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1.
Disabil Rehabil ; : 1-11, 2024 Feb 09.
Article in English | MEDLINE | ID: mdl-38339778

ABSTRACT

PURPOSE: eHealth-based exercise therapies were developed to increase stroke patients' adherence to home-based motor rehabilitation. However, these eHealth tools face a rapid decrease in use after a couple of weeks. This study investigates stroke patients' motivation for home-based upper extremity rehabilitation with eHealth tools and their relation with Basic Psychological Needs. MATERIALS AND METHODS: This is a qualitative study using thematic analysis. We conducted semi-structured interviews with stroke patients with upper extremity motor impairments, who were discharged home from a rehabilitation centre, after they interacted with a novel eHealth coach demonstrator in their homes for five consecutive days. RESULTS: We included ten stroke patients. Thematic analysis resulted in eight themes for home-based rehabilitation motivation: Curiosity, Rationale, Choice, Optimal challenge, Reference, Encouragement, Social Support and Trustworthiness. Those themes are embedded into three Basic Psychological Needs: "Autonomy", "Competence", and "Relatedness". CONCLUSION: Eight motivational themes related to the three Basic Psychological Needs describe stroke patients' motivation for home-based upper extremity rehabilitation. We recommend considering those themes when developing a home-based eHealth intervention for stroke patients to increase the alignment of eHealth tools to the patient's needs and reduce motivational decreases in home-based rehabilitation.


Stroke patients show motivational decreases and decreased use of eHealth tools in home-based rehabilitation after a couple of weeks.Eight motivational themes describe home-based rehabilitation motivation in stroke patients: Curiosity, Rationale, Choice, Optimal challenge, Reference, Encouragement, Social Support and Trustworthiness.Those themes are embedded into three Basic Psychological Needs: "Autonomy", "Competence", and "Relatedness".Those themes should be considered when developing a home-based eHealth intervention for stroke patients to increase the alignment of eHealth tools to the patient's needs and reduce motivational decreases in home-based rehabilitation.

2.
Work ; 61(1): 21-39, 2018.
Article in English | MEDLINE | ID: mdl-30223410

ABSTRACT

BACKGROUND: Supporting teamwork in healthcare is a way to foster both the quality and safety of care, and better working conditions for all the team members. Although increasing attention is paid to this topic on a general level, there is less knowledge about its unfolding in orthopaedic units and its translation to interventions. OBJECTIVE: To identify concrete opportunities for teamwork intervention through a design thinking approach by analysing the teamwork dynamics of an orthopaedic team. METHODS: An adaptation of the learning history method, comprising shadowing, observations and interviews involving 26 orthopaedic team members at a top clinical teaching hospital in the Netherlands, was applied. A thematic analysis was conducted to derive themes that describe team dynamics and to subsequently extrapolate opportunities for intervention. RESULTS: We identified five themes and translated them into four design opportunities for intervention, namely: a) Improve daily rounds by reducing cognitive overload and promoting confidence; b) Improve collaboration by building empathy; c) Connect the patient with the professional team; and d) Support changes by fostering learning. Suggestions for concrete actions are presented for each opportunity. CONCLUSIONS: Opportunities to improve teamwork among healthcare professionals, specifically those in orthopaedics, revolve around the creation of common knowledge, the fostering of mutual understanding, and the design of tools and activities that support these processes.


Subject(s)
Orthopedics/standards , Patient Care Team/standards , Adult , Cooperative Behavior , Female , Humans , Interpersonal Relations , Length of Stay/statistics & numerical data , Male , Netherlands , Orthopedics/methods , Patient Care Team/trends , Qualitative Research , Quality of Health Care
3.
Clin Exp Immunol ; 189(3): 304-309, 2017 09.
Article in English | MEDLINE | ID: mdl-28439882

ABSTRACT

The prevalence and clinical relevance of thyroid stimulating hormone (TSH) receptor (TSHR) blocking antibodies (TBAb) in patients with autoimmune thyroid disease (AITD) was investigated. Serum TBAb were measured with a reporter gene bioassay using Chinese hamster ovary cells. Blocking activity was defined as percentage inhibition of luciferase expression relative to induction with bovine TSH alone (cut-off 40% inhibition). All samples were measured for TSHR stimulatory antibody (TSAb) and TSHR binding inhibiting immunoglobulins (TBII). A total of 1079 unselected, consecutive patients with AITD and 302 healthy controls were included. All unselected controls were negative for TBAb and TSAb. In contrast, the prevalence of TBAb-positive patients with Hashimoto's thyroiditis and Graves' disease was 67 of 722 (9·3%) and 15 of 357 (4·2%). Of the 82 TBAb-positive patients, thirty-nine (48%), 33 (40%) and 10 (12%) were hypothyroid, euthyroid and hyperthyroid, respectively. Ten patients were both TBAb- and TSAb-positive (four hypothyroid, two euthyroid and four hyperthyroid). Thyroid-associated orbitopathy was present in four of 82 (4·9%) TBAb-positive patients, with dual TSHR antibody positivity being observed in three. TBAb correlated positively with TBII (r = 0·67, P < 0·001) and negatively with TSAb (r = -0·86, P < 0·05). The percentage of TBII-positive patients was higher the higher the level of inhibition in the TBAb assay. Of the TBAb-positive samples with  > 70% inhibition, 87% were TBII-positive. Functional TSHR antibodies impact thyroid status. TBAb determination is helpful in the evaluation and management of patients with AITD. The TBAb assay is a relevant and important tool to identify potentially reversible hypothyroidism.


Subject(s)
Autoantibodies/blood , Receptors, Thyrotropin/immunology , Thyroiditis, Autoimmune/immunology , Adolescent , Adult , Animals , Autoantibodies/immunology , Biological Assay , CHO Cells , Cricetinae , Cricetulus , Female , Graves Disease/blood , Graves Disease/immunology , Hashimoto Disease/blood , Hashimoto Disease/immunology , Humans , Male , Middle Aged , Prevalence , Receptors, Thyrotropin/blood , Thyroid Gland/immunology , Thyroid Gland/pathology , Thyroiditis, Autoimmune/blood , Young Adult
4.
Clin Exp Immunol ; 173(3): 390-7, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23647395

ABSTRACT

Autoantibodies to the thyrotrophin (TSH) receptor (anti-TSHR) are unique, in that they are involved directly in the pathophysiology of certain autoimmune thyroid diseases (AITD). Thyroid-stimulating antibodies (TSAb) act as agonists that activate the thyroid gland and cause Graves' disease. Other anti-TSHR antibodies block TSH and can cause hypothyroidism. Thyroid-blocking antibodies (TBAb) have not been studied as extensively as TSAb. We developed a TBAb bioassay based on a cell line that expresses a chimeric TSHR. The 50% inhibitory concentration of the chimeric Chinese hamster ovary (CHO)-Luc cells was more than five-fold lower compared with the wild-type CHO-Luc cells. We tested the performance of this bioassay using a thyroid-blocking monoclonal antibody K1-70, established an assay cut-off and detected TBAb in 15 of 50 (30%) patients with AITD. Interestingly, the assay detects both TSAb and TBAb and measures the net activity of a mixture of both types of antibodies. There was a high correlation (R(2) 0·9, P < 0·0001) between the results of the TSAb assay and the negative percentage inhibition of the TBAb assay. The TBAb bioassay was approximately 20-fold more sensitive than a commercially available TSHR binding assay (TRAb). In contrast to TRAb, sera with high levels of TBAb activity were able to be diluted several hundred-fold and still exhibit blocking activity above the cut-off level. Thus, this TBAb bioassay provides a useful tool for measuring the activity of anti-TSHR antibodies and may help clinicians to characterize the diverse clinical presentations of patients with AITD.


Subject(s)
Autoantibodies/immunology , Immunoassay/methods , Receptors, Thyrotropin/immunology , Animals , Antibodies, Blocking/immunology , Autoimmune Diseases/diagnosis , Autoimmune Diseases/immunology , CHO Cells , Cell Line , Cricetinae , Dose-Response Relationship, Drug , Gene Expression/drug effects , Genes, Reporter , Humans , Immunoglobulins, Thyroid-Stimulating/immunology , Protein Binding/immunology , Receptors, Thyrotropin/agonists , Receptors, Thyrotropin/antagonists & inhibitors , Reproducibility of Results , Sensitivity and Specificity , Thyroid Diseases/diagnosis , Thyroid Diseases/immunology , Thyrotropin/pharmacology
5.
Clin Exp Immunol ; 162(3): 438-46, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21070207

ABSTRACT

Thyroid-stimulating immunoglobulins (TSI) are a functional biomarker of Graves' disease (GD). To develop a novel TSI bioassay, a cell line (MC4-CHO-Luc) was bio-engineered to constitutively express a chimeric TSH receptor (TSHR) and constructed with a cyclic adenosine monophosphate (cAMP)-dependent luciferase reporter gene that enables TSI quantification. Data presented as percentage of specimen-to-reference ratio (SRR%) were obtained from 271 patients with various autoimmune and thyroid diseases and 180 controls. Sensitivity of 96% and specificity of 99% for untreated GD were attained by receiver operating characteristic analysis, area under the curve 0·989, 95% confidence interval 0·969-0·999, P = 0·0001. Precision testing of manufactured reagents of high, medium, low and negative SRR% gave a percentage of coefficient-of-variation of 11·5%, 12·8%, 14·5% and 15·7%, respectively. There was no observed interference by haemoglobin, lipids and bilirubin and no non-specific stimulation by various hormones at and above physiological concentrations. TSI levels from GD patients without (SRR% 406 ± 134, mean ± standard deviation) or under anti-thyroid treatment (173 ± 147) were higher (P < 0·0001) compared with TSI levels of patients with Hashimoto's thyroiditis (51 ± 37), autoimmune diseases without GD (24 ± 10), thyroid nodules (30 ± 26) and controls (35 ± 18). The bioassay showed greater sensitivity when compared with anti-TSHR binding assays. In conclusion, the TSI-Mc4 bioassay measures the functional biomarker accurately in GD with a standardized protocol and could improve substantially the diagnosis of autoimmune diseases involving TSHR autoantibodies.


Subject(s)
Graves Disease/diagnosis , Receptors, Thyrotropin/metabolism , Recombinant Fusion Proteins/metabolism , Animals , Biological Assay , CHO Cells , Cricetinae , Cricetulus , Graves Disease/blood , Graves Disease/immunology , Graves Disease/physiopathology , Humans , Immunoglobulins, Thyroid-Stimulating/blood , Protein Binding/genetics , Protein Engineering , Receptors, Thyrotropin/genetics , Recombinant Fusion Proteins/genetics , Reproducibility of Results , Sensitivity and Specificity , Transgenes/genetics
7.
Lancet ; 355(9200): 275-80, 2000 Jan 22.
Article in English | MEDLINE | ID: mdl-10675075

ABSTRACT

BACKGROUND: Previous studies concerning the relative infectiousness of HIV-1-positive individuals with pulmonary tuberculosis have produced conflicting results. Thus, we assessed the effect of HIV-1 on the infectiousness of Mycobacterium tuberculosis in a prospective study. METHODS: We organised in Santo Domingo, Dominican Republic, a cohort study of household contacts of HIV-1-positive and HIV-1-negative individuals with newly diagnosed pulmonary tuberculosis. Household contacts were assessed at their houses at baseline and followed up for 14 months for evidence of M tuberculosis infection and tuberculosis with a multi-step tuberculin skin test, anergy skin test, physical examinations, chest radiographs, and sputum smears. FINDINGS: Tuberculin induration of 5 mm or greater was seen in 153 (61%) of 252 household contacts of HIV-1-positive index cases and in 418 (76%) of 551 household contacts of HIV-1-negative index cases (odds ratio 0.49 [95% CI 0.35-0.67], p=0.00001). In multivariate logistic-regression analysis after allowance for between-household variation in tuberculin response, HIV-1 infection of the index case remained inversely associated with the tuberculin response of the household contacts (0.52 [0.29-0.93], p=0.02). When the analysis was restricted to household contacts aged between 2 years and 15 years the adjusted association remained significant (0.37 [0.14-0.98], p=0.04). Among household contacts who had a negative tuberculin skin test at baseline, conversion to tuberculin skin test positivity was less frequent among household contacts of HIV-1-positive index cases (cut-off > or =5 mm: 32/131 [24%] vs 71/204 [35%], p=0.05; cut-off > or =10 mm: 23/153 [15%] vs 55/245 [22%], p=0.07). INTERPRETATION: These data suggest that HIV-1-positive individuals with tuberculosis are less likely than HIV-1-negative individuals with tuberculosis to transmit M tuberculosis to their close contacts. No changes in the current policy regarding tuberculosis contact tracing are needed in the presence of HIV-1.


Subject(s)
AIDS-Related Opportunistic Infections/microbiology , Contact Tracing , HIV Infections/complications , HIV-1 , Mycobacterium tuberculosis/isolation & purification , Tuberculosis, Pulmonary/microbiology , AIDS-Related Opportunistic Infections/transmission , Adolescent , Adult , Child , Child, Preschool , Cohort Studies , Dominican Republic/epidemiology , Female , HIV Infections/epidemiology , Humans , Infant , Logistic Models , Male , Prospective Studies , Risk Assessment , Tuberculin Test , Tuberculosis, Pulmonary/transmission
8.
J Virol ; 73(3): 1998-2005, 1999 Mar.
Article in English | MEDLINE | ID: mdl-9971780

ABSTRACT

We describe the use of herpesvirus promoters to regulate the expression of a Sindbis virus replicon (SINrep/LacZ). We isolated cell lines that contain the cDNA of SINrep/LacZ under the control of a promoter from a herpesvirus early gene which requires regulatory proteins encoded by immediate-early genes for expression. Wild-type Sindbis virus and replicons derived from this virus cause death of most vertebrate cells, but the cells discussed here grew normally and expressed the replicon and beta-galactosidase only after infection with a herpesvirus. Vero cell lines in which the expression of SINrep/LacZ was regulated by the herpes simplex virus type 1 (HSV-1) infected-cell protein 8 promoter were generated. One Vero cell line (V3-45N) contained, in addition to the SINrep/LacZ cDNA, a Sindbis virus-defective helper cDNA which provides the structural proteins for packaging the replicon. Infection of V3-45N cells with HSV-1 resulted in the production of packaged SINrep/LacZ replicons. HSV-1 induction of the Sindbis virus replicon and packaging and spread of the replicon led to enhanced expression of the reporter gene, suggesting that this type of cell could be used to develop sensitive assays to detect herpesviruses. We also isolated a mink lung cell line that was transformed with SINrep/LacZ cDNA under the control of the promoter from the human cytomegalovirus (HCMV) early gene UL45. HCMV carries out an abortive infection in mink lung cells, but it was able to induce the SINrep/LacZ replicon. These results, and those obtained with an HSV-1 mutant, demonstrate that this type of signal amplification system could be valuable for detecting herpesviruses for which a permissive cell culture system is not available.


Subject(s)
Cytomegalovirus/genetics , Herpesvirus 1, Human/genetics , Promoter Regions, Genetic , Replicon , Sindbis Virus/genetics , Animals , Base Sequence , Chlorocebus aethiops , Cricetinae , Molecular Sequence Data , Vero Cells , Virus Assembly
9.
Virology ; 251(1): 198-205, 1998 Nov 10.
Article in English | MEDLINE | ID: mdl-9813215

ABSTRACT

We describe here a novel approach for detecting and quantitating human respiratory syncytial virus (RSV) based on expression of a reporter gene from an RSV minigenome. BHK cells were cytoplasmically transformed with a noncytopathic Sindbis virus replicon expressing T7 RNA polymerase. These cells were then cotransfected with T7 expression plasmids that contain the cDNA of an RSV minigenome and the genes for RSV nucleocapsid proteins N, P, and L. The minigenome contains a reporter gene such as lacZ or CAT flanked by cis-acting RSV transcription signals. Subsequent infection of these cells with RSV resulted in a high level of reporter gene expression which could be inhibited by ribavirin. Mock-infected cells exhibited background levels of expression. This assay can be used to quantitate RSV and titer neutralizing antibody and may be a valuable tool for screening compounds for anti-RSV activity. It serves as a prototype for other negative-strand RNA viruses.


Subject(s)
Genome, Viral , Replicon , Respiratory Syncytial Virus, Human/isolation & purification , Sindbis Virus/genetics , Animals , Antibodies, Viral/immunology , Cell Line , Cricetinae , DNA, Complementary/genetics , DNA-Directed RNA Polymerases/genetics , DNA-Directed RNA Polymerases/metabolism , Gene Expression Regulation, Viral/drug effects , Genes, Reporter/genetics , Humans , Nucleocapsid Proteins/genetics , Promoter Regions, Genetic/genetics , Protein Biosynthesis , RNA, Viral/biosynthesis , Respiratory Syncytial Virus, Human/genetics , Respiratory Syncytial Virus, Human/physiology , Ribavirin/pharmacology , Transcription, Genetic/drug effects , Transfection , Viral Plaque Assay/methods , Viral Proteins , Virus Replication/drug effects , Virus Replication/genetics , gamma-Globulins/immunology
10.
J Infect Dis ; 177(1): 217-20, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9419192

ABSTRACT

A rapid assay was developed to screen for herpes simplex virus (HSV) isolates that are resistant to acyclovir and other antiviral agents. The assay is a modified plaque reduction assay (PRA) in which the number of plaques seen in the absence of acyclovir was compared with that seen in the presence of a single cutoff concentration of acyclovir (2 microg/mL). This assay utilizes a cell line that expresses beta-galactosidase only after infection with HSV. Since histochemically stained plaques are easily visualized, small plaques can be easily enumerated. This allows the assay to be performed on dilutions of untitered specimens in the small wells of a 24-well plate and allows the results to be read only 2 days after inoculation of the virus. The assay performed well compared with a standard PRA and should be a valuable tool in identifying drug-resistant HSV in a timely manner.


Subject(s)
Acyclovir/pharmacology , Antiviral Agents/pharmacology , Microbial Sensitivity Tests/methods , Simplexvirus/drug effects , Cells, Cultured/metabolism , Drug Resistance, Microbial , Sensitivity and Specificity , Viral Plaque Assay/methods , beta-Galactosidase/metabolism
11.
J Virol ; 70(8): 5476-86, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8764059

ABSTRACT

Herpes simplex virus establishes a latent infection in peripheral neurons. We examined viral gene expression in rat peripheral neurons in vitro and determined that viral gene expression is attenuated and delayed in these neurons compared with that in Vero cells. In addition, using pharmacologic and genetic blocks to viral DNA synthesis, we found that viral alpha and beta gene expression was upregulated by viral DNA synthesis. Although maximal gene expression in neurons requires viral DNA synthetic activity, activation of viral gene expression was seen even in the presence of herpes simplex virus DNA polymerase inhibitors, but not in the absence of the origin-binding protein. Initiation of viral DNA synthesis is apparently a key regulatory event in the balance between the lytic and latent pathways in peripheral neurons.


Subject(s)
DNA, Viral/biosynthesis , Gene Expression Regulation, Viral , Herpes Simplex/virology , Neurons/virology , Simplexvirus/physiology , Animals , Chlorocebus aethiops , DNA, Viral/genetics , Rats , Vero Cells , Virus Activation , Virus Latency
12.
Clin Microbiol Rev ; 9(3): 321-34, 1996 Jul.
Article in English | MEDLINE | ID: mdl-8809463

ABSTRACT

Rapid diagnostic assays based on direct detection of viral antigen or nucleic acid are being used with increasing frequency in clinical virology laboratories. Virus culture, however, remains the only way to detect infectious virus and to analyze clinically relevant viral phenotypes, such as drug resistance. Growth of viruses in cell culture is labor intensive and time-consuming and requires the use of many different cell lines. Transgenic technology, together with increasing knowledge of the molecular pathways of virus replication, offers the possibility of using genetically modified cell lines to improve virus growth in cell culture and to facilitate detection of virus-infected cells. Genetically modifying cells so that they express a reporter gene only after infection with a specific virus can allow the detection of infectious virus by rapid and simple enzyme assays such as beta-galactosidase assays without the need for antibodies. Although transgenic cells have recently been successfully used for herpes simplex virus detection, much more work needs to be done to adapt this technology to other human viral pathogens such as cytomegalovirus and respiratory viruses. This review offers some strategies for applying this technology to a wide spectrum of animal viruses.


Subject(s)
Cell Culture Techniques/methods , Genetic Engineering/methods , Virus Diseases/virology , Viruses/growth & development , Animals , Animals, Genetically Modified , Cells, Cultured , DNA Viruses/growth & development , Gene Expression Regulation, Viral , Genetic Predisposition to Disease , HIV/growth & development , Herpesviridae/growth & development , Host-Parasite Interactions , Humans , Immunity, Innate/genetics , RNA Viruses/growth & development , Receptors, Virus/genetics , Simian Immunodeficiency Virus/growth & development , Transformation, Genetic , Virus Physiological Phenomena , Virus Replication
13.
J Virol ; 69(7): 4515-8, 1995 Jul.
Article in English | MEDLINE | ID: mdl-7769714

ABSTRACT

Varicella-zoster virus (VZV) gene 51 encodes a protein which is homologous to UL9, the origin of DNA replication-binding protein of herpes simplex virus type 1. No genetic information is available on VZV gene 51, but its product has been shown to bind to virtually the same recognition sequence as does UL9 (D. Chen and P. D. Olivo, J. Virol. 68:3841-3849, 1994; N. D. Stow, H. M. Weir, and E. C. Stow, Virology 177:570-577, 1990). We report here that gene 51 can complement a UL9 null mutant (hr94) (A. K. Malik, R. Martinez, L. Muncy, E. P. Carmichael, and S. K. Weller, Virology 190:702-715, 1992), but at a level which is only 20% of that of UL9. Quantitation of viral DNA synthesis suggests that this phenotype is due to a defect in viral DNA synthesis. Regardless, the ability of VZV gene 51 to complement UL9 suggests that alphaherpesviruses have a highly conserved mechanism of initiation of viral DNA synthesis.


Subject(s)
DNA, Viral/biosynthesis , DNA-Binding Proteins/genetics , Genes, Viral , Herpesvirus 1, Human/genetics , Herpesvirus 3, Human/genetics , Viral Proteins/genetics , Animals , Cell Line , Cricetinae , Mutation
14.
Antimicrob Agents Chemother ; 39(6): 1287-91, 1995 Jun.
Article in English | MEDLINE | ID: mdl-7574517

ABSTRACT

Despite increasing concern about drug-resistant herpes simplex virus (HSV), antiviral susceptibility testing is not routinely performed by most clinical virology laboratories. This omission is in large part because the most widely accepted method, the plaque reduction assay (PRA), is cumbersome to perform and results are rarely available in time to influence treatment. We report here the development of a sensitivity test for HSV which utilizes a cell line (VeroICP6LacZ#7) that expresses beta-galactosidase activity after infection with HSV such that infected cells can be detected by histochemical staining. We designed an assay in which 10-fold dilutions of virus stocks with undetermined titers were inoculated onto VeroICP6LacZ#7 cells in a 24-well tissue culture dish. Forty-eight hours after infection, the cell monolayers were histochemically stained. Plaques appear blue against a clear background and are thus easily visualized at 48 h. As with the standard PRA, the 50% inhibitory concentration (IC50) was reported as the concentration of an antiviral drug that reduces the number of plaques by 50%. Evaluation of 10 well-characterized laboratory strains and 12 clinical HSV isolates showed that the IC50 determined by this method correlated in all instances with the IC50 determined by the PRA. This method is easy to use and eliminates the need to determine the titer of the virus, and results are available within 48 h of the detection of the virus. VeroICP6Lac#7 cells are a useful tool for performing HSV antiviral susceptibility testing and could be used in a number of different formats to facilitate the identification of drug-resistant isolates of HSV.


Subject(s)
Simplexvirus/drug effects , Viral Plaque Assay/methods , Acyclovir/pharmacology , Animals , Cell Line, Transformed , Chlorocebus aethiops , DNA Replication , Foscarnet/pharmacology , Humans , Simplexvirus/growth & development , Vero Cells , beta-Galactosidase/biosynthesis
15.
Virology ; 206(1): 655-60, 1995 Jan 10.
Article in English | MEDLINE | ID: mdl-7831822

ABSTRACT

We isolated two recombinant baculoviruses each of which expresses a varicella-zoster virus (VZV) homolog of one of the seven herpes simplex virus type 1 (HSV-1) genes required for DNA replication. We performed transient origin-dependent DNA replication assays in insect cells in which we substituted a baculovirus which expresses a VZV protein for a baculovirus which expresses its HSV homolog. VZV gene 51 protein was found to be able to support origin-dependent DNA synthesis when it was substituted for UL9, the HSV-1 origin-binding protein (OBP). This occurred whether an HSV-1 or a VZV origin-containing plasmid was used in the assay. These results suggest that VZV gene 51 protein is able to interact with the HSV replication machinery, and in light of the extensive structural divergence of these proteins, it suggests that initiation of VZV and HSV-1 DNA synthesis may involve a limited number of interactions between the OBP and other replication factors. Substitution of infected-cell protein 8 (ICP8), the major single-stranded DNA-binding protein of HSV-1, with VZV gene 29 protein, however, did not result in amplification of plasmids containing either an HSV-1 or a VZV origin. In the absence of ICP8, addition of both VZV gene 51 protein and gene 29 protein was also negative for origin-dependent replication whether or not UL9 was present. Although demonstration that our baculovirus-expressed VZV gene 29 protein is functional for DNA replication will await development of a VZV replication system, our results suggest that VZV gene 29 protein is unable to interact functionally with one or more of the HSV replication proteins. This approach should contribute to efforts to define the interactions among the alphaherpesvirus DNA replication proteins.


Subject(s)
DNA Replication , DNA-Binding Proteins/physiology , Herpesvirus 3, Human/metabolism , Viral Proteins/physiology , Animals , Baculoviridae/genetics , Cells, Cultured , Spodoptera
16.
Neurobiol Dis ; 1(1-2): 83-94, 1994 Nov.
Article in English | MEDLINE | ID: mdl-9216990

ABSTRACT

Infection of non-neuronal cell types with herpes simplex virus type 1 (HSV-1) results in the degradation of host mRNA (Kwong & Frenkel 1987) and a shutoff in host protein synthesis (Roizman et al. 1965). This effect is mediated by a virion associated protein that is encoded by the viral vhs gene (Read & Frenkel 1983). This virion host shutoff (VHS) helps regulate viral gene expression and promotes efficient viral replication during the lytic cycle (Kwong & Frenkel 1987). Cultured sympathetic and sensory neurones, in contrast to primary rat fibroblasts, PC-12 cells, and Vero cells, showed no reduction in protein synthesis following infection with HSV-1. The resistance of neurones to VHS may be important in allowing establishment of a latent infection. In addition, this finding has a favourable impact on the idea of using HSV as a vector to deliver foreign genes into neurones.


Subject(s)
Herpes Simplex/metabolism , Neurons, Afferent/virology , Protein Biosynthesis , Simplexvirus/physiology , Sympathetic Nervous System/virology , Animals , Cells, Cultured , Immunohistochemistry , PC12 Cells , Rats , Rats, Sprague-Dawley
17.
J Virol ; 68(6): 3841-9, 1994 Jun.
Article in English | MEDLINE | ID: mdl-8189521

ABSTRACT

The varicella-zoster virus (VZV) genome contains homologs to each of the seven herpes simplex virus (HSV) genes that are required for viral DNA synthesis. VZV gene 51 is homologous to HSV UL9, which encodes an origin of DNA replication binding protein (OBP). It was previously shown, by using a protein A fusion protein, that the product of gene 51 is a site-specific DNA-binding protein which binds to sequences within the VZV origin (Stow et al., Virology 177:570-577, 1990). In this report, gene 51 was expressed in an in vitro translation system. Rabbit antiserum raised against the carboxyl-terminal 20 amino acids was used to confirm expression of the full-length gene 51 protein, and site-specific DNA-binding activity was demonstrated in a gel retardation assay. The origin-binding domain was located within a 263-amino-acid region of the carboxyl terminus by using a series of deletion mutants. The affinity of binding of the VZV OBP to the three binding sites in the VZV origin was found to be similar. In addition, as with UL9, a CGC triplet within a 10-bp consensus sequence is critical to the interaction between the OBP and the origin. The HSV and VZV OBPs, therefore, appear to have virtually identical recognition sequences despite only 33% identity and 44% similarity in the primary structure of their site-specific DNA-binding domains.


Subject(s)
DNA-Binding Proteins/metabolism , Herpesvirus 3, Human/metabolism , Viral Proteins/metabolism , Amino Acid Sequence , Animals , Antibodies, Viral , Base Sequence , Binding Sites , DNA, Viral/genetics , DNA, Viral/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/immunology , Gene Expression , Genes, Viral , Herpesvirus 3, Human/genetics , Molecular Sequence Data , Mutagenesis, Site-Directed , Oligonucleotide Probes/genetics , Point Mutation , Protein Biosynthesis , Rabbits , Sequence Homology, Amino Acid , Simplexvirus/genetics , Species Specificity , Transcription, Genetic , Viral Proteins/genetics , Viral Proteins/immunology
18.
J Virol Methods ; 47(1-2): 117-28, 1994 Apr.
Article in English | MEDLINE | ID: mdl-8051220

ABSTRACT

A stably transformed cell line (BHKICP6LucA6) has been isolated which expresses high levels of luciferase activity following infection with herpes simplex virus (HSV). The genome of this cell line contains an HSV-1 promoter-luciferase chimeric gene. Infected BHKICP6LucA6 cells exhibit a level of luciferase activity 5 x 10(5) higher than mock-infected cells. This signal-to-noise ratio is of a sufficient magnitude that measurement of the luciferase activity of an infected-cell lysate can detect a single infected cell when a practical number of cells is used in the assay. This approach to the detection of infectious virus could be useful in a number of circumstances and may be adaptable to an automated assay which could become a useful means for diagnostic laboratories to detect viruses in clinical specimens.


Subject(s)
Herpes Simplex/enzymology , Luciferases/metabolism , Simplexvirus/isolation & purification , Animals , Cell Line, Transformed , Coleoptera , Cricetinae , Luciferases/genetics , Sensitivity and Specificity , Time Factors , Transfection
19.
Virology ; 198(1): 381-4, 1994 Jan.
Article in English | MEDLINE | ID: mdl-8259675

ABSTRACT

We describe a stably transformed cell line (BHKSINLuc2) that contains a defective Sindbis virus genome under the control of a Rous sarcoma virus promoter and the luciferase gene downstream of the viral subgenomic RNA promoter. This cell line expresses high levels of luciferase activity following infection with Sindbis virus and provides a sensitive assay for titering variants of Sindbis virus that lack the structural protein genes, in particular, Sindbis virus replicons that express heterologous proteins. Cell lines such as this may be of value for detection of positive-strand RNA viruses.


Subject(s)
Genes, Reporter , Sindbis Virus/isolation & purification , Virus Cultivation , Alphavirus/genetics , Alphavirus/isolation & purification , Animals , Cell Line, Transformed , Cricetinae , RNA, Viral/analysis , Replicon , Sindbis Virus/genetics , Virus Cultivation/methods
20.
Nucleic Acids Res ; 21(22): 5203-11, 1993 Nov 11.
Article in English | MEDLINE | ID: mdl-8255778

ABSTRACT

We have studied the DNA binding properties of a polypeptide consisting of the carboxyl terminal 37% of UL9, the herpes simplex virus type 1 (HSV-1) origin of replication binding protein. Using a Sindbis virus expression system, we expressed and partially purified this truncated form of UL9 (UL9CT) which contains the site-specific DNA binding domain. UL9CT specifically recognized UL9 binding sites on a 200 base pair DNA fragment containing the HSV origin ori(s) and appeared to bind as a dimer to each site. DNAse I footprint analysis showed that UL9CT protected the two high affinity binding sites of ori(s), but unlike full-length UL9, UL9CT did not induce a conformational change in the origin. Addition of anti-UL9CT antibody to the UL9CT-origin complex, however, caused a conformational change in the origin to be evident. Our results suggest that a domain, or domains, in the amino terminus are necessary for a UL9-induced origin conformational change to occur and that UL9-UL9 interactions between binding sites are involved.


Subject(s)
DNA Replication , DNA, Viral/metabolism , DNA-Binding Proteins/metabolism , Nucleic Acid Conformation , Simplexvirus/genetics , Viral Proteins/metabolism , Animals , Base Sequence , Binding Sites , Blotting, Western , Cell Line , Cricetinae , DNA, Viral/chemistry , DNA, Viral/genetics , DNA-Binding Proteins/chemistry , Deoxyribonuclease I , Molecular Sequence Data , Peptide Fragments/metabolism , Viral Proteins/chemistry
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