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1.
Psychol Health Med ; 21(4): 401-412, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26325347

ABSTRACT

Mental health care workers face heavy emotional demand and are prone to work burnout. Work burnout has been associated with poor mental health and work climate, which refers to individual perceptions about work setting. The purpose of this study was to examine whether intra-individual changes in work climate were associated with intra-individual changes in burnout and depression over two years. The present sample included Chinese mental health care workers (N = 312; mean age = 38.6, SD = 9.9) working in a psychosocial rehabilitation institution. The participants completed questionnaires on work climate, work burnout and depression at seven time points across two years. Parallel process latent growth modeling was used to analyze the associations of change between work climate and burnout and depression. Work climate displayed a logarithmic decreasing trend while burnout and depression displayed logarithmic increasing trends over two years. Baseline levels of work climate were negatively and moderately associated with baseline levels of burnout and depression (r = -.44 to -.60, p < .01). Changes in work climate were negatively and moderately associated with change in burnout (r = -.43, p < .01) and change in depression (r = -.31, p < .05). Change in burnout was positively and strongly associated (r = .58, p < .01) with change in depression. The current results support temporal relationships among changes in work climate, burnout and depression across time. Practical implications for future preventive work in burnout interventions were discussed within this population.

2.
Ann Oncol ; 25(6): 1116-21, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24685829

ABSTRACT

BACKGROUND: Results from the phase III trial CLEOPATRA in human epidermal growth factor receptor 2-positive first-line metastatic breast cancer demonstrated significant improvements in progression-free and overall survival with pertuzumab, trastuzumab, and docetaxel over placebo, trastuzumab, and docetaxel. We carried out exploratory analyses of the incidence and time to development of central nervous system (CNS) metastases in patients from CLEOPATRA. PATIENTS AND METHODS: Patients received pertuzumab/placebo: 840 mg in cycle 1, then 420 mg; trastuzumab: 8 mg/kg in cycle 1, then 6 mg/kg; docetaxel: initiated at 75 mg/m(2). Study drugs were administered i.v. every 3 weeks. The log-rank test was used for between-arm comparisons of time to CNS metastases as first site of disease progression and overall survival in patients with CNS metastases as first site of disease progression. The Kaplan-Meier approach was used to estimate median time to CNS metastases as first site of disease progression and median overall survival. RESULTS: The incidence of CNS metastases as first site of disease progression was similar between arms; placebo arm: 51 of 406 (12.6%), pertuzumab arm: 55 of 402 (13.7%). Median time to development of CNS metastases as first site of disease progression was 11.9 months in the placebo arm and 15.0 months in the pertuzumab arm; hazard ratio (HR) = 0.58, 95% confidence interval (CI) 0.39-0.85, P = 0.0049. Overall survival in patients who developed CNS metastases as first site of disease progression showed a trend in favor of pertuzumab, trastuzumab, and docetaxel; HR = 0.66, 95% CI 0.39-1.11. Median overall survival was 26.3 versus 34.4 months in the placebo and pertuzumab arms, respectively. Treatment comparison of the survival curves was not statistically significant for the log-rank test (P = 0.1139), but significant for the Wilcoxon test (P = 0.0449). CONCLUSIONS: While the incidence of CNS metastases was similar between arms, our results suggest that pertuzumab, trastuzumab, and docetaxel delays the onset of CNS disease compared with placebo, trastuzumab, and docetaxel. CLINICALTRIALSGOV: NCT00567190.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/pathology , Central Nervous System Neoplasms/epidemiology , Central Nervous System Neoplasms/secondary , Adult , Aged , Antibodies, Monoclonal, Humanized/administration & dosage , Breast Neoplasms/drug therapy , Breast Neoplasms/mortality , Docetaxel , Double-Blind Method , Female , Humans , Incidence , Kaplan-Meier Estimate , Middle Aged , Proportional Hazards Models , Receptor, ErbB-2/genetics , Taxoids/administration & dosage , Trastuzumab
3.
Health Educ Res ; 26(5): 896-907, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21715653

ABSTRACT

We assessed the effectiveness of a brief structured diabetes education programme based on the concept of self-efficacy on self-care and glycaemic control using single-blind study design. One hundred and sixty-four participants with poorly controlled diabetes from two settings were randomized using computer-generated list into control (n = 82) and intervention (n = 82) groups, of which 151 completed the study. Monthly interventions over 12 weeks addressed the self-care practices of diet, physical activity, medication adherence and self-monitoring of blood glucose (SMBG). These self-care practices were assessed at Weeks 0 and 12 using pre- and post-questionnaires in both groups together with glycated haemoglobin A1c (HbA1c) and diabetes knowledge. In the intention-to-treat analysis (n = 164), the intervention group improved their SMBG (P = <0.001), physical activity (P = 0.001), HbA1c (P = 0.03), diabetes knowledge (P = <0.001) and medication adherence. At Week 12, HbA1c difference adjusted for SMBG frequency, medication adherence and weight change remained significant (P = 0.03) compared with control group. For within group comparisons, diabetes knowledge (P = <0.001), HbA1c level (P = <0.001), SMBG (P = <0.001) and medication adherence (P = 0.008) improved from baseline in the intervention group. In the control group, only diabetes knowledge improved (P = <0.001). These findings can contribute to the development of self-management diabetes education in Malaysia.


Subject(s)
Diabetes Mellitus, Type 1/therapy , Diabetes Mellitus, Type 2/therapy , Glycated Hemoglobin/analysis , Health Knowledge, Attitudes, Practice , Self Care/methods , Blood Glucose Self-Monitoring , Diet, Diabetic/standards , Female , Humans , Malaysia , Male , Medication Adherence , Middle Aged , Motor Activity , Outcome and Process Assessment, Health Care , Patient Education as Topic/methods , Self Efficacy , Single-Blind Method
4.
Poult Sci ; 89(10): 2083-91, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20852098

ABSTRACT

Marek's disease (MD) is a T-cell lymphoma disease of domestic chickens induced by MD virus (MDV), a naturally oncogenic and highly contagious cell-associated α-herpesvirus. Earlier reports have shown that the MHC haplotype as well as non-MHC genes are responsible for genetic resistance to MD. The MHC was also shown to affect efficiency of vaccine response. Using specific-pathogen-free chickens from a series of 19 recombinant congenic strains and their 2 progenitor lines (lines 6(3) and 7(2)), vaccine challenge experiments were conducted to examine the effect of host genetic variation on vaccine efficacy. The 21 inbred lines of White Leghorns share the same B*2 MHC haplotype and the genome of each recombinant congenic strain differs by a random 1/8 sample of the susceptible donor line (7(2)) genome. Chickens from each of the lines were divided into 2 groups. One was vaccinated with turkey herpesvirus strain FC126 at the day of hatch and the other was treated as a nonvaccinated control. Chickens of both groups were inoculated with a very virulent plus strain of MDV on the fifth day posthatch. Analyses of the MD data showed that the genetic line significantly influenced MD incidence and days of survival post-MDV infection after vaccination of chickens (P<0.01). The protective indices against MD varied greatly among the lines with a range of 0 up to 84%. This is the first evidence that non-MHC host genetic variation significantly affects MD vaccine efficacy in chickens in a designed prospective study.


Subject(s)
Chickens/genetics , Chickens/immunology , Genetic Variation , Marek Disease Vaccines/immunology , Marek Disease/prevention & control , Animals , Marek Disease/immunology , Specific Pathogen-Free Organisms
5.
Virology ; 379(2): 256-65, 2008 Sep 30.
Article in English | MEDLINE | ID: mdl-18675437

ABSTRACT

The bursa of Fabricius serves as an important tissue in the process of Marek's disease virus (MDV) pathogenesis, since B cells of the bursa harbor the cytolytic phase of MDV replication cycle. In the present study, host responses associated with MDV infection in the bursa of Fabricius of chickens were investigated. The expression of MDV phosphoprotein (pp)38 antigen, MDV glycoprotein (gB) and MDV viral interleukin (vIL)-8 transcripts was at the highest at 4 days post-infection (d.p.i.) and then showed a declining trend. On the contrary, the expression of meq (MDV EcoRI Q) gene as well as the viral genome load increased gradually until day 14 post-infection. The changes in viral parameters were associated with significantly higher infiltration of macrophages and T cell subsets, particularly CD4+ T cells into the bursa of Fabricius. Of the genes examined, the expression of interferon (IFN)-alpha, IFN-gamma genes and inducible nitric oxide synthase (iNOS) was significantly up-regulated in response to MDV infection in the bursa of Fabricius. The results suggest a role for these cells and cytokines in MDV-induced responses in the bursa of Fabricius.


Subject(s)
Bursa of Fabricius/virology , Mardivirus/pathogenicity , Animals , Animals, Newborn , Antigens, Viral/metabolism , Base Sequence , Bursa of Fabricius/immunology , Bursa of Fabricius/pathology , Chickens , Cytokines/genetics , DNA Primers/genetics , Gene Expression , Host-Pathogen Interactions/genetics , Host-Pathogen Interactions/immunology , Macrophages/pathology , Macrophages/virology , Mardivirus/genetics , Mardivirus/immunology , Mardivirus/physiology , Marek Disease/genetics , Marek Disease/immunology , Marek Disease/pathology , Marek Disease/virology , Nitric Oxide Synthase Type II/genetics , Phosphoproteins/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , T-Lymphocyte Subsets/pathology , T-Lymphocyte Subsets/virology , Virulence , Virus Replication
6.
Avian Pathol ; 37(1): 7-13, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18202944

ABSTRACT

Immunohistochemistry and polymerase chain reaction (PCR) were used to test for the presence of avian leukosis virus (ALV) J viral antigen gp85 and proviral DNA, respectively, in various tissues (adrenal gland, bone marrow, gonad, heart, kidney, liver, lung, pancreas, proventriculus, sciatic nerve, spleen, and thymus). Tissues were collected from 32-week-old commercial meat-type and Avian Disease and Oncology Laboratory experimental White Leghorn Line 0 chickens with the following different infection profiles: tV + A-, included in ovo-tolerized viraemic chickens with no neutralizing antibodies (NAbs) on any sampling; ntV + A-, included chickens that were viraemic and NAb-negative at the time of termination at 32 weeks post hatch, but had NAbs on up to two occasions; V+ A+, included chickens that were viraemic and NAb-positive at the time of termination at 32 weeks post hatch, and had NAbs on more than two occasions; V - A+, included chickens that were negative for viraemia and NAb-positive at the time of termination at 32 weeks post hatch, and had antibody on more than two occasions; V - A-, included chickens that were never exposed to ALV J virus. There was a direct correlation between viraemia and tissue distribution of gp85, regardless of the NAb status and strain of chickens, as expression of ALV J gp85 was noted in only viraemic chickens (tV + A-, ntV + A-, V+ A+), but not in non-viraemic seroconverted chickens (V - A+). Of the four oligonucleotide primers pairs used in PCR to identify ALV J provirus, only one primer set termed H5/H7 was useful in demonstrating ALV J proviral DNA in the majority of the tissues tested from non-viraemic, antibody-positive chickens (V - A+). The results suggest that PCR using primer pair H5/H7 is more sensitive than immunohistochemistry in identifying ALV J in chickens that have been exposed to virus, but are not actively viraemic.


Subject(s)
Antigens, Viral/isolation & purification , Avian Leukosis Virus/classification , Avian Leukosis/virology , Chickens/genetics , Proviruses/isolation & purification , Animals , Antigens, Viral/metabolism , Avian Leukosis/metabolism , DNA, Viral/isolation & purification , Meat , Retrospective Studies
7.
J Vet Med A Physiol Pathol Clin Med ; 54(10): 553-8, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18045338

ABSTRACT

Avian leukosis virus (ALV) subgroup J (ALV-J) is an exogenous ALV and causes myeloid leukosis in meat-type chickens. We have previously reported the isolation and identification of ALV-J in commercial layer flocks from 12 farms in northern China. In this report, we further characterized this virus by in situ polymerase chain reaction (PCR) hybridization in various affected organs of chickens from six of the 12 farms. A routine method for hybridization of nucleic acid uses radioactive probe, such as a P32-labelled probe. We found that the non-radioactive digoxigenin (DIG) probe is sensitive enough to detect the nucleic acid of virus in chicken tissues. We used a pair of published primers (H5/H7) specific to the gp85 envelope gene and 3' region of pol gene of prototype ALV-J strain HPRS-103. The total RNA extracted from tumour, bone marrow, oviduct, liver and spleen of the diseased chickens from six commercial flocks, and cDNA was successfully amplified. Using the primers and cDNA, we obtained an ALV-J-specific cDNA probe of 545 bp in length by PCR. In situ PCR with H5/H7 primers was carried out in the paraffin sections from tissues of the diseased chickens, followed by in situ hybridization using the DIG-labelled cDNA probe. Positive hybridization signals were detected in the cytoplasm of paraffin sections of tumours and other organ tissues. The intensity of the signals was documented using an image analysis system measuring integral optical density (IOD). The IOD values for tissue sections treated by in situ PCR hybridization are significantly higher than that by in situ hybridization alone (P < 0.01). These data taken together suggest that in situ PCR hybridization is a more sensitive technique for detection of ALV-J in tissue sections.


Subject(s)
Avian Leukosis Virus/isolation & purification , Avian Leukosis/transmission , Avian Leukosis/virology , Poultry Diseases/virology , Animals , Chickens , China , Female , In Situ Hybridization/veterinary , Kidney/pathology , Kidney/virology , Liver/pathology , Liver/virology , Oviducts/pathology , Oviducts/virology , Polymerase Chain Reaction/methods , Polymerase Chain Reaction/veterinary , Poultry Diseases/transmission
8.
Avian Dis ; 51(3): 713-8, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17992931

ABSTRACT

Marek's disease virus (MDV) is an oncogenic cell-associated herpesvirus that causes T-cell lymphoma in chickens. Lymphoproliferative neoplasms in Marek's disease (MD) occur in various organs and tissues, including the viscera, peripheral nerves, skin, gonads, and musculatures. MDV is restrictively produced in the feather follicle epithelial (FFE) cells, and it gains access to the external environment via infected cells or as infectious enveloped cell-free virus particles. The goals of the present study were to 1) determine whether the MDV-induced skin lesions are neoplastic in nature or inflammatory reactions to viral infection, 2) determine whether physical presence of feather follicles (FF) is necessary for skin tumor development, and 3) study the role of skin epithelial cells not associated with feathers or FF in the replication and dissemination of infectious virus particles. Scaleless chickens that produce only a few scattered feathers and no sculate scales along the anterior metatarsi were used as a unique model to study the pathogenesis of dermal lesions. Histologic and immunohistochemical analysis revealed that the cutaneous lesions were tumorous as was manifested by massive accumulation of lymphoblasts and extensive activation of meq oncoprotein, the hallmark of MDV oncogenesis, within the skin lesions. Neoplastic cutaneous lesions in the scaleless chickens indicate that feather follicles are not necessary for skin tumor development. Finally, our preliminary data indicate that inoculation with supernatant fluid from homogenized and sonicated skin samples of MDV-infected scaleless chickens induces MD in susceptible birds, suggesting that skin epithelial cells not associated with FF also harbor infectious viral particles.


Subject(s)
Chickens/virology , Feathers , Marek Disease/pathology , Skin Neoplasms/veterinary , Skin/pathology , Skin/virology , Animals , Female , Skin Neoplasms/pathology , Skin Neoplasms/virology
9.
J Virol ; 79(7): 4545-9, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15767457

ABSTRACT

Marek's disease virus has a unique phosphoprotein, pp38, which is suspected to play an important role in Marek's disease pathogenesis. The objective of the present study was to utilize a mutant virus lacking the pp38 gene (rMd5Deltapp38) to better characterize the biological function of pp38. This work shows that the pp38 gene is necessary to establish cytolytic infection in B cells but not in feather follicle epithelium, to produce an adequate level of latently infected T cells, and to maintain the transformed status in vivo.


Subject(s)
Antigens, Viral/physiology , B-Lymphocytes/virology , Cell Transformation, Viral/physiology , Epithelial Cells/virology , Herpesvirus 2, Gallid/genetics , Herpesvirus 2, Gallid/physiology , Phosphoproteins/physiology , Animals , Antigens, Viral/genetics , Chickens , Gene Deletion , Genes, Viral , Phosphoproteins/genetics
10.
Proc Natl Acad Sci U S A ; 101(38): 13879-84, 2004 Sep 21.
Article in English | MEDLINE | ID: mdl-15356338

ABSTRACT

Animal models are essential for elucidating the molecular mechanisms of carcinogenesis. Hodgkin's and many diverse non-Hodgkin's lymphomas overexpress the Hodgkin's disease antigen CD30 (CD30(hi)), a tumor necrosis factor receptor II family member. Here we show that chicken Marek's disease (MD) lymphoma cells are also CD30(hi) and are a unique natural model for CD30(hi) lymphoma. Chicken CD30 resembles an ancestral form, and we identify a previously undescribed potential cytoplasmic signaling domain conserved in chicken, human, and mouse CD30. Our phylogeneic analysis defines a relationship between the structures of human and mouse CD30 and confirms that mouse CD30 represents the ancestral mammalian gene structure. CD30 expression by MD virus (MDV)-transformed lymphocytes correlates with expression of the MDV Meq putative oncogene (a c-Jun homologue) in vivo. The chicken CD30 promoter has 15 predicted high-stringency Meq-binding transcription factor recognition motifs, and Meq enhances transcription from the CD30 promoter in vitro. Plasma proteomics identified a soluble form of CD30. CD30 overexpression is evolutionarily conserved and defines one class of neoplastic transformation events, regardless of etiology. We propose that CD30 is a component of a critical intracellular signaling pathway perturbed in neoplastic transformation. Specific anti-CD30 Igs occurred after infection of genetically MD-resistant chickens with oncogenic MDV, suggesting immunity to CD30 could play a role in MD lymphoma regression.


Subject(s)
Hodgkin Disease/genetics , Ki-1 Antigen/genetics , Mardivirus/immunology , Marek Disease/genetics , Amino Acid Sequence , Animals , Antigens, CD/genetics , Cell Transformation, Neoplastic/immunology , Chickens , Conserved Sequence , Disease Models, Animal , Gene Expression Regulation, Neoplastic/immunology , Hodgkin Disease/immunology , Humans , Lymphocyte Activation/immunology , Marek Disease/immunology , Mice , Molecular Sequence Data , Molecular Weight , Phylogeny , Sequence Alignment , Signal Transduction/immunology
11.
Avian Pathol ; 33(1): 13-7, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14681063

ABSTRACT

Mortality from myeloid leukosis was observed in commercial layers from 12 farms in northern China. Affected chickens were extremely thin and dehydrated, bleeding occurred in feather follicles and claws, combs were pale and anaemic, phalanges were swollen, and many yellowish-white tumours were seen on the visceral surface of the sternum. Focal tumour cells, with spherical eosinophilic granules in the cytoplasm, were found in the liver, spleen, kidney, ovary, oviduct, lung, bone marrow, proventriculus and gut by histopathological examination. Immunohistochemical studies with a monoclonal antibody to gp85 of avian leukosis virus subgroup J (ALV-J) revealed antigen in all organs examined. Polymerase chain reaction tests using a pair of ALV-J-specific primers H5/H7 (Smith et al., 1998) produced a 545 basepair fragment. The sequence of the Polymerase chain reaction product was compared with that of the ALV-J HPRS-103 prototype strain. The identity of nucleotides and predicted amino acids was 97.4% and 96.1%, respectively. On this basis the disease in the egg-type chickens was diagnosed as an ALV-J infection. This is the first report of field cases of myeloid leukosis caused by ALV-J in commercial egg-type chickens.


Subject(s)
Avian Leukosis Virus/isolation & purification , Avian Leukosis/epidemiology , Chickens , Poultry Diseases/epidemiology , Animals , Antigens, Viral/analysis , Avian Leukosis/pathology , Avian Leukosis/virology , Avian Leukosis Virus/genetics , Avian Leukosis Virus/immunology , Base Sequence , China/epidemiology , Female , Immunohistochemistry/veterinary , Molecular Sequence Data , Polymerase Chain Reaction/veterinary , Poultry Diseases/pathology , Poultry Diseases/virology , Sequence Homology, Nucleic Acid
12.
Anal Chem ; 73(21): 5015-9, 2001 Nov 01.
Article in English | MEDLINE | ID: mdl-11721893

ABSTRACT

The mechanism of tuning fork-based shear-force near-field scanning optical microscopy is investigated to determine optimal experimental conditions for imaging soft samples immersed in liquid. High feedback sensitivity and stability are obtained when only the fiber probe, i.e., excluding the tuning fork prongs, is immersed in solution, which also avoids electrical shorting in conductive (i.e., buffer) solutions. Images of MEH-PPV were obtained with comparable spatial resolution in both air and water. High optical resolution (approximately160 nm fwhm) was observed.


Subject(s)
Microscopy, Confocal/instrumentation , Microscopy, Confocal/methods , Solvents , Ethylenes/chemistry , Hexanols/chemistry , Methanol/analogs & derivatives , Methanol/chemistry , Phenol/chemistry , Polymers/chemistry , Sensitivity and Specificity , Stress, Mechanical , Vibration , Vinyl Compounds/chemistry
13.
Mol Cell Biol ; 21(24): 8385-97, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11713275

ABSTRACT

The bombesin/gastrin-releasing peptide (GRP) family of neuropeptides has been implicated in various in vitro and in vivo models of human malignancies including prostate cancers. It was previously shown that bombesin and/or neurotensin (NT) acts as a survival and migratory factor(s) for androgen-independent prostate cancers. However, a role in the transition from an androgen-dependent to -refractory state has not been addressed. In this study, we investigate the biological effects and signal pathways of bombesin and NT on LNCaP, a prostate cancer cell line which requires androgen for growth. We show that both neurotrophic factors can induce LNCaP growth in the absence of androgen. Concurrent transactivation of reporter genes driven by the prostate-specific antigen promoter or a promoter carrying an androgen-responsive element (ARE) indicate that growth stimulation is accompanied by androgen receptor (AR) activation. Furthermore, neurotrophic factor-induced gene activation was also present in PC3 cells transfected with the AR but not in the parental line which lacks the AR. Given that bombesin does not directly bind to the AR and is known to engage a G-protein-coupled receptor, we investigated downstream signaling events that could possibly interact with the AR pathway. We found that three nonreceptor tyrosine kinases, focal adhesion kinase (FAK), Src, and Etk/BMX play important parts in this process. Etk/Bmx activation requires FAK and Src and is critical for neurotrophic factor-induced growth, as LNCaP cells transfected with a dominant-negative Etk/BMX fail to respond to bombesin. Etk's activation requires FAK, Src, but not phosphatidylinositol 3-kinase. Likewise, bombesin-induced AR activation is inhibited by the dominant-negative mutant of either Src or FAK. Thus, in addition to defining a new G-protein pathway, this report makes the following points regarding prostate cancer. (i) Neurotrophic factors can activate the AR, thus circumventing the normal growth inhibition caused by androgen ablation. (ii) Tyrosine kinases are involved in neurotrophic factor-mediated AR activation and, as such, may serve as targets of future therapeutics, to be used in conjunction with current antihormone and antineuropeptide therapies.


Subject(s)
Androgens/metabolism , Neuropeptides/metabolism , Protein-Tyrosine Kinases/physiology , src-Family Kinases/physiology , Bombesin/metabolism , Bombesin/pharmacology , Bromodeoxyuridine/metabolism , Cell Division , Enzyme Activation , Focal Adhesion Kinase 1 , Focal Adhesion Protein-Tyrosine Kinases , Genes, Dominant , Genes, Reporter , Humans , Luciferases/metabolism , Male , Models, Biological , Plasmids/metabolism , Precipitin Tests , Prostatic Neoplasms/metabolism , Protein Binding , Signal Transduction , Time Factors , Transcriptional Activation , Transfection , Tumor Cells, Cultured
14.
Vet Pathol ; 38(5): 491-503, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11572556

ABSTRACT

Marek's disease virus (MDV) infection in the brain was studied chronologically after inoculating 3-week-old chickens of two genetic lines with two strains of serotype I MDV representing two pathotypes (v and vv+). Viral replication in the brain was strongly associated with the development of lesions. Three viral antigens (pp38, gB, and meq) were detected in the brain of infected chickens. Marked differences between v and vv+ pathotypes of MDV were identified for level of virus replication, time course of brain lesions, and expression of major histocompatibility complex (MHC) antigens. Two pathologic phenomena (inflammatory and proliferative) were detected in the brain of chickens inoculated with vv+MDV, but only inflammatory lesions were observed in those inoculated with vMDV. Inflammatory lesions, mainly composed of macrophages, CD4+ T cells, and CD8+ T cells, started at 6-10 days postinoculation (dpi) and were transient. Proliferative lesions, characterized by severe infiltrates of CD4+CD8- T cells (blasts), started at 19-26 dpi and persisted. Expression of MHC antigens in endothelial cells and infiltrating cells within the brain was influenced by MDV infection. Upregulation of MHC class II antigen occurred in all treatment groups, although it was more severe in those inoculated with vv+MDV. MHC class I antigen was downregulated only in those groups inoculated with vv+MDV. These results enhance our understanding of the nature and pattern of MDV infection in the brain and help to explain the neurovirulence associated with highly virulent MDV.


Subject(s)
Brain/virology , Chickens , Herpesvirus 2, Gallid/physiology , Histocompatibility Antigens Class II/immunology , Histocompatibility Antigens Class I/immunology , Marek Disease/immunology , Animals , Antigens, Viral/analysis , Antigens, Viral/immunology , Brain/pathology , CD4 Lymphocyte Count/veterinary , DNA, Viral/analysis , Female , Herpesvirus 2, Gallid/immunology , Herpesvirus 2, Gallid/isolation & purification , Immunohistochemistry/veterinary , Male , Marek Disease/pathology , Marek Disease/virology , Polymerase Chain Reaction/veterinary , Viremia/veterinary , Viremia/virology , Virus Replication
15.
Arch Virol ; 146(5): 983-92, 2001.
Article in English | MEDLINE | ID: mdl-11448035

ABSTRACT

Glycoproteins H and L form a hetero-oligomeric complex (gH-L) which plays an important role in virus entry to host cells and cell-to-cell infection in herpesviruses. Interaction of gH and gL is considered to be critical for the biological function of these two glycoproteins. To investigate the interaction of MDV gH and gL, both gH and gL were expressed in in vitro cell culture systems using indirect immunofluorescence assay with gH and gL antibodies. The results suggested that co-expression of gH and gL in the same cells are required and necessary for both gH and gL subcellular translocation and cell surface expression. gL expressed in recombinant fowlpox virus (rFPV) infected chicken embryo fibroblasts (CEF) was consistently secreted into the culture medium. The primary peptide of gL binds with that of gH in the cytosol or ER lumen. By binding with gH, gL could anchor itself on the cell surface allowing for surface expression and viral spread to uninfected cells. The binding domain of gH was mapped to the amino acids 451-659 (SacI-HindIII) fragment and was essential for gH-L complex formation.


Subject(s)
Herpesvirus 2, Gallid/physiology , Viral Envelope Proteins/physiology , Animals , Antibodies, Viral/immunology , Binding Sites , Biopolymers , Cells, Cultured/virology , Chick Embryo , Culture Media, Conditioned , Fibroblasts/virology , Fluorescent Antibody Technique, Indirect , Genetic Vectors/genetics , Herpesvirus 2, Gallid/genetics , Herpesvirus 2, Gallid/immunology , Macromolecular Substances , Nucleopolyhedroviruses/genetics , Protein Binding , Protein Conformation , Protein Structure, Tertiary , Protein Transport , Recombinant Fusion Proteins/physiology , Spodoptera , Viral Envelope Proteins/chemistry , Viral Envelope Proteins/genetics , Viral Envelope Proteins/immunology , Virus Cultivation
16.
J Virol ; 75(11): 5159-73, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11333897

ABSTRACT

Chemokines induce chemotaxis, cell migration, and inflammatory responses. We report the identification of an interleukin-8 (IL-8) homolog, termed vIL-8, encoded within the genome of Marek's disease virus (MDV). The 134-amino-acid vIL-8 shares closest homology to mammalian and avian IL-8, molecules representing the prototype CXC chemokine. The gene for vIL-8 consists of three exons which map to the BamHI-L fragment within the repeats flanking the unique long region of the MDV genome. A 0.7-kb transcript encoding vIL-8 was detected in an n-butyrate-treated, MDV-transformed T-lymphoblastoid cell line, MSB-1. This induction is essentially abolished by cycloheximide and herpesvirus DNA polymerase inhibitor phosphonoacetate, indicating that vIL-8 is expressed with true late (gamma2) kinetics. Baculovirus-expressed vIL-8 was found to be secreted into the medium and shown to be functional as a chemoattractant for chicken peripheral blood mononuclear cells but not for heterophils. To characterize the function of vIL-8 with respect to MDV infection in vivo, a recombinant MDV was constructed with a deletion of all three exons and a soluble-modified green fluorescent protein (smGFP) expression cassette inserted at the site of deletion. In two in vivo experiments, the vIL-8 deletion mutant (RB1BvIL-8DeltasmGFP) showed a decreased level of lytic infection in comparison to its parent virus, an equal-passage-level parent virus, and to another recombinant MDV containing the insertion of a GFP expression cassette at the nonessential US2 gene. RB1BvIL-8DeltasmGFP retained oncogenicity, albeit at a greatly reduced level. Nonetheless, we have been able to establish a lymphoblastoid cell line from an RB1BvIL-8DeltasmGFP-induced ovarian lymphoma (MDCC-UA20) and verify the presence of a latent MDV genome lacking vIL-8. Taken together, these data describe the identification and characterization of a chemokine homolog encoded within the MDV genome that is dispensable for transformation but may affect the level of MDV in vivo lytic infection.


Subject(s)
Chemotactic Factors/genetics , Herpesvirus 2, Gallid/immunology , Interleukin-8/biosynthesis , Amino Acid Sequence , Animals , Animals, Newborn , Baculoviridae/genetics , Base Sequence , Cell Line , Cell Line, Transformed , Chickens , Cloning, Molecular , Cycloheximide , Gene Deletion , Green Fluorescent Proteins , Herpesvirus 2, Gallid/genetics , Interleukin-8/genetics , Leukocytes, Mononuclear/metabolism , Luminescent Proteins/genetics , Molecular Sequence Data , Mutagenesis, Insertional , Phosphonoacetic Acid , RNA, Messenger/analysis , Recombinant Proteins/biosynthesis , Sequence Alignment , Viral Proteins/biosynthesis , Viral Proteins/genetics , Virus Replication
17.
Virology ; 282(1): 198-205, 2001 Mar 30.
Article in English | MEDLINE | ID: mdl-11259202

ABSTRACT

Infection of chicken cells with three Marek's disease virus (MDV) serotypes interferes with expression of the major histocompatibility complex (MHC or B complex) class I (BF) glycoproteins. BF surface expression is blocked after infection of OU2 cells with MDV serotypes 1, 2, and 3. MDV-induced T-cell tumors suffer a nearly complete loss of cell surface BF upon virus reactivation with 5-bromo-2'-deoxyuridine (BUdR). The recombinant virus (RB1BUS2gfpDelta) transforming the MDCC-UA04 cell line expresses green fluorescent protein (GFP) during the immediate early phase of viral gene expression. Of the UA04 cells induced to express the immediate early GFP, approximately 60% have reduced levels of BF expression. All of the reactivated UA04 and MSB1 tumor cells expressing the major early viral protein pp38 display reduced levels of BF. Thus, BF down-regulation begins in the immediate early phase and is complete by the early phase of viral gene expression. The intracellular pool of BF is not appreciably affected, indicating that the likely mechanism is a block in BF transport and not the result of transcriptional or translational regulation.


Subject(s)
Cell Membrane/metabolism , Herpesvirus 2, Gallid/pathogenicity , Histocompatibility Antigens Class I/metabolism , Animals , Blotting, Western , Cell Line , Chickens , Down-Regulation , Flow Cytometry , Herpesvirus 2, Gallid/genetics
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