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PubMed1999

[Respiratory syncytial virus pneumonia in four immunocompromised adults].

INTRODUCTION: In hematologic malignancies, respiratory syncytial viral infections can be explained by neutropenia, and cellular and humoral immunodepression, and may cause severe respiratory infections. EXEGESIS: Four patients with hematologic malignancies developed a severe respiratory syncytial virus infection. Three of them had previously received autologous bone marrow transplantation (ABMT). Progress was favorable for three patients. One patient died of acute respiratory failure. CONCLUSION: When such patients present with respiratory symptoms, especially during the winter months, they should be screened for RSV. Bronchoalveolar lavage allowed quick and accurate diagnosis by immunofluorescence. Treatment with nebulized ribavirin is controversial. Its use may be interesting in patients with high-risk factors (intensive chemotherapy, ABMT, diffuse pneumonia with hypoxemia).

Antiviral Agents↗
PubMed1997

Adjuvants influence the quantitative and qualitative immune response in BALB/c mice immunized with respiratory syncytial virus FG subunit vaccine.

The ability of monophosphoryl lipid A (MPL), QS-21 and alum to alter the immunologic response to immunization with respiratory syncytial virus a chimeric FG construct (FG) subunit vaccine was examined in BALB/c mice. FG/MPL, FG/alum, and FG/MPL/QS-21 combinations increased non-neutralizing antibody response, while FG/QS-21 did not. FG subunit vaccine with MPL, QS-21, or both had cytokine responses more closely resembling primary infection than FG/alum, with decreased interleukin-4 mRNA levels and increased IgG2a isotype antibody. The lungs of the mice immunized with FG subunit vaccines showed a heightened inflammatory response to respiratory syncytial virus challenge as compared to live virus immunization. Adjuvants can be used to alter the humoral and cellular responses to RSV subunit immunization.

Adjuvants, Immunologic↗
PubMed1970

The late detection of respiratory syncytial virus in cells of respiratory tract by immunofluorescence.

Paired nasopharyngeal secretions were studied in 27 infants infected with respiratory syncytial virus, one taken at onset of illness and one about 7 days later. Both specimens were examined by immunofluorescence and tissue culture for respiratory syncytial virus. In 25 out of 27 (93%) specific fluorescence was still present in cells of the convalescent specimen but was much duller. Virus was difficult to isolate in convalescent specimens; only 8 out of 27 (26%) proved to be positive. Eight single secretions which were taken late in a respiratory illness were also shown to have this altered fluorescence with absence of virus isolation. Preliminary experiments using antihuman globulin suggest that the findings may be due to the attachment of local secretory antibody to the cells causing ;blocking' of staining reaction.

Antibodies↗
PubMed1972

Adenovirus, parainfluenza virus and respiratory syncytial virus antibodies in the sera of Jamaicans.

Surveys for respiratory virus antibodies in the Jamaican population have shown that adenovirus, respiratory syncytial virus and parainfluenza types 1 and 3 virus antibodies are acquired early in life. The incidence of haemagglutination-inhibiting antibodies to parainfluenza viruses increases rapidly with age and almost all adults possess parainfluenza type 3 antibody, usually in high titre. Parainfluenza type 1 antibodies are only slightly less common. Complement-fixing antibodies to the adenovirus group were also observed to increase in incidence with age.Complement-fixing antibody to respiratory syncytial virus was less common in Jamaican sera than antibody to the other respiratory viruses described here. The highest titres were observed in the youngest age-group.

Adenoviridae↗
PubMed1999

Clinical and epidemiological aspects of respiratory syncytial virus lower respiratory tract infections.

This paper has analyzed respiratory syncytial virus lower respiratory tract infections in 201 hospitalized children. In children with wheezing, erythrocyte sedimentation rate (ESR) was significantly higher in those with pneumonia than with syndroma pertussis, while the white blood cell (WBC) count was significantly lower in patients with bronchitis than in those with bronchiolitis and syndroma pertussis. Bronchodilatators were applied in 75.6% and corticosteroids in 20% of patients. Ten patients were ventilated. Fatal disease outcome was observed in one infant. Twelve consecutive-year study of respiratory syncytial virus (RSV) infections showed that 27.3% of these diseases were bronchiolitis and pneumonia.

Blood Sedimentation↗
PubMed2001

Rescue of bovine respiratory syncytial virus from cloned cDNA: entire genome sequence of BRSV strain A51908.

Infectious bovine respiratory syncytial virus (BRSV) was produced by intracellular co-expression of five plasmid borne cDNAs, each under the control of a T7 RNA polymerase promoter. These separately encoded a full-length, genetically-marked copy of BRSV antigenome along with either BRSV or human respiratory syncytial virus (HRSV) support plasmids, which express N, P, L and M2-1 proteins. HEp2 cells were used in transfection and recombinant vaccinia virus (MVA-T7) provided T7 RNA polymerase to drive the transcription. The recovery of recombinant BRSV (rBRSV) was confirmed by immunological staining of plaques, restriction enzyme digestion and nucleotide sequencing of PCR fragments carrying the genetic markers from the rescued virus. The rBRSV was indistinguishable from its parental wild-type virus in its growth characteristics in cell culture. The present work has completed the entire genome sequence of BRSV strain A51908 (15,140 nt) and has also identified changes in sequence and growth characteristics in cell culture from the original BRSV strain A51908 laboratory isolate.

Animals↗
PubMed2000

Synthesis and characterization of Respiratory Syncytial Virus protein G related peptides containing two disulfide bridges.

Respiratory Syncytial Virus (RSV) is the most important cause of bronchiolitis and viral pneumonia in infants and young children. Approximately 100000 children are hospitalized in the USA each year as a result of RSV infections. During the research and development of subunit human Respiratory Syncytial Virus vaccines (hRSV), we have produced numerous synthetic peptides and recombinant proteins containing the four cysteines of the highly conserved central region of the G attachment protein. For several of these disulfide-containing peptides, all possible oxidized isomers were synthesized using various oxidation conditions and resulting in different ratios of isomers. Each isolated isomer was fully characterized by RP-HPLC, FZCE and ES-MS after purification by preparative RP-HPLC. The different cysteine pairings were unambiguously established after enzymatic digestion, LC-MS analysis and peptide microsequencing. These synthesis and analytical methods were developed for the characterization on one hand, of recombinant fusion protein BBG2Na which is currently being investigated in advanced clinical phases as a very promising vaccine candidate, and on the other hand, for peptides which were synthesized to be evaluated as conjugate vaccines or as immunochemical tools, after covalent coupling to carrier proteins. Furthermore, these studies allowed us to determine which of the different possible isomers was the most stable and probably the preferred form in native conditions. Finally, the different oxidation and analysis conditions, should be useful for disulfide pairing studies of other peptides and proteins having the same 'xCxxCxxxxxCxxxCx' framework, such as G proteins of non-human RSV strains, developed by other groups as veterinary vaccine candidates for example.

Amino Acid Sequence↗
PubMed2003

Recognition of bovine respiratory syncytial virus proteins by bovine CD8+ T lymphocytes.

CD8+ T lymphocytes play a major role in the clearance of bovine respiratory syncytial virus (BRSV), an important respiratory pathogen of young calves that shares many of the epidemiological and pathological features of human respiratory syncytial virus (HRSV) in infants. Recombinant vaccinia virus (rVV) and recombinant fowlpox virus (rFPV), expressing individual BRSV proteins, were used to demonstrate that the F, N and M2 proteins were the major antigens recognized by bovine CD8+ T cells in major histocompatibility complex (MHC)-defined cattle. BRSV protein recognition by CD8+ T cells was analysed using cytotoxic T lymphocyte (CTL) assays or by the production of interferon-gamma (IFN-gamma) following restimulation with BRSV proteins. Strong recognition of the G protein by CD8+ T cells was observed in cattle that had been vaccinated with rVV expressing this protein and subsequently challenged with BRSV. Although there is variation in the number of expressed MHC genes in cattle with different class I haplotypes, this did not appear to influence BRSV protein recognition by CD8+ T cells. Knowledge of the antigenic specificity of BRSV-specific CD8+ T cells will facilitate the qualitative and quantitative analysis of BRSV-specific CD8+ T-cell memory in cattle and help to ensure that potential vaccines induce a qualitatively appropriate CD8+ T-cell response.

Animals↗
PubMed2001

The use of palivizumab monoclonal antibody to control an outbreak of respiratory syncytial virus infection in a special care baby unit.

An outbreak of respiratory syncytial virus (RSV) infection affected seven premature infants in a special care baby unit during November and December 1999. Conventional infection control measures (cohorting infected babies, strict reinforcement of the use of gloves and aprons, emphasis on hand disinfection) failed to prevent spread. Palivizumab, a respiratory syncytial virus monoclonal antibody, was given to eight high-risk preterm infants. There were no further cases of RSV in the unit and none of the babies given palivizumab developed RSV. One baby who acquired RSV during the outbreak (and who was not given palivizumab) was subsequently admitted to hospital with another episode of RSV bronchiolitis. The role of palivizumab in the control of hospital outbreaks of RSV infection merits further investigation.

Antibodies, Monoclonal↗
PubMed1975

Nosocomial respiratory syncytial virus infections.

We studied the frequency and severity of respiratory syncytial virus infections acquired nosocomially on an infants' ward during a community outbreak. Every three or four days all infants and staff were examined, and specimens were obtained for viral isolation. During two months, 14 of 44 contact infants acquired the virus. All were ill, and four had pneumonia. Infected infants had a significantly longer mean hospital stay (21.5 days) than uninfected ones (9.2 days, P less than 0.001). Risk of nosocomial infection could not be related to age or to underlying disease, but was linked to length of hospitalization: 45 per cent of infants hospitalized for one week or more became infected, and the percentage increased with length of stay. Ten of 24 staff members also acquired the virus and appeared to play a major role as virus carriers. Nosocomial respiratory syncytial virus infection poses a major risk for hospitalized infants and adds to hospital costs.

Adult↗
PubMed1976

Respiratory syncytial virus infections within families.

To examine intrafamily spread of respiratory syncytial virus infections and their associated illnesses, 36 families with 188 members were studied during an outbreak of such infections. Nurses visited every three to four days to obtain specimens for viral isolation and interview household members. The virus infected 44.4 per cent of families, and 21.9 per cent of all members. All age groups had appreciable attack rates (with a range of 16.8 per cent in adults to 29.4 per cent in infants). In infected families, 45.9 per cent of members became infected, including 10 of 16 infants. Secondary attack rate for all ages was 27 per cent, and that for infants 45.4 per cent. An infant's older sibling appeared most likely to introduce the virus into the family. Associated acute respiratory illnesses occurred in 94.9 per cent of cases, and appeared more severe than those not associated with respiratory syncytial virus. When the virus was introduced into a family the high attack rate produced an illness of age-related severity.

Adolescent↗
PubMed1979

Neonatal respiratory syncytial virus infection.

Respiratory syncytial virus infections are thought to be uncommon in the first month of life. During a community outbreak, we prospectively studied such infection in our neonatal units. Of 82 neonates studied, 66 were hospitalized for six days or longer, and 23 (35 per cent) acquired this virus. Four infants died, two unexpectedly. Infected infants had a significantly shorter gestation and birth weight. Illness was often atypical, with nonspecific signs, especially in infants under three weeks of age, who had significantly less lower-respiratory-tract involvement and lower quantities of virus in their nasal washes. The titer of virus shed correlated with the infants' postnatal, but not gestational, age. Infection was also acquired by 34 per cent of the staff, who appeared to be important in the spread of the virus. These findings suggest that respiratory syncytial virus may readily infect neonates, but the disease may be atypical and may be overlooked.

Adult↗
PubMed1983

Aerosolized ribavirin treatment of infants with respiratory syncytial viral infection. A randomized double-blind study.

We evaluated a new antiviral agent, ribavirin, in the treatment of infants hospitalized with lower-respiratory-tract disease from respiratory syncytial virus. Ribavirin or placebo was administered to 33 infants in a double-blind manner by continuous aerosol for three to six days. Seventeen infants were treated with placebo, and 16 with ribavirin. By the end of treatment, infants receiving ribavirin had significantly greater improvement in their overall score for severity of illness, in lower-respiratory-tract signs, and in arterial oxygen saturation. Viral shedding was also diminished in the treated groups as compared with the placebo group. No side effects or toxicity were associated with the aerosol therapy. Isolates of respiratory syncytial virus obtained from the infants over the course of therapy showed no change in sensitivity to ribavirin.

Aerosols↗
PubMed2000

The pharmacologic mechanism by which inhaled epinephrine reduces airway obstruction in respiratory syncytial virus-associated bronchiolitis.

Inhaled racemic epinephrine relieves airway obstruction in patients with respiratory syncytial virus bronchiolitis. The contribution of alpha- versus beta-adrenoreceptor stimulation toward this clinical effect is unknown. We describe an infant treated with propranolol for supraventricular tachycardia in whom respiratory syncytial virus bronchiolitis developed. Inhaled racemic epinephrine improved his respiratory symptoms, whereas nebulized albuterol did not.

Administration, Inhalation↗
PubMed1983

Construction and characterization of cDNA clones for four respiratory syncytial viral genes.

Cytoplasmic poly(A)-containing RNA from respiratory syncytial virus-infected cells was used as a template to synthesize oligo(dT)-primed cDNAs. Discrete size classes of single-stranded cDNAs, resolved by alkali agarose gel electrophoresis, were used separately to construct double-stranded cDNAs that were subsequently inserted into the plasmid vector pBR322 at the Pst I site by means of oligo(dG)oligo(dC) tailing. After transfection of Escherichia coli, recombinant plasmids were screened mostly by serial rounds of hybrid selection of mRNAs from virus-infected cells and subsequent in vitro translation of the selected mRNAs. Comparative peptide mapping of the translation products with those of authentic virion proteins served to establish the viral origin of the cDNA recombinants. In this manner, four distinct classes of recombinant plasmids were identified. These encode sequences corresponding to those of respiratory syncytial virus nucleocapsid protein, matrix protein, phosphoprotein, and a nonstructural protein.

DNA↗
PubMed1991

Rescue of synthetic analogs of respiratory syncytial virus genomic RNA and effect of truncations and mutations on the expression of a foreign reporter gene.

The viral genomic RNA (vRNA) of human respiratory syncytial virus is a nonsegmented negative strand that is not infectious alone. To develop methods for complementing synthetic vRNA with viral proteins, a cDNA was constructed to encode a vRNA in which all of the viral protein-coding sequences were removed and replaced with a negative-sense copy of the bacterial chloramphenicol acetyltransferase gene. Upon transfection into respiratory syncytial virus-infected cells, the synthetic vRNA was "rescued" such that it was amplified, expressed, and packaged into infectious virions. A heterologous paramyxovirus, parainfluenza virus 3, was inactive in rescue. Further internal deletions mapped the cis-acting viral sequences required for rescue to two segments totaling 105 nucleotides (nt) derived from the two vRNA ends. Rescue was unaffected by replacement of the 44-nt 3'-terminal leader region with a 50-nt sequence that is complementary to the 5' terminus and represents the 3' end of the positive-sense replicative intermediate RNA. This 5'-end complement was related to the parental leader region only near the 3' terminus (91% or 73% identical for the first 11 or 22 nt, respectively). The addition of 11 heterologous nt to the 3' end of the parental leader region ablated rescue, suggesting that the 3'-proximal conserved domain is required and cannot function from an internal site. However, deletion of the 3'-terminal 3 nt, or a double transition at positions 4 and 5, had no effect on rescue. Thus, the 3'-terminal 5 nt, although conserved between 3' ends of the negative- and positive-sense RNAs, do not appear to be essential.

Base Sequence↗
PubMed2001

Antiviral activity and structural characteristics of the nonglycosylated central subdomain of human respiratory syncytial virus attachment (G) glycoprotein.

Segments of the cystine noose-containing nonglycosylated central subdomain, residues 149-197, of the attachment (G) glycoprotein of human respiratory syncytial virus (HRSV) have been assessed for impact on the cytopathic effect (CPE) of respiratory syncytial virus (RSV). Nalpha-acetyl residues 149-197-amide (G149-197), G149-189, and G149-177 of the A2 strain of HRSV protected 50% of human epithelial HEp-2 cells from the CPE of the A2 strain at concentrations (IC(50)) between 5 and 80 microm. Cystine noose-containing peptides G171-197 and G173-197 did not inhibit the CPE even at concentrations above 150 microm. Systematic C- and N-terminal truncations from G149-189 and G149-177 and alanine substitutions within G154-177 demonstrated that residues 166-170 (EVFNF), within a sequence that is conserved in HRSV strains, were critical for inhibition. Concordantly, G154-177 of bovine RSV and of an antibody escape mutant of HRSV with residues 166-170 of QTLPY and EVSNP, respectively, were not inhibitory. Surprisingly, a variant of G154-177 with an E166A substitution had an IC(50) of 750 nm. NMR analysis demonstrated that G149-177 adopted a well-defined conformation in solution, clustered around F168 and F170. G154-170, particularly EVFNF, may be important in binding of RSV to host cells. These findings constitute a promising platform for the development of antiviral agents for RSV.

Alanine↗