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PubMed1992

Sequence comparison between the phosphoprotein mRNAs of human and bovine respiratory syncytial viruses identifies a divergent domain in the predicted protein.

The nucleotide and deduced amino acid sequences of the phosphoprotein (P) mRNA of bovine respiratory syncytial virus (BRSV) strain A51908 have been determined. The P mRNA is 860 nucleotides long with a single large open reading frame and the encoded polypeptide is 241 amino acids long. Comparison with the corresponding sequences of human respiratory syncytial virus (HRSV) subgroups A and B revealed 72 to 74% identity at the nucleotide level, and 81% at the amino acid level. The P protein contains a single divergent domain (37% amino acid identity) flanked by highly conserved domains (87% amino acid identity). The 3' end non-coding region is 47 nucleotides shorter than the corresponding region of HRSV. Comparison of the P mRNA sequences of two strains of BRSV (A51908 and FS-1) showed that there was extensive sequence identity at both the nucleotide (97%) and amino acid (97.9%) levels.

Amino Acid Sequence↗
PubMed1993

Sequence variability of the glycoprotein gene of bovine respiratory syncytial virus.

Sequence variation in the attachment glycoprotein G of bovine respiratory syncytial virus (BRSV) was determined. The nucleotide sequences of the G mRNAs of the A51908, VC464 and FS-1 strains of BRSV were compared with the published sequence of the BRSV strain 391-2. Nucleotide sequence alignment showed that overall they are highly conserved, with 90 to 97% identity. In addition, the coding region of strain A51908 was longer by 18 nucleotides at the 3' end. An 84 to 95% level of identity was observed among the deduced amino acid sequences of the G proteins of BRSV strains. A maximum divergence of 19% was found when the extracellular domains of the G proteins were compared. The level of diversity would be consistent, by analogy to the human respiratory syncytial viruses, with these BRSV strains forming a single subgroup.

Amino Acid Sequence↗
PubMed1998

Genetic and antigenic analysis of the G attachment protein of bovine respiratory syncytial virus strains.

Antigenic and genetic studies of bovine respiratory syncytial virus (BRSV) were made on isolates obtained from three continents over 27 years. Antigenic variation between eight isolates was initially determined using protein G-specific monoclonal antibodies. Four distinct reaction patterns were observed, two of which corresponded to the previously established subgroups A and AB. A third pattern was produced by five Scandinavian strains and a fourth was observed from a single Dutch isolate. The genetic diversity of 27 strains of BRSV was investigated by comparative nucleotide sequence analysis of a 731 nucleotide fragment in the G protein gene. Nine of the BRSV strains were analysed by direct sequencing of RT-PCR amplicons whereas sequences of 18 BRSV and three human respiratory syncytial virus (HRSV) strains were obtained from GenBank. The analysis revealed similarities of 88-100% among BRSV strains and 38-41% between BRSV and HRSV. A phylogenetic tree created for BRSV revealed two main branches, one of which divided into five further lineages, each representing a geographic cluster. A correlation was evident between the positions of some strains in the phylogenetic tree and their antigenic pattern. For HRSV strains, a genetic similarity of only 62% allowed the distinction of two antigenic subgroups, A and B, a pattern which was not seen for BRSV. This study showed that genetic analysis was an accurate method for discriminating BRSV strains and that these viruses should be regarded as a single genetic and antigenic group, within which variants can be distinguished.

Amino Acid Sequence↗
PubMed1998

Sequence analysis of a functional polymerase (L) gene of bovine respiratory syncytial virus: determination of minimal trans-acting requirements for RNA replication.

The complete nucleotide sequence of a functional clone of the large polymerase (L) gene of bovine respiratory syncytial virus (BRSV) strain A51908 was determined by analysis of cloned cDNAs obtained from genomic and mRNAs. The BRSV L gene is 6573 nt in length and the derived polypeptide has 2162 aa. Alignment of the sequences of the BRSV L gene, and its encoded protein, with sequences of the L gene and protein of human respiratory syncytial virus strain A2 showed 77% identity at the nucleotide level and 84% identity at the amino acid level. By comparison, the L gene and protein of avian pneumovirus showed only 50% identity at the nucleotide level and 64% identity at the amino acid level. A minigenome was constructed to encode a BRSV vRNA analogue containing the gene for chloramphenicol acetyltransferase (CAT) under the control of putative BRSV transcription motifs and flanked by the BRSV genomic termini. Transfection of plasmids encoding the BRSV minigenome, nucleocapsid protein (N), phosphoprotein (P) and L protein, each under the control of T7 promoter, into cells infected with a vaccinia virus recombinant expressing the T7 RNA polymerase gave rise to CAT activity and progeny with the minigenome. This result indicates that the N, P and L proteins are necessary and sufficient for transcription and replication of the BRSV minigenome and are functional. Further, inclusion of small amounts of the M2 protein along with the N, P and L proteins greatly augmented minigenome transcription.

Amino Acid Sequence↗
PubMed2005

Neutrophil-mediated inflammation in respiratory syncytial viral bronchiolitis.

BACKGROUND: The involvement of neutrophil-mediated inflammation may play an important role in the pathogenesis of acute respiratory syncytial virus bronchiolitis. However, no measurable marker is sensitive enough to assess neutrophil-mediated inflammation in the airways. Released neutrophil elastase (NE) in intraluminal airways has been reported to induce pulmonary inflammation. The aim of this study was to determine whether the amount of urinary trypsin inhibitor (UTI) in serum, a degenerate induced by NE, reflects the degree of airway inflammation in children with respiratory syncytial viral (RSV) bronchiolitis and whether the severity of inflammation is evaluated. The pre-alpha-/inter-alpha-trypsin inhibitor is assumed to be precursors of the UTI. When NE degrades these inhibitors, UTI is liberated. METHODS: Serum UTI concentrations in infants admitted with RSV bronchiolitis, other viral infections, bacterial pneumonia and control subjects were measured by means of one-step sandwich-type enzyme immunoassay. RESULTS: Serum UTI concentrations in 25 patients on admission were significantly higher than the 15 infantile control values (mean +/- SEM, 22.126 +/- 2.317 and 6.701 +/- 0.719 U/mL, respectively; P < 0.0001). The elevated levels returned to baseline values with improvement in the respiratory symptoms. Higher levels of serum UTI with RSV infection were consistently associated with clinical symptoms and artificial ventilation. Serum NE concentrations of patients were elevated in some patients but not significantly different from controls in the patients who showed only upper respiratory symptoms with RSV infections. CONCLUSION: The findings strongly suggested that neutrophil-mediated events are involved in the pathogenesis of RSV bronchiolitis, and the monitoring of UTI concentrations might be useful for evaluating the neutrophil-mediated airway inflammation.

Bronchiolitis↗
PubMed2004

Sequence and structure relatedness of matrix protein of human respiratory syncytial virus with matrix proteins of other negative-sense RNA viruses.

Matrix proteins of viruses within the order Mononegavirales have similar functions and play important roles in virus assembly. Protein sequence alignment, phylogenetic tree derivation, hydropathy profiles and secondary structure prediction were performed on selected matrix protein sequences, using human respiratory syncytial virus matrix protein as the reference. No general conservation of primary, secondary or tertiary structure was found, except for a broad similarity in the hydropathy pattern correlating with the fact that all the proteins studied are membrane-associated. Interestingly, the matrix proteins of Ebola virus and human respiratory syncytial virus shared secondary structure homology.

Amino Acid Sequence↗
PubMed1986

Neutralizing activity in human milk fractions against respiratory syncytial virus.

Neutralizing activity against respiratory syncytial virus (RSV) was measured in milk samples from 17 healthy women whose infants had an acute infection with respiratory syncytial virus (RSV) and from 27 women with healthy infants. All milk samples were obtained 2-8 months post partum. Neutralizing activity was detected in 36 samples. No major difference in neutralizing titers was observed between the two groups, and the titers were low. RSV-specific IgA was found in two samples, and RSV-specific IgG in one sample. RSV-specific IgM was not detected. In gel filtration studies, the neutralizing activity was eluted with an apparent molecular weight above 400,000. The neutralizing activity remained after removal of IgA by affinity chromatography. These findings suggest that both immunoglobulin and non-immunoglobulin components in human milk can neutralize RSV.

Antibodies, Viral↗
PubMed1995

Treatment of respiratory failure in an infant with bronchopulmonary dysplasia infected with respiratory syncytial virus using inhaled nitric oxide and high frequency ventilation.

A 2-month-old, former 28-week premature infant with bronchopulmonary dysplasia infected with respiratory syncytial virus was treated with nitric oxide and high frequency oscillatory ventilation after conventional therapy failed. Nitric oxide and high frequency oscillatory ventilation rapidly improved oxygenation allowing recovery without the need for extracorporeal membrane oxygenation. This treatment regimen should be considered as an option in high-risk infants with respiratory syncytial virus infection who meet extracorporeal membrane oxygenation criteria.

Administration, Inhalation↗
PubMed1997

Effect of human milk prostaglandins and lactoferrin on respiratory syncytial virus and rotavirus.

The effect of lactoferrin and prostaglandins E and F2 alpha on the growth of rotavirus and respiratory syncytial virus in cell culture was investigated. Lactoferrin inhibited the growth of respiratory syncytial virus at a concentration tenfold lower than that normally present in human milk. The prostaglandins had no effect on either virus growth, even at a concentration of 100-fold more than that found in human milk. Lactoferrin may have some antiviral properties in human milk in addition to its known antibacterial functions.

Animals↗
PubMed2001

Recent advances in the management and prophylaxis of respiratory syncytial virus infection.

Respiratory syncytial virus (RSV) infection is an important cause of morbidity, particularly in prematurely born infants who have had chronic lung disease. Current therapy is essentially supportive. Overall, the results of randomized trials do not support the use of bronchodilators, corticosteroids or Ribavirin. Nitric oxide and exogenous surfactant may improve the respiratory status of those infants who require ventilatory support. Nosocomial infection can be reduced by appropriate handwashing. There is no safe and effective vaccine for use in infants. Immunoprophylaxis reduces hospitalization and requirement for intensive care. Palivizumab, a humanized monoclonal antibody, is preferred to RSV immune globulin as the immunoprophylactic agent. Immunoprophylaxis should be reserved for infants at highest risk of severe respiratory syncytial virus infection, if this strategy is to be used most cost-effectively.

Hospitalization↗
PubMed1980

Effects of ribavirin on respiratory syncytial virus in vitro.

Ribavirin was demonstrated to have an antiviral effect on respiratory syncytial virus in vitro. A 50% reduction in plaque number was observed at concentrations of 3 or 10 micrograms of ribavirin per ml. This effect was observed when the drug was added as late as 12 h postinfection. At concentrations of greater than 10 micrograms of ribavirin per ml, the size of the syncytial plaque also noticeably decreased. Ribavirin similarly decreased the number of infectious units released into the culture supernatant. The antiviral effect was observed to be inversely related to the size of the viral inoculum, although all concentrations above 3.2 micrograms of ribavirin per ml visibly lessened the cytopathic effect regardless of the inoculum. Cloning of respiratory synctial virus in inhibitory concentrations of ribavirin failed to show increased resistance to the drug.

Cytopathogenic Effect, Viral↗
PubMed1995

Development of interleukin 6 and tumor necrosis factor alpha activity in nasopharyngeal secretions of infants and children during infection with respiratory syncytial virus.

Cytokine (interleukin 6 [IL-6] and tumor necrosis factor alpha [TNF-alpha]) activity in nasopharyngeal secretions of 21 infants and children (19 days to 16 months old) infected with primary respiratory syncytial virus was determined by an enzyme-linked immunosorbent assay. IL-6 and TNF-alpha were detectable in 100% (21 of 21) and 67% (14 of 21) of cases during the course of infection, respectively. Generally, TNF-alpha activity was high in the acute phase and declined thereafter, sometimes to undetectable levels. IL-6 activity was also highest in the acute phase and declined thereafter in infants younger than 5 months, while in patients older than 5 months, it-increased during the course of the disease to peak in the early convalescent phase. These observations suggest that inflammatory cytokines are produced in vivo in infants and children in response to primary respiratory syncytial virus infection and may be involved in disease pathogenesis. However, the mechanism of induction of cytokines may be different for infants and children in different age groups.

Antibody Specificity↗
PubMed1974

Serological evidence for the association of bovine respiratory syncytial virus with respiratory tract disease in Alabama cattle.

A serological investigation for neutralizing antibody to bovine respiratory syncytial virus (BRSV) was conducted using an antigenically related human strain of respiratory syncytial virus. Results demonstrated the effectiveness of the procedure. Sixty-seven percent of healthy, adult cattle tested were found to have antibody to BRSV. Calves in several herds were exposed to conditions to encourage development of respiratory tract disease. In three herds in which respiratory tract disease subsequently developed, the incidence of BRSV seroconversions approached 100%. In a herd in which no respiratory tract disease was detected, BRSV seroconversions indicated a high incidence of subclinical infections. It was concluded that, in this country as has been shown in others, BRSV is probably a significant pathogen of the bovine respiratory tract.

Alabama↗
PubMed1979

Intramuscular inoculation of live respiratory syncytial virus induces immunity in cotton rats.

Intramuscular inoculation of infant or weanling cotton rats with 10(2.2) to 10(4) plaque-forming units of respiratory syncytial virus induced significant or complete resistance to infection in both the upper and lower portions of the respiratory tract. This resistance did not appear to be the result of in vitro neutralization of virus during homogenization of tissue. Virus was not recovered from the local site of inoculation after 5 min and was never detected in the respiratory tract of intramuscularly inoculated rats. Attempts to detect viral antigens at the site of inoculation by using indirect immunofluorescence were unsuccessful. However, inactivation of infectivity of three different strains of respiratory syncytial virus markedly reduced or completely ablated antigenicity and protective efficacy by the intramuscular route. This suggests that these viruses underwent limited replication, perhaps restricted to an abortive cycle, at the local site of inoculation. An immunosuppressive effect of passive maternally derived immunity was observed. Only 50% of weanling rats possessing passive maternal serum antibody were successfully immunized by intramuscular vaccination with live virus.

Animals↗
PubMed1979

Respiratory syncytial virus infection in owl monkeys: viral shedding, immunological response, and associated illness caused by wild-type virus and two temperature-sensitive mutants.

Intranasal inoculation of owl monkeys with wild-type respiratory syncytial virus induced upper respiratory tract disease in each of seven animals. The response of owl monkeys to two highly defective, temperature-sensitive, multiple-lesion mutants was then compared to the pattern seen with wild-type respiratory syncytial virus. These mutants, ts-1 NG-1 and ts-1 NG-16, were derived from the ts-1 mutant that had been remutagenized with nitrosoguanidine (NG). Previously the ts-1 NG-1 and ts-1 NG-16 mutants had been shown to be more temperature sensitive and more stable genetically than their ts-1 parent. Both ts-1 NG-1 and ts-1 NG-16 produced infection that was delayed in onsent compared to wild-type virus infection. However, the mutants were shed from the upper respiratory tract for the same period of time and at the same titer as wild-type virus. The serum neutralizing antibody response to infection with the mutants was nearly equivalent to that elicited by wild-type virus. However, the extent of disease induced by the mutants was significantly less than that seen with wild-type virus. These observations suggest that the mutants are potential vaccine condidates and should be subjected to additional in vivo testing in primates and, ultimately, humans.

Animals↗
PubMed1982

Immunochemical identification of viral and nonviral proteins of the respiratory syncytial virus virion.

We identified by immunochemical methods 13 polypeptides associated with the infectious respiratory syncytial virus virion. Eight of these polypeptides (VP200, VP84, VP66, VP43, VP40, VP37, VP28, and VP19) were identified as virus specific. Two other polypeptides, (VP) 22 and (VP) 12, are provisionally considered to be of viral origin. Three nonviral proteins are also intimately associated with the infectious virion. These nonviral proteins were identified as cellular actin and two proteins with bovine serum albumin immunospecificity. VP40 was identified as the major ribonucleoprotein. Based on biochemical and biophysical similarities with paramyxovirus proteins, other respiratory syncytial virus proteins are believed to have these specific viral functions: VP84, "hemagglutinin"; VP66, undissociated fusion protein, F1,2; VP43, F1; and VP19, F2, VP66 contains a major determinant involved in viral infectivity since all neutralizing antibodies tested, including a monoclone, precipitated this protein.

Actins↗
PubMed1983

Mechanisms of immunity to respiratory syncytial virus in cotton rats.

Active immunity and maternally transmitted passive immunity to respiratory syncytial virus (RSV) were studied in cotton rats. Animals infected with respiratory syncytial virus developed complete resistance to pulmonary reinfection, which lasted at least 18 months. Nasal resistance was of shorter duration and began to diminish in 8 months. Pulmonary resistance was transferred by parabiosis, but nasal resistance was not. Adoptive transfer studies with fractionated convalescent blood showed that serum antibody, but not circulating lymphocytes, conferred pulmonary resistance. Immune females conferred antibody to their young prenatally and postnatally, with most of the antibody being transferred via colostrum and milk. Maternally transmitted immunity was more effective in the lungs than in the nose and was transient in both organs. Foster nursing experiments showed colostrum and milk to be the most important routes of immune transfer. Although resistance in infants generally correlated with serum neutralizing antibody levels, several exceptions to this correlation suggested that immune factors other than neutralizing antibody may also play an important role in maternal passive immunity.

Animals↗
PubMed1984

Protection from respiratory syncytial virus infection in cotton rats by passive transfer of monoclonal antibodies.

The effects of passive administration of neutralizing monoclonal antibodies (MAB) to respiratory syncytial virus glycoproteins (GP90 and VP70) was evaluated in cotton rats challenged with respiratory syncytial virus. Animals injected with MAB to VP70 had lower mean viral titers in lung tissues than did controls (log10 2.5 versus 5.4 PFU/g; P less than 0.001), as did cotton rats given MAB to GP90 (log10 2.1 versus 5.0 PFU/g; P less than 0.001). Fifty percent of animals given either MAB had no detectable virus in lung tissues, whereas virus was detected in the lungs of all controls. Virus growth in nasal turbinates was decreased but not eliminated in recipients of either MAB.

Animals↗