrome de Guillain-Barré/virología , Humanos , Modelos Logísticos , Complejo Mayor de Histocompatibilidad/genética , Microscopía Electrónica de Transmisión/métodos , Neurosífilis , Lectinas de Plantas , Médula Espinal/patología , Médula Espinal/ultraestructura , Nervios Espinales/patología , Nervios Espinales/ultraestructura , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/metabolismo
2.
Avian Dis ; 54(1 Suppl): 660-7, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20521711

RESUMEN

The role of wild ducks as vectors of avian influenza viruses (AIVs) is well known but the immune response induced by AIV has different patterns according to the species of duck. The local antibody produced on the mucosal surface may play an important role not only in protection but also in limitation of the primary replication at the portal of entry and shedding of the virus. With this aim, specific enzyme-linked immunosorbent assays (ELISAs) for duck IgY, Ig light chain, IgY (heavy chain), IgA, and IgM were developed and used to evaluate the systemic and mucosal response induced in ducks after low pathogenic avian influenza (LPAI) infections. Two different species of ducks (Mule and Pekin), ages (1 wk and 3 wk), and virus strains (H7N1 and H5N1 low pathogenic viruses) were tested in two studies to evaluate the developed tools. In the two studies, systemic and mucosal AIV-specific duck IgY, Ig (light chain), IgY (heavy chain), IgA, and IgM were detected and followed. Therefore, the developed ELISAs proved to be efficient tools allowing the follow-up of the systemic and mucosal responses induced by LPAI infection in ducklings. These tools can be very helpful for the development and evaluation of AI vaccines for ducks.


Asunto(s)
Patos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Subtipo H5N1 del Virus de la Influenza A , Gripe Aviar/inmunología , Animales , Cloaca/virología , Inmunidad Mucosa , Gripe Aviar/virología , Boca/virología
3.
Avian Pathol ; 38(2): 89-95, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19322707

RESUMEN

In this study, an indirect Newcastle disease virus enzyme-linked immunosorbent assay (ELISA) for waterfowl was evaluated concerning its efficiency and its suitability to monitor the antibody response in Muscovy ducks (Cairina moschata) and domestic geese (Anser anser var. domestica) following vaccination with a commercial inactivated NDV vaccine for chickens. Three weeks after vaccination seroconversion was already evident in the ELISA. Comparison of the ELISA results with those of the haemagglutination inhibition (HI) test provided a positive linear correlation between both tests (Pearson's product-moment correlation; r=0.652; P<0.001). However, a discrepancy of test results was evident in weeks 7 and 10, with 10 sera of vaccinated birds evaluated negative by HI test but positive by ELISA. Eight of these sera were confirmed to yield avian paramyxovirus specific reactivity by western blot analysis. Relative diagnostic sensitivity and specificity were determined to be 100.0% and 91.7% for the ELISA, compared with 91.1% and 97.2% for the HI test. Thus, the established ELISA represents a suitable alternative to the HI test in the monitoring of the immune response of waterfowl after vaccination, particularly for the analysis of high sample numbers. Further on, the results emphasize the immunogenicity of the inactivated Newcastle disease virus vaccine in domestic geese and Muscovy ducks.


Asunto(s)
Formación de Anticuerpos , Patos/inmunología , Gansos/inmunología , Enfermedad de Newcastle/inmunología , Vacunas Virales/inmunología , Animales , Anticuerpos Antivirales/sangre , Relación Dosis-Respuesta a Droga , Ensayo de Inmunoadsorción Enzimática/métodos , Virus de la Enfermedad de Newcastle/inmunología , Virus de la Enfermedad de Newcastle/aislamiento & purificación , Vacunas de Productos Inactivados/inmunología
4.
Dev Comp Immunol ; 32(9): 1015-26, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18374414

RESUMEN

TNF family members play crucial roles in mammalian B-cell differentiation and function, many of which have not been demonstrated in other species. To investigate the avian CD40/CD40L system, a chicken CD40 cDNA, obtained by expression screening, was used to raise monoclonal antibodies showing that CD40 was expressed on chicken B cells, monocytes and macrophages, like mammalian CD40. CD40 ligand fusion protein supported the proliferation of B cells in culture for up to 3 weeks, during which they differentiated towards a plasma cell phenotype. CD40L-activated B cells from immunised birds secreted antigen-specific IgM and IgG. These results showed important conserved functions of CD40 and its ligand in mammals and birds. CD40L provides a means for maintenance and differentiation of untransformed chicken B cells in culture, for the first time, allowing new approaches to study of post-bursal B cell biology and host-pathogen interactions with B cell tropic viruses.


Asunto(s)
Linfocitos B/inmunología , Antígenos CD40/metabolismo , Ligando de CD40/metabolismo , Antígenos de Histocompatibilidad Clase II/metabolismo , Secuencia de Aminoácidos , Animales , Formación de Anticuerpos , Linfocitos B/citología , Linfocitos B/metabolismo , Antígenos CD40/química , Antígenos CD40/inmunología , Ligando de CD40/inmunología , Diferenciación Celular , Proliferación Celular , Pollos , Perros , Hemocianinas/inmunología , Antígenos de Histocompatibilidad Clase II/inmunología , Humanos , Interleucina-6/biosíntesis , Interleucina-6/inmunología , Activación de Linfocitos , Ratones , Datos de Secuencia Molecular , Células Mieloides/inmunología , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/metabolismo , Alineación de Secuencia
5.
Dev Comp Immunol ; 32(9): 1076-87, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18395254

RESUMEN

The TNF superfamily cytokine BAFF has crucial roles in homoeostatic regulation of B cell populations in mammals. Similar effects on peripheral B cells have been reported for chicken as for mammalian BAFF. Unlike mammalian BAFF, chicken BAFF is produced by B cells, implying an autocrine loop and consequent differences in regulation of B cell homoeostasis. Understanding of these mechanisms requires investigation of BAFF-binding receptors in chickens. We identified and characterised chicken receptors BAFFR and TACI, but found that the gene encoding the third BAFF-binding receptor, BCMA, was disrupted, implying differences in mechanisms for maintenance of long-lived antibody responses. A BAFFR-Ig fusion protein expressed in vivo lowered B cell numbers, showing that it was functional under physiological conditions. We found changes in the ratio of BAFFR and TACI mRNAs in the bursa after hatch that may account for the altered requirements for B cell survival at this stage of development.


Asunto(s)
Receptor del Factor Activador de Células B/metabolismo , Linfocitos B/inmunología , Bolsa de Fabricio/inmunología , Proteína Activadora Transmembrana y Interactiva del CAML/metabolismo , Secuencia de Aminoácidos , Animales , Bolsa de Fabricio/citología , Línea Celular , Embrión de Pollo , Pollos , Humanos , Ratones , Datos de Secuencia Molecular , Proteínas Recombinantes de Fusión/metabolismo , Alineación de Secuencia , Proteína Activadora Transmembrana y Interactiva del CAML/química
6.
Avian Pathol ; 37(3): 323-8, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18568660

RESUMEN

In the present study a monoclonal antibody (mAb 14A3) was tested for its reactivity against serum immunoglobulin Y (IgY) of several waterfowl species, and subsequently for its applicability as anti-species antibody in common immunoassays. Western blot analyses demonstrated its broad cross-reactivity with the serum IgY light chain of different duck species: Muscovy duck (Cairina moschata), Mallard (Anas platyrhynchos), white-winged wood duck (Asarcornis scutulatus), common pintail (Dafila acuta). Reactivity was also evident with IgY of two swan species--mute swan (Cygnus olor) and black-necked swan (Sthenelides melanocoryphus)--and two goose species--domestic goose (Anser anser var. domestica) and red-breasted goose (Rufibrenta ruficollis). Applying the mAb for Newcastle disease virus (avian paramyxovirus serotype 1 [APMV-1]) test systems, its functionality within indirect immunoassays was evaluated. Using APMV-1-positive sera of domestic geese and Muscovy ducks, mAb 14A3 facilitated specific staining of APMV-1-infected cells in an immunofluorescence test. In addition, it proved to be functional in an indirect enzyme-linked immunosorbent assay (ELISA) and a western blot assay. Thus, the analysed mAb represents an attractive and versatile reagent that offers the opportunity to develop serological tests for waterfowl, allowing a high sample throughput using the ELISA technique or the fine analysis of humoral immune responses using the western blot.


Asunto(s)
Anticuerpos Monoclonales/química , Patos , Inmunoensayo/veterinaria , Cadenas Ligeras de Inmunoglobulina/inmunología , Virus de la Enfermedad de Newcastle/inmunología , Animales , Patos/genética , Inmunoglobulinas/inmunología , Enfermedad de Newcastle/diagnóstico , Enfermedad de Newcastle/virología , Filogenia , Factores de Tiempo , Vacunas Virales/inmunología
7.
J Interferon Cytokine Res ; 27(2): 97-101, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17316136

RESUMEN

Recognition of pathogens by toll-like receptors (TLRs) causes activation of signaling cascades that trigger cytokine secretion and, ultimately, innate immunity. Genes encoding proteins with substantial homology to mammalian TLR1, TLR2, TLR3, TLR4, TLR5, and TLR7 are present in the chicken genome, whereas orthologs of TLR8, TLR9, and TLR10 seem to be defective or missing. Except for chicken TLR2 (ChTLR2), which was previously shown to recognize lipopeptides and lipopolysaccharides (LPS), the ligand specificity of ChTLRs had not been determined. We found that polyI:C, LPS, R848, S-28463, and ODN2006, which are specifically recognized by TLR3, TLR4, TLR7/8, and TLR9 in mammals, induced substantial amounts of type I interferon (IFN) and interleukin-6 (IL-6) in freshly prepared chicken splenocytes. To determine the ligand specificity of ChTLR3 and ChTLR7, we used a standard reporter assay frequently employed for analysis of mammalian TLRs. Neither S-28463 nor any other TLR ligand induced reporter activity in human 293 cells expressing ChTLR7. However, human 293 cells expressing ChTLR3 strongly and specifically responded to polyI:C, demonstrating that this chicken receptor represents a true ortholog of mammalian TLR3.


Asunto(s)
Pollos/inmunología , Receptor Toll-Like 3/inmunología , Animales , Línea Celular , Pollos/genética , Pollos/metabolismo , Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/inmunología , Humanos , Inductores de Interferón/farmacología , Interferón Tipo I/biosíntesis , Interferón Tipo I/inmunología , Interleucina-6/biosíntesis , Interleucina-6/inmunología , Lipopolisacáridos/farmacología , Poli I-C/farmacología , Bazo/citología , Bazo/inmunología , Receptor Toll-Like 3/biosíntesis , Receptor Toll-Like 3/genética , Receptores Toll-Like/biosíntesis , Receptores Toll-Like/genética , Receptores Toll-Like/inmunología
8.
Vet Microbiol ; 121(3-4): 278-87, 2007 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-17254721

RESUMEN

Mycoplasma synoviae is a major pathogen of chickens and turkeys, causing respiratory disease and infectious synovitis. M. synoviae haemagglutinin VlhA is an abundant surface-exposed lipoprotein and immunodominant antigen. Post-translational cleavage of VlhA generates two proteins, MSPB and MSPA. MSPB, the amino-terminal end of VlhA, is a lipoprotein of about 40-50 kDa but can appear in truncated forms (tMSPB) of about 20-30 kDa. The aim of this study was to determine whether MSPB and tMSPB can stimulate chicken macrophages to secrete NO and cytokines. Macrophages derived from chicken monocytes (MDM) or the MQ-NCSU macrophage cell line were stimulated with M. synoviae protein extracts containing MSPB or tMSPB, as well as with purified MSPB and tMSPB. Proteins from detergent extractions induced IL-6 secretion in MDM and NO secretion in MQ-NCSU. Both MSPB and tMSPB were capable of inducing NO secretion in MQ-NCSU, as well as IL-6 and IL-1beta in MDM. The activity of IL-6 induced by purified tMSPB was similar to the effect of 60 pg/ml of recombinant chicken IL-6. The effect of IL-1beta induced by tMSPB was comparable to the effect of 10 ng/ml of recombinant IL-1beta. Whereas all samples containing MSPB were able to induce NO, IL-6 and IL-1beta, it seemed that the purified tMSPB of about 20 kDa was the most potent in its ability to induce IL-6 and IL-1beta in MDM. Compared to MSPB, tMSPB lacks about 200 amino acids in its carboxyl-terminal part. Therefore, our results suggest that the major part of the stimulating activity is associated with the amino-terminal part of MSPB, most likely with its lipid moiety.


Asunto(s)
Proteínas Bacterianas/farmacología , Pollos/inmunología , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Lectinas/farmacología , Macrófagos/inmunología , Macrófagos/microbiología , Mycoplasma synoviae/inmunología , Óxido Nítrico/metabolismo , Animales , Proteínas Bacterianas/química , Proteínas Bacterianas/inmunología , Pollos/sangre , Electroforesis en Gel de Poliacrilamida/veterinaria , Hemaglutininas/química , Hemaglutininas/inmunología , Hemaglutininas/farmacología , Interleucina-1beta/inmunología , Interleucina-6/inmunología , Lectinas/química , Lectinas/inmunología , Macrófagos/metabolismo , Óxido Nítrico/inmunología
9.
Dev Comp Immunol ; 29(8): 733-48, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15854685

RESUMEN

cDNAs encoding CD3epsilon, CD4 and the alpha-chain of CD8 of ducks were cloned. Monoclonal antibodies against Pekin duck CD4 and CD8alpha revealed that the antigens were expressed by the majority of thymocytes and by subpopulations of CD3+ cells in peripheral tissues. CD8alpha cell surface expression was also found on 90% of bursal cells. The B cell specificity of a newly developed mab to the immunoglobulin light-chain (L-chain) was confirmed by double labelling studies with the chicken B-cell cytokine BAFF. Using these tools and a mab reacting with the cytoplasmic domain of CD3epsilon, we demonstrated that the CD8alpha molecule is expressed to high levels in CD3-positive T cells and at lower levels in CD3-negative bursal and peripheral B cells. Mab 2-4, which recognizes the chicken CD28 molecule, was found to react with CD4-positive duck lymphocytes and with CD8-positive duck T cells but not with CD8-positive B cells. Mab K1, which recognizes a common antigen on chicken thrombocytes and monocytes/macrophages, was found to react with duck thrombocytes and macrophages. Thus, a range of mabs is now available which will allow to phenotype the major leucocyte populations in ducks, a surrogate infection model for hepatitis B virus.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Antígenos CD/inmunología , Antígenos CD/metabolismo , Patos/inmunología , Inmunofenotipificación , Leucocitos/inmunología , Leucocitos/metabolismo , Secuencia de Aminoácidos , Animales , Antígenos CD/química , Antígenos CD/genética , Linfocitos B/inmunología , Linfocitos B/metabolismo , Biomarcadores/metabolismo , Plaquetas/inmunología , Plaquetas/metabolismo , Bolsa de Fabricio/citología , Bolsa de Fabricio/inmunología , Complejo CD3/análisis , Complejo CD3/genética , Complejo CD3/inmunología , Antígenos CD4/análisis , Antígenos CD4/genética , Antígenos CD4/inmunología , Antígenos CD8/análisis , Antígenos CD8/genética , Antígenos CD8/inmunología , Diferenciación Celular , Clonación Molecular , Reacciones Cruzadas , Humanos , Leucocitos/citología , Macrófagos/inmunología , Macrófagos/metabolismo , Datos de Secuencia Molecular , Alineación de Secuencia , Linfocitos T/inmunología , Linfocitos T/metabolismo
10.
Viruses ; 2(4): 927-938, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21994661

RESUMEN

Like other pathogens that readily persist in animal hosts, members of the Bornaviridae family have evolved effective mechanisms to evade the innate immune response. The prototype of this virus family, Borna disease virus employs an unusual replication strategy that removes the triphosphates from the 5' termini of the viral RNA genome. This strategy allows the virus to avoid activation of RIG-I and other innate immune response receptors in infected cells. Here we determined whether the newly discovered avian bornaviruses (ABV) might use a similar strategy to evade the interferon response. We found that de novo infection of QM7 and CEC32 quail cells with two different ABV strains was efficiently inhibited by exogenous chicken IFN-α. IFN-α also reduced the viral load in QM7 and CEC32 cells persistently infected with both ABV strains, suggesting that ABV is highly sensitive to type I IFN. Although quail cells persistently infected with ABV contained high levels of viral RNA, the supernatants of infected cultures did not contain detectable levels of biologically active type I IFN. RNA from cells infected with ABV failed to induce IFN-ß synthesis if transfected into human cells. Furthermore, genomic RNA of ABV was susceptible to 5'-monophosphate-specific RNase, suggesting that it lacks 5'-triphospates like BDV. These results indicate that bornaviruses of mammals and birds use similar strategies to evade the host immune response.

11.
Toxicol Lett ; 199(1): 43-50, 2010 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-20708668

RESUMEN

The trichothecene deoxynivalenol (DON) is the most common mycotoxin contaminant of cereal-based food products. Several studies revealed DON as a potent inducer of the three major mitogen-activated protein kinases (MAPKs). Until now, little is known about the role of negative regulators of MAPK pathway in the cellular response to DON. In this report we evaluated, for the first time, the impact of mitogen-activated protein kinase phosphatases (MKPs), particularly dual specific phosphatase 1 (DUSP1), on the toxic potential of DON in the epithelial cell line HepG2. Our results indicate that both low and high concentrations of DON trigger a strong and sustained DUSP1 mRNA and protein expression, mediated by the sustained activation of MEK/ERK pathway. Furthermore, the expression of DUSP1 protein correlates with the inactivation of JNK1/2, whereas a sustained activation of p38 and ERK1/2 was observed in the presence of DON. In contrast, treatment of DUSP1 knock-down cells with DON triggers a prolonged activation of JNK1/2, which leads to the induction of apoptosis. Taken together, we propose DUSP1 as a novel target gene of DON, which is essential for the prevention of DON induced apoptosis in the epithelial cell line HepG2.


Asunto(s)
Apoptosis/efectos de los fármacos , Fosfatasa 1 de Especificidad Dual/metabolismo , Hepatocitos/efectos de los fármacos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Tricotecenos/toxicidad , Fosfatasa 1 de Especificidad Dual/genética , Activación Enzimática , Expresión Génica , Técnicas de Silenciamiento del Gen , Células Hep G2 , Hepatocitos/metabolismo , Hepatocitos/patología , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , ARN Mensajero/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
12.
Mol Immunol ; 47(7-8): 1619-28, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20149459

RESUMEN

Chickens provide an important model for developmental biology as well as phylogenetic studies of the immune system. In many species cytokines are important regulators of immune functions and recently we identified the chicken homologue of BAFF (B cell activating factor of the TNF family), shown to be an essential survival factor for B cells in mammals. Characterisation of BAFF function in the phylogenetically distant chicken requires in vivo studies, but despite considerable progress to date no efficient transgene or knockout technology for chickens is available. Thus the retroviral vector system RCAS (replication-competent ASLV long terminal repeat (LTR) with a Splice acceptor) was used to generate chickens stably expressing chBAFF or a soluble chBAFF neutralizing decoy receptor. Expression of RCAS based proteins was demonstrated in ovo and for the complete observation period of 2 month after hatch. In contrast to injections with recombinant proteins the prolonged RCAS based cytokine expression allowed assessment of BAFF function not only in newly hatched chicks but also in more mature birds. We demonstrate that RCAS based secreted products were biologically active, with chBAFF overexpression leading to a drastic and continuous increase in B cell numbers and neutralisation of chBAFF by expression of a soluble decoy receptor leading to severely reduced B cell numbers in transduced birds. This increase in B cell numbers was matched by increased immunoglobulin levels. Using RCASBP transduced birds we provide evidence that the RCAS system provides a fast and highly efficient gene transfer system for analysis of secreted protein function in the chicken and we show that in the chicken BAFF is necessary for B cell survival but in contrast to mammals, not only mature B cells but also immature B cells in the bursa of Fabricius are maintained by BAFF.


Asunto(s)
Proteínas Aviares/inmunología , Factor Activador de Células B/inmunología , Linfocitos B/citología , Linfocitos B/inmunología , Diferenciación Celular , Retroviridae/genética , Animales , Formación de Anticuerpos , Proteínas Aviares/genética , Factor Activador de Células B/genética , Células Cultivadas , Pollos , ADN Satélite/genética , Humanos , Secuencias Repetidas Terminales , Transgenes
13.
Dev Comp Immunol ; 34(5): 518-29, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20043941

RESUMEN

The avian Metapneumovirus (aMPV) causes an economically important acute respiratory disease in turkeys (turkey rhinotracheitis, TRT). While antibodies were shown to be insufficient for protection against aMPV-infection, the role of T-lymphocytes in the control of aMPV-infection is not clear. In this study we investigated the role of T-lymphocytes in aMPV-pathogenesis in a T-cell-suppression model in turkeys. T-cell-intact turkeys and turkeys partly depleted of functional CD4(+) and CD8(+) T-lymphocytes by Cyclosporin A (CsA) treatment were inoculated with the virulent aMPV subtype A strain BUT 8544. CsA-treatment resulted in a significant reduction of absolute numbers of circulating CD4(+) and CD8alpha(+) T-lymphocytes by up to 82 and 65%, respectively (P<0.05). Proportions of proliferating T-cells within mitogen-stimulated peripheral blood mononuclear cells were reduced by similar levels in CsA-treated birds compared to untreated controls (P<0.05). CsA-treated turkeys showed delayed recovery from aMPV-induced clinical signs and histopathological lesions and a prolonged detection of aMPV in choanal swabs. The results of this study show that T-lymphocytes play an important role in the control of primary aMPV-infection in turkeys.


Asunto(s)
Depleción Linfocítica , Metapneumovirus/inmunología , Infecciones por Paramyxoviridae/inmunología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Animales , Antígenos CD4/biosíntesis , Antígenos CD8/biosíntesis , Recuento de Células , Proliferación Celular/efectos de los fármacos , Ciclosporina/administración & dosificación , Inmunidad Celular , Metapneumovirus/patogenicidad , Infecciones por Paramyxoviridae/sangre , Subgrupos de Linfocitos T/efectos de los fármacos , Subgrupos de Linfocitos T/patología , Pavos
14.
Int Immunol ; 19(2): 203-15, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17220480

RESUMEN

The chicken represents the best-characterized animal model for B cell development in the so-called gut-associated lymphoid tissue (GALT) and the molecular processes leading to B cell receptor diversification in this species are well investigated. However, the mechanisms regulating B cell development and homeostasis in GALT species are largely unknown. Here we investigate the role played by the avian homologue of B cell-activating factor of the tumor necrosis factor family (BAFF). Flow cytometric analysis showed that the receptor for chicken B cell-activating factor of the tumor necrosis factor family (chBAFF) is expressed by mature and immature B cells. Unlike murine and human BAFF, chBAFF is primarily produced by B cells both in peripheral lymphoid organs and in the bursa of Fabricius, the chicken's unique primary lymphoid organ. In vitro and in vivo studies revealed that chBAFF is required for mature B cell survival. In addition, in vivo neutralization with a decoy receptor led to a reduction of the size and number of B cell follicles in the bursa, demonstrating that, in contrast to humans and mice, in chickens BAFF is also required for the development of immature B cells. Collectively, we show that chBAFF has phylogenetically conserved functions in mature B cell homeostasis but displays unique and thus far unknown properties in the regulation of B cell development in birds.


Asunto(s)
Factor Activador de Células B/metabolismo , Linfocitos B/citología , Linfocitos B/inmunología , Tejido Linfoide/crecimiento & desarrollo , Tejido Linfoide/inmunología , Animales , Factor Activador de Células B/inmunología , Receptor del Factor Activador de Células B/inmunología , Receptor del Factor Activador de Células B/metabolismo , Northern Blotting , Diferenciación Celular/inmunología , Embrión de Pollo , Pollos , Citometría de Flujo , Humanos , Hibridación in Situ , Tejido Linfoide/citología , Filogenia
15.
J Gen Virol ; 88(Pt 5): 1403-1409, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17412966

RESUMEN

Non-structural protein NS1 of influenza A virus counteracts the host immune response by blocking the synthesis of type I interferon (IFN). As deletion of the complete NS1 gene has to date been reported only in the human H1N1 strain A/PR/8/34, it remained unclear whether NS1 is a non-essential virulence factor in other influenza A virus strains as well. In this report, the properties of NS1-deficient mutants derived from strain SC35M (H7N7) are described. A mutant of SC35M that completely lacks the NS1 gene was an excellent inducer of IFN in mammalian and avian cells in culture and, consequently, was able to multiply efficiently only in cell lines with defects in the type I IFN system. Virus mutants carrying C-terminally truncated versions of NS1 were less powerful inducers of IFN and were attenuated less strongly in human A549 cells. Although attenuated in wild-type mice, these mutants remained highly pathogenic for mice lacking the IFN-regulated antiviral factor Mx1. In contrast, the NS1-deficient SC35M mutant was completely non-pathogenic for wild-type mice, but remained pathogenic for mice lacking Mx1 and double-stranded RNA-activated protein kinase (PKR). Wild-type SC35M, but not the NS1-deficient mutant virus, was able to replicate in the upper respiratory tract of birds, but neither virus induced severe disease in adult chickens. Altogether, this study supports the view that NS1 represents a non-essential virulence factor of different influenza A viruses.


Asunto(s)
Subtipo H7N7 del Virus de la Influenza A/fisiología , Gripe Aviar/inmunología , Proteínas no Estructurales Virales/deficiencia , Animales , Línea Celular , Pollos , Chlorocebus aethiops , Perros , Humanos , Subtipo H7N7 del Virus de la Influenza A/clasificación , Subtipo H7N7 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana , Interferón beta/genética , Interferones/antagonistas & inhibidores , Pulmón/inmunología , Pulmón/virología , Ratones , Infecciones por Orthomyxoviridae , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Vero , Virulencia
16.
Eur J Immunol ; 37(10): 2856-67, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17823890

RESUMEN

Fever is associated with improved survival during infection in endothermic and ectothermic species although the protective mechanisms are largely undefined. Previous studies indicate that fever-range thermal stress increases the binding activity of the L-selectin homing receptor in human or mouse leukocytes, thereby promoting trafficking to lymphoid tissues across high endothelial venules (HEV). Here, we examined the evolutionary conservation of thermal regulation of L-selectin-like adhesion. Leukocytes from animals representing four taxa of vertebrates (mammals, avians, amphibians, teleosts) were shown to mediate L-selectin-like adhesion under shear to MECA-79-reactive ligands on mouse HEV in cross-species in vitro adherence assays. L-selectin-like binding activity was markedly increased by fever-range thermal stress in leukocytes of all species examined. Comparable increases in L-selectin-like adhesion were induced by thermal stress, IL-6, or the IL-6/soluble IL-6 receptor fusion protein, hyper-IL-6. Analysis of the molecular basis of thermal regulation of L-selectin-like adhesion identified a common IL-6 trans-signaling mechanism in endotherms and ectotherms that resulted in activation of JAK/STAT signaling and was inhibited by IL-6 neutralizing antibodies or recombinant soluble gp130. Conservation of IL-6-dependent mechanisms controlling L-selectin adhesion over hundreds of millions of years of vertebrate evolution strongly suggests that this is a beneficial focal point regulating immune surveillance during febrile inflammatory responses.


Asunto(s)
Fiebre/metabolismo , Interleucina-6/fisiología , Selectina L/metabolismo , Transducción de Señal/fisiología , Estrés Fisiológico/inmunología , Estrés Fisiológico/metabolismo , Secuencia de Aminoácidos , Animales , Bovinos , Adhesión Celular/inmunología , Células Cultivadas , Secuencia Conservada , Perros , Evolución Molecular , Fiebre/inmunología , Fiebre/patología , Humanos , Selectina L/genética , Selectina L/fisiología , Leucocitos/inmunología , Leucocitos/metabolismo , Leucocitos/patología , Ratones , Unión Proteica/inmunología , Conejos , Ratas , Estrés Fisiológico/patología
17.
Int Immunol ; 16(1): 139-48, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-14688069

RESUMEN

Members of the tumor necrosis factor (TNF) family play key roles in the regulation of inflammation, immune responses and tissue homeostasis. Here we describe the identification of the chicken homologue of mammalian B cell activating factor of the TNF family (BAFF/BLyS). By searching a chicken EST database we identified two overlapping cDNA clones that code for the entire open reading frame of chicken BAFF (chBAFF), which contains a predicted transmembrane domain and a putative furin protease cleavage site like its mammalian counterparts. The amino acid identity between soluble chicken and human BAFF is 76%, considerably higher than for most other known cytokines. The chBAFF gene is most strongly expressed in the bursa of Fabricius. Soluble recombinant chBAFF produced by human 293T cells interacted with the mammalian cell-surface receptors TACI, BCMA and BAFF-R. It bound to chicken B cells, but not to other lymphocytes, and it promoted the survival of splenic chicken B cells in culture. Furthermore, bacterially expressed chBAFF induced the selective expansion of B cells in the spleen and cecal tonsils when administered to young chicks. Our results suggest that like its mammalian counterpart, chBAFF plays an important role in survival and/or proliferation of chicken B cells.


Asunto(s)
Linfocitos B/inmunología , Pollos/inmunología , Proteínas de la Membrana/genética , Proteínas de la Membrana/inmunología , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunología , Secuencia de Aminoácidos , Animales , Factor Activador de Células B , Northern Blotting , Western Blotting , Bolsa de Fabricio/inmunología , Supervivencia Celular , Células Cultivadas , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Humanos , Datos de Secuencia Molecular , Tonsila Palatina/inmunología , Reacción en Cadena de la Polimerasa , Pruebas de Precipitina , Proteínas Recombinantes/inmunología , Homología de Secuencia , Especificidad de la Especie , Bazo/inmunología , Timo/inmunología
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