Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “antiviral development”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

Clinical research and drug development of antivirals in HIV: an industry perspective.

Clinical research can be viewed from three perspectives: research, patient care, and regulatory. Clinical research strategies can be either drug oriented, following the traditional phase I-II-III flow, or disease oriented. The drug-oriented strategy has as its goal regulatory approval, which means widespread patient-care usage. The disease-oriented strategy focuses on improving the overall care of the disease in question. At times, a dynamic tension exists between the two strategies. In HIV, as in all diseases, industry mainly is involved in drug-oriented studies emphasizing the regulatory perspective. In HIV a critical issue involves accelerated approval, following expanded access, based on surrogate markers. This initial approval is for end-stage therapy (the expanded access population). Additional claims require a full supplemental New Drug Application utilizing clinical end points. This leads to a situation in which the label, over time, becomes less relevant to how the drug is used in actual practice. This has caused concern among the patient advocates and is becoming a major challenge for the industry.

Antiviral Agents↗

Monitoring Influenza A Virus Entry Using Quantitative Fluorescence Microscopy.

Influenza A virus (IAV) is a major threat to global human health and is a topic of intense research. With the continuous problem of seasonal influenza and the threat of potential pandemics due to frequent emergence of new viral strains, development of new, broad-spectrum antivirals is an urgent priority. In antiviral development against influenza, the process of host cell entry of IAV is of particular interest as inhibiting the virus at the entry step should stop infection early on, blocking the downstream infection processes including viral replication and transcription. Therefore, a detailed understanding of the IAV entry processes is essential to illuminate virus-assisting host factors that can serve as potentially valuable targets for therapeutic interventions. To accelerate the identification of novel antivirals or host-directed targets that play essential role in IAV entry, quantitative assays that can be used to monitor the virus at sequential entry steps would be important for performing high-content genetic or inhibitor screens. In this chapter, we describe how IAV entry can be monitored at the sequential entry steps, spanning from the initial attachment of the virus particle to the cell surface to the transmission of the viral genome to the nucleus, by fluorescence microscopy. Further, we provide the methods to quantify the images acquired with high-content microscope for each of the major IAV entry steps. The fluorescence microscopy-based IAV entry assays and the image quantification methods described here can be used to boost our understanding of the virus-host cell interactions and can lead to the discovery of novel host-directed prophylactic or therapeutic interventions.

Humans↗

An overview of the evolution of enterovirus 71 and its clinical and public health significance.

Since its discovery in 1969, enterovirus 71 (EV71) has been recognised as a frequent cause of epidemics of hand-foot-and-mouth disease (HFMD) associated with severe neurological sequelae in a small proportion of cases. There has been a significant increase in EV71 epidemic activity throughout the Asia-Pacific region since 1997. Recent HFMD epidemics in this region have been associated with a severe form of brainstem encephalitis associated with pulmonary oedema and high case-fatality rates. The emergence of large-scale epidemic activity in the Asia-Pacific region has been associated with the circulation of three genetic lineages that appear to be undergoing rapid evolutionary change. Two of these lineages (B3 and B4) have not been described previously and appear to have arisen from an endemic focus in equatorial Asia, which has served as a source of virus for HFMD epidemics in Malaysia, Singapore and Australia. The third lineage (C2) has previously been identified [Brown, B.A. et al. (1999) J. Virol. 73, 9969-9975] and was primarily responsible for the large HFMD epidemic in Taiwan during 1998. As EV71 appears not to be susceptible to newly developed antiviral agents and a vaccine is not currently available, control of EV71 epidemics through high-level surveillance and public health intervention needs to be maintained and extended throughout the Asia-Pacific region. Future research should focus on (1) understanding the molecular genetics of EV71 virulence, (2) identification of the receptor(s) for EV71, (3) development of antiviral agents to ameliorate the severity of neurological disease and (4) vaccine development to control epidemics. Following the successful experience of the poliomyelitis control programme, it may be possible to control EV71 epidemics if an effective live-attenuated vaccine is developed.

Amino Acid Sequence↗

Computational design of antiviral RNA interference strategies that resist human immunodeficiency virus escape.

Recently developed antiviral strategies based upon RNA interference (RNAi), which harnesses an innate cellular system for the targeted down-regulation of gene expression, appear highly promising and offer alternative approaches to conventional highly active antiretroviral therapy or efforts to develop an AIDS vaccine. However, RNAi is faced with several challenges that must be overcome to fully realize its promise. Specifically, it degrades target RNA in a highly sequence-specific manner and is thus susceptible to viral mutational escape, and there are also challenges in delivery systems to induce RNAi. To aid in the development of anti-human immunodeficiency virus (anti-HIV) RNAi therapies, we have developed a novel stochastic computational model that simulates in molecular-level detail the propagation of an HIV infection in cells expressing RNAi. The model provides quantitative predictions on how targeting multiple locations in the HIV genome, while keeping the overall RNAi strength constant, significantly improves efficacy. Furthermore, it demonstrates that delivery systems must be highly efficient to preclude leaving reservoirs of unprotected cells where the virus can propagate, mutate, and eventually overwhelm the entire system. It also predicts how therapeutic success depends upon a relationship between RNAi strength and delivery efficiency and uniformity. Finally, targeting an essential viral element, in this case the HIV TAR region, can be highly successful if the RNAi target sequence is correctly selected. In addition to providing specific predictions for how to optimize a clinical therapy, this system may also serve as a future tool for investigating more fundamental questions of viral evolution.

Computational Biology↗

Antiviral drug discovery and development: where chemistry meets with biomedicine.

The successful development of antiviral drugs is highly dependent on a close interaction and collaboration between the chemist and the biologist (biomedic). This is illustrated by a number of representative examples: S-adenosylhomocysteine (SAH) hydrolase inhibitors which display broad-spectrum antiviral activity, bromovinyldeoxyuridine (BVDU) and derivatives thereof, that are highly selective inhibitors of varicella-zoster virus (VZV), (dideoxy)nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) which are now widely used in the treatment of HIV infections (AIDS), the bicyclams (i.e. AMD3100) which were originally discovered as anti-HIV agents, then found to be potent CXCR4 antagonists and now being pursued for a number of indications such as stem cell mobilization, and the acyclic nucleoside phosphonates which have heralded a new strategy for the treatment of various DNA virus (herpes-, adeno-, pox-, papillomavirus) infections (cidofovir), hepatitis B (adefovir) and AIDS (tenofovir).

Animals↗

Inhibition of transcription and translation in Sindbis virus-infected cells.

Alphaviruses are arthropod-borne viruses (arboviruses) that include a number of important human and animal pathogens. The natural transmission cycle of alphaviruses requires their presence at high concentrations in the blood of amplification hosts for efficient infection of mosquito vectors. The high-titer viremia development implies multiple rounds of infection that proceed in the background of the developing antiviral cell response aimed at blocking virus spread on an organismal level. Therefore, as for many viruses, if not most of them, alphaviruses have evolved mechanisms directed toward downregulating different components of the antiviral cell reaction and increasing viremia to a level sufficient for the next round of transmission. Using Sindbis virus (SIN) as a model, we demonstrated that (i) the replication of wild-type SIN strongly affects major cellular processes, e.g., transcription and translation of mRNAs; (ii) transcriptional and translational shutoffs are distinctly independent events, and their development can be differentially manipulated by creating different mutations in SIN nonstructural protein nsP2; and (iii) inhibition of transcription, but not translation, is a critical mechanism that SIN employs to suppress the expression of cellular viral stress-inducible genes in cells of vertebrate origin. Downregulation of transcription of all of the cellular mRNAs appears to be a very efficient means of reducing the development of an antiviral response. The ability to cause transcriptional shutoff may partially determine SIN host range and replication in particular tissues.

Animals↗

A continuous nonradioactive assay for RNA-dependent RNA polymerase activity.

Current assays for the activity of viral RNA-dependent RNA polymerases (RdRps) are inherently end-point measurements, often requiring the use of radiolabeled or chemically modified nucleotides to detect reaction products. In an effort to improve the characterization of polymerases that are essential to the life cycle of RNA viruses and develop antiviral therapies that target these enzymes, a continuous nonradioactive assay was developed to monitor the activity of RdRps by measuring the release of pyrophosphate (PP(i)) generated during nascent strand synthesis. A coupled-enzyme assay method based on the chemiluminescent detection of PP(i), using ATP sulfurylase and firefly luciferase, was adapted to monitor poliovirus 3D polymerase (3D(pol)) and the hepatitis C virus nonstructural protein 5B (NS5B) RdRp reactions. Light production was dependent on RdRp and sensitive to the concentration of oligonucleotide primer directing RNA synthesis. The assay system was found to be amenable to sensitive kinetic studies of RdRps, requiring only 6nM 3D(pol) to obtain a reliable estimate of the initial velocity in as little as 4 min. The assay can immediately accommodate the use of both homopolymer and heteropolymer RNA templates lacking uridylates and can be adapted to RNA templates containing uridine by substituting alpha-thio ATP for ATP. The low background signal produced by other NTPs can be corrected from no enzyme (RdRp) controls. The effect of RdRp/RNA template preincubation was assessed using NS5B and a homopolymer RNA template and a time-dependent increase of RdRp activity was observed. Progress curves for a chain terminator (3(')-deoxyguanosine 5(')-triphosphate) and an allosteric NS5B inhibitor demonstrated the predicted time- and dose-dependent reductions in signal. This assay should facilitate detailed kinetic studies of RdRps and their potential inhibitors using either standard or single-nucleotide approaches.

Allosteric Regulation↗

Development of new antivirals for herpesviruses.

The long-term treatment of herpesvirus infections with current antivirals in immunocompromised hosts leads to the development of drug-resistant viruses. Because nearly all currently available antivirals finally target viral DNA polymerase, virus resistant to one drug often shows cross-resistance to other drugs. In addition, nearly all the antivirals show various kinds of side effects or poor bioavailability. This evidence highlights the need for developing new antivirals for herpesviruses that have the different viral targets. Recently, high-throughput screening of large compound collections for inhibiting specific viral enzymes, or in vitro cell culture assay, has identified several new antivirals that target different viral proteins. These include the inhibitors of helicase/primase complex, terminase complex, portal protein and UL97 protein kinase. In addition, non-nucleoside inhibitors for viral DNA polymerase have been also developed. This review will focus on these new compounds that directly inhibit viral replication.

Antiviral Agents↗

Enhanced establishment of a virus carrier state in adult CD4+ T-cell-deficient mice.

CD4+ T cells play an important role in regulating the immune response; their contribution to virus clearance is variable. Mice that lack CD4+ T cells (CD4-/- mice) and are therefore unable to produce neutralizing antibodies cleared viscero-lymphotropic lymphocytic choriomeningitis virus (LCMV) strain WE when infected intravenously with a low dose (2 x 10(2) PFU) because of an effective CD8+ cytotoxic T-cell (CTL) response. In contrast, infection with a high dose (2 x 10(6) PFU) of LCMV strain WE led to expansion of antiviral CTL, which disappeared in CD4-/- mice; in contrast, CD4+ T-cell-competent mice developed antiviral memory CTL. This exhaustion of specific CTL caused viral persistence in CD4-/- mice, whereas CD4+ T-cell-competent mice eliminated the virus. After infection of CD4-/- mice with the faster-replicating LCMV strain DOCILE, abrogation of CTL response and establishment of viral persistence developed after infection with a low dose (5 x 10(2) PFU), i.e., an about 100-fold lower dose than in CD(4+)-competent control mice. These results show that absence of T help enhances establishment of an LCMV carrier state in selected situations.

Animals↗

Liver-targeted antiviral nucleosides: enhanced antiviral activity of phosphatidyl-dideoxyguanosine versus dideoxyguanosine in woodchuck hepatitis virus infection in vivo.

It would be desirable to develop antiviral agents that can be targeted to liver to enhance their antiviral effects and reduce nonhepatic toxicity. 2',3'-Dideoxyguanosine (ddG) has been found to be a potent and selective antihepatitis B agent both in vitro and in vivo. To evaluate ddG and its liver-targeted analog, we synthesized a series of phosphatidyl-ddGs and incubated them with 2.2.15 cells, which chronically produce hepatitis B virus. 1,2-Dipalmitoylphosphatidyl-dideoxyguanosine (DPP-ddG) inhibited the production of hepatitis B virus (HBV) DNA in the culture medium by 90% at 4.5 mumol/L versus 9.1 mumol/L for ddG, while the liposome vehicle itself had no effect. To compare the efficacy of free ddG with its lipid prodrug in vivo, we treated woodchucks that were experimentally infected with woodchuck hepatitis virus (WHV) for 4 weeks by intraperitoneal injection of 2.6 mumol/kg/d of free ddG or liposomes containing 2.6 mumol/kg/d of DPP-ddG. Liposomal DPP-ddG reduced serum WHV DNA by 23- to 46-fold at the end of the fourth week, while free ddG reduced serum WHV DNA by 2.2- to 10.4-fold. Treatment with small unilamellar liposomes containing DPP-ddG is substantially more effective than free ddG in reducing WHV-DNA levels in serum in WHV-infected woodchucks. The data suggest that the use of lipid prodrugs to target the liver may be useful in enhancing antiviral therapy of hepatitis.

Animals↗

Influence of Major Histocompatibility Complex (MHC) Diversity on Immune Modulation, Pathogenesis, and Control of Lumpy Skin Disease Virus.

INTRODUCTION: Lumpy Skin Disease Virus (LSDV), a member of the genus Capripoxvirus within the family Poxviridae, is an economically important transboundary viral pathogen affecting cattle and water buffalo. The disease causes severe production losses through decreased milk yield, infertility, hide damage, reduced growth performance, and occasional mortality. The rapid geographic spread of LSDV, together with its vectorborne transmission and emerging recombinant strains, has intensified the need for improved understanding of viral pathogenesis, host immune responses, and effective prevention strategies. In particular, the role of the bovine Major Histocompatibility Complex (BoLA/MHC) in regulating antiviral immunity, disease susceptibility, and vaccine responsiveness has gained increasing scientific attention. METHODS: This review summarises the published literature related to the epidemiology, transmission, structure, pathogenesis, diagnosis, prevention, and control of LSDV, with special emphasis on the immunological and molecular role of bovine MHC molecules. Relevant studies concerning BoLA-mediated antigen presentation, immunoinformaticsbased epitope prediction, vaccine development, antiviral drug repurposing, molecular docking, genomic surveillance, and diagnostic approaches, including PCR- and ELISAbased assays, were critically evaluated. Recent advances in computational biology, molecular virology, and host-pathogen interaction studies were also reviewed. RESULTS: The reviewed studies demonstrate that Lumpy Skin Disease Virus (LSDV) possesses a complex double-stranded DNA genome enabling immune modulation and efficient transmission through arthropod vectors such as mosquitoes, ticks, and biting flies. Disease progression involves systemic viral replication, vascular injury, dermal necrosis, and inflammatory skin lesions. Real-time PCR remains the most sensitive diagnostic method for early detection, while ELISA supports surveillance. Evidence highlights the central role of bovine Major Histocompatibility Complex (BoLA) molecules in antigen presentation and T-cell activation. Computational studies identified promising BoLA-binding epitopes and repurposed antiviral candidates, including ivermectin, theaflavin, canagliflozin, and tepotinib, for future therapeutic development. DISCUSSION: Current evidence indicates that effective LSDV control requires integration of molecular diagnostics, vector management, vaccination, and host immunogenetics. BoLAguided immunoinformatics provides promising opportunities for developing multi-epitope vaccines, although experimental validation remains essential. Similarly, repurposed antiviral candidates require comprehensive in vivo and pharmacological evaluation before clinical application. Future research should focus on elucidating viral immune-evasion mechanisms, validating predicted epitopes, and translating computational findings into practical vaccines and therapeutics for sustainable disease control. CONCLUSION: Lumpy Skin Disease continues to pose a major threat to global cattle health and livestock economies. Advances in molecular diagnostics, genomic surveillance, antiviral drug discovery, and BoLA-guided vaccine design provide promising opportunities for improved disease control. Understanding the interaction between LSDV and the bovine MHC system is essential for developing next-generation vaccines, immunotherapeutics, and precision disease-management strategies. Future research should prioritise experimental validation of predicted epitopes, large-scale vaccine trials, and mechanistic studies on host-virus immune interactions to establish effective and sustainable global control programs for LSDV.

BoLA↗

Emerging techniques of CRISPR/Cas system in antiviral therapy and diagnostics: Applications, limitations, and translational perspectives.

The CRISPR/Cas (clustered regularly interspaced short palindromic repeats) system is a versatile technology for developing antiviral medicines and editing viral genomes in both diagnostics and vaccine synthesis. Emerging insights into class 2 effectors, such as Cas9, Cas12, and Cas13, which target viral DNA and RNA, have revolutionized vaccines against viruses such as HIV, HPV, HBV, and EBV. Innovative diagnostic techniques such as SHERLOCK, DETECTR, and FELUDA have demonstrated system's diversity and accuracy in detecting the virus markers, supporting clinical decision-making, indicating adaptability and precision of CRISPR. This review critically evaluates CRISPR's role in RNA editing, emphasizing its importance for functional genomics and development of recombinant vaccines. Translational challenges are critically discussed, including off-target effects, delivery limitations, and ethical issues, for which unique approaches such as high-fidelity Cas variants, non-viral delivery systems, and bioethical frameworks are evaluated to address these limitations. This review also covers other social implications, such as accessibility and biosecurity risks, associated with CRISPR technologies Collectively, these advances underscore the transformative potential of CRISPR technologies in shaping next-generation antiviral diagnostics and therapeutics.

CRISPR-Cas Systems↗