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PubMedDate not supplied

Metabolic networks: a signal-oriented approach to cellular models.

Complete genomes, far advanced proteomes, and even 'metabolomes' are available for at least a few organisms, e.g., Escherichia coli. Systematic functional analyses of such complete data sets will produce a wealth of information and promise an understanding of the dynamics of complex biological networks and perhaps even of entire living organisms. Such complete and holistic descriptions of biological systems, however, will increasingly require a quantitative analysis and the help of mathematical models for simulating whole systems. In particular, new procedures are required that allow a meaningful reduction of the information derived from complex systems that will consequently be used in the modeling process. In this review the biological elements of such a modeling procedure will be described. In a first step, complex living systems must be structured into well-defined and clearly delimited functional units, the elements of which have a common physiological goal, belong to a single genetic unit, and respond to the signals of a signal transduction system that senses changes in physiological states of the organism. These functional units occur at each level of complexity and more complex units originate by grouping several lower level elements into a single, more complex unit. To each complexity level corresponds a global regulator that is epistatic over lower level regulators. After its structuring into modules (functional units), a biological system is converted in a second step into mathematical submodels that by progressive combination can also be assembled into more aggregated model structures. Such a simplification of a cell (an organism) reduces its complexity to a level amenable to present modeling capacities. The universal biochemistry, however, promises a set of rules valid for modeling biological systems, from unicellular microorganisms and cells, to multicellular organisms and to populations.

Animals↗
PubMed2026

Age-associated epigenomic heterogeneity in papillary tumors of the pineal region: a multicenter YoungNOA investigation.

BACKGROUND: Papillary tumors of the pineal region (PTPR) are rare CNS neoplasms with adult and pediatric presentations, but whether age defines distinct molecular biology is unclear. METHODS: We assembled a multicenter retrospective cohort of 86 histologically confirmed PTPR with genome-wide DNA methylation data, comprising 62 adult and 24 pediatric tumors. Molecular subgroup, array platform, sex, and tumor purity were incorporated into multivariable models. Analyses included DNA methylation class assignment, differential methylation, copy-number variation (CNV), epigenetic mitotic-clock scores, methylation-based tumor microenvironment deconvolution, and descriptive survival evaluation. RESULTS: Adult and pediatric tumors mapped within the established PTPR-A and PTPR-B methylation framework rather than forming age-defined methylation classes. Pediatric tumors were enriched for PTPR-B (22 of 24 tumors [91.7%]) compared with adult tumors (39 of 62 [62.9%]). After adjustment for methylation-based subgroup as well as technical and biological covariates, 2,923 CpG probes were associated with age at a false discovery rate (FDR) threshold below 0.05, and 530 also met the prespecified effect-size threshold. Global methylation summaries were similar between age groups. CNV patterns were dominated by molecular subgroup; adjusted genomic CNV load was not independently associated with pediatric age. In contrast, epiTOC2 intrinsic rate score and the methylation signature represented by the first principal component (PC1) showed age-associated effects independent of molecular subgroup. Methylation-based deconvolution suggested a limited microenvironmental signal, with neutrophil fraction showing the most consistent adjusted association. CONCLUSIONS: Adult and pediatric PTPR share the established PTPR-A/PTPR-B framework. Pediatric tumors, particularly within PTPR-B, showed age-associated DNA methylation differences and higher epigenetic mitotic-clock (epiTOC2) scores in this retrospective cohort. These tissue-level associations do not establish clinical risk or treatment implications and require prospective clinical annotation and orthogonal validation.

Humans↗
PubMed2001

Gene structure prediction and alternative splicing analysis using genomically aligned ESTs.

With the availability of a nearly complete sequence of the human genome, aligning expressed sequence tags (EST) to the genomic sequence has become a practical and powerful strategy for gene prediction. Elucidating gene structure is a complex problem requiring the identification of splice junctions, gene boundaries, and alternative splicing variants. We have developed a software tool, Transcript Assembly Program (TAP), to delineate gene structures using genomically aligned EST sequences. TAP assembles the joint gene structure of the entire genomic region from individual splice junction pairs, using a novel algorithm that uses the EST-encoded connectivity and redundancy information to sort out the complex alternative splicing patterns. A method called polyadenylation site scan (PASS) has been developed to detect poly-A sites in the genome. TAP uses these predictions to identify gene boundaries by segmenting the joint gene structure at polyadenylated terminal exons. Reconstructing 1007 known transcripts, TAP scored a sensitivity (Sn) of 60% and a specificity (Sp) of 92% at the exon level. The gene boundary identification process was found to be accurate 78% of the time. also reports alternative splicing patterns in EST alignments. An analysis of alternative splicing in 1124 genic regions suggested that more than half of human genes undergo alternative splicing. Surprisingly, we saw an absolute majority of the detected alternative splicing events affect the coding region. Furthermore, the evolutionary conservation of alternative splicing between human and mouse was analyzed using an EST-based approach. (See http://stl.wustl.edu/~zkan/TAP/)

Alternative Splicing↗
PubMed1996

The role of manganese in promoting multimerization and assembly of human immunodeficiency virus type 1 integrase as a catalytically active complex on immobilized long terminal repeat substrates.

The integration of a DNA copy of the viral genome into the genome of the host cell is an essential step in the replication of all retroviruses. Integration requires two discrete biochemical reactions; specific processing of each viral long terminal repeat terminus or donor substrate, and a DNA strand transfer step wherein the processed donor substrate is joined to a nonspecific target DNA. Both reactions are catalyzed by a virally encoded enzyme, integrase. A microtiter assay for the strand transfer activity of human immunodeficiency virus type 1 integrase which uses an immobilized oligonucleotide as the donor substrate was previously published (D. J. Hazuda, J. C. Hastings, A. L. Wolfe, and E. A. Emini, Nucleic Acids Res. 22;1121-1122, 1994). We now describe a series of modifications to the method which facilitate study of both the nature and the dynamics of the interaction between integrase and the donor DNA. The enzyme which binds to the immobilized donor is shown to be sufficient to catalyze strand transfer with target DNA substrates added subsequent to assembly; in the absence of the target substrate, the complex was retained on the donor in an enzymatically competent state. Assembly required high concentrations of divalent cation, with optimal activity achieved at 25 mM MnCl2. In contrast, preassembled complexes catalyzed strand transfer equally efficiently in either 1 or 25 mM MnCl2, indicating mechanistically distinct functions for the divalent cation in assembly and catalysis, respectively. Prior incubation of the enzyme in 25 mM MnCl2 was shown to promote the multimerization of integrase in the absence of a DNA substrate and alleviate the requirement for high concentrations of divalent cation during assembly. The superphysiological requirement for MnCl2 may, therefore, reflect an insufficiency for functional self-assembly in vitro. Subunits were observed to exchange during the assembly reaction, suggesting that multimerization can occur either before or coincident with but not after donor binding. These studies both validate and illustrate the utility of this novel methodology and suggest that the approach may be generally useful in characterizing other details of this biochemical reaction.

Base Sequence↗
PubMed2004

[Analysis, identification and correction of some errors of model refseqs appeared in NCBI Human Gene Database by in silico cloning and experimental verification of novel human genes].

We found that human genome coding regions annotated by computers have different kinds of many errors in public domain through homologous BLAST of our cloned genes in non-redundant (nr) database, including insertions, deletions or mutations of one base pair or a segment in sequences at the cDNA level, or different permutation and combination of these errors. Basically, we use the three means for validating and identifying some errors of the model genes appeared in NCBI GENOME ANNOTATION PROJECT REFSEQS: (I) Evaluating the support degree of human EST clustering and draft human genome BLAST. (2) Preparation of chromosomal mapping of our verified genes and analysis of genomic organization of the genes. All of the exon/intron boundaries should be consistent with the GT/AG rule, and consensuses surrounding the splice boundaries should be found as well. (3) Experimental verification by RT-PCR of the in silico cloning genes and further by cDNA sequencing. And then we use the three means as reference: (1) Web searching or in silico cloning of the genes of different species, especially mouse and rat homologous genes, and thus judging the gene existence by ontology. (2) By using the released genes in public domain as standard, which should be highly homologous to our verified genes, especially the released human genes appeared in NCBI GENOME ANNOTATION PROJECT REFSEQS, we try to clone each a highly homologous complete gene similar to the released genes in public domain according to the strategy we developed in this paper. If we can not get it, our verified gene may be correct and the released gene in public domain may be wrong. (3) To find more evidence, we verified our cloned genes by RT-PCR or hybrid technique. Here we list some errors we found from NCBI GENOME ANNOTATION PROJECT REFSEQs: (1) Insert a base in the ORF by mistake which causes the frame shift of the coding amino acid. In detail, abase in the ORF of a gene is a redundant insertion, which causes a reading frame shift in the translation of an alternative protein, such as LOC124919 is wrong form of C17 orf32 (with mouse and rat orthologs determined by us). (2) Put together by mistake (with force). This is a wrong assembly of non-relating cDNA segment, such as LOC147007 is wrong form of C17orf32. (3) Mistakenly insert a base or one section of cDNA in the ORF which causes it ending beforehand, only coding cDNA sequence of N-terminal amino acids, incomplete. For example, LOC123722 is wrong form of SPRYD1, and even the human hypothetical gene LOC126250 or PDCD5 is wrong form of our PDCD5 (TFAR19). (4) Incomplete, only coding cDNA sequence of C-terminal amino acids. For example, human LOC149076 and mouse LOC230761 are wrong form of our verified human ZNF362 and mouse Zfp362, respectively. (5) Incomplete, only coding one section of coding protein cDNA sequence of correct gene ORF, lacking N-terminal and C-terminal amino acids sequence, and at the same time, mistakenly anticipates the first non-initiation codon amino acid of the incomplete protein amino acid as the initiation codon, e.g. anticipating L as M. For example, LOC200084 is wrong form of ZNF362. (6) Mistakenly insert a base or one section of cDNA in the ORF, wrongly causing unwanted termination codon before the insertion, so the coding protein lacks the first part of the amino acids. For example, the GenBank Acc. No. AL096883 ( LOCUS No. HS323M22B) is wrong form of an experimentally verified human NM_012263 with mouse ortholog of BC010510 determined. (7) It may regard the polluted genomic sequence as complete gene cDNA sequence and anticipate the so-called single exon gene, even the real one, only a small ORF in the very long single exon mRNA, while there really exists termination code in the same phase of the upper part of the ORF initiation code, no other characters accord with the gene's condition. For example, LOC91126 is wrong form of ZNF362. (8) The anticipated genes only have ORF which has no EST proofs on both terminal sides. Depending on this ORF, a complete gene cDNA with double support of EST and human genome (there are termination codes at the same phase of the upper part of ORF) which indicates the anticipated ORF reference sequence may be incorrect. For example, LOC164395 may be wrong form of novel human gene bankit4590055. (9) A similar but smaller protein-coding gene is anticipated in the range of the human genome sequence that has the support of EST experimental proof, so other new anticipated gene may be incorrect. For example, LOC167563 may be wrong form of CMYA5. However,these errors can be corrected or avoided by using our strategy. Here we give one example in detail: Comparision of the sequence SPRYD1 with human hypothetical gene LOC123722. The TAA bases in the position of 478-480 in LOC123722 cDNA is redundant, which causes a reading frame shift in the translation of an alternative protein. The redundancy of GTAAA of LOC123722 is not supported by our experimental clone,and is almost fully rejected by human EST alignment, and is shown as the next intron sequence by genomic GT/AG organization analysis. The verification of cDNA or genomic DNA sequence of SPRYD1 implies that LOC123722 has a wrong stop codon within its ORF because of the prediction program, thus being not complete cds. To sum up, by combining bioinformatics analyses with experimental verification, we have found that there are many errors of at least nine kinds appeared in NCBI GENOME ANNOTATION PROJECT REFSEQs through BLAST of our cloned genes in non-redundant database, and our strategy is helpful in correcting them, such as LOC14907, LOC200084 and LOC91126 (all of them should be ZNF362, but are three different kinds of wrong forms of ZNF362), three model reference sequences predicted from NCBI contig NT_004511 by automated computational analysis using gene prediction method, or such as LOC124919 and LOC147007 (both should be C17orf32, but are two different kinds of wrong forms of C17orf32), two model reference sequences predicted from NCBI contig NT_010808 by automated computational analysis using gene prediction method. Therefore, the correct identification and annotation of novel human genes may be still a heavy task, which can be finished within a long period of time. So human genome coding regions annotated by computer should be used with caution. The articles published in the past did not clearly point out the existence of mistakes in the NCBI human gene mode reference sequence. At the Seventh International Human Genome Conference held in April 2002, we first published the researching result on this aspect in the communication form of Posterly insert a base or one section of cDNA in the ORF, wrongly causing unwanted termination codon before the insertion, so the coding protein lacks the first part of the amino acids. For example, the GenBank Acc. No. AL096883 ( LOCUS No. HS323M22B) is wrong form of an experimentally verified human NM_012263 with mouse ortholog of BC010510 determined. (7) It may regard the polluted genomic sequence as complete gene cDNA sequence and anticipate the so-called single exon gene, even the real one, only a small ORF in the very long single exon mRNA, while there really exists termination code in the same phase of the upper part of the ORF initiation code, no other characters accord with the gene's condition. For example, LOC91126 is wrong form of ZNF362. (8) The anticipated genes only have ORF which has no EST proofs on both terminal sides. Depending on this ORF, a complete gene cDNA with double support of EST and human genome (there are termination codes at the same phase of the upper part of ORF) which indicates the anticipated ORF reference sequence may be incorrect. For example, LOC164395 may be wrong form of novel human gene bankit4590055. (9) A similar but smaller protein-coding gene is anticipated in the range of the human genome sequence that has the support of EST experimental proof, so other new anticipated gene may be incorrect. For example, LOC167563 may be wrong form of CMYA5. However, these errors can be corrected or avoided by using our strategy. Here we give one example in detail: Comparision of the sequence SPRYD1 with human hypothetical gene LOC123722. The TAA bases in the position of 478-480 in LOC123722 cDNA is redundant, which causes a reading frame shift in the translation of an alternative protein. The redundancy of GTAAA of LOC123722 is not supported by our experimental clone, and is almost fully rejected by human EST alignment, and is shown as the next intron sequence by genomic GT/AG organization analysis. The verification of cDNA or genomic DNA sequence of SPRYD1 implies that LOC123722 has a wrong stop codon within its ORF because of the prediction program, thus being not complete cds. To sum up, by combining bioinformatics analyses with experimental verification, we have found that there are many errors of at least nine kinds appeared in NCBI GENOME ANNOTATION PROJECT REFSEQs through BLAST of our cloned genes in non-redundant database, and our strategy is helpful in correcting them, such as LOC14907, LOC200084 and LOC91126 (all of them should be ZNF362, but are three different kinds of wrong forms of ZNF362), three model reference sequences predicted from NCBI contig NT_004511 by automated computational analysis using gene prediction method, or such as LOC124919 and LOC147007 (both should be C17orf32, but are two different kinds of wrong forms of C17orf32), two model reference sequences predicted from NCBI contig NT_010808 by automated computational analysis using gene prediction method. Therefore, the correct identification and annotation of novel human genes may be still a heavy task, which can be finished within a long period of time. So human genome coding regions annotated by computer should be used with caution. (ABSTRACT TRUNCATED)

Amino Acid Sequence↗
PubMed2026

Optimizing GRIDSS for clinical use: A targeted NGS filtering strategy for germline structural variant detection.

Detecting intermediate-sized structural variants (SVs) remains challenging in diagnostics, as tools for single-nucleotide and copy-number variants, particularly read-depth-based methods, are often insufficient. GRIDSS addresses this gap by integrating paired-end mapping, split-read analysis, and assembly-based approaches. However, its use in targeted sequencing and diagnostic workflows remains complex. NGS panel data from 9726 patients with suspected hereditary cancer were analyzed using GRIDSS. A filtering strategy was developed to prioritize clinically relevant germline SVs. Multiple parameter settings were tested to optimize performance. The initial dataset of 1,307,592 variants was reduced to 89 candidates after applying the selected filtering strategy. Of these, 24 had been previously detected by routine callers and were not further analyzed. Among the remaining 65, 13 were considered likely true positives after visual inspection using IGV. Experimental validation was performed by Sanger/Nanopore long-read sequencing for these variants, all of which were confirmed. Eight were classified as (likely) pathogenic, including two frameshift duplications in MSH6, one splicing variant in BARD1, and five mobile element insertions in APC, BRCA2, and PALB2. Altogether, GRIDSS implementation increased diagnostic yield while maintaining feasibility for diagnostic workflows. Comprehensive workflow scheme for germline structural variant detection and results in our diagnostic setting.

Humans↗
PubMed2002

Tight junction messenger RNA expression levels in bovine embryos are dependent upon the ability to compact and in vitro culture methods.

We have established a transcription map of individual bovine embryos using semiquantitative reverse transcriptase-polymerase chain reaction to detect the levels of six marker genes involved in early embryo differentiation. The critical step of compaction during preimplantation development is often not accomplished or it takes place for only a short period in in vitro generated embryos, which may result in reduced viability. Compaction is accompanied by the assembly of intercellular tight junctions (TJs) as a barrier against the extraembryonic environment and as a prerequisite for blastocele formation. In the present study, we have related the expression of TJ gene mRNA in individual bovine embryos to their developmental stage, their competence to undergo a clear period of compaction before blastocyst formation, and their in vitro or in vivo origin. Our results indicate that embryos that showed a detectable and well-formed compaction period in vitro are of similar quality to their in vivo counterparts. Starting from the same amount of maternal message, in vivo and in vitro development differ most during the critical period of the major switch from maternal to embryonic genomic control before a dramatic increase of TJ mRNAs occurs upon blastocyst formation. Failure to compact in vitro results in significant reduction of specific transcript levels, in a manner that depends on culture conditions, which may contribute to reduced viability. We conclude that TJ mRNA expression levels are sensitive to environmental conditions that may influence the developmental potential of bovine blastocysts.

Animals↗
PubMed2004

EST clustering error evaluation and correction.

MOTIVATION: The gene expression intensity information conveyed by (EST) Expressed Sequence Tag data can be used to infer important cDNA library properties, such as gene number and expression patterns. However, EST clustering errors, which often lead to greatly inflated estimates of obtained unique genes, have become a major obstacle in the analyses. The EST clustering error structure, the relationship between clustering error and clustering criteria, and possible error correction methods need to be systematically investigated. RESULTS: We identify and quantify two types of EST clustering error, namely, Type I and II in EST clustering using CAP3 assembling program. A Type I error occurs when ESTs from the same gene do not form a cluster whereas a Type II error occurs when ESTs from distinct genes are falsely clustered together. While the Type II error rate is <1.5% for both 5' and 3' EST clustering, the Type I error in the 5' EST case is approximately 10 times higher than the 3' EST case (30% versus 3%). An over-stringent identity rule, e.g., P >/= 95%, may even inflate the Type I error in both cases. We demonstrate that approximately 80% of the Type I error is due to insufficient overlap among sibling ESTs (ISO error) in 5' EST clustering. A novel statistical approach is proposed to correct ISO error to provide more accurate estimates of the true gene cluster profile.

Algorithms↗
PubMed2026

Hypervirulence-associated pseudo-compound transposons as fundamental mobile units driving cross-species virulence dissemination in Enterobacteriaceae.

BACKGROUND: The rapid global spread of hypervirulence in Enterobacteriaceae, particularly in carbapenem-resistant Klebsiella pneumoniae, poses a significant public health threat. However, the key genetic vehicles and mechanisms driving horizontal transfer of hypervirulence-associated genes (iucA, iroB, rmpA, rmpA2, and peg-344) remain poorly defined, limiting effective surveillance. METHODS: We performed a large-scale genomic survey of 2,869 virulence-associated plasmid sequences and 2,337 complete Enterobacteriaceae chromosomes. Using comparative genomics and evolutionary analyses, we systematically identified and characterized Hypervirulence-associated Pseudo-Compound Transposons (Hva-PCTs), defined as structured mobile elements in which hypervirulence-associated genes are flanked by insertion sequences. RESULTS: Our results demonstrate that hypervirulence-associated genes are transmitted primarily as discrete IS-bounded units, which we term Hva-PCTs. We identified 29 distinct plasmid-borne Hva-PCTs (pHva-PCTs) and 30 chromosomal Hva-PCTs (cHva-PCTs). These modules show clear species-specific patterns: iucA/iroB-associated Hva-PCTs mainly originate in Escherichia coli and spread through IncFIB-containing multi-replicon plasmids (commonly combined with IncFIC(FII) and/or IncFII, while rmpA/rmpA2/peg-344-containing modules originate in K. pneumoniae and are disseminated via IncHI1B/repB plasmids. Three Hva-PCTs were detected on both plasmids and chromosomes (xHva-PCTs). In one clinical K. pneumoniae isolate (LS356), the identical composite module was present on both replicons. Simpler sub-modules, such as ISKqu3-rmpA2-iucA_1-IS102 and IS102-rmpA-peg-344-iroB_1-IS1A, frequently co-occur on the same plasmid; when positioned in tandem, they reconstitute the full composite structure. This assembly pattern is further supported by a partial duplication event in plasmid pP901. CD-HIT clustering (80% nucleotide identity and 90% coverage) showed that 13 of 22 major clusters contained both plasmid and chromosomal copies, with intra-cluster identities >80% across multiple sequence types and host species. CONCLUSION: Hypervirulence-associated genes in Enterobacteriaceae are disseminated mainly as IS-flanked Hva-PCTs rather than solely through intact virulence plasmids. These modules exhibit strong but not absolute host specificity. The presence of identical Hva-PCTs on plasmids and chromosomes suggests inter-replicon mobility, while their stepwise assembly from simpler sub-modules highlights modular accretion as a key evolutionary process. Tracking Hva-PCTs as distinct mobile units may complement existing plasmid- and gene-centric surveillance approaches for hypervirulent and convergent strains. Experimental validation of their transposition activity and phenotypic effects is still required.

Virulence↗
PubMed2003

Evaluation of a modular strategy for the construction of novel polydactyl zinc finger DNA-binding proteins.

In previous studies, we have developed a technology for the rapid construction of novel DNA-binding proteins with the potential to recognize any unique site in a given genome. This technology relies on the modular assembly of modified zinc finger DNA-binding domains, each of which recognizes a three bp subsite of DNA. A complete set of 64 domains would provide comprehensive recognition of any desired DNA sequence, and new proteins could be assembled by any laboratory in a matter of hours. However, a critical parameter for this approach is the extent to which each domain functions as an independent, modular unit, without influence or dependence on its neighboring domains. We therefore examined the detailed binding behavior of several modularly assembled polydactyl zinc finger proteins. We first demonstrated that 80 modularly assembled 3-finger proteins can recognize their DNA target with very high specificity using a multitarget ELISA-based specificity assay. A more detailed analysis of DNA binding specificity for eight 3-finger proteins and two 6-finger proteins was performed using a target site selection assay. Results showed that the specificity of these proteins was as good or better than that of zinc finger proteins constructed using methods that allow for interdependency. In some cases, near perfect specificity was achieved. Complications due to target site overlap were found to be restricted to only one particular amino acid interaction (involving an aspartate in position 2 of the alpha-helix) that occurs in a minority of cases. As this is the first report of target site selection for designed, well characterized 6-finger proteins, unique insights are discussed concerning the relationship of protein length and specificity. These results have important implications for the design of proteins that can recognize extended DNA sequences, as well as provide insights into the general rules of recognition for naturally occurring zinc finger proteins.

DNA↗
PubMed2005

An orally bioavailable antipoxvirus compound (ST-246) inhibits extracellular virus formation and protects mice from lethal orthopoxvirus Challenge.

ST-246 is a low-molecular-weight compound (molecular weight = 376), that is potent (concentration that inhibited virus replication by 50% = 0.010 microM), selective (concentration of compound that inhibited cell viability by 50% = >40 microM), and active against multiple orthopoxviruses, including vaccinia, monkeypox, camelpox, cowpox, ectromelia (mousepox), and variola viruses. Cowpox virus variants selected in cell culture for resistance to ST-246 were found to have a single amino acid change in the V061 gene. Reengineering this change back into the wild-type cowpox virus genome conferred resistance to ST-246, suggesting that V061 is the target of ST-246 antiviral activity. The cowpox virus V061 gene is homologous to vaccinia virus F13L, which encodes a major envelope protein (p37) required for production of extracellular virus. In cell culture, ST-246 inhibited plaque formation and virus-induced cytopathic effects. In single-cycle growth assays, ST-246 reduced extracellular virus formation by 10 fold relative to untreated controls, while having little effect on the production of intracellular virus. In vivo oral administration of ST-246 protected BALB/c mice from lethal infection, following intranasal inoculation with 10x 50% lethal dose (LD(50)) of vaccinia virus strain IHD-J. ST-246-treated mice that survived infection acquired protective immunity and were resistant to subsequent challenge with a lethal dose (10x LD(50)) of vaccinia virus. Orally administered ST-246 also protected A/NCr mice from lethal infection, following intranasal inoculation with 40,000x LD(50) of ectromelia virus. Infectious virus titers at day 8 postinfection in liver, spleen, and lung from ST-246-treated animals were below the limits of detection (<10 PFU/ml). In contrast, mean virus titers in liver, spleen, and lung tissues from placebo-treated mice were 6.2 x 10(7), 5.2 x 10(7), and 1.8 x 10(5) PFU/ml, respectively. Finally, oral administration of ST-246 inhibited vaccinia virus-induced tail lesions in Naval Medical Research Institute mice inoculated via the tail vein. Taken together, these results validate F13L as an antiviral target and demonstrate that an inhibitor of extracellular virus formation can protect mice from orthopoxvirus-induced disease.

Administration, Oral↗