Replication-competent or attenuated, nonpropagating vesicular stomatitis viruses expressing respiratory syncytial virus (RSV) antigens protect mice against RSV challenge

Foreign glycoproteins expressed in recombinant vesicular stomatitis virus (VSV) can elicit specific and protective immunity in the mouse model. We have previously demonstrated the expression of respiratory syncytial virus (RSV) G (attachment) and F (fusion) glycoprotein genes in recombinant VSV. In this study, we demonstrate the expression of RSV F and G glycoproteins in attenuated, nonpropagating VSVs which lack the VSV G gene (VSVDeltaG) and the incorporation of these RSV proteins into recombinant virions. We also show that intranasal vaccination of mice with nondefective VSV recombinants expressing RSV G (VSV-RSV G) or RSV F (VSV-RSV F) elicited RSV-specific antibodies in serum (by enzyme-linked immunosorbent assay [ELISA]) as well as neutralizing antibodies to RSV and afford complete protection against RSV challenge. In contrast, VSVDeltaG-RSV F induced detectable serum antibodies to RSV by ELISA, but no detectable neutralizing antibodies, yet it still protected from RSV challenge. VSVDeltaG-RSV G failed to induce any detectable serum (by ELISA) or neutralizing antibodies and failed to protect from RSV challenge. The attenuated, nonpropagating VSVDeltaG-RSV F is a particularly attractive candidate for a live attenuated recombinant RSV vaccine.

Conservation of the respiratory syncytial virus SH gene

Respiratory syncytial virus (RSV) encodes a short (64 or 65 amino acids) hydrophobic (SH) protein whose function in viral replication and pathogenesis is not understood. We carried out molecular epidemiological studies of the SH gene during the 1998-1999 seasonal epidemic in New Haven, Connecticut. Strains circulating during the epidemic were related to viruses identified worldwide. The SH gene transcriptional control signals were conserved in 70 (98.6%) of 71 isolates that we sequenced. The deduced amino acid sequence of the SH protein was nearly identical to subgroup A and subgroup B reference strains that were isolated in 1961 and 1962, respectively. Twenty-six (96.3%) of 27 subgroup A strains contained 0 or 1 amino acid substitution, compared with that of the reference A2 strain. Most subgroup B isolates (38 [86.4%] of 44 strains) contained 0, 1, or 2 amino acid substitutions, compared with that of the reference B18537 strain.

Respiratory syncytial virus vaccine development

Respiratory syncytial virus is the major respiratory pathogen of infants and children worldwide. Currently, there is no effective vaccine to protect against respiratory syncytial virus infection. Immunoprophylaxis with hyperimmune globulin or with a humanized monoclonal antibody is expensive, limited to children with underlying disease, and not practical for general use. Antiviral therapy is controversial and of limited effectiveness. New approaches to the development of a vaccine for respiratory syncytial virus infection are promising. Several subunit vaccines and live attenuated virus vaccines are immunogenic and safe in children and adults. This review focuses on potential vaccine candidates and the challenges these candidate vaccines must overcome.

Fever without apparent source on clinical examination, lower respiratory infections in children, and enterovirus infections

This section focuses on issues in infectious disease that are commonly encountered in pediatric office practice. McCarthy discusses recent literature regarding the evaluation and management of acute fevers without apparent source on clinical examination in infants and children and the evaluation of children with prolonged fevers of unknown origin. Klig reviews recent literature about lower respiratory tract infection in children. Finally, Kennedy and Kahn discuss recent developments in infectious diseases pertinent to office practice.

Recombinant vesicular stomatitis virus expressing respiratory syncytial virus (RSV) glycoproteins: RSV fusion protein can mediate infection and cell fusion

The genes encoding the respiratory syncytial virus (RSV) attachment (G) and fusion (F) envelope glycoproteins were expressed separately as additional genes in recombinant vesicular stomatitis viruses (VSV). Cells infected with the VSV-RSV F recombinant formed large syncytia illustrating the fusion activity of F in absence of other RSV proteins. Both F and G glycoproteins were expressed at the cell surface and incorporated into virions. Incorporation of these proteins did not require cytoplasmic tail sequences of VSV G. Using a compound, ammonium chloride, that raises the endosomal pH, we showed that presence of the RSV F glycoprotein in the envelope of recombinant VSV allowed for infectivity through a low-pH-independent pathway. Recombinant VSV expressing RSV glycoproteins could be useful as an RSV vaccine.

Fever without apparent source on clinical examination, lower respiratory infections in children, and other infectious diseases

This section focuses on issues in infectious disease that are commonly encountered in pediatric office practice. Paul McCarthy discusses recent literature regarding the evaluation and management of acute fevers without apparent source on clinical examination in infants and children and the evaluation of children with prolonged fevers of unknown origin. Jean Klig reviews recent literature about lower respiratory tract infection in children. Finally, Jeffrey Kahn discusses recent developments concerning rotavirus vaccine.

Fever without apparent source on clinical examination, infectious diseases, and lower respiratory infections in children

This section focuses on issues in infectious diseases that are commonly encountered in pediatric office practice. Paul McCarthy discusses recent literature regarding the evaluation and management of acute fevers without apparent source on clinical examination in infants and children, and the evaluation of children with prolonged fevers of unknown origin. Jean Klig reviews recent literature about lower respiratory tract infection in children. Jeffrey Kahn and Eugene Shapiro discuss recent developments in pediatric infectious diseases concerning neonatal herpes infections, poliovirus immunization schedule, and group B streptococcus screening and treatment.

Fever without apparent source on clinical examination, lower respiratory infections in children, other infectious diseases, and acute gastroenteritis and diarrhea of infancy and early childhood

This section focuses on issues in infectious disease that are commonly encountered in pediatric office practice. Paul McCarthy discusses recent literature regarding the evaluation and management of acute fevers without apparent source on clinical examination in infants and children and the evaluation of children with prolonged fevers of unknown origin. Jean Klig reviews recent literature about lower respiratory tract infection in children. Jeffrey Kahn and Eugene Shapiro discuss literature concerning several infectious diseases commonly seen in office settings and concerning which recent developments are of interest. Michael Baron reviews recent literature about gastroenteritis and diarrhea of infancy and early childhood.

A mutation of the nucleoside triphosphate phosphohydrolase I (NPH-I) gene confers sensitivity of vaccinia virus to interferon

The role of vaccinia virus nucleoside triphosphate phosphohydrolase I (NPH-I) in determining the resistance of this virus to alpha-interferon (IFN) was analyzed by using a well-defined temperature-sensitive mutant (ts36) in the NPH-I gene. Detailed analysis of viral proteins and mRNAs produced in cultured cells treated with or without IFN-alpha showed a strong inhibition by IFN of the synthesis of late virus polypeptides at the nonpermissive temperature, e.g., 83.8% inhibition for the luciferase reporter gene, which is associated with a decrease in steady-state mRNA levels. Sensitivity of ts36 to IFN was only the consequence of the point mutation in the NPH-1 gene, as shown by characterization of the rescued virus, R36. Our findings demonstrate that functional NPH-1 is required, at least in part, for resistance of vaccinia virus to IFN.

The cis-acting DNA sequences required in vivo for bacteriophage Mu helper-mediated transposition and packaging

The 37,000 bp double-stranded DNA genome of bacteriophage Mu behaves as a plaque-forming transposable element of Escherichia coli. We have defined the cis-acting DNA sequences required in vivo for transposition and packaging of the viral genome by monitoring the transposition and maturation of Mu DNA-containing pSC101 and pBR322 plasmids with an induced helper Mu prophage to provide the trans-acting functions. We found that nucleotides 1 to 54 of the Mu left end define an essential domain for transposition, and that sequences between nucleotides 126 and 203, and between 203 and 1,699, define two auxiliary domains that stimulate transposition in vivo. At the right extremity, the essential sequences for transposition require not more than the first 62 base pairs (bp), although the presence of sequences between 63 and 117 bp from the right end increases the transposition frequency about 15-fold in our system. Finally, we have delineated the pac recognition site for DNA maturation to nucleotides 32 to 54 of the Mu left end which reside inside of the first transposase binding site (L1) located between nucleotides 1-30. Thus, the transposase binding site and packaging domains of bacteriophage Mu DNA can be separated into two well-defined regions which do not appear to overlap.

Identification of the point mutations in two vaccinia virus nucleoside triphosphate phosphohydrolase I temperature-sensitive mutants and role of this DNA-dependent ATPase enzyme in virus gene expression

The biological function of the nucleoside triphosphate phosphohydrolase I (NTPase I) enzyme of vaccinia virus is not yet known. In this investigation we have identified the genetic lesion of two temperature-sensitive mutants of vaccinia virus, ts50 and ts36, as single point mutations contained within the 5'615 nucleotides of the NTPase I gene (ts50, G to A at position 131; ts36, C to T at position 556). The point mutations result in amino acid substitutions of Gly to Glu-44 (ts50) and Pro to Ser-186 (ts36). In monkey BSC-40 cells, ts50 and ts36 behave phenotypically like wild-type virus with respect to replication and synthesis of viral DNA but are defective in late polypeptide synthesis. However, these two ts mutants displayed a drastically different phenotype in virus-infected human HeLa cells at the restrictive temperature; viral DNA replication did not occur and late polypeptide synthesis was absent. Moreover, if the early block was overcome by a temperature shift-up, then HeLa cells infected with the ts mutants displayed a profile characteristic of defective late viral polypeptide synthesis. Our results reveal that vaccinia NTPase I enzyme functions early and late in the viral replication cycle and that the phenotype of these ts mutants is dependent upon the cell type.

Molecular cloning, encoding sequence, and expression of vaccinia virus nucleic acid-dependent nucleoside triphosphatase gene

A rabbit poxvirus genomic library contained within the expression vector lambda gt11 was screened with polyclonal antiserum prepared against vaccinia virus nucleic acid-dependent nucleoside triphosphatase (NTPase)-I enzyme. Five positive phage clones containing from 0.72- to 2.5-kilobase-pair (kbp) inserts expressed a beta-galactosidase fusion protein that was reactive by immunoblotting with the NTPase-I antibody. Hybridization analysis allowed the location of this gene within the vaccinia HindIIID restriction fragment. From the known nucleotide sequence of the 16-kbp vaccinia HindIIID fragment, we identified a region that contains a 1896-base open reading frame coding for a 631-amino acid protein. Analysis of the complete sequence revealed a highly basic protein, with hydrophilic COOH and NH2 termini, various hydrophobic domains, and no significant homology to other known proteins. Translational studies demonstrate that NTPase-I belongs to a late class of viral genes. This protein is highly conserved among Orthopoxviruses.

Orientation and sequence analysis of right ends and target sites of bacteriophage mu and D108 insertions in the plasmid pSC101

We have isolated four independent insertions of the entire 37-kb D108cts 10 genome in the low-copy-number plasmid pSC101 in vivo. They were all formed by replicative transposition during the D108 lytic cycle. The orientation of these four insertions was found to be the same, with the left ends facing towards pSC101 replication, and the right end facing in the direction of all pSC101 transcription, as was previously found for a Mucts62 insertion in pSC101, pMC321. The exact sites of insertion of two of the D108 prophages, as well as the Mu prophage, have been determined by sequence analysis. All three insertions caused a 5-bp duplication of pSC101 sequences at the target site, as has been found for insertions formed by conservative integration upon lysogeny. Moreover, we have determined the nucleotide sequence of the first 75 bp of the right end of D108 and, though this end is interchangeable with the right end of Mu as a substrate for either phage's transposition functions, there are a number of nucleotide differences between them.

Activation of Coupling Factor 1 from Euglena gracilis Chloroplasts : Conditions for Optimal Activation and Their Possible Physiological Significance

The recently described method for the activation of the Ca(2+)-ATPase of coupling factor 1 from chloroplasts (CF(1)) of Euglena gracilis by low pH occurs optimally in high concentrations of NaCl, and is unaffected by the acid used to lower the pH to 4.5. Activation is inhibited by light, and this effect can be reversed by the presence of NADP(+), ADP + inorganic phosphate, or an uncoupler. There appears to be no difference between the activities in the soluble and the particulate phases, and they seem to represent the same enzyme. The response of the activation process to light and to effectors of electron transport and phosphorylation indicates a possible physiological role for the acid activation of Euglena CF(1).

A Novel Method for the Activation and Solubilization of Coupling Factor 1 from Chloroplasts of Euglena gracilis

A method was found for the in situ activation of the latent Ca(2+)-ATPase of the coupling factor from chloroplasts of Euglena gracilis and its resultant solubilization. The activation causes the concomitant solubilization of the enzyme and facilitates easy and nearly complete extraction. The activation consists of lowering the pH of isolated chloroplasts for 2 minutes to pH 4.5 to 4.7 with acetic acid, followed by neutralization. Increases in activity as high as 18-fold can be obtained. The method does not appear to work with chloroplasts from other sources.

The epsilon Subunit of the Chloroplast Coupling Factor 1 from Euglena gracilis: A Possible Role in Controlling ATPase Activity

The coupling factor from chloroplasts (CF(1)) of Euglena gracilis Z strain is an active ATPase in situ, and its activity cannot be increased by treatment with trypsin or heating as is the case with the CF(1) from other sources. The smallest subunit of CF(1), the epsilon subunit, is supposed to be involved in controlling the ATPase activity. We have devised a simple technique for rapid and large-scale isolation of this subunit. The epsilon subunit from Euglena CF(1), although having only a limited inhibitory effect on Euglena CF(1), drastically inhibited the ATPase activity of heat-activated spinach CF(1). The inhibition of spinach CF(1) could be reversed by passage through Sephadex G-50 or by a second heat activation. An antibody to the epsilon subunit of Euglena CF(1) cross-reacted only weakly with CF(1) from spinach, Sorghum, Kalanchoë, or Anacystis nidulans, but reacted well with whole Euglena CF(1) in addition to its epsilon subunit. The antibody increased the ATPase activity of Euglena and Anacystis CF(1) and of unactivated or partially activated spinach CF(1). The results suggest that the function of the epsilon subunit in Euglena CF(1) is similar to its function in CF(1) from other sources. The data also suggest that changes induced in spinach CF(1) by activation involves modifications in subunits other than the epsilon one.

Some biochemical properties of mitochondria isolated from Euglena gracilis

Mitochondria were isolated from Euglena gracilis strain Z by pressure-breakage of the cells and sucrose-cushion centrifugation. Multiple peaks (2-4) were observed in the rate of phosphorylation with Mg-ADP-phosphate concentration curves. The phosphorylative and oxidative activities were highest with NADH as the substrate, moderate with succinate, and lowest with glutamate. Inhibition of phosphorylation with 2,4-dinitrophenol and carbonyl cyanide, m-chlorophenylhydrazone gave sigmoidal concentration curves, with the extent of inhibition by DNP depending on the substrate used. Inhibition of phosphorylation by valinomycin, atractyloside, or carboxyatractyloside was only approximately 60%. Oligomycin inhibited phosphorylation in 2 phases at low and high concentrations; it inhibited Mg-ATPase in a sigmoidal fashion. Both phosphorylation and oxidation had discontinuities in Arrhenius plots at 34 C and 18 C. The relative Mg2+-dependent nucleoside triphosphatase activity was: 1 for ATP and GTP, 0.6 for ITP, 0.15 for CTP and UTP; with Ca2+ in place pf Mg2+ this activity was 0.35. Both DNP and CCCP stimulated the Mg-ATPase 50-200%. The optimal pH for the stimulation was approximately 7 regardless of the uncoupler used, and approximately 8 without the uncouplers. The few differences observed between mitochodria from Euglena and those from other sources are probably due to the fragmentation of the reticular mitochondrial structure during isolation and not to unique characteristics of these mitochondria.

High-Pressure Phase Transformation of CaSO 4 (Anhydrite) During a Nuclear Explosion

Examination of the postshot cores from the portion of the Tatum Salt Dome that had been subjected to a nuclear explosion (Salmon Event) has indicated evidence for the high-pressure phase transformation of anhydrite. This evidence consists of distinctly different optical domains within the shocked anhydrite. Evidence for the transition exists out to approximately 1.5 cavity radii. Excellent agreement exists between experimental work and the theoretical calculations of the predicted pressure profile.

Light Activation of Mg-dependent Adenosine 5'-Triphosphatase in Isolated Euglena Chloroplasts

Enhancement of Mg(2+)-dependent ATPase activity in Euglena gracilis chloroplasts by light in the presence of a sulfhydryl compound has been demonstrated. A number of uncouplers and energy transfer inhibitors were studied for their effects on the light enhancement of ATPase activity simultaneously with their effects on photophosphorylation. Results suggest that the light-enhanced ATPase activity in Euglena chloroplasts is an energy-initiated process and that the energy is supplied through electron flow upon illumination of the chloroplasts. However, by studying the difference in their response toward the various uncouplers and inhibitors, it seems that the two processes (photohydrolysis of ATP and photophosphorylation) share only the latter part of their energy-transferring pathway.

Absence of a common intermediate pool among individual enzyme chains of the energy-conservation pathway in chloroplasts of Euglena gracilis

Tri-n-butyltin chloride is a specific inhibitor that binds stoicheiometrically and irreversibly with the ATP-synthesizing sites of chloroplasts. Titration of Euglena chloroplasts with tri-n-butyltin chloride shows about six ATP-synthesizing sites per molecule of cytochrome c(552) or per 380 molecules of chlorophyll. This system was used to study the possibility of linkage between individual enzyme chains of the energy-conservation pathway or the possible existence of a common pool of an intermediate in this pathway. The inhibition of ATP synthesis by tri-n-butyltin chloride at low rates of electron transport (low light-intensities, NADP(+) or ferricyanide as electron acceptor) agrees with a kinetic model of two to four ATP-synthesizing sites per energy-conservation chain. At high rates of electron transport, however, the results occasionally agree with a model of 20 or more sites per chain. The results are interpreted as indicating the absence of a common intermediate pool, but the presence of a limited degree of linkage between individual chains. It also indicates the presence of two energy-conservation sites in these chloroplasts.

Iron Minerals Formed by a Nuclear Explosion in a Salt Bed

The nuclear event, Gnome, was carried out in halite in the Salado formation and yielded a varied mineral assemblage. The iron suppor members reacted in the salt melt and formed several iron oxide phases. The magnetite which formed during the fireball stage reached in various ways with the environment to form higher oxides and hydrated oxides.