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PubMed2000

Evaluation of the antibody specificities of human convalescent-phase sera against the attachment (G) protein of human respiratory syncytial virus: influence of strain variation and carbohydrate side chains.

The C-terminal third of the attachment protein (G) of several human respiratory syncytial virus isolates was obtained as either a glycosylated protease-resistant fragment of the purified protein or a nonglycosylated GST fusion protein expressed in bacteria. The reactivity of human convalescent-phase sera with both forms of the protein segment was evaluated in immunoblots. While all serum samples reacted with the mature intact protein of the different isolates, only certain samples reacted with the nonglycosylated C-terminal segment of some viral isolates. The number of human serum samples reacting with the glycosylated C-terminal fragment was even more limited. These results highlight the heterogeneity of the human antibody response against epitopes located in the C-terminal hypervariable region of the G molecule and the influence of carbohydrate side chains for expression of these epitopes. We also have analysed the specificities of human sera by competitive enzyme-linked immunosorbent assay with murine monoclonal antibodies (MAbs). Most human serum samples inhibited virus binding of MAbs that recognised conserved or group-specific epitopes of the G protein, while only a limited fraction of those samples inhibited binding of MAbs that recognised strain-specific epitopes. These results are discussed in terms of the antibody repertoire induced after human respiratory syncytial virus infection and the relevance of escape mechanisms to preexisting antibodies for the evolution of this virus.

Adolescent↗
PubMed2000

Bovine respiratory syncytial virus (BRSV): a review.

Bovine respiratory syncytial virus (BRSV) infection is the major cause of respiratory disease in calves during the first year of life. The study of the virus has been difficult because of its lability and very poor growth in cell culture. However, during the last decade, the introduction of new immunological and biotechnological techniques has facilitated a more extensive study of BRSV as illustrated by the increasing number of papers published. Despite this growing focus, many aspects of the pathogenesis, epidemiology, immunology etc. remain obscure. The course and outcome of the infection is very complex and unpredictable which makes the diagnosis and subsequent therapy very difficult. BRSV is closely related to human respiratory syncytial virus (HRSV) which is an important cause of respiratory disease in young children. In contrast to BRSV, the recent knowledge of HRSV is regularly extensively reviewed in several books and journals. The present paper contains an updated review on BRSV covering most aspects of the structure, molecular biology, pathogenesis, pathology, clinical features, epidemiology, diagnosis and immunology based on approximately 140 references from international research journals.

Amino Acid Sequence↗
PubMed2000

Prevention of respiratory syncytial virus infection with palivizumab.

Respiratory syncytial virus (RSV) infects virtually all children by the age of 2 yrs. Premature infants with chronic lung disease (CLD) are at risk of greater morbidity due to RSV infection. However, these infants represent a small proportion of all infants admitted to hospital with RSV infection, and hospitalization rates for this group appear to have decreased over the past decade. Prophylaxis against RSV infection has recently become available in the form of palivizumab, a humanized monoclonal antibody preparation. The IMpact trial demonstrated a 39% relative risk reduction in hospital admissions for RSV in cases in which palivizumab was administered to premature infants with CLD. However, palivizumab is a very expensive drug and cost-effectiveness analyses do not support its use in the majority of premature infants with or without CLD. The only group in which palivizumab should even be considered for use is premature infants with chronic lung disease at home on oxygen during their first respiratory syncytial virus season. In this group of infants, a detailed postlicensing audit needs to be performed to determine efficacy.

Antibodies, Monoclonal↗
PubMed1999

2-5A-antisense chimeras: inhibitors of respiratory syncytial virus infection.

A new approach to the chemical control of respiratory syncytial virus infection is reviewed in the context of the biology of the virus and previous treatment approaches. Conjugation of the interferon action mediator, 2',5'-oligoadenylate (2-5A), to antisense agents provides a strategy for the selective ablation of RNA. This application of this technology to respiratory syncytial virus has provided a potent selective inhibitor of virus replication.

2',5'-Oligoadenylate Synthetase↗
PubMed1997

[Inhibition of respiratory syncytial virus (RSV) by moroxydine, allicin, alpha-interferon and their joint application].

This paper reported the inhibition of respiratory syncytial virus by Moroxydine (ABOB), Allicin, alpha-interferon and their joint application. The results indicated that each of the three drugs inhibited RSV in HeLa cells, and the effective dosage of ABOB was 100 mg/L, alpha-interferon 1.5 x 10(4) U/L and Allicin one eight hundred thousandth of the pure material. The combinations of 3 drugs showed synergism without antagonism, this not only decreased the dosage, toxicity but also enhanced the inhibition effects on respiratory syncytial virus obviously.

Biguanides↗
PubMed1995

Occurrence of respiratory syncytial virus subtypes in Mexican infants with acute lower respiratory tract disease.

The occurrence of respiratory syncytial virus (RSV) subtypes in Mexico City was studied by searching for the virus in nasopharyngeal aspirates of 82 infants, less than 12 months of age, hospitalized for acute lower respiratory tract disease with diagnosis of bronchitis, bronchiolitis, pneumonia and laryngotracheobronchitis. The presence of respiratory virus was determined by observation of cytopathic effect in cell monolayers; samples which produced a clear syncytia were considered positive and were treated with anti-respiratory syncytial virus serum. Viral infectivity was neutralized in 21 samples which were regarded as having RSV. These specimens were characterized into subtypes A and B with specific monoclonals by indirect immunofluorescence. Subtype A predominated over subtype B, 19 vs. 2. Patients with pneumonia and laryngotracheobronchitis had subtype A and both subtypes were found in infants with bronchitis and bronchiolitis.

Acute Disease↗
PubMed1995

Asthma and immunoglobulin E antibodies after respiratory syncytial virus bronchiolitis: a prospective cohort study with matched controls.

OBJECTIVE: To study the occurrence of bronchial obstructive symptoms and immunoglobulin (Ig) E antibodies after respiratory syncytial virus (RSV) bronchiolitis in infancy. Previous studies of this subject have mostly been retrospective or without controls, or the controls have not been followed prospectively. DESIGN: This was a prospective cohort study with matched controls. PARTICIPANTS: Forty-seven infants had experienced RSV bronchiolitis severe enough to cause hospitalization at a mean age of 3 1/2 months. For each child with RSV infection, two controls were acquired from the local Child Health Center and matched for date of birth, sex, and residence. Only one control was obtained for one RSV child, and the control group thus contained 93 children. METHODS: All the children underwent two follow-up examinations, the first one at a mean age of 1 year and the second at a mean age of 3 years. At the first follow-up, a skin-prick test against egg white was performed, and serum IgG antibodies against RSV were measured. At the second follow-up, serum IgE antibodies were measured using screening tests for common food and inhalant antibodies, and skin-prick tests against egg white, cat, birch, and mite allergen were performed. Hereditary and environmental factors (passive smoking, indoor furred animals) and duration of breast-feeding were recorded. RESULTS: At the first follow-up, 89% in the RSV group and 27% in the control group had IgG antibodies against RSV (P < .001). At the second follow-up, asthma, defined as three episodes of bronchial obstruction verified by a physician, was found in 11 of 47 children (23%) in the RSV group and in 1 of 93 children (1%) in the control group (P < .001). A positive test for IgE antibodies was noted in 14 of 44 (32%) RSV children and in 8 of 92 (9%) children in the control group (P = .002). An analysis of risk factors for the development of asthma and IgE antibodies on the whole group of 140 children showed that RSV bronchiolitis was the most important risk factor, and a family history of atopy or asthma further increased the risk. CONCLUSIONS: Respiratory syncytial virus bronchiolitis during the first year of life apparently is an important risk factor for the development of asthma and sensitization to common allergens during the subsequent 2 years, particularly in children with hereditary for atopy/asthma.

Asthma↗
PubMed1995

Lesions in lambs experimentally infected with bovine respiratory syncytial virus.

An experimental model was designed to characterize lesions in the lung of lambs inoculated with bovine respiratory syncytial virus (BRSV). 25 Merino lambs of both sexes, with a live weight of 17 +/- 3 Kg, received an intratracheal inoculation of 20 ml saline solution containing 1.26 x 10(6) TCID50 BRSV (strain NMK-7) per ml. Lambs were slaughtered 1, 3, 7, 11 and 15 postinoculation days (PID), and histopathological, immunohistochemical and electron microscopic studies were performed. Results reflected a series of lesions, the most noteworthy of which were bronchiolitis obliterants with destruction of the mucociliary apparatus, the presence of syncytial cells in alveoli and a progressive interstitial reaction. BRSV antigen was detected in lung samples. These changes might be expected to decrease the efficiency of respiratory tract defence mechanisms, rendering the lung parenchyma susceptible to opportunist bacterial infection.

Animals↗
PubMed1997

[Ribavirin in the treatment of bronchiolitis caused by syncytial respiratory virus].

OBJECTIVE: The aim of this study was to evaluate ribavirin therapy for acute bronchiolitis caused by viral syncytial respiratory infection. PATIENTS AND METHODS: Ninety-seven patients with acute bronchiolitis in which respiratory syncytial virus was identified by direct immunofluorescence and admitted to the hospital between October 1990 and May 1995 were studied. Data pertaining to age, sex, weight, respiratory frequency at admission, respiratory frequency on the fourth day, day in which respiratory ausculation was normal, day in which there were no thoracic retractions, number of days that the infants needed oxygen, duration of hospital stay, and whether or not they were treated with ribavirin were collected retrospectively. RESULTS: At admission there were no statistically significant differences in patients treated or not with ribavirin or in age, sex or weight, but the respiratory frequency was higher in those patients treated with ribavirin than in those who were not. The number of days of oxygen therapy was statistically different between these groups, with infants treated with ribavirin requiring oxygen for 2.7 days and the nontreated group requiring 1.7 days. However, we think that this difference is not clinically relevant. CONCLUSIONS: We did not find any difference of clinical relevance between patients treated or not with ribavirin.

Acute Disease↗
PubMed1978

Respiratory syncytial virus infection. Rapid diagnosis in children by use of indirect immunofluorescence.

Specimens of 387 nasopharyngeal suction smears obtained from 354 children hospitalized with acute respiratory infections during an eight-month period were examined for the presence of respiratory syncytial (RS) virus by the indirect immunofluorescence antibody technique (IFAT) and by conventional tissue culture infectivity techniques. Respiratory syncytial virus was identified in nasopharyngeal suction smear specimens from 123 of these specimens (32%) with the use of both techniques. Of the specimens positive on tissue culture 92% were also positive for RS virus by IFAT. However, eight specimens positive for RS virus by tissue culture were negative by IFAT, although three of the specimens were technically unsuitable. Six percent of the specimens negative for RS virus by tissue culture were positive for RS virus antigen when tested by IFAT. Using IFAT, identification of RS virus could be accomplished within four to six hours, whereas isolation by tissue culture took an average period of ten days. These data suggest that IFAT is a reliable means for the rapid diagnosis of RS virus infection in infants and children.

Adolescent↗
PubMed1986

Risk of primary infection and reinfection with respiratory syncytial virus.

Respiratory syncytial virus is the most important cause of serious lower respiratory tract infection in children. For children followed up from birth in the Houston Family Study, the infection rate was 68.8/100 children less than 12 months of age and 82.6/100 during the second year of life. Virtually all children had been infected at least once by 24 months of age, and about one half had experienced two infections. Although lower respiratory tract disease (LRD) was common (22.4/100 during year 1 and 13.0/100 during year 2), most children had only one LRD illness. The risk of reinfection was inversely related to the level of neutralizing antibodies in the serum. Reinfection illnesses were generally mild, and risk of reinfection decreased to only 33.3/100 during year 4. Studies of children with LRD and surveys of hospitalizations provide the basis for an estimate of the number of children hospitalized each year during the respiratory syncytial virus epidemics. Almost 100,000 children in the United States experience an illness of sufficient severity to require hospitalization.

Child, Preschool↗
PubMed2006

Immunoglobulin treatment for respiratory syncytial virus infection.

BACKGROUND: Respiratory syncytial virus (RSV) bronchiolitis and pneumonia hospitalize hundreds of thousands of infants every year. Treatment is largely supportive therapy, (for example, oxygen, fluids and occasionally mechanical ventilation). Ribavirin, an antiviral agent, is licensed for severe RSV infection, although systematic reviews find it of no benefit. Passive protection against RSV can be achieved through monthly intramuscular injection of the humanized monoclonal anti-RSV antibody palivizumab (Synagis), and yields a 55% reduction in RSV hospitalisation in susceptible infants. This review assesses immunoglobulin treatment of RSV infection rather than its role as a prophylactic measure. OBJECTIVES: To assess the efficacy of adding human or humanized immunoglobulin therapy to supportive therapy in infants hospitalized with laboratory-determined RSV infection. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2006), MEDLINE (1966 to Week 4, January 2006) and EMBASE (1980 to September 2005). We also ran searches of reference lists of relevant trials and review articles and searches of personal files. We did not impose any language restrictions. SELECTION CRITERIA: We selected randomised controlled trials (RCTs) that compared immunoglobulin treatment with a placebo control in children hospitalized for RSV infection with bronchiolitis or pneumonia or other lower respiratory tract infection (LRTI) with laboratory-documented RSV infection. The primary outcomes of interest were mortality, length of hospitalisation, length of ventilation and oxygen dependence. Secondary outcome measures were pulmonary function and re-hospitalisations for recurrent breathing difficulties in subsequent years. Any adverse effects of the treatments were also noted, for example, hypersensitivity reactions. DATA COLLECTION AND ANALYSIS: Data were extracted but cross-comparison was not possible due to the shortage of studies and lack comparative measurements. MAIN RESULTS: Four papers fitted the search criteria. None demonstrated statistically significant benefit of intravenous immunoglobulin (IVIG) treatment added to supportive care compared with supportive care alone. The evidence does not support a role for RSVIG in such a setting, with the doses used in the studies. AUTHORS' CONCLUSIONS: The evidence on the role of respiratory syncytial virus immunoglobulin (RSVIG) in treating RSV severe infections is limited. Future research might consider using stronger titres of neutralising antibodies; and further analyse severely ill children (who might respond differentially compared to those less ill, but yet hospitalised).

Child↗
PubMed1978

Experimental respiratory syncytial virus pneumonia in cebus monkeys.

Into 14 juvenile cebus monkeys that lacked serum antibodies for RS virus 10(8) plaque-forming units (pfu) of wild-type respiratory syncytial (RS) virus were inoculated transtracheally. Roentgenographic evidence of pneumonia developed in 13 of 14 infected animals. Gross pathologic changes occurred in each of the 13 monkeys that were sacrificed. Patchy areas of red consolidation were seen in the lower lobes 24 hours after inoculation, and there was progression to gray consolidation seven days later. Each of the infected animals had histologic evidence of interstitial pneumonia. Changes were detected in the lung as early as 24 hours after inoculation; they consisted primarily of infiltration of the alveolar wall. By the fourth to sixth day after inoculation there was marked interstitial thickening, pulmonary consolidation, formation of multinucleated giant cells and development of eosinophilic cytoplasmic inclusion bodies within alveolar cells. RS viral antigens, detected by indirect immunofluorescence, were distributed throughout cells of the alveolar wall and the bronchiolar epithelium. The virus grew to highest titer in the lungs on the fourth to sixth day after inoculation; up to 10(8) pfu/gram of tissue were detected. The cebus monkey represents the first experimental host to develop extensive pulmonary lesions during infection with respiratory syncytial virus.

Animals↗
PubMed1981

Maternal antibody and respiratory syncytial virus infection in infancy.

One hundred newborn infants were studied prospectively for 1 year for evidence of infection with respiratory syncytial virus (RSV). The indirect membrane fluorescence technique was used to determine specific antibody in sera. Infection was shown in 29 cases. In 31 infants exposed to an RSV epidemic season, there was no evidence of infection. Maternal antenatal sera were also tested, and wide range of IgG antibody to RSV was found. Mean titre of maternal IgG antibody to RSV was significantly higher (P less than 0.001) in those mothers whose babies remained uninfected than in those whose babies had proved RSV infection before 6 months of age. Babies born to mothers with high levels of IgG antibody to respiratory syncytial virus were protected against infection with this virus during the first months of life when the risk of severe disease was greatest.

Adult↗
PubMed1982

Appearance of complement components and immunoglobulins on nasopharyngeal epithelial cells following naturally acquired infection with respiratory syncytial virus.

Nasopharyngeal epithelial cells (NPEC) were collected from 144 infants and children with respiratory syncytial virus (RSV) infection, and were analyzed by fluorescent antibody techniques for the presence of cell-bound complement (C'3), IgA, IgG, and IgM class of immunoglobulins (Ig), and respiratory syncytial virus antigen. Viral antigen was present on the surface of NPEC in 100% of samples obtained in the first 3 days or illness. The percentage of patients positive for RSV antigen declined steadily, so that no patient still expressed viral antigen on NPEC by 57 days after the onset of illness. Cell-bound IgA, IgG, and IgM could be detected in most of the samples tested in the first 13 days after the onset of illness. Subsequently, the frequency of detection of cell-bound Ig gradually declined. Only 8-33% of patients tested 57 days after the onset of illness expressed IgA, IgG, or IgM on NPEC. About 45% of samples tested in the first 8 weeks after the onset of illness exhibited complement binding to NPEC. The percentage of subjects showing cell-bound C'3 reached a maximum at 8-13 says after the onset of illness, while cell-bound C'3 could not be detected in any of the samples collected 57-90 days after the onset of illness. Although cell-bound C'3 was generally present in association with cell-bound Ig on NPEC, in a small percentage (4.6%) of patients cell-bound C'3 could be detected in the absence of any cell-bound Ig. Cell-bound C'3 and IgA, IgG, and IgM were present with equal frequency in patients with all forms of clinical disease caused by RSV, and in patients less than or greater than 6 months of age at the onset of illness.

Antigens, Viral↗
PubMed1986

The detection of respiratory syncytial virus in nasopharyngeal aspirates: assessment, formulation, and evaluation of monoclonal antibodies as a diagnostic reagent.

Comparisons were made between standard methods of cell culture, indirect immunofluorescence (IF) using hyperimmune respiratory syncytial virus (RSV) antiserum, and indirect IF using mouse monoclonal antibodies directed against various epitopes of RSV for the detection of RSV in nasopharyngeal aspirates. The monoclonal antibodies were used singly and in pools of different specificities which in turn were tested in both direct and indirect IF. In a preliminary study, aspirates from 227 infants were examined for RSV by standard methods. The results were compared with the detection of RSV in these aspirates using nine separate monoclonal antibodies and a pool consisting of five monoclonal antibodies. Respiratory syncytial virus was detected in 64 (28%) by cell culture, in 68 (30%) by indirect IF using bovine polyclonal antibody (BPA), and in 75 (33%) by indirect IF using the monoclonal antibody pool. The nine individual monoclonal antibodies when tested separately were less sensitive, detecting between 8 and 77% of all aspirates found to be positive by culture. After statistical analysis of the results obtained in the preliminary study, a refined monoclonal antibody pool was prepared and in a further study was tested by both direct and indirect IF in parallel with our two standard methods. Slides prepared from 303 nasopharyngeal aspirates collected between 1981 and 1984 and either tested the same day or stored at -20 degrees C were used to evaluate these reagents. Overall agreement between the four tests was found in 274 (90%) specimens. Cell culture detected RSV in 68 (22%) specimens, indirect IF with BPA in 67 (22%), indirect IF with monoclonal antibody in 72 (24%), and direct IF with monoclonal antibody in 79 (26%). The pool of monoclonal antibodies used in direct or indirect IF was thus more sensitive than our standard methods for the detection of RSV in nasopharyngeal aspirates, and direct IF tests could be completed in 40 minutes.

Adult↗
PubMed1997

Expression in Escherichia coli and purification of soluble forms of the F protein of bovine respiratory syncytial virus.

Six fragments of the F gene from bovine respiratory syncytial virus (BRSV) were engineered into the pMAL-c2 Escherichia coli expression vector and expressed as C-terminal maltose-binding protein (MBP) fusion products. The resulting polypeptides were partially soluble and single-step purified by affinity chromatography. These fusion proteins were recognized in Western blots by several MAbs directed against human respiratory syncytial virus F protein. In addition, rabbit polyclonal antisera raised against two purified MBP-derived proteins reacted with the BRSV-F protein.

Blotting, Western↗
PubMed1993

Bovine respiratory syncytial virus nucleocapsid protein expressed in insect cells specifically interacts with the phosphoprotein and the M2 protein.

The coding region of the gene for the nucleocapsid (N) protein of bovine respiratory syncytial virus has been inserted into the genome of Autographa californica nuclear polyhedrosis virus (AcNPV) using transfer vector pVL 1393. Infection of Spodoptera frugiperda cells with recombinant virus resulted in the synthesis of high levels of N protein. This protein was indistinguishable from the authentic bovine respiratory syncytial virus (BRSV) N protein by SDS-gel electrophoresis and immunoprecipitation with anti-BRSV serum. [35S]methionine-labeled N protein synthesized in S. frugiperda cells was used in a protein-blotting protein overlay assay for its interactions with BRSV-infected cell proteins. The N protein synthesized in S. frugiperda cells was found to specifically interact with the phosphoprotein (P) and M2 protein of BRSV but only with the P protein of human RSV. Our results suggest that the recombinant N protein produced in S. frugiperda cells could be used to determine the domains on N protein required for binding to P and M2 proteins.

Animals↗