Review: Capripoxvirus Diseases: Current Status and Opportunities for Control

Lumpy skin disease, sheeppox and goatpox are high-impact diseases of domestic ruminants with a devastating effect on cattle, sheep and goat farming industries in endemic regions. In this article, we review the current geographical distribution, economic impact of an outbreak, epidemiology, transmission and immunity of capripoxvirus. The special focus of the article is to scrutinize the use of currently available vaccines to investigate the resource needs and challenges that will have to be overcome to improve disease control and eradication, and progress on the development of safer and more effective vaccines. In addition, field evaluation of the efficacy of the vaccines and the genomic database available for poxviruses are discussed.

Analogues of Triprolidine: Structural Influences upon Antihistamine Activity

The synthesis of some geometrical isomers related to triprolidine is reported. Previous configurational assignments, by UV and proton NMR, are validated by high field nuclear Overhauser enhancement methods and the isomeric purity of tested E- and Z-isomers was greater than 99.5% as assessed by an HPLC method developed for these compounds. Affinity constants for triprolidine (E and Z) in guinea-pig ileum showed a potency ratio of ∼600 whereas at cerebellar sites this ratio was only ∼100, suggesting that the H1 receptor in these two tissues may not be identical. In-vivo tests using a lethal dose of compound 48/80 (a potent histamine-releasing agent) demonstrated that triprolidine itself was the most active compound to protect the animal among all the isomeric compounds tested: in all isomeric pairs the E-configuration possessed superior activity over Z. The disposition of the aryl groups in these geometrically constrained compounds mimics that seen in the structurally related chiral pheniramines which are sp3 hybridized and whose absolute stereochemistry is known.

A systematic review to examine the impact of psycho-educational interventions on health outcomes and costs in adults and children with difficult asthma

OBJECTIVES

Prior research has highlighted the importance of psychosocial factors in 'difficult' asthma. This study aimed to review the content, effectiveness and cost-effectiveness of psycho-educational interventions designed to address these factors in patients with severe and difficult asthma.

DATA SOURCES

Thirty-two electronic databases and other sources were searched for studies of educational, self-management, psychosocial and multifaceted interventions.

REVIEW METHODS

Abstracts were screened in duplicate, against prior definitions, to identify eligible interventions targeted to patients with forms of or risk factors for difficult asthma. Studies were classified by patient group (child, adult) and graded along two dimensions related to study design and relevance in terms of the degree to which they were judged to have targeted difficult asthma. Detailed data were extracted from studies meeting a minimum design and relevance threshold. Characteristics of studies were tabulated and results qualitatively synthesised. Where sufficiently similar studies reported adequate data about comparable outcomes, quantitative syntheses of results were undertaken using a random effects approach to calculate pooled relative risks (RR) or standardised mean differences (SMD), with 95% confidence intervals (CI).

RESULTS

Searches identified over 23,000 citations. After initial screening and removal of duplicates, 4240 possibly relevant abstracts were assessed. Papers associated with 188 studies were initially obtained and classified. Fifty-seven studies including control groups and those that were judged to have at least 'possible' targeting of difficult asthma (35 in children, 21 in adults, 1 in both) were selected for in-depth review. The delivery, setting, timing and content of interventions varied considerably even within broad types. Reporting of interventions and methodological quality was often poor, but studies demonstrated some success in targeting and following up at-risk patients. Studies reporting data suitable for calculation of summary statistics were of higher quality than those that did not. There was evidence from these that, compared to usual or non-psycho-educational care, psycho-educational interventions reduced admissions when data from the latest follow-ups reported were pooled across nine studies in children (RR = 0.64, CI = 0.46-0.89) and six studies with possible targeting of difficult asthma in adults (RR = 0.57, CI = 0.34-0.93). In children, the greatest and only significant effects were confined to individual studies with limited targeting of difficult asthma and no long-term follow-up. Limited data in adults also suggested effects may not extend to those most at risk. There was no evidence of pooled effects of psycho-educational interventions on emergency attendances from eight studies in children (RR = 0.97, CI = 0.78-1.21) and four in adults (RR = 1.03, CI = 0.82-1.29). There were overall significant reductions in symptoms, similar in different sub-groups of difficult asthma, across four paediatric studies that could be combined (SMD = -0.45, CI = -0.68 to -0.22), but mixed results across individual adult studies. A few individual studies in children showed mainly positive effects on measures of self-care behaviour, but with respect to all other outcomes in adults and children, studies showed mixed results or suggested limited effectiveness of psycho-educational interventions. No studies of psychosocial interventions were included in any quantitative syntheses and it was not possible to draw clear conclusions regarding the relative effectiveness of educational, self-management and multifaceted programmes. Data on costs were very limited. Of the two well-designed economic evaluations identified, both of multifaceted interventions, one in children suggested an additional cost of achieving health gain in terms of symptom-free days. Provisional data from the other study suggested that in adults the significantly increased costs of providing an intervention were not offset by any short-term savings in use of healthcare resources or associated with improvements in health outcomes.

CONCLUSIONS

There was some evidence of overall positive effects of psycho-educational interventions on hospital admissions in adults and children, and on symptoms in children, but limited evidence of effects on other outcomes. The majority of research and greatest effects, especially in adults, were confined to patients with severe disease but who lacked other characteristics indicative of difficult asthma or likely to put them at risk. A lack of good-quality research limited conclusions about cost-effectiveness. Although psycho-educational interventions may be of some benefit to patients with severe disease, there is currently a lack of evidence to warrant significant changes in clinical practice with regard to the care of patients with more difficult asthma. Further research is needed to: (1) standardise reporting of complex interventions; (2) extend and update this review; (3) improve identification of patients at risk from their asthma; (4) develop and test appropriate outcome measures for this group; and (5) design and evaluate, via the conduct of high-quality pragmatic RCTs, more powerful psycho-educational interventions that are conceptualised in terms of the ways in which psychosocial factors and asthma interact.

Use of modified U1 snRNAs to inhibit HIV-1 replication

Control of RNA processing plays a central role in regulating the replication of HIV-1, in particular the 3' polyadenylation of viral RNA. Based on the demonstration that polyadenylation of mRNAs can be disrupted by the targeted binding of modified U1 snRNA, we examined whether binding of U1 snRNAs to conserved 10 nt regions within the terminal exon of HIV-1 was able to inhibit viral structural protein expression. In this report, we demonstrate that U1 snRNAs complementary to 5 of the 15 regions targeted result in significant suppression of HIV-1 protein expression and viral replication coincident with loss of viral RNA. Suppression of viral gene expression is dependent upon appropriate assembly of a U1 snRNP particle as mutations of U1 snRNA that affect binding of U1 70K or Sm proteins significantly reduced efficacy. However, constructs lacking U1A binding sites retained significant anti-viral activity. This finding suggests a role for these mutants in situations where the wild-type constructs cause toxic effects. The conserved nature of the sequences targeted and the high efficacy of the constructs suggests that this strategy has significant potential as an HIV therapeutic.

Genomic cartography of varicella-zoster virus: a complete genome-based analysis of strain variability with implications for attenuation and phenotypic differences

In order to gain a better perspective on the true variability of varicella-zoster virus (VZV) and to catalogue the location and number of differences, 11 new complete genome sequences were compared with those previously in the public domain (18 complete genomes in total). Three of the newly sequenced genomes were derived from a single strain in order to assess variations that can occur during serial passage in cell culture. The analysis revealed that while VZV is relatively stable genetically it does posses a certain degree of variability. The reiteration regions, origins of replication and intergenic homopolymer regions were all found to be variable between strains as well as within a given strain. In addition, the terminal viral sequences were found to vary within and between strains specifically at the 3' end of the genome. Analysis of single nucleotide polymorphisms (SNPs) identified a total of 557 variable sites, 451 of which were found in coding regions and resulted in 187 different in amino acid substitutions. A comparison of the SNPs present in the two gE mutant strains, VZV-MSP and VZV-BC, suggested that the missense mutation in gE was primarily responsible for the accelerated cell spread phenotype. Some of the variations noted with high passage in cell culture are consistent with variations seen in the IE62 gene of the vaccine strains (S628G, R958G and I1260V) that may help in pinpointing variations essential for attenuation. Although VZV has been considered to be one of the most genetically stable human herpesviruses, this initial assessment of genomic VZV cartography provides insight into ORFs with previously unreported variations.

Poxviruses: past, present and future

The analysis of poxvirus genomes is complex, in part, because of their size (130-360 kb) and the fact that gene content is variable; a common set of 49 genes has been found in all sequenced poxviruses and an additional 41 genes are also present in all sequenced orthopoxviruses. As a group, poxviruses have a very broad range of eukaryotic hosts (including mammals, birds, reptiles and insects) and many poxvirus genes are associated with blocking host anti-viral responses. One consequence of this is that many poxvirus genes are not essential for growth in tissue culture and that extensive passaging in vitro results in the accumulation of mutations, including deletions that result in loss of gene function. Here, we review various comparative analyses of the poxviruses including gene prediction, gene conservation and function, genome organization, and poxvirus taxonomy and evolution.

Complete coding sequences of the rabbitpox virus genome

Rabbitpox virus (RPXV) is highly virulent for rabbits and it has long been suspected to be a close relative of vaccinia virus. To explore these questions, the complete coding region of the rabbitpox virus genome was sequenced to permit comparison with sequenced strains of vaccinia virus and other orthopoxviruses. The genome of RPXV strain Utrecht (RPXV-UTR) is 197 731 nucleotides long, excluding the terminal hairpin structures at each end of the genome. The RPXV-UTR genome has 66.5 % A + T content, 184 putative functional genes and 12 fragmented ORF regions that are intact in other orthopoxviruses. The sequence of the RPXV-UTR genome reveals that two RPXV-UTR genes have orthologues in variola virus (VARV; the causative agent of smallpox), but not in vaccinia virus (VACV) strains. These genes are a zinc RING finger protein gene (RPXV-UTR-008) and an ankyrin repeat family protein gene (RPXV-UTR-180). A third gene, encoding a chemokine-binding protein (RPXV-UTR-001/184), is complete in VARV but functional only in some VACV strains. Examination of the evolutionary relationship between RPXV and other orthopoxviruses was carried out using the central 143 kb DNA sequence conserved among all completely sequenced orthopoxviruses and also the protein sequences of 49 gene products present in all completely sequenced chordopoxviruses. The results of these analyses both confirm that RPXV-UTR is most closely related to VACV and suggest that RPXV has not evolved directly from any of the sequenced VACV strains, since RPXV contains a 719 bp region not previously identified in any VACV.

Genome segment RNA-1 of a flat apple isolate of Cherry rasp leaf virus: nucleotide sequence analysis and RT-PCR detection

The sequence of the RNA-1 of a flat apple isolate of Cherry rasp leaf virus (CRLV-FA) was determined using overlapping cDNA fragments. CRLV-FA RNA-1 consists of 6992 nucleotides (nt), excluding a 3' poly (A) tail. A single open reading frame (ORF) consisting of 6705 nt was identified. This ORF encodes a putative polyprotein consisting of 2235 amino acid (aa) residues, approximately 249.6 kDa. When compared to CRLV-pot (potato isolate) RNA-1 ORF, 2 deletions of 5 aa and 10 aa (total 15 aa) were observed at the variable N-terminus of the protease cofactor of CRLV-FA. Non-coding regions were identified at the 5'-(142 nt) and 3'-end (145 nt). CRLV-FA and CRLV-pot are isolates of the same virus with identity levels for the RNA-1 associated nt and deduced aa of 94% and 95%, respectively. RT-PCR targeting CRLV-FA RNA-1 appear to be of similar sensitivity and just as reliable as RT-PCR targeting RNA-2.

Proteomic analysis of melanoma-derived exosomes by two-dimensional polyacrylamide gel electrophoresis and mass spectrometry

Exosomes are 40-100 nm vesicles released by numerous cell types and are thought to have a variety of roles depending on their origin. Exosomes derived from antigen presenting cells have been shown to be capable of initiating immune responses in vivo and eradicating established tumours in murine models. Tumour-derived exosomes can be utilised as a source of tumour antigen for cross-priming to T-cells and are thus of interest for use in anti-tumour immunotherapy. Further exploration into the protein composition of exosomes may increase our understanding of their potential roles in vivo and this study has examined the proteome of exosomes purified from cell supernatants of the melanoma cell lines MeWo and SK-MEL-28. The vesicular nature and size (30-100 nm) of the purified exosomes was confirmed by electron microscopy and sucrose density gradient centrifugation. Western blotting demonstrated the absence of calnexin and cytochrome c, verifying the purity of the exosome preparations, as well as enrichment of MHC class I and the tumour-associated antigens Mart-1 and Mel-CAM. The two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) protein profiles of exosomes from the two cell lines were highly comparable and strikingly different from the profiles of the total cell lysates. Mass spectrometric sequencing identified proteins present in 49 protein spots in the exosome lysates. Several of these have been identified previously in exosomes but some are novel, including p120 catenin, radixin, and immunoglobulin superfamily member 8 (PGRL). Proteins present in whole-cell lysates that were significantly reduced or excluded from exosomes were also identified and included several mitochondrial and lysosomal proteins, again confirming the proposed endosomal origin of exosomes. This study presents a starting point for future more in-depth protein studies of tumour-derived exosomes which will aid the understanding of their biogenesis and targeting for use in anti-tumour immunotherapy protocols.

Emergency asthma inhalers in school

Despite there being a lack of direct evidence of the effectiveness of providing emergency inhalers to schools, the balance of evidence at present suggests the benefits outweigh any possible harm. However, unless UK prescribing law or its interpretation is changed, this will remain an action which opens teachers, nurses, and doctors to possible legal and professional sanctions, and may nullify their institutional or professional indemnity. As a consequence, provision will remain patchy and research into the value of emergency inhalers will be inhibited. A position statement from one or more responsible organisations such as the Royal College of Paediatrics and Child Health, the British Thoracic Society, or the British Paediatric Respiratory Society could persuade a reassessment from the Medicines Control Agency. This is also an issue which could be addressed in the forthcoming National Service Framework for children.

Nucleotide sequence analysis of RNA-2 of a flat apple isolate of Cherry rasp leaf virus with regions showing greater identity to animal picornaviruses than to related plant viruses

RNA-2 of a flat apple isolate of Cherry rasp leaf virus (CRLV-FA) appears to consist of 3274 nucleotides, excluding a 3' poly (A) tail. The data supports re-classification of CRLV in a new genus in the family Comoviridae. A single open reading frame (ORF) encoding a putative 108 kDa polyprotein was identified. Potential protease cleavage sites were identified which would result in the production of a putative movement protein (41 kDa), and 3 capsid protein subunits (24, 20, and 22 kDa, respectively). A 5'-UTR and 3'-UTR were identified, 248 nt and 146 nt long, respectively. The genome organisation of CRLV-FA RNA-2 is similar to that of Apple latent spherical virus (ALSV) RNA-2, a new member of the family Comoviridae. The Vp25 amino acid sequences were unique to CRLV-FA and ALSV (54% identity), with no relationship identified to any other virus. CRLV-FA Vp20 and Vp24 amino acid sequences were closely related to ALSV (59 and 65%, respectively) but the only other relationships identified were with a range of animal ssRNA positive-strand viruses.

Avoiding drug errors

Although no statistics are available, medication errors occur relatively frequently and should be a target for Clinical Governance activities. Organisations need to create a culture where risk management regarding medication is incorporated.

Screening predicted coding regions in poxvirus genomes

The amino acid composition and pI values were calculated for the predicted proteins of a series of complete poxvirus genomes. Many of the vaccinia virus (strain Copenhagen) minor ORFs, thought not to be functional genes, were found to have significantly more or less of several amino acids than a set of the largest 150 vaccinia virus proteins. Very high isoelectric point (pI) values were also correlated with a group of the minor ORFs. Analysis of molluscum contagiosum virus ORFs by amino acid composition and pI identified a number of ORFs previously denoted as doubtful and highlighted several others that could be similarly classified. The use of amino acid composition and pI appears to be a generally applicable tool to aid identification of viral ORFs that are unlikely to be functional genes.

BLAST Search Updater: a notification system for new database matches

BLAST Search Updater (BSU) can help molecular biologists perform large numbers of BLAST searches routinely and screen the results for novel matches. The search result files (HTML format) and delta files (novel matches) are WWW viewable and BSU also emails users alignments of new matches.

AVAILABILITY

BSU runs on UNIX machines and is freely available to academic users at http://athena.bioc.uvic.ca/genomes/. Additional figures and description are also available.

CONTACT

cupton@uvic.ca

Viral genome organizer: a system for analyzing complete viral genomes

The viral genome organizer (VGO) is designed to simplify the characterization and annotation of complete viral genomes (particularly those of large poxviruses) and to help researchers discover new genes and detect gene fragmentation. VGO is based on Genotator [Harris, N.L., 1997. Genome Res. 7, 754-762], an annotation workbench designed for the analysis of eukaryotic genomic sequences. VGO automates a number of database search routines (FASTA, BLASTP, PSI-BLAST and TBLASTN), processes the results through a multiple-alignment viewer (MView; [Brown, N.P., Leroy, C., Sander, C. , 1998. Bioinformatics 14, 380-381]) and serves to manage the hundreds of DNA, protein and database search results files that must be organized when dealing with large complete poxviral genomes. It also directs the generation a self-dotplot of the genome by Dotter [Sonnhammer, E.L.L., Durbin, R., 1995. A dot-matrix program with dynamic threshold control suited for genomic DNA and protein sequence analysis. Gene 167: GC1-10. http://www.sanger.ac. uk/Software/Dotter/] to uncover repeated genes and sequences and provides Internet links to programs for generation of restriction maps and analysis of potential PCR primers. The user-friendly graphical interface displays DNA and protein sequences, links to search results, ORFs, stop-start codons, restriction sites and flags of database searches. Currently, VGO and associated programs run in an X-windows environment on commonly available UNIX machines.

Nucleotide sequence and genome organisation of cherry mottle leaf virus and its relationship to members of the Trichovirus genus

The nucleotide sequence of cherry mottle leaf virus (CMLV) was determined and compared to sequences of a number of plant viruses including the type member of the Trichovirus genus (apple chlorotic leafspot virus, ACLSV), and members of the Vitivirus genus including grapevine virus B, (GVB). The CMLV genome was determined to consist of 8003 nt excluding the poly(A) tail at the 3' end of the genome. The overall A + U content of CMLV genomic RNA was 59.1%, which is similar to ACLSV, but significantly different from GVB. Four putative open reading frames were identified (ORFs 1, 2, 3, and 4) encoding proteins of M(r) 215.8 kDa, 47 kDa, 21.6 kDa, and 15.3 kDa, respectively. This differs from ACLSV which has 3 ORFS, and GVB which has 5 ORFs. Protein database searches showed no matches of CMLV ORF4 with ACLSV sequences, but found similarities between ORF4 of CMLV and ORF5 of GVB, suggesting that this may be a nucleic acid-binding protein. CMLV and ACLSV formed a common virus clade in phylogenetic analysis of the coat protein amino acid sequence and except for CMLV's ORF4, these viruses show high levels of similarity throughout the genome. CMLV appears to be a member of the Trichovirus genus.

Conformationally-restricted ligands for the histamine H1 receptor

Potent H1-antagonistic activity in a series of novel indeno[2,1-c]pyridines and their 4-arylpiperidinol precursors is reported; one compound shows an in vitro activity four times that of the standard mepyramine that it was screened against. Their failure to translate this protection to in vivo tests is discussed.

Viral Genome DataBase: storing and analyzing genes and proteins from complete viral genomes

SUMMARY

The Viral Genome DataBase (VGDB) contains detailed information of the genes and predicted protein sequences from 15 completely sequenced genomes of large (&100 kb) viruses (2847 genes). The data that is stored includes DNA sequence, protein sequence, GenBank and user-entered notes, molecular weight (MW), isoelectric point (pI), amino acid content, A + T%, nucleotide frequency, dinucleotide frequency and codon use. The VGDB is a mySQL database with a user-friendly JAVA GUI. Results of queries can be easily sorted by any of the individual parameters.

AVAILABILITY

The software and additional figures and information are available at http://athena.bioc.uvic.ca/genomes/index.html .

Ectromelia virus virulence factor p28 acts upstream of caspase-3 in response to UV light-induced apoptosis

Ectromelia virus (EV) virulence factor p28 (EVp28) is a member of a family of poxvirus proteins that are defined largely by the presence of a C-terminal RING finger motif and localization to virus factories within the cytoplasm of infected cells. Previously, overexpression of the Shope fibroma virus (SFV) homologue, N1R, in vaccinia virus (VV)-infected BGMK cells was found to inhibit virus-induced apoptosis. Here, we report that both EVp28 and overexpression of SFV N1R in poxvirus-infected HeLa cells protect specifically from UV light-induced apoptosis, but not from apoptosis induced by Fas or TNF. Further, we report that both VV and EV protect from apoptosis induced by UV, Fas and TNF. Immunoblot analysis indicates that EVp28 acts upstream of caspase-3, blocking activation of the protease in response to UV irradiation. Although no difference was found in replication of an EVp28(-) mutant virus, which expresses a truncated p28 protein lacking the RING motif, compared to EV wild-type in HeLa cells, UV irradiation of infected HeLa cells reduced the replication of the EV mutant compared with wild-type EV.

Analysis of host response modifier ORFs of ectromelia virus, the causative agent of mousepox

From the right-hand end of the ectromelia virus (strain Moscow) genome, 32318 bps have been sequenced, and characterized to include a total of 18 open reading frames (ORFs) and six regions which apparently no longer code for functional proteins. At least six of the ORFs appear to be involved in blocking the inflammatory/immune host response to infection, and therefore probably contribute significantly to the virulence of this virus in its natural host, the mouse. One of these genes encoded an isolog of the poxvirus chemokine binding protein, and was shown to be the most abundant protein secreted from ectromelia virus infected cells. Two regions were found to have significant similarity to poxvirus genes encoding tumor necrosis factor (TNF) binding proteins. Both are distinct from cytokine response modifier (crm)B and crmC but only one is predicted to encode a functional TNF binding protein. A novel similarity between the C-terminal domain of poxvirus TNF binding proteins and several other poxvirus proteins is also presented. The results are discussed in the context of ectromelia virus pathogenesis of mice.

Single primer pair designs that facilitate simultaneous detection and differentiation of peach mosaic virus and cherry mottle leaf virus

Peach mosaic virus (PMV) and cherry mottle leaf virus (CMLV) are viruses which are related serologically and share common Prunus hosts, but cause distinct diseases. An RT-PCR procedure using a single oligonucleotide primer pair that allows simultaneous detection and differentiation of the two viruses was developed. A sense primer with 100% complementarity to PMV and 83% complementarity to the corresponding site of the CMLV genome was combined with either of two antisense primers (one of PMV origin and the other of CMLV origin) with 3' end complementarity at variable sites. This allowed the differential amplification of PMV and CMLV specific fragments, 419 and 705 bp, respectively. When oligo (dT) was used to generate the cDNA template, differential amplification was not observed, only amplification of the homologous virus associated with the antisense primer. This indicates polyadenylation of both viruses. Incorporation of the antisense primer into cDNA at the reverse transcription step was shown to be essential for this approach. The PMV primer pair reliably detected all isolates of PMV tested by RT-PCR analysis, both in peach leaf and budwood tissue.

Novel nitrated derivatives of 5,8-diazabenzo[c]phenanthrene and 9,14-diazadibenz[a,e]acephenanthrylene: new classes of potent mutagenic compounds

We report the synthesis of 4-nitro-5,8-diazabenzo[c]phenanthrene (4-NDBP) and 11-nitro-9,14-diazadibenz[a,e]acephenanthrylene (11-NDDA) and the remarkable mutagenic activity of the latter. These two compounds and their non-nitrated parents, 5, 8-diazabenzo[c]phenanthrene (DBP) and 9,14-diazadibenz[a, e]acephenanthrylene (DDA), were screened in Ames plate incorporation assays against Escherichia coli WP2uvrA and Salmonella typhimurium TA98 both in the presence and absence of S9 liver fraction from Aroclor 1254-induced rats. None of the four compounds were cytotoxic up to the limits of their solubility and none showed mutagenic activity in E.coli WP2uvrA, which suggested that any such activity they may have had was not mediated via a base substitution mechanism. DBP and DDA also displayed a lack of activity in TA98 up to their precipitating doses (560 and 33.5 microg/plate, respectively). The two nitrated compounds, however, were genotoxic. 4-NDBP was active at a dose of 500 ng/plate, in the absence of S9, producing 80.0 +/- 28.0 prototrophic organisms (equivalent to 44 revertants/nmol) and at 0.5 ng/plate, in the presence of S9, giving 147 +/- 6.6 revertants (equivalent to 81 000/nmol) and allowed the description of this tetracycle as a potent mutagen. Much more striking was the activity of 11-NDDA: in the absence of S9 a dose of 8.0 ng produced 2000 revertants/nmol and, remarkably, in the presence of S9 80 pg produced the equivalent of 643 000 revertants/nmol. This makes the hexacyclic 11-NDDA the most potent mutagen to date, in the Ames procedures described here.

Cytotoxic response of ovarian cancer cell lines to IFN-gamma is associated with sustained induction of IRF-1 and p21 mRNA

Interferon-gamma (IFN-gamma) has some anti-tumour activity in human ovarian cancer. This cytokine inhibited proliferation in three of four ovarian cancer cell lines in vitro. We then compared the action of IFN-gamma in two cell lines, one sensitive and one resistant to its growth inhibitory effects. IFN-gamma signalling appeared normal in both cell lines, with stat1 DNA binding activity detectable at 30 min. Continuous exposure to IFN-gamma for 2-3 days was necessary for an irreversible effect on cell growth and apoptosis in cells sensitive to growth inhibition. During this time there was an increase in mRNA for the CKI p21, but no alterations in mRNA levels for other members of the CKI family. Maintenance of p21 mRNA required continuous mRNA synthesis. mRNA for the transcription factor IRF-1 was also induced in growth inhibited cells with similar kinetics to those observed for p21. Maximal induction of both p21 and IRF-1 mRNA was observed after 2-3 days IFN-gamma exposure as the cells became committed to cell death. There was also a rapid increase in p21 and IRF-1 mRNA in cells resistant to the growth inhibitory effects of IFN-gamma, but this increase was not maintained. Thus, continuous interaction with the IFN-gamma receptor, together with a sustained induction of p21 and IRF-1, is associated with growth inhibitory and apoptotic effects of IFN-gamma in ovarian cancer cells.

Specific Detection of Cherry Mottle Leaf Virus Using Digoxigenin-Labeled cDNA Probes and RT-PCR

Cherry mottle leaf virus (CMLV)-associated double-stranded RNA (dsRNA) was isolated from the propagation host Chenopodium quinoa. The dsRNA band, with a molecular weight estimated at 7.0 × 10⁶ Da, was used to produce cDNA. Two recombinant plasmids from the cloned cDNA library were identified that specifically bound with CMLV-associated RNA in dot blot hybridization studies. The cDNA inserts were sequenced, and oligonucleotide primers were designed that specifically amplify an 848-bp fragment of the CMLV genome by reverse-transcription polymerase chain reaction. Also, a poly(T) primer was reliably used for reverse transcription, with specific amplification using the CMLV primers, suggesting polyadenylation of the virus genome. Search of the database revealed some sequence homology of the partially characterized genome of CMLV with that of apple chlorotic leafspot virus. Additional sequence data are required, however, to establish the taxonomic position of the filamentous CMLV.

Subversion of cytokine networks by viruses

Viruses and the immune system have been competitors throughout their co-evolution. It is therefore not surprising that the viruses in circulation today possess a variety of strategies to counteract those aspects of the immune system that are involved in virus clearance. Examination of these virus encoded functions provides an important view of immune function and an appreciation of the complexity of the virus-host interaction. It is clear that viruses, seeking to subvert the immune system, have become adept in blocking the communication channels of the immune system. There are numerous examples of viral proteins that target the cytokine networks, disrupting the processes by which the delicately balanced immune system is regulated. This review focuses on the gene products of poxviruses, adenoviruses and herpesviruses that function primarily as immune-modulators.

Shope fibroma virus RING finger protein N1R binds DNA and inhibits apoptosis

Shope fibroma virus (SFV) N1R gene encodes a RING finger protein that localizes to virus factories within the cytoplasm of infected cells. Altered proteins, with deletions and site-specific mutations, were transiently expressed in vaccinia virus-infected cells to discern regions of the protein that are required for localization. We have determined that at least part of the RING finger region is necessary for localization but that the RING motif alone is not sufficient. A chimeric protein, however, in which the RING finger region of the herpes simplex virus-1 ICP0 protein replaces the SFV N1R RING motif does localize to virus factories. A region of five highly conserved amino acids at the amino terminus of SFV N1R is also critical for localization. We report that the SFV N1R protein binds double- and single-stranded DNA, suggesting a mechanism for localization, and that overexpression of this protein in vaccinia virus-infected cells reduces apoptosis-associated fragmentation of nuclear DNA.

Stereochemical studies of the isomerization of novel 2-alkyl-9-phenyl-2,3,4,4a- and 2,3,4,9-tetrahydro-1H-indeno[2,1-c]pyridines

The published synthetic route to the antihistaminic tetrahydroindeno[2,1-c]pyridines (phenindamines) relies on catalytic reduction of the precursor dihydroindenopyridines. This reduction gives mixtures of 9,9a- and 4a,9a-enes and the clinically active 4a,9a isomer has to be isolated by recrystallization of an appropriate salt. The structure of the product recovered depends on the anion used to isolate the proton salt and appears to be arbitrary. To rationalize this outcome a series of novel N-2 alkylated tetrahydroindeno[2,1-c]pyridines and their diene precursors has been synthesized from accessible piperidines. The structures and geometry of the piperidines and the dihydro- and tetrahydroindenopyridines have been determined by 1H and 13C NMR. An unusual feature of the proton spectra of the piperidines is the resonance of the axial protons at lower field than their equatorial counterparts. By controlling the reaction conditions for the reduction of the dihydroindenopyridines to their tetrahydro derivatives the kinetic or thermodynamic product can be selected as required. A predictable outcome for the reductions investigated was achieved and is generally applicable.

Novel 5,8-diazabenzo[c]phenanthrenes: synthesis and mutagenicity

The polycyclic aromatic hydrocarbons have been recognized as carcinogens and mutagens since the early part of this century. More recently their aza and polyaza derivatives have been shown to have the same biological activity. A major source of these compounds is the combustion of fresh or metamorphosed plant materials; this contributes to the environmental burden of, and exposure to, these carcinogens. We report the synthesis and characterization of a series of novel 5,8-diazabenzo[c]phenanthrenes which are isosteric with the known epidermal carcinogen benzo[c]phenanthrene but have not yet been reported as components of soot or diesel particulate matter. The synthesis of the compounds exploits a versatile, double Friedlander reaction between the appropriately substituted 2,2'-diaminobenzophenone and beta-diketones, with yields of purified product ranging from 30-90%. The nucleophilic substitution of these diazabenzophenanthrenes with ethanolamine is also described. This strategy will enable further elaboration of these heterocyclic nuclei at a later date. Mutagenicity testing of these agents was performed using spot tests and in Ames plate-incorporation assays using Escherichia coli WP2 and WP2uvrA as test organisms. The plate-incorporation assays were performed in the presence or absence of metabolic enzymes contained in the S9 liver fraction from Aroclor 1254-induced rats, to investigate whether bioactivation of the diazabenzophenanthrenes contributed to their toxicity. No differences between these two protocols were observed, with neither test showing reversion to prototrophic behaviour. Furthermore, the compounds were not toxic to the test organism. These initial results suggest that these compounds are not mutagenic in the Ames tests employed.

A novel poxvirus gene and its human homolog are similar to an E. coli lysophospholipase

A novel poxvirus gene has been characterized within the genome of ectromelia virus. It has significant similarity to a family of lysophospholipases suggesting that it may function in the degradation of lysophospholipids. Since these molecules are active in the stimulation of inflammation, we hypothesize that this gene may play a role in virus virulence. This gene is expressed early in the ectromelia virus replication cycle, before DNA replication. We have also characterized a human cDNA that encodes a protein which is 49.5% identical to the ectromelia virus protein. By its presence in multiple cDNA libraries, this human gene is known to be expressed in a variety of body tissues and is likely to function in the normal regulation of lysophospholipid levels. This family of proteins have conserved blocks of amino acids that are indicative of a serine-aspartic acid-histidine catalytic triad, similar to those used by true lipases and a number of esterases.

Interferon gamma induces cell cycle arrest and apoptosis in a model of ovarian cancer: enhancement of effect by batimastat

Locoregional human IFN-gamma may have activity against refractory ovarian cancer. We investigated this further in an ovarian cancer xenograft model. Administered at clinically relevant doses, intraperitoneal IFN-gamma prolonged the survival of mice bearing multiple established peritoneal tumours, with optimal treatment giving a 3-6-fold increase in median survival time. Daily dosing, which was superior to intermittent treatment, decreased DNA synthesis and induced apoptosis in tumour cells with maximal effects after 7-21 days treatment. This was preceded by an increase in p53 protein at 48 h. The effect of IFN-gamma was not enhanced by sequential treatment with carboplatin. However, the matrix metalloprotease inhibitor, batimastat, further increased mouse survival when given after IFN-gamma. Thus IFN-gamma is cytotoxic to ovarian epithelial cells in vivo and intensive locoregional dosing over short periods is effective. Sequential administration of novel agents that perturb the host/tumour relationship may be of benefit.

Generation of an anti-tumour immune response in a non-immunogenic tumour: HSVtk killing in vivo stimulates a mononuclear cell infiltrate and a Th1-like profile of intratumoural cytokine expression

Direct delivery of the herpes simplex virus thymidine kinase (HSVtk) gene, in combination with the prodrug ganciclovir (GC), has been used for the treatment of localised, inoperable tumours. Several groups have shown that when rodent tumours are ablated in vivo with suicide genes, anti-tumour immunity can also be generated. Hence, this approach may also be useful in treating disseminated disease. Here we have studied the mechanisms associated with this anti-tumour immunity. In B16 HSVtk+ tumours being killed in vivo with GC treatment, we observed the induction of a pronounced intratumoural infiltrate of macrophages, CD4+ and CD8+ T cells. In addition, using reverse transcriptase polymerase chain reaction, expression of interleukin (IL)-2, IL-12, interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) and granulocyte/macrophage colony-stimulating factor (GM-CSF) but not IL-4, IL-6 or IL-10, was observed, a profile of cytokine expression which resembles that of a Th1 immune response. To complement these findings, we also investigated the mechanisms by which expression of HSVtk leads to cell death. Our data show that B16/HSVtk+ cells die predominantly by necrosis, rather than apoptosis, on exposure to GC, a process which may be associated with the generation of anti-tumour inflammatory responses. From these data we propose a model for the induction of anti-tumour immunity using suicide genes and discuss the development of improved vectors for gene therapy to augment these effects in vivo.

A human homolog of the vaccinia virus HindIII K4L gene is a member of the phospholipase D superfamily

We have identified a human gene encoding a protein with 48% amino acid identity to the vaccinia virus (VV) K4L gene product. Both contain motifs characteristic of the phospholipase D (PLD) protein superfamily. These proteins are also related to vaccinia virus p37, encoded by the F13L gene, which is required for envelopment and spread of the virus. The similarity to phospholipase D provides insight into the mechanisms and evolution of these processes.

Approaches to detection of distantly related proteins by database searches

The searching of protein databases as a method of identifying newly sequenced genes is commonplace in molecular biology laboratories. However, it is a procedure that is not usually formally taught to students, and method cookbooks discuss it only briefly. This article uses a single family of highly diverged uracil-DNA glycosylases, which fall into two distinct groups, to highlight some of the difficulties associated with identification of such proteins by database searching.

Blocking effects of promethazine, triprolidine and their analogues on the excitation caused by the peptide, achatin-I

An Achatina endogenous tetrapeptide, achatin-I (Gly-D-Phe-Ala-Asp), applied by brief pressure, produced an inward current (Iin) on an Achatina giant neurone type, PON (periodically oscillating neurone). Promethazine, triprolidine and their analogues tested, applied by perfusion, showed a tendency to inhibit the Iin, suggesting that the effective structures vary to a wide extent. With respect to promethazine and its analogues, the presence of 2-bromo, 5-oxo, 3-dimethylsulfamido and 2-methoxy weakened the effects. 10-(2-methylamino-2-methylethyl) instead of 10-(2-dimethylamino-2-methylethyl) of promethazine and the azepine ring instead of phenothiazine ring potentiated the effects. From the dose (pressure duration)-response study of achatin-I, the two promethazine analogues, RP 6497 and RP 6549 (the structures are shown in Fig. 1), inhibited the Iin in partly competitive and partly noncompetitive manners. Regarding triprolidine and its analogues, the compounds in Z-configuration seemed to be more effective than those in E-configuration. The presence of 4-methyl in 1-phenyl, and 1-(4-pyridyl) instead of 1-(2-pyridyl) potentiated the effects. 3-Dimethylamino instead of 3-pyrrolidino weakened the effects. The two triprolidine analogues, Trip Der 3 and Trip Der 6 (the structures in Fig. 2), inhibited the Iin in an uncompetitive manner.

Improved stereospecific synthesis of novel 1-alkyl-3-benzoyl-4-hydroxy-4-phenylpiperidines

The stereoselective synthesis of conformationally restricted 1-alkyl-3-benzoyl-4-hydroxy-4-phenylpiperidine hydrochlorides via the Mannich reaction followed by an intramolecular aldol condensation is reported. The compounds were evaluated by 1H NMR and 13C NMR techniques.

A new family of lipolytic plant enzymes with members in rice, arabidopsis and maize

We have noted a striking similarity between the sequences of proteins in a novel family of lipases we recently reported [Upton, C. and Buckley, J. T. (1995) Trends Biol. Sci. 20, 178-9] and more than 120 sequences from the database of Expressed Sequence Tags (dbEST) which correspond to at least 30 unique genes from arabidopsis, rice and maize. A cDNA (Arab-1) corresponding to one of these sequences was isolated, sequenced and translated. There was significant similarity to sequences in the new lipase family over the entire open reading frame of Arab-1 and when expressed in E. coli, the gene product was lipolytic. Arab-1 and genes for some of the other plant proteins appear to be differentially expressed. They may play a role in the regulation of lipid metabolism during plant development.

Technical report. Using a world wide web server as a local organizer for protein and DNA sequences

We have used a local World Wide Web (WWW) server to organize protein and DNA sequences that are used frequently in our laboratory. WWW server programs are available for most computer platforms and are easily set up with minimal computer skills. This approach allows for the easy retrieval of sequence data, which can then be used as input for other analysis programs. This format is especially simple to use in conjunction with WWW database searches. The sequence files may be served to the "public" Internet or kept private by requiring a password for access. Other advantages are (i) sequences can be accessed from multiple computer platforms using the appropriate WWW-browser; (ii) files can be accessed remotely from any computer on the Internet; (iii) only a single sequence format is used, simplifying the updating and archiving of data; and (iv) links to remote files can also be served in addition to local files.

Changes in endogenous cytokines, adhesion molecules and platelets during cytokine-induced tumour necrosis

The aim of this study was to investigate mechanisms of anti-tumour activity and necrosis induced by combinations of tumour necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma). In a breast cancer xenograft model, locally injected recombinant human TNF-alpha arrested growth of established tumours in the absence of overt necrosis. Macroscopic necrosis occurred when rat IFN-gamma, which had no anti-tumour activity as a single agent, was given systemically. Treatment with TNF-alpha and IFN-gamma caused focal engorgement of tumour capillaries with erythrocytes, intravascular recruitment of polymorphonuclear cells and platelet adherence to the tumour vascular endothelium 4 h after the combined treatment. This was followed by destruction of tumour vascular endothelium and both necrosis and apoptosis of tumour cells. Concomitant with these changes, semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed the increase of stromal (murine) mRNA levels for TNF-alpha, TNF receptor 55 kDa, TNF receptor 75 kDa, intracellular adhesion molecule 1, vascular cell adhesion molecule 1, P-selectin and interleukin 6 (IL-6). Thus, the effect of the combined TNF-alpha and IFN-gamma therapy involved the selective destruction of the tumour vasculature, death of tumour cells and increased expression of a series of stromal cytokines, cytokine receptors and adhesion molecules, which could be implicated in the observed events.

A possible screening test for inherited p53-related defects based on the apoptotic response of peripheral blood lymphocytes to DNA damage

The cellular response, in terms of cell cycle arrest(s) and apoptosis, to radiation-induced DNA damage was studied. Experiments were performed on both mitogen-stimulated and resting peripheral blood lymphocytes (PBLs) from normal and cancer-prone (C-P) individuals. The C-P individuals comprised three patients carrying germline p53 mutations and three members of two families apparently without such mutations, but with an inherited defect which results in p53 deregulation as shown by high levels of stabilised p53 protein in normal tissues. Interestingly, mitogen-stimulated PBL, from both normal and C-P individuals failed to demonstrate a G1 arrest after gamma radiation. However, a clear difference was seen in the apoptotic response to DNA damage, of PBL from normal and C-P individuals; PBLs from C-P individuals with inherited p53-related defects had a reduced apoptotic response (P = 0.0003). There was a wide margin of separation, with no overlap between the two groups, supporting the possibility of using this altered apoptotic response as a screening test. This simple and rapid procedure could be used to identify those individuals in a C-P family who carry germline p53-related defects. The method appears to detect both individuals with p53 mutations and those apparently without mutations but with other p53-related defects.

Species specificity of ectromelia virus and vaccinia virus interferon-gamma binding proteins

Interferon-gamma functions within the immune system as a potent anti-viral and immunoregulatory cytokine. In order to successfully replicate within a host cell, poxviruses have evolved a number of strategies to counteract the pleiotropic effects of interferon-gamma. In particular, the leporipoxvirus myxoma virus was shown to express an extracellular soluble interferon-gamma receptor homolog, denoted M-T7, which is capable of inhibiting the anti-viral activities of rabbit interferon-gamma (C. Upton, K. Mossman, and G. McFadden, 1992, Science 258, 1369-1372). Here, we demonstrate that expression of soluble interferon-gamma receptor homologs appears to be characteristic of all poxviruses tested, including Shope fibroma virus, vaccinia virus (strains WR and IHDW), ectromelia virus, cowpox virus, and rabbitpox virus. We have cloned, sequenced, and characterized the interferon-gamma binding protein in supernatants from ectromelia virus-infected cells, and demonstrate the capability of this soluble protein to bind human, murine, and rabbit interferon-gamma with similar affinity. We also investigate the properties of the vaccinia virus interferon-gamma binding protein and demonstrate that this protein binds human and rabbit interferon-gamma with similar affinity and binds murine interferon-gamma with a significantly lower relative affinity. The implications of these studies with respect to viral pathogenesis and the evolutionary relationship between a virus and its host are discussed.

The myxoma virus-soluble interferon-gamma receptor homolog, M-T7, inhibits interferon-gamma in a species-specific manner

The myxoma virus M-T7 protein contains significant sequence similarity to the ligand binding domain of the mammalian interferon-gamma receptors, and functions as a soluble homolog which can bind and inhibit the biological activities of rabbit interferon-gamma (Upton, C., Mossman, K., and McFadden, G. (1992) Science 258:1369-1372). M-T7, the most abundantly secreted protein from myxoma virus-infected cells, was shown to be expressed in significant biological amounts as a typical poxvirus early gene product, efficiently secreted at early times of infection to levels that exceed 5 x 10(7) molecules/cell, and function as a stable inhibitory protein in infected cell supernatants until late times of infection. M-T7 was specific in binding and inhibiting rabbit interferon-gamma, and did not bind either human or murine interferon-gamma. Scatchard analysis of rabbit interferon-gamma binding curves yielded a single high affinity binding site on M-T7, with a Kd of 1.2 x 10(-9) M, which is comparable to the affinity between soluble forms of cellular interferon-gamma receptors and their cognate ligands. In comparison, rabbit interferon-gamma was shown to bind its cellular receptor with a Kd of 5.9 x 10(-10) M, again comparable to the affinity of membrane bound forms of other mammalian interferon-gamma receptors for interferon-gamma. Thus, the myxoma virus M-T7 protein is a functional soluble interferon-gamma receptor homolog which binds and inhibits interferon-gamma with high affinity in a species-specific manner.

Myxoma virus and Shope fibroma virus encode dual-specificity tyrosine/serine phosphatases which are essential for virus viability

Sequence analysis of the genomes of the Leporipoxviruses myxoma virus and Shope fibroma virus (SFV) led to the discovery of open reading frames homologous to the vaccinia H1L gene encoding a soluble protein phosphatase with dual tyrosine/serine specificity. These viral phosphatase genes were subsequently localized to the myxoma BamHI-I fragment and the SFV BamHI-M fragment, and the resulting encoded proteins were designated I1L and M1L, respectively. The localization and orientation of the myxoma I1L and SFV M1L open reading frames within the well conserved central core of the viral genomes closely mirror that of the Orthopoxviruses vaccinia virus and variola virus. The myxoma I1L and SFV M1L phosphatases each contain the conserved tyrosine phosphatase signature sequence motif, (I/V)HCXAGXXR(S/T)G, including the active site cysteine, found previously to be essential for phosphotyrosine dephosphorylation. The vaccinia H1L phosphatase was originally shown to have the ability to dephosphorylate phosphotyrosyl and phosphoseryl residues in vitro. To assess whether this is a common feature of poxvirus phosphatases, myxoma I1L was expressed as a GST-fusion protein, purified, and shown to dephosphorylate substrates containing tyrosine and serine phosphorylated residues, in a similar fashion to vaccinia H1L. A myxoma I1L variant, in which the active site cysteine 110 was mutated to serine, was expressed in a parallel fashion to the wild-type I1L protein and found to be completely deficient in its ability to dephosphorylate both phosphotyrosine and phosphoserine amino acids. In an attempt to ascertain the biological requirement for the myxoma I1L phosphatase, we constructed a recombinant myxoma virus containing a disrupted I1L open reading frame. This I1L mutant virus was able to successfully propagate in tissue culture only in the presence of a wild-type complementing gene, and pure virus clones containing only the disrupted allele were not viable. Thus, we conclude that the myxoma I1L dual specificity phosphatase is an essential factor for virus viability.

Sleep disturbance in children treated with ofloxacin

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A poxvirus protein with a RING finger motif binds zinc and localizes in virus factories

Shope fibroma virus (SFV) is a Leporipoxvirus closely related to the highly virulent myxoma virus. The DNA sequence of the BamHI N fragment of the SFV DNA genome was determined, and the single complete open reading frame (N1R) was characterized. The protein encoded by the N1R gene was found to contain a C3HC4 RING finger motif at the C terminus. This C3HC4 motif is the hallmark of a growing family of proteins, many of which are involved in regulation of gene expression, DNA repair, or DNA recombination. Complete homologs of the SFV N1R gene were also detected in variola virus, myxoma virus, and vaccinia virus strain IHD-W. In contrast, the gene is completely absent from vaccinia virus strain Copenhagen, and in vaccinia virus strain WR, the open reading frame is truncated prior to the zinc binding domain because of an 11-bp deletion, thus producing a frameshift and premature stop codon. Recombinant N1R protein from SFV was expressed in Escherichia coli and shown to bind zinc in a specific manner. Using fluorescence microscopy to visualize a peptide epitope tag (derived from ICP27 of herpes simplex virus) fused to the N terminus of the poxvirus proteins, we observed that the N1R protein of SFV and its homologs in myxoma virus and vaccinia virus IHD-W were localized primarily to the virus factories in the cytoplasm of infected cells and, to a lesser degree, the host cell nucleus. The truncated protein of vaccinia virus strain WR failed to localize in this manner but instead was observed throughout the cytoplasm.