RNA Virus Infections
DEAD-box RNA Helicases
Interferon-beta
Immunity, Innate
Virus Replication
RNA
RNA, Small Interfering
Vaccinia virus
Receptors, Virus
RNA, Double-Stranded
RNA Editing
RNA Splicing
Sindbis Virus
Molecular Sequence Data
Influenza A Virus, H1N1 Subtype
Virus Assembly
Virus Shedding
Antiviral Agents
Defective Viruses
Measles virus
Respiratory Syncytial Viruses
West Nile virus
Rabies virus
RNA, Messenger
Respiratory Syncytial Virus Infections
Simian virus 40
Influenza A Virus, H5N1 Subtype
Vesicular stomatitis Indiana virus
DNA-Directed RNA Polymerases
RNA, Ribosomal
Vero Cells
Hepatitis B virus
Influenza A Virus, H3N2 Subtype
RNA Interference
Cercopithecus aethiops
RNA, Bacterial
Hepacivirus
Comparative study of viral encephalopathy and retinopathy in juvenile sea bass Dicentrarchus labrax infected in different ways. (1/218)
The transmission of viral encephalopathy and retinopathy (VER) was investigated in juvenile sea bass (3 g) Dicentrarchus labrax by using cell culture supernatant (SSN-1 cell line) containing nodavirus. Five methods of infection were tested: intramuscular injection (IM), intraperitoneal injection (IP), oral infection, bath exposure and cohabitation of healthy fish with infected fish. Some differences were observed in time of disease onset and severity of symptoms depending on the mode of infection used. Clinical symptoms such as whirling swimming and lethargic or hyperactive behaviour were generally reproduced, except for fish infected via oral and IP infection. First mortalities occurred 3 d after IM and IP infection and 6 d after for the other modes of infection. Cumulative mortalities were also variable: 100% after IM infection, 10% after IP infection, 32% for bath exposure, 43% after cohabitation and 24% via oral infection. Histopathologically, vacuolation was observed in the central nervous tissues and in the retina. The observed lesions were more or less severe depending on the mode of infection, the sampling time and the organs: lesions on the surviving fish (42 days post infection, d p.i.) seemed to be generally more conspicuous in the retina than in the brain of the same fish. In most cases, the presence of nodavirus was confirmed in the same samples of brain and retina by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). The virus was not detected in other organs examined. The present results suggest that 2 forms of VER can be induced: IM injection leads to an acute form (severe nervous disorders with high and fast mortality) whereas oral infection, bath exposure and cohabitation induce a subacute form (less severe disorders and weak daily mortality). This experiment demonstrates experimentally induced horizontal transmission of VER in sea bass for the first time. (+info)Transmission of viral encephalopathy and retinopathy (VER) to yolk-sac larvae of the Atlantic halibut Hippoglossus hippoglossus: occurrence of nodavirus in various organs and a possible route of infection. (2/218)
The susceptibility of the Atlantic halibut Hippoglossus hippoglossus yolk-sac larvae to viral encephalopathy and retinopathy (VER) was investigated by waterborne challenge experiments with nodavirus. Transfer of VER was indicated by several lines of evidence. A significantly higher cumulative mortality was observed after challenge with virus compared to mock challenge, and increasing doses of virus resulted in shorter incubation periods. When the challenge was performed on the day after hatching, the time from inoculation to the time when 50% of the larvae were dead (LT50) ranged from 26 to 32 d. Postponement of challenge for 13 d reduced the LT50 to 14 d, indicating that the susceptibility of the larvae to the present nodavirus strain was low during the first 2 wk after hatching. The progression of the infection was monitored by sequential immunohistochemistry and electron microscopy. On Day 18 after hatching the initial signs of infection were observed as a prominent focus of immunolabelling in the caudal part of the brain stem. In the same larvae immunolabelled single cell lesions were observed in the stratified epithelium of the cranial part of the intestine. The portal of entry into the larvae may thus have been the intestinal epithelium, while the route of infection to the CNS may have been axonal transport to the brain stem through cranial nerves such as the vagus nerves. Later in the infection, lesions became more severe and widespread and were also found throughout the brain and spinal cord and in the retina, cranial ganglia, intestine, liver, olfactory epithelium, yolk-sac epithelium, gills and pectoral fins. The mortality in all virus-challenged groups was 100%. This study thus demonstrates that the present nodavirus strain is able to replicate and cause VER in Atlantic halibut yolk-sac larvae at temperatures as low as 6 degrees C. (+info)Pathogenesis of borna disease virus: granulocyte fractions of psychiatric patients harbor infectious virus in the absence of antiviral antibodies. (3/218)
Borna disease virus (BDV) causes acute and persistent infections in various vertebrates. During recent years, BDV-specific serum antibodies, BDV antigen, and BDV-specific nucleic acid were found in humans suffering from psychiatric disorders. Furthermore, viral antigen was detected in human autopsy brain tissue by immunohistochemical staining. Whether BDV infection can be associated with psychiatric disorders is still a matter of debate; no direct evidence has ever been presented. In the present study we report on (i) the detection of BDV-specific nucleic acid in human granulocyte cell fraction from three different psychiatric patients and (ii) the isolation of infectious BDV from these cells obtained from a patient with multiple psychiatric disorders. In leukocyte preparations other than granulocytes, either no BDV RNA was detected or positive PCR results were obtained only if there was at least 20% contamination with granulocytes. Parts of the antigenome of the isolated virus were sequenced, demonstrating the close relationship to the prototype BDV strains (He/80 and strain V) as well as to other human virus sequences. Our data provide strong evidence that cells in the granulocyte fraction represent the major if not the sole cell type harboring BDV-specific nucleic acid in human blood and contain infectious virus. In contrast to most other reports of putative human isolates, where sequences are virtually identical to those of the established laboratory strains, this isolate shows divergence in the region previously defined as variable in BDV from naturally infected animals. (+info)Molecular characterization of a ranavirus isolated from largemouth bass Micropterus salmoides. (4/218)
An iridovirus, isolated from largemouth bass Micropterus salmoides following a die-off among adult fish and provisionally designated largemouth bass virus (LMBV), was characterized by analysis of viral protein synthesis in infected cells, viral DNA restriction fragment length polymorphisms (RFLP), and sequence determination of the major capsid protein and viral DNA methyltransferase genes. All 3 approaches yielded results consistent with the suggestion that LMBV was a member of the genus Ranavirus. Moreover, LMBV was nearly identical to 2 isolates from Southeast Asia which had been previously detected in imported ornamental fish. It remains to be determined whether infection of largemouth bass resulted from exposure to an imported virus, or whether the presence of similar viruses in southeast Asia and the southeastern United States indicates that iridovirus species are not geographically limited as suggested earlier, but rather globally distributed. (+info)Emerging infectious diseases and amphibian population declines. (5/218)
We review recent research on the pathology, ecology, and biogeography of two emerging infectious wildlife diseases, chytridiomycosis and ranaviral disease, in the context of host-parasite population biology. We examine the role of these diseases in the global decline of amphibian populations and propose hypotheses for the origins and impact of these panzootics. Finally, we discuss emerging infectious diseases as a global threat to wildlife populations. (+info)Pathogenicity of nodavirus strains from striped jack Pseudocaranx dentex and Atlantic halibut Hippoglossus hippoglossus, studied by waterborne challenge of yolk-sac larvae of both teleost species. (6/218)
The present study shows that differences in pathogenicity exist among fish nodavirus strains. In challenge trials, a Japanese strain (SJ93Nag) was highly virulent to larvae of the striped jack Pseudocaranx dentex but replication was not detected in larvae of Atlantic halibut Hippoglossus hippoglossus at 6 degrees C. Conversely, a Norwegian nodavirus strain (AH95NorA) that was highly virulent to the Atlantic halibut larvae did not replicate in striped jack larvae at 20 degrees C. Occurrence of the disease viral encephalopathy and retinopathy (VER) and cumulative mortality were significantly different in the 2 species when challenged with the 2 nodavirus strains. The presence of nodavirus in nervous tissue was monitored by immunohistochemical methods. Our results support the view that the genetic diversity among nodavirus strains reflects the existence of different viral phenotypes which may be adapted to infect different host species and/or for replicating at different temperatures. Fish nodaviruses represent surveyable pathogens well suited for studying the relation between viral genotypic and phenotypic properties such as host specificity, temperature optima, neuroinvasiveness and neurovirulence. (+info)Surface disinfection of Atlantic halibut Hippoglossus hippoglossus eggs with ozonated sea-water inactivates nodavirus and increases survival of the larvae. (7/218)
Disinfection by ozonation of sea-water may reduce the risk of transmission of nodavirus, a major fish pathogen, via Atlantic halibut Hippoglossus hippoglossus eggs. In the present study, eggs at 4 d prior to hatching were exposed to nodavirus and then to ozonated sea-water using different concentrations (0.3 to 10 mg l-1) and exposure times (0.5 to 10 min). None of the larvae from virus-exposed eggs washed with ozonated sea-water developed viral encephalopathy and retinopathy (VER), which was detected in all dead larvae from eggs exposed to nodavirus but not washed with ozonated sea-water. In the non-treated control group about 20% of the dead larvae developed the disease. This suggests that the halibut eggs taken from a large-scale production facility were already contaminated with nodavirus. The egg groups which had been treated with 4 mg O3 l-1 for 0.5 min or with lower total ozone exposures had a higher survival and no adverse effects on the development of the larvae after hatching were observed. Although a slight delay in hatching was found, after 2 d the cumulative hatching had normalised. In the egg groups with high total exposure (4 mg O3 l-1 for 1 min or higher total ozone exposures) a pronounced negative effect on hatching was observed. Our results indicate that the egg surface may be important in the transfer of nodavirus and that nodavirus associated with the surface of the egg may be inactivated by ozonated sea-water. (+info)Enteric virus infections and diarrhea in healthy and human immunodeficiency virus-infected children. (8/218)
Forty-three stool samples from 27 human immunodeficiency virus (HIV)-seropositive children and 38 samples from 38 HIV-negative children, collected during a 15-month period, were examined for enteric viruses. Diagnostic assays included enzyme immunoassays for rotavirus, adenovirus, and Norwalk virus; polyacrylamide gel electrophoresis for picobirnavirus and atypical rotavirus; and PCR for astrovirus and enterovirus. Specimens from HIV-positive children were more likely than those of HIV-negative children to have enterovirus (56 versus 21%; P < 0.0002) and astrovirus (12 versus 0%; P < 0.02), but not rotavirus (5 versus 8%; P > 0.5). No adenoviruses, picobirnaviruses, or Norwalk viruses were found. The rates of virus-associated diarrhea were similar among HIV-positive and HIV-negative children. Enteroviruses were excreted for up to 6 months in HIV-positive children; however, no evidence for prolonged excretion of poliovirus vaccine was observed. These results suggest that although infection with enterovirus and astrovirus may be frequent in HIV-infected children, enteric viruses are not associated with the diarrhea frequently suffered by these children. (+info)RNA virus infections refer to diseases or conditions caused by the invasion and replication of RNA (Ribonucleic acid) viruses in host cells. These viruses use RNA as their genetic material, which is different from DNA (Deoxyribonucleic acid) viruses. Upon entering a host cell, the RNA virus releases its genetic material, which then uses the host cell's machinery to produce new viral components and replicate. This process can lead to various outcomes, depending on the specific virus and the host's immune response:
1. Asymptomatic infection: Some RNA virus infections may not cause any noticeable symptoms and may only be discovered through diagnostic testing.
2. Acute infection: Many RNA viruses cause acute infections, characterized by the rapid onset of symptoms that typically last for a short period (days to weeks). Examples include the common cold (caused by rhinoviruses), influenza (caused by orthomyxoviruses), and some gastrointestinal infections (caused by noroviruses or rotaviruses).
3. Chronic infection: A few RNA viruses can establish chronic infections, where the virus persists in the host for an extended period, sometimes leading to long-term health complications. Examples include HIV (Human Immunodeficiency Virus), HCV (Hepatitis C Virus), and HTLV-1 (Human T-lymphotropic virus type 1).
4. Latent infection: Some RNA viruses, like herpesviruses, can establish latency in the host, where they remain dormant for extended periods but can reactivate under certain conditions, causing recurrent symptoms or diseases.
5. Oncogenic potential: Certain RNA viruses have oncogenic properties and can contribute to the development of cancer. For example, retroviruses like HTLV-1 can cause leukemia and lymphoma by integrating their genetic material into the host cell's DNA and altering gene expression.
Treatment for RNA virus infections varies depending on the specific virus and the severity of the infection. Antiviral medications, immunotherapy, and supportive care are common treatment strategies. Vaccines are also available to prevent some RNA virus infections, such as measles, mumps, rubella, influenza, and hepatitis A and B.
RNA viruses are a type of virus that contain ribonucleic acid (RNA) as their genetic material, as opposed to deoxyribonucleic acid (DNA). RNA viruses replicate by using an enzyme called RNA-dependent RNA polymerase to transcribe and replicate their RNA genome.
There are several different groups of RNA viruses, including:
1. Negative-sense single-stranded RNA viruses: These viruses have a genome that is complementary to the mRNA and must undergo transcription to produce mRNA before translation can occur. Examples include influenza virus, measles virus, and rabies virus.
2. Positive-sense single-stranded RNA viruses: These viruses have a genome that can serve as mRNA and can be directly translated into protein after entry into the host cell. Examples include poliovirus, rhinoviruses, and coronaviruses.
3. Double-stranded RNA viruses: These viruses have a genome consisting of double-stranded RNA and use a complex replication strategy involving both transcription and reverse transcription. Examples include rotaviruses and reoviruses.
RNA viruses are known to cause a wide range of human diseases, ranging from the common cold to more severe illnesses such as hepatitis C, polio, and COVID-19. Due to their high mutation rates and ability to adapt quickly to new environments, RNA viruses can be difficult to control and treat with antiviral drugs or vaccines.
DEAD-box RNA helicases are a family of proteins that are involved in unwinding RNA secondary structures and displacing proteins bound to RNA molecules. They get their name from the conserved amino acid sequence motif "DEAD" (Asp-Glu-Ala-Asp) found within their catalytic core, which is responsible for ATP-dependent helicase activity. These enzymes play crucial roles in various aspects of RNA metabolism, including pre-mRNA splicing, ribosome biogenesis, translation initiation, and RNA decay. DEAD-box helicases are also implicated in a number of human diseases, such as cancer and neurological disorders.
Interferon-beta (IFN-β) is a type of cytokine - specifically, it's a protein that is produced and released by cells in response to stimulation by a virus or other foreign substance. It belongs to the interferon family of cytokines, which play important roles in the body's immune response to infection.
IFN-β has antiviral properties and helps to regulate the immune system. It works by binding to specific receptors on the surface of cells, which triggers a signaling cascade that leads to the activation of genes involved in the antiviral response. This results in the production of proteins that inhibit viral replication and promote the death of infected cells.
IFN-β is used as a medication for the treatment of certain autoimmune diseases, such as multiple sclerosis (MS). In MS, the immune system mistakenly attacks the protective coating around nerve fibers in the brain and spinal cord, causing inflammation and damage to the nerves. IFN-β has been shown to reduce the frequency and severity of relapses in people with MS, possibly by modulating the immune response and reducing inflammation.
It's important to note that while IFN-β is an important component of the body's natural defense system, it can also have side effects when used as a medication. Common side effects of IFN-β therapy include flu-like symptoms such as fever, chills, and muscle aches, as well as injection site reactions. More serious side effects are rare but can occur, so it's important to discuss the risks and benefits of this treatment with a healthcare provider.
Innate immunity, also known as non-specific immunity or natural immunity, is the inherent defense mechanism that provides immediate protection against potentially harmful pathogens (like bacteria, viruses, fungi, and parasites) without the need for prior exposure. This type of immunity is present from birth and does not adapt to specific threats over time.
Innate immune responses involve various mechanisms such as:
1. Physical barriers: Skin and mucous membranes prevent pathogens from entering the body.
2. Chemical barriers: Enzymes, stomach acid, and lysozyme in tears, saliva, and sweat help to destroy or inhibit the growth of microorganisms.
3. Cellular responses: Phagocytic cells (neutrophils, monocytes, macrophages) recognize and engulf foreign particles and pathogens, while natural killer (NK) cells target and eliminate virus-infected or cancerous cells.
4. Inflammatory response: When an infection occurs, the innate immune system triggers inflammation to increase blood flow, recruit immune cells, and remove damaged tissue.
5. Complement system: A group of proteins that work together to recognize and destroy pathogens directly or enhance phagocytosis by coating them with complement components (opsonization).
Innate immunity plays a crucial role in initiating the adaptive immune response, which is specific to particular pathogens and provides long-term protection through memory cells. Both innate and adaptive immunity work together to maintain overall immune homeostasis and protect the body from infections and diseases.
A viral RNA (ribonucleic acid) is the genetic material found in certain types of viruses, as opposed to viruses that contain DNA (deoxyribonucleic acid). These viruses are known as RNA viruses. The RNA can be single-stranded or double-stranded and can exist as several different forms, such as positive-sense, negative-sense, or ambisense RNA. Upon infecting a host cell, the viral RNA uses the host's cellular machinery to translate the genetic information into proteins, leading to the production of new virus particles and the continuation of the viral life cycle. Examples of human diseases caused by RNA viruses include influenza, COVID-19 (SARS-CoV-2), hepatitis C, and polio.
A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.
Virus replication is the process by which a virus produces copies or reproduces itself inside a host cell. This involves several steps:
1. Attachment: The virus attaches to a specific receptor on the surface of the host cell.
2. Penetration: The viral genetic material enters the host cell, either by invagination of the cell membrane or endocytosis.
3. Uncoating: The viral genetic material is released from its protective coat (capsid) inside the host cell.
4. Replication: The viral genetic material uses the host cell's machinery to produce new viral components, such as proteins and nucleic acids.
5. Assembly: The newly synthesized viral components are assembled into new virus particles.
6. Release: The newly formed viruses are released from the host cell, often through lysis (breaking) of the cell membrane or by budding off the cell membrane.
The specific mechanisms and details of virus replication can vary depending on the type of virus. Some viruses, such as DNA viruses, use the host cell's DNA polymerase to replicate their genetic material, while others, such as RNA viruses, use their own RNA-dependent RNA polymerase or reverse transcriptase enzymes. Understanding the process of virus replication is important for developing antiviral therapies and vaccines.
RNA (Ribonucleic Acid) is a single-stranded, linear polymer of ribonucleotides. It is a nucleic acid present in the cells of all living organisms and some viruses. RNAs play crucial roles in various biological processes such as protein synthesis, gene regulation, and cellular signaling. There are several types of RNA including messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), small nuclear RNA (snRNA), microRNA (miRNA), and long non-coding RNA (lncRNA). These RNAs differ in their structure, function, and location within the cell.
Small interfering RNA (siRNA) is a type of short, double-stranded RNA molecule that plays a role in the RNA interference (RNAi) pathway. The RNAi pathway is a natural cellular process that regulates gene expression by targeting and destroying specific messenger RNA (mRNA) molecules, thereby preventing the translation of those mRNAs into proteins.
SiRNAs are typically 20-25 base pairs in length and are generated from longer double-stranded RNA precursors called hairpin RNAs or dsRNAs by an enzyme called Dicer. Once generated, siRNAs associate with a protein complex called the RNA-induced silencing complex (RISC), which uses one strand of the siRNA (the guide strand) to recognize and bind to complementary sequences in the target mRNA. The RISC then cleaves the target mRNA, leading to its degradation and the inhibition of protein synthesis.
SiRNAs have emerged as a powerful tool for studying gene function and have shown promise as therapeutic agents for a variety of diseases, including viral infections, cancer, and genetic disorders. However, their use as therapeutics is still in the early stages of development, and there are challenges associated with delivering siRNAs to specific cells and tissues in the body.
Vaccinia virus is a large, complex DNA virus that belongs to the Poxviridae family. It is the virus used in the production of the smallpox vaccine. The vaccinia virus is not identical to the variola virus, which causes smallpox, but it is closely related and provides cross-protection against smallpox infection.
The vaccinia virus has a unique replication cycle that occurs entirely in the cytoplasm of infected cells, rather than in the nucleus like many other DNA viruses. This allows the virus to evade host cell defenses and efficiently produce new virions. The virus causes the formation of pocks or lesions on the skin, which contain large numbers of virus particles that can be transmitted to others through close contact.
Vaccinia virus has also been used as a vector for the delivery of genes encoding therapeutic proteins, vaccines against other infectious diseases, and cancer therapies. However, the use of vaccinia virus as a vector is limited by its potential to cause adverse reactions in some individuals, particularly those with weakened immune systems or certain skin conditions.
A plant virus is not defined in medical terms, as viruses are typically considered within the context of living organisms and plants are not classified as such. However, I can provide a general virology definition for you:
Plant viruses are small infectious agents that consist of nucleic acid (DNA or RNA) enclosed in a protein coat. They infect various plant species, causing a wide range of symptoms and diseases, which can result in significant economic losses in agriculture and horticulture. Plant viruses lack the ability to replicate outside a host cell, and they rely on the host's metabolic machinery for their reproduction. They can be transmitted through various means, such as insect vectors, seeds, or mechanical contact.
Viral diseases are illnesses caused by the infection and replication of viruses in host organisms. These infectious agents are obligate parasites, meaning they rely on the cells of other living organisms to survive and reproduce. Viruses can infect various types of hosts, including animals, plants, and microorganisms, causing a wide range of diseases with varying symptoms and severity.
Once a virus enters a host cell, it takes over the cell's machinery to produce new viral particles, often leading to cell damage or death. The immune system recognizes the viral components as foreign and mounts an immune response to eliminate the infection. This response can result in inflammation, fever, and other symptoms associated with viral diseases.
Examples of well-known viral diseases include:
1. Influenza (flu) - caused by influenza A, B, or C viruses
2. Common cold - usually caused by rhinoviruses or coronaviruses
3. HIV/AIDS - caused by human immunodeficiency virus (HIV)
4. Measles - caused by measles morbillivirus
5. Hepatitis B and C - caused by hepatitis B virus (HBV) and hepatitis C virus (HCV), respectively
6. Herpes simplex - caused by herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2)
7. Chickenpox and shingles - both caused by varicella-zoster virus (VZV)
8. Rabies - caused by rabies lyssavirus
9. Ebola - caused by ebolaviruses
10. COVID-19 - caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
Prevention and treatment strategies for viral diseases may include vaccination, antiviral medications, and supportive care to manage symptoms while the immune system fights off the infection.
Virus cultivation, also known as virus isolation or viral culture, is a laboratory method used to propagate and detect viruses by introducing them to host cells and allowing them to replicate. This process helps in identifying the specific virus causing an infection and studying its characteristics, such as morphology, growth pattern, and sensitivity to antiviral agents.
The steps involved in virus cultivation typically include:
1. Collection of a clinical sample (e.g., throat swab, blood, sputum) from the patient.
2. Preparation of the sample by centrifugation or filtration to remove cellular debris and other contaminants.
3. Inoculation of the prepared sample into susceptible host cells, which can be primary cell cultures, continuous cell lines, or embryonated eggs, depending on the type of virus.
4. Incubation of the inoculated cells under appropriate conditions to allow viral replication.
5. Observation for cytopathic effects (CPE), which are changes in the host cells caused by viral replication, such as cell rounding, shrinkage, or lysis.
6. Confirmation of viral presence through additional tests, like immunofluorescence assays, polymerase chain reaction (PCR), or electron microscopy.
Virus cultivation is a valuable tool in diagnostic virology, vaccine development, and research on viral pathogenesis and host-virus interactions. However, it requires specialized equipment, trained personnel, and biosafety measures due to the potential infectivity of the viruses being cultured.
Virus receptors are specific molecules (commonly proteins) on the surface of host cells that viruses bind to in order to enter and infect those cells. This interaction between the virus and its receptor is a critical step in the infection process. Different types of viruses have different receptor requirements, and identifying these receptors can provide important insights into the biology of the virus and potential targets for antiviral therapies.
DNA viruses are a type of virus that contain DNA (deoxyribonucleic acid) as their genetic material. These viruses replicate by using the host cell's machinery to synthesize new viral components, which are then assembled into new viruses and released from the host cell.
DNA viruses can be further classified based on the structure of their genomes and the way they replicate. For example, double-stranded DNA (dsDNA) viruses have a genome made up of two strands of DNA, while single-stranded DNA (ssDNA) viruses have a genome made up of a single strand of DNA.
Examples of DNA viruses include herpes simplex virus, varicella-zoster virus, human papillomavirus, and adenoviruses. Some DNA viruses are associated with specific diseases, such as cancer (e.g., human papillomavirus) or neurological disorders (e.g., herpes simplex virus).
It's important to note that while DNA viruses contain DNA as their genetic material, RNA viruses contain RNA (ribonucleic acid) as their genetic material. Both DNA and RNA viruses can cause a wide range of diseases in humans, animals, and plants.
I'm happy to help! However, it seems there might be a slight misunderstanding in your question. RNA, or ribonucleic acid, is typically single-stranded. Unlike DNA, which is double-stranded and forms a double helix, RNA usually exists as a single strand of nucleotides.
There are exceptions to this rule, such as certain types of RNA molecules that can form double-stranded structures in specific contexts. For example:
1. Double-Stranded RNA (dsRNA) viruses: These viruses have genomes made entirely of RNA, which is double-stranded throughout or partially double-stranded. The dsRNA viruses include important pathogens such as rotaviruses and reoviruses.
2. Hairpin loops in RNA structures: Some single-stranded RNA molecules can fold back on themselves to form short double-stranded regions, called hairpin loops, within their overall structure. These are often found in ribosomal RNA (rRNA), transfer RNA (tRNA), and messenger RNA (mRNA) molecules.
So, while 'double-stranded RNA' is not a standard medical definition for RNA itself, there are specific instances where RNA can form double-stranded structures as described above.
RNA editing is a process that alters the sequence of a transcribed RNA molecule after it has been synthesized from DNA, but before it is translated into protein. This can result in changes to the amino acid sequence of the resulting protein or to the regulation of gene expression. The most common type of RNA editing in mammals is the hydrolytic deamination of adenosine (A) to inosine (I), catalyzed by a family of enzymes called adenosine deaminases acting on RNA (ADARs). Inosine is recognized as guanosine (G) by the translation machinery, leading to A-to-G changes in the RNA sequence. Other types of RNA editing include cytidine (C) to uridine (U) deamination and insertion/deletion of nucleotides. RNA editing is a crucial mechanism for generating diversity in gene expression and has been implicated in various biological processes, including development, differentiation, and disease.
RNA splicing is a post-transcriptional modification process in which the non-coding sequences (introns) are removed and the coding sequences (exons) are joined together in a messenger RNA (mRNA) molecule. This results in a continuous mRNA sequence that can be translated into a single protein. Alternative splicing, where different combinations of exons are included or excluded, allows for the creation of multiple proteins from a single gene.
Sindbis virus is an alphavirus that belongs to the Togaviridae family. It's named after the location where it was first isolated, in Sindbis, Egypt, in 1952. This virus is primarily transmitted by mosquitoes and can infect a wide range of animals, including birds and humans. In humans, Sindbis virus infection often causes a mild flu-like illness characterized by fever, rash, and joint pain. However, some people may develop more severe symptoms, such as neurological disorders, although this is relatively rare. There is no specific treatment for Sindbis virus infection, and management typically involves supportive care to alleviate symptoms.
Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.
Viral proteins are the proteins that are encoded by the viral genome and are essential for the viral life cycle. These proteins can be structural or non-structural and play various roles in the virus's replication, infection, and assembly process. Structural proteins make up the physical structure of the virus, including the capsid (the protein shell that surrounds the viral genome) and any envelope proteins (that may be present on enveloped viruses). Non-structural proteins are involved in the replication of the viral genome and modulation of the host cell environment to favor viral replication. Overall, a thorough understanding of viral proteins is crucial for developing antiviral therapies and vaccines.
'Influenza A Virus, H1N1 Subtype' is a specific subtype of the influenza A virus that causes flu in humans and animals. It contains certain proteins called hemagglutinin (H) and neuraminidase (N) on its surface, with this subtype specifically having H1 and N1 antigens. The H1N1 strain is well-known for causing the 2009 swine flu pandemic, which was a global outbreak of flu that resulted in significant morbidity and mortality. This subtype can also cause seasonal flu, although the severity and symptoms may vary. It is important to note that influenza viruses are constantly changing, and new strains or subtypes can emerge over time, requiring regular updates to vaccines to protect against them.
Virus assembly, also known as virion assembly, is the final stage in the virus life cycle where individual viral components come together to form a complete viral particle or virion. This process typically involves the self-assembly of viral capsid proteins around the viral genome (DNA or RNA) and, in enveloped viruses, the acquisition of a lipid bilayer membrane containing viral glycoproteins. The specific mechanisms and regulation of virus assembly vary among different viral families, but it is often directed by interactions between viral structural proteins and genomic nucleic acid.
Virus shedding refers to the release of virus particles by an infected individual, who can then transmit the virus to others through various means such as respiratory droplets, fecal matter, or bodily fluids. This occurs when the virus replicates inside the host's cells and is released into the surrounding environment, where it can infect other individuals. The duration of virus shedding varies depending on the specific virus and the individual's immune response. It's important to note that some individuals may shed viruses even before they show symptoms, making infection control measures such as hand hygiene, mask-wearing, and social distancing crucial in preventing the spread of infectious diseases.
Antiviral agents are a class of medications that are designed to treat infections caused by viruses. Unlike antibiotics, which target bacteria, antiviral agents interfere with the replication and infection mechanisms of viruses, either by inhibiting their ability to replicate or by modulating the host's immune response to the virus.
Antiviral agents are used to treat a variety of viral infections, including influenza, herpes simplex virus (HSV) infections, human immunodeficiency virus (HIV) infection, hepatitis B and C, and respiratory syncytial virus (RSV) infections.
These medications can be administered orally, intravenously, or topically, depending on the type of viral infection being treated. Some antiviral agents are also used for prophylaxis, or prevention, of certain viral infections.
It is important to note that antiviral agents are not effective against all types of viruses and may have significant side effects. Therefore, it is essential to consult with a healthcare professional before starting any antiviral therapy.
Defective viruses are viruses that have lost the ability to complete a full replication cycle and produce progeny virions independently. These viruses require the assistance of a helper virus, which provides the necessary functions for replication. Defective viruses can arise due to mutations, deletions, or other genetic changes that result in the loss of essential genes. They are often non-infectious and cannot cause disease on their own, but they may interfere with the replication of the helper virus and modulate the course of infection. Defective viruses can be found in various types of viruses, including retroviruses, bacteriophages, and DNA viruses.
Measles virus is a single-stranded, negative-sense RNA virus belonging to the genus Morbillivirus in the family Paramyxoviridae. It is the causative agent of measles, a highly contagious infectious disease characterized by fever, cough, runny nose, and a red, blotchy rash. The virus primarily infects the respiratory tract and then spreads throughout the body via the bloodstream.
The genome of the measles virus is approximately 16 kilobases in length and encodes for eight proteins: nucleocapsid (N), phosphoprotein (P), matrix protein (M), fusion protein (F), hemagglutinin (H), large protein (L), and two non-structural proteins, V and C. The H protein is responsible for binding to the host cell receptor CD150 (SLAM) and mediating viral entry, while the F protein facilitates fusion of the viral and host cell membranes.
Measles virus is transmitted through respiratory droplets and direct contact with infected individuals. The virus can remain airborne for up to two hours in a closed space, making it highly contagious. Measles is preventable through vaccination, which has led to significant reductions in the incidence of the disease worldwide.
Respiratory Syncytial Viruses (RSV) are a common type of virus that cause respiratory infections, particularly in young children and older adults. They are responsible for inflammation and narrowing of the small airways in the lungs, leading to breathing difficulties and other symptoms associated with bronchiolitis and pneumonia.
The term "syncytial" refers to the ability of these viruses to cause infected cells to merge and form large multinucleated cells called syncytia, which is a characteristic feature of RSV infections. The virus spreads through respiratory droplets when an infected person coughs or sneezes, and it can also survive on surfaces for several hours, making transmission easy.
RSV infections are most common during the winter months and can cause mild to severe symptoms depending on factors such as age, overall health, and underlying medical conditions. While RSV is typically associated with respiratory illnesses in children, it can also cause significant disease in older adults and immunocompromised individuals. Currently, there is no vaccine available for RSV, but antiviral medications and supportive care are used to manage severe infections.
West Nile Virus (WNV) is an Flavivirus, which is a type of virus that is spread by mosquitoes. It was first discovered in the West Nile district of Uganda in 1937 and has since been found in many countries throughout the world. WNV can cause a mild to severe illness known as West Nile fever.
Most people who become infected with WNV do not develop any symptoms, but some may experience fever, headache, body aches, joint pain, vomiting, diarrhea, or a rash. In rare cases, the virus can cause serious neurological illnesses such as encephalitis (inflammation of the brain) or meningitis (inflammation of the membranes surrounding the brain and spinal cord). These severe forms of the disease can be fatal, especially in older adults and people with weakened immune systems.
WNV is primarily transmitted to humans through the bite of infected mosquitoes, but it can also be spread through blood transfusions, organ transplants, or from mother to baby during pregnancy, delivery, or breastfeeding. There is no specific treatment for WNV, and most people recover on their own with rest and supportive care. However, hospitalization may be necessary in severe cases. Prevention measures include avoiding mosquito bites by using insect repellent, wearing long sleeves and pants, and staying indoors during peak mosquito activity hours.
Orthomyxoviridae is a family of viruses that includes influenza A, B, and C viruses, which can cause respiratory infections in humans. Orthomyxoviridae infections are typically characterized by symptoms such as fever, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, and fatigue.
Influenza A and B viruses can cause seasonal epidemics of respiratory illness that occur mainly during the winter months in temperate climates. Influenza A viruses can also cause pandemics, which are global outbreaks of disease that occur when a new strain of the virus emerges to which there is little or no immunity in the human population.
Influenza C viruses are less common and typically cause milder illness than influenza A and B viruses. They do not cause epidemics and are not usually included in seasonal flu vaccines.
Orthomyxoviridae infections can be prevented through vaccination, good respiratory hygiene (such as covering the mouth and nose when coughing or sneezing), hand washing, and avoiding close contact with sick individuals. Antiviral medications may be prescribed to treat influenza A and B infections, particularly for people at high risk of complications, such as older adults, young children, pregnant women, and people with certain underlying medical conditions.
Rabies is a viral disease that affects the nervous system of mammals, including humans. It's caused by the rabies virus (RV), which belongs to the family Rhabdoviridae and genus Lyssavirus. The virus has a bullet-shaped appearance under an electron microscope and is encased in a lipid envelope.
The rabies virus primarily spreads through the saliva of infected animals, usually via bites. Once inside the body, it travels along nerve fibers to the brain, where it multiplies rapidly and causes inflammation (encephalitis). The infection can lead to symptoms such as anxiety, confusion, hallucinations, seizures, paralysis, coma, and ultimately death if left untreated.
Rabies is almost always fatal once symptoms appear, but prompt post-exposure prophylaxis (PEP), which includes vaccination and sometimes rabies immunoglobulin, can prevent the disease from developing when administered after an exposure to a potentially rabid animal. Pre-exposure vaccination is also recommended for individuals at high risk of exposure, such as veterinarians and travelers visiting rabies-endemic areas.
Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.
Respiratory Syncytial Virus (RSV) infections refer to the clinical illnesses caused by the Respiratory Syncytial Virus. RSV is a highly contagious virus that spreads through respiratory droplets, contact with infected surfaces, or direct contact with infected people. It primarily infects the respiratory tract, causing inflammation and damage to the cells lining the airways.
RSV infections can lead to a range of respiratory illnesses, from mild, cold-like symptoms to more severe conditions such as bronchiolitis (inflammation of the small airways in the lungs) and pneumonia (infection of the lung tissue). The severity of the infection tends to depend on factors like age, overall health status, and presence of underlying medical conditions.
In infants and young children, RSV is a leading cause of bronchiolitis and pneumonia, often resulting in hospitalization. In older adults, people with weakened immune systems, and those with chronic heart or lung conditions, RSV infections can also be severe and potentially life-threatening.
Symptoms of RSV infection may include runny nose, cough, sneezing, fever, wheezing, and difficulty breathing. Treatment typically focuses on managing symptoms and providing supportive care, although hospitalization and more aggressive interventions may be necessary in severe cases or for high-risk individuals. Preventive measures such as hand hygiene, wearing masks, and avoiding close contact with infected individuals can help reduce the spread of RSV.
Simian Virus 40 (SV40) is a polyomavirus that is found in both monkeys and humans. It is a DNA virus that has been extensively studied in laboratory settings due to its ability to transform cells and cause tumors in animals. In fact, SV40 was discovered as a contaminant of poliovirus vaccines that were prepared using rhesus monkey kidney cells in the 1950s and 1960s.
SV40 is not typically associated with human disease, but there has been some concern that exposure to the virus through contaminated vaccines or other means could increase the risk of certain types of cancer, such as mesothelioma and brain tumors. However, most studies have failed to find a consistent link between SV40 infection and cancer in humans.
The medical community generally agrees that SV40 is not a significant public health threat, but researchers continue to study the virus to better understand its biology and potential impact on human health.
"Influenza A Virus, H5N1 Subtype" is a specific subtype of the Influenza A virus that is often found in avian species (birds) and can occasionally infect humans. The "H5N1" refers to the specific proteins (hemagglutinin and neuraminidase) found on the surface of the virus. This subtype has caused serious infections in humans, with high mortality rates, especially in cases where people have had close contact with infected birds. It does not commonly spread from person to person, but there is concern that it could mutate and adapt to efficiently transmit between humans, which would potentially cause a pandemic.
Vesicular stomatitis Indiana virus (VSIV) is a single-stranded, negative-sense RNA virus that belongs to the family Rhabdoviridae and genus Vesiculovirus. It is the causative agent of vesicular stomatitis (VS), a viral disease that primarily affects horses and cattle, but can also infect other species including swine, sheep, goats, and humans.
The virus is transmitted through direct contact with infected animals or their saliva, as well as through insect vectors such as black flies and sandflies. The incubation period for VS ranges from 2 to 8 days, after which infected animals develop fever, lethargy, and vesicular lesions in the mouth, nose, and feet. These lesions can be painful and may cause difficulty eating or walking.
In humans, VSIV infection is typically asymptomatic or causes mild flu-like symptoms such as fever, muscle aches, and headache. Occasionally, individuals may develop vesicular lesions on their skin or mucous membranes, particularly if they have had contact with infected animals.
Diagnosis of VSIV infection is typically made through virus isolation from lesion exudates or blood, as well as through serological testing. Treatment is generally supportive and aimed at relieving symptoms, as there are no specific antiviral therapies available for VS. Prevention measures include vaccination of susceptible animals, vector control, and biosecurity measures to prevent the spread of infection between animals.
An antigen is any substance that can stimulate an immune response, particularly the production of antibodies. Viral antigens are antigens that are found on or produced by viruses. They can be proteins, glycoproteins, or carbohydrates present on the surface or inside the viral particle.
Viral antigens play a crucial role in the immune system's recognition and response to viral infections. When a virus infects a host cell, it may display its antigens on the surface of the infected cell. This allows the immune system to recognize and target the infected cells for destruction, thereby limiting the spread of the virus.
Viral antigens are also important targets for vaccines. Vaccines typically work by introducing a harmless form of a viral antigen to the body, which then stimulates the production of antibodies and memory T-cells that can recognize and respond quickly and effectively to future infections with the actual virus.
It's worth noting that different types of viruses have different antigens, and these antigens can vary between strains of the same virus. This is why there are often different vaccines available for different viral diseases, and why flu vaccines need to be updated every year to account for changes in the circulating influenza virus strains.
DNA-directed RNA polymerases are enzymes that synthesize RNA molecules using a DNA template in a process called transcription. These enzymes read the sequence of nucleotides in a DNA molecule and use it as a blueprint to construct a complementary RNA strand.
The RNA polymerase moves along the DNA template, adding ribonucleotides one by one to the growing RNA chain. The synthesis is directional, starting at the promoter region of the DNA and moving towards the terminator region.
In bacteria, there is a single type of RNA polymerase that is responsible for transcribing all types of RNA (mRNA, tRNA, and rRNA). In eukaryotic cells, however, there are three different types of RNA polymerases: RNA polymerase I, II, and III. Each type is responsible for transcribing specific types of RNA.
RNA polymerases play a crucial role in gene expression, as they link the genetic information encoded in DNA to the production of functional proteins. Inhibition or mutation of these enzymes can have significant consequences for cellular function and survival.
Ribosomal RNA (rRNA) is a type of RNA molecule that is a key component of ribosomes, which are the cellular structures where protein synthesis occurs in cells. In ribosomes, rRNA plays a crucial role in the process of translation, where genetic information from messenger RNA (mRNA) is translated into proteins.
Ribosomal RNA is synthesized in the nucleus and then transported to the cytoplasm, where it assembles with ribosomal proteins to form ribosomes. Within the ribosome, rRNA provides a structural framework for the assembly of the ribosome and also plays an active role in catalyzing the formation of peptide bonds between amino acids during protein synthesis.
There are several different types of rRNA molecules, including 5S, 5.8S, 18S, and 28S rRNA, which vary in size and function. These rRNA molecules are highly conserved across different species, indicating their essential role in protein synthesis and cellular function.
Antibodies, viral are proteins produced by the immune system in response to an infection with a virus. These antibodies are capable of recognizing and binding to specific antigens on the surface of the virus, which helps to neutralize or destroy the virus and prevent its replication. Once produced, these antibodies can provide immunity against future infections with the same virus.
Viral antibodies are typically composed of four polypeptide chains - two heavy chains and two light chains - that are held together by disulfide bonds. The binding site for the antigen is located at the tip of the Y-shaped structure, formed by the variable regions of the heavy and light chains.
There are five classes of antibodies in humans: IgA, IgD, IgE, IgG, and IgM. Each class has a different function and is distributed differently throughout the body. For example, IgG is the most common type of antibody found in the bloodstream and provides long-term immunity against viruses, while IgA is found primarily in mucous membranes and helps to protect against respiratory and gastrointestinal infections.
In addition to their role in the immune response, viral antibodies can also be used as diagnostic tools to detect the presence of a specific virus in a patient's blood or other bodily fluids.
A viral genome is the genetic material (DNA or RNA) that is present in a virus. It contains all the genetic information that a virus needs to replicate itself and infect its host. The size and complexity of viral genomes can vary greatly, ranging from a few thousand bases to hundreds of thousands of bases. Some viruses have linear genomes, while others have circular genomes. The genome of a virus also contains the information necessary for the virus to hijack the host cell's machinery and use it to produce new copies of the virus. Understanding the genetic makeup of viruses is important for developing vaccines and antiviral treatments.
Vero cells are a line of cultured kidney epithelial cells that were isolated from an African green monkey (Cercopithecus aethiops) in the 1960s. They are named after the location where they were initially developed, the Vervet Research Institute in Japan.
Vero cells have the ability to divide indefinitely under certain laboratory conditions and are often used in scientific research, including virology, as a host cell for viruses to replicate. This allows researchers to study the characteristics of various viruses, such as their growth patterns and interactions with host cells. Vero cells are also used in the production of some vaccines, including those for rabies, polio, and Japanese encephalitis.
It is important to note that while Vero cells have been widely used in research and vaccine production, they can still have variations between different cell lines due to factors like passage number or culture conditions. Therefore, it's essential to specify the exact source and condition of Vero cells when reporting experimental results.
Hepatitis B virus (HBV) is a DNA virus that belongs to the Hepadnaviridae family and causes the infectious disease known as hepatitis B. This virus primarily targets the liver, where it can lead to inflammation and damage of the liver tissue. The infection can range from acute to chronic, with chronic hepatitis B increasing the risk of developing serious liver complications such as cirrhosis and liver cancer.
The Hepatitis B virus has a complex life cycle, involving both nuclear and cytoplasmic phases. It enters hepatocytes (liver cells) via binding to specific receptors and is taken up by endocytosis. The viral DNA is released into the nucleus, where it is converted into a covalently closed circular DNA (cccDNA) form, which serves as the template for viral transcription.
HBV transcribes several RNAs, including pregenomic RNA (pgRNA), which is used as a template for reverse transcription during virion assembly. The pgRNA is encapsidated into core particles along with the viral polymerase and undergoes reverse transcription to generate new viral DNA. This process occurs within the cytoplasm of the hepatocyte, resulting in the formation of immature virions containing partially double-stranded DNA.
These immature virions are then enveloped by host cell membranes containing HBV envelope proteins (known as surface antigens) to form mature virions that can be secreted from the hepatocyte and infect other cells. The virus can also integrate into the host genome, which may contribute to the development of hepatocellular carcinoma in chronic cases.
Hepatitis B is primarily transmitted through exposure to infected blood or bodily fluids containing the virus, such as through sexual contact, sharing needles, or from mother to child during childbirth. Prevention strategies include vaccination, safe sex practices, and avoiding needle-sharing behaviors. Treatment for hepatitis B typically involves antiviral medications that can help suppress viral replication and reduce the risk of liver damage.
"Influenza A Virus, H3N2 Subtype" is a specific subtype of the influenza A virus that causes respiratory illness and is known to circulate in humans and animals, including birds and pigs. The "H3N2" refers to the two proteins on the surface of the virus: hemagglutinin (H) and neuraminidase (N). In this subtype, the H protein is of the H3 variety and the N protein is of the N2 variety. This subtype has been responsible for several influenza epidemics and pandemics in humans, including the 1968 Hong Kong flu pandemic. It is one of the influenza viruses that are monitored closely by public health authorities due to its potential to cause significant illness and death, particularly in high-risk populations such as older adults, young children, and people with certain underlying medical conditions.
Viral genes refer to the genetic material present in viruses that contains the information necessary for their replication and the production of viral proteins. In DNA viruses, the genetic material is composed of double-stranded or single-stranded DNA, while in RNA viruses, it is composed of single-stranded or double-stranded RNA.
Viral genes can be classified into three categories: early, late, and structural. Early genes encode proteins involved in the replication of the viral genome, modulation of host cell processes, and regulation of viral gene expression. Late genes encode structural proteins that make up the viral capsid or envelope. Some viruses also have structural genes that are expressed throughout their replication cycle.
Understanding the genetic makeup of viruses is crucial for developing antiviral therapies and vaccines. By targeting specific viral genes, researchers can develop drugs that inhibit viral replication and reduce the severity of viral infections. Additionally, knowledge of viral gene sequences can inform the development of vaccines that stimulate an immune response to specific viral proteins.
RNA interference (RNAi) is a biological process in which RNA molecules inhibit the expression of specific genes. This process is mediated by small RNA molecules, including microRNAs (miRNAs) and small interfering RNAs (siRNAs), that bind to complementary sequences on messenger RNA (mRNA) molecules, leading to their degradation or translation inhibition.
RNAi plays a crucial role in regulating gene expression and defending against foreign genetic elements, such as viruses and transposons. It has also emerged as an important tool for studying gene function and developing therapeutic strategies for various diseases, including cancer and viral infections.
'Cercopithecus aethiops' is the scientific name for the monkey species more commonly known as the green monkey. It belongs to the family Cercopithecidae and is native to western Africa. The green monkey is omnivorous, with a diet that includes fruits, nuts, seeds, insects, and small vertebrates. They are known for their distinctive greenish-brown fur and long tail. Green monkeys are also important animal models in biomedical research due to their susceptibility to certain diseases, such as SIV (simian immunodeficiency virus), which is closely related to HIV.
Bacterial RNA refers to the genetic material present in bacteria that is composed of ribonucleic acid (RNA). Unlike higher organisms, bacteria contain a single circular chromosome made up of DNA, along with smaller circular pieces of DNA called plasmids. These bacterial genetic materials contain the information necessary for the growth and reproduction of the organism.
Bacterial RNA can be divided into three main categories: messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA). mRNA carries genetic information copied from DNA, which is then translated into proteins by the rRNA and tRNA molecules. rRNA is a structural component of the ribosome, where protein synthesis occurs, while tRNA acts as an adapter that brings amino acids to the ribosome during protein synthesis.
Bacterial RNA plays a crucial role in various cellular processes, including gene expression, protein synthesis, and regulation of metabolic pathways. Understanding the structure and function of bacterial RNA is essential for developing new antibiotics and other therapeutic strategies to combat bacterial infections.
Viral DNA refers to the genetic material present in viruses that consist of DNA as their core component. Deoxyribonucleic acid (DNA) is one of the two types of nucleic acids that are responsible for storing and transmitting genetic information in living organisms. Viruses are infectious agents much smaller than bacteria that can only replicate inside the cells of other organisms, called hosts.
Viral DNA can be double-stranded (dsDNA) or single-stranded (ssDNA), depending on the type of virus. Double-stranded DNA viruses have a genome made up of two complementary strands of DNA, while single-stranded DNA viruses contain only one strand of DNA.
Examples of dsDNA viruses include Adenoviruses, Herpesviruses, and Poxviruses, while ssDNA viruses include Parvoviruses and Circoviruses. Viral DNA plays a crucial role in the replication cycle of the virus, encoding for various proteins necessary for its multiplication and survival within the host cell.
Hepacivirus is a genus of viruses in the family Flaviviridae. The most well-known member of this genus is Hepatitis C virus (HCV), which is a major cause of liver disease worldwide. HCV infection can lead to chronic hepatitis, cirrhosis, and liver cancer.
Hepaciviruses are enveloped viruses with a single-stranded, positive-sense RNA genome. They have a small icosahedral capsid and infect a variety of hosts, including humans, non-human primates, horses, and birds. The virus enters the host cell by binding to specific receptors on the cell surface and is then internalized through endocytosis.
HCV has a high degree of genetic diversity and is classified into seven major genotypes and numerous subtypes based on differences in its RNA sequence. This genetic variability can affect the virus's ability to evade the host immune response, making treatment more challenging.
In addition to HCV, other hepaciviruses have been identified in various animal species, including equine hepacivirus (EHCV), rodent hepacivirus (RHV), and bat hepacivirus (BtHepCV). These viruses are being studied to better understand the biology of hepaciviruses and their potential impact on human health.
Orthomyxoviridae is a family of viruses that includes influenza A, B, and C viruses, which are the causative agents of flu in humans and animals. These viruses are enveloped, meaning they have a lipid membrane derived from the host cell, and have a single-stranded, negative-sense RNA genome. The genome is segmented, meaning it consists of several separate pieces of RNA, which allows for genetic reassortment or "shuffling" when two different strains infect the same cell, leading to the emergence of new strains.
The viral envelope contains two major glycoproteins: hemagglutinin (HA) and neuraminidase (NA). The HA protein is responsible for binding to host cells and facilitating entry into the cell, while NA helps release newly formed virus particles from infected cells by cleaving sialic acid residues on the host cell surface.
Orthomyxoviruses are known to cause respiratory infections in humans and animals, with influenza A viruses being the most virulent and capable of causing pandemics. Influenza B viruses typically cause less severe illness and are primarily found in humans, while influenza C viruses generally cause mild upper respiratory symptoms and are also mainly restricted to humans.
Craig E. Cameron
Richard Lathe
RNA virus
RNA interference
Parotitis
Bacteriophage experimental evolution
Mycovirus
Ribonuclease L
Mycophenolic acid
IFIT1
Ervin Fodor
OyaGen
Phorbol-12-myristate-13-acetate-induced protein 1
Cyclic GMP-AMP synthase
Kawasaki disease
Virusoid
Batai orthobunyavirus
Favipiravir
COVID-19 drug repurposing research
Wendy Barclay
Heterocapsa circularisquama
Nudivirus
HNRNPA1
Umifenovir
PSI-6130
Dicer
Sudhanshu Vrati
Maurice Green (virologist)
MDA5
Sonja M. Best
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Polymerase6
- No statistically significant differences were identified in the by a positive nucleic acid amplification test (e.g., reverse transcription- polymerase chain reaction), possible Zika virus infection during pregnancy proportions of children with differing evidence of Zika virus based on presence of serologic evidence of a Zika virus infection, or serologic evidence of an unspecified flavivirus infection. (cdc.gov)
- It is indicated for treatment of Zaire ebolavirus in adults and children, including neonates born to a mother who is reverse-transcriptase polymerase chain reaction (RT-PCR) positive for Zaire ebolavirus infection. (medscape.com)
- In each infection, several RNAs transcribed by RNA polymerase III (Pol3) specifically engaged RLRs, particularly the family of Y RNAs. (pasteur.fr)
- After cellular uptake, it is phosphoribosylated and recognized as a substrate for the viral RNA-dependent RNA polymerase (RdRp) and can cause chain termination or lethal mutagenesis [ 1 , 4 ]. (springer.com)
- Retrospective laboratory evaluation of the detection rate of CHIKV infection by real-time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) on urine. (clinicaltrials.gov)
- The antiviral drug favipiravir inhibits the RNA-dependent RNA polymerase (RdRp) of RNA viruses [ 1 ]. (springer.com)
SARS-CoV-2 RNA2
- Presumably, favipiravir is inserted into the newly synthesized SARS-CoV-2 RNA chain, which caused a detrimental effect on the viral replication. (springer.com)
- SARS-CoV-2 RNA has been identified in the eye up to 22 days post onset of self-reported symptoms. (canada.ca)
Acute12
- In abstract, it seems that the absence to date of maternal-fetal transmission of the SARS-CoV-2 virus throughout the COVID-19 pandemic is just like different coronaviruses, and can be per the acute rarity of steered or confirmed circumstances of intrauterine transmission of different respiratory RNA viruses. (hudsen.org)
- Data were from an international collaboration of nine prospective cohorts studying acute HCV infection (InC(3) study). (ox.ac.uk)
- In this study, the scientists studied the immune responses induced by infection with the dengue and measles viruses, which cause acute infections, and also the HIV virus, which causes chronic infection. (pasteur.fr)
- Hepatitis viruses constitute a major public health problem because of the morbidity and mortality associated with the acute and chronic consequences of these infections. (cdc.gov)
- Terms and Abbreviations Used in This Publication Acute hepatitis C Newly acquired symptomatic hepatitis C virus (HCV) infection. (cdc.gov)
- detectable in persons with acute, chronic, and resolved infection. (cdc.gov)
- https://stacks.cdc.gov/view/cdc/90288 ) and reflects updated guidance from professional organizations that recommend treatment for acute HCV infection. (cdc.gov)
- This notion is supported by the finding that bats tolerate many viral infections some of which have spread to humans causing zoonoses such as Ebola, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) ( 7 ). (frontiersin.org)
- Estimations of SARS-CoV-2 reactive memory B cells post-acute infection have led to the isolation of a novel neutralizing mAb. (uvm.edu)
- HHV-6, which can produce acute infection in CD4 + T lymphocytes, causes roseola infantum , a febrile illness that affects young children. (medscape.com)
- 7 These NHPs were cynomolgus macaques used The World Health Organization (WHO) Rapid Risk As- for preclinical research, drug development, disease sessment of Acute Public Health Events Manual 14 was modelling, experimental infections, and biological used for this risk assessment. (who.int)
- This surveillance system was useful in identifying the variable endemicity of acute HAV infection in different regions and for better understanding the epidemiology of HBV and HCV infection. (who.int)
Dengue10
- Researchers at the University of North Carolina School of Medicine are conducting studies that utilize blood donations from individuals who have been diagnosed with or potentially exposed to mosquito-borne viruses as part of ongoing dengue and Zika research and vaccine development. (news-medical.net)
- Malaria and dengue are endemic in similar tropical regions, and therefore, may result in the possibility of co-infection. (who.int)
- Concurrent infections of malaria and dengue are when both the diseases occur simultaneously in an individual. (who.int)
- Since there are similarities in the clinical characteristics between these two infections, diagnosis of malaria and dengue co-infections might be either misdiagnosed or misinterpreted as mono-infections. (who.int)
- This point out the high level of co-infection with malaria amongst patients with severe symptoms who tested positive for Dengue Fever, and has implications on the approach for vector control and surveillance activities. (who.int)
- Importantly, this "recognition pocket" is found not only in RVF virus but also in the envelope proteins of other viral families transmitted by arthropods, such as the dengue, Zika and chikungunya viruses, which have caused major worldwide epidemics in recent years. (pasteur.fr)
- Through this investigation we have uncovered a central role for ER remodeling proteins in regulating virus replication and assembly for several flaviviruses, including dengue virus, Zika virus and West Nile virus. (tigem.it)
- 33 Antigen detection assays are not available for MVEV, but have been used for JEV and Dengue fever virus. (mja.com.au)
- Aspirin and other nonsteroidal anti-inflammatory drugs, non-steroidal should be avoided until dengue can be discarded to reduce the risk of hemorrhage.When traveling to countries where the Zika virus or other viruses transmitted by mosquitoes have been reported, the recommendation is to use insect repellent, long sleeves and pants, and stay in places with air conditioning or window and door fitted with insect screens. (bvsalud.org)
- Yellow fever (the prototype virus of the Flaviviridae family), dengue, Hantavirus pulmonary syndrome (HPS), and hemorrhagic fever with renal failure syndrome (HFRS) are discussed in separate chapters (see Differentials). (medscape.com)
Response to RNA viruses1
- In a recent study published in the journal iScience , French and US research teams investigated the innate immune mechanisms used by the body in response to RNA viruses. (pasteur.fr)
Inhibits6
- Studies with EBOV and MeV demonstrate that the matrix protein is involved in early infection events, as inhibits viral replication. (uky.edu)
- We also show that a nanobody (a single-domain antibody) that interferes with FluPol A dimerization inhibits the synthesis of vRNA and, consequently, inhibits virus replication in infected cells. (nature.com)
- Fig. 4: Nb8205, which binds FluPol A at the dimer interface, inhibits cRNA to vRNA replication and virus growth. (nature.com)
- This prevents viral replication and inhibits normal cell ribosome function, killing both the virus and the host cell if the response is active for a sufficient amount of time. (wikidoc.org)
- The drug inhibits the HBV receptor (NTCP receptor) on the hepatocyte surface and prevents the infection of healthy cells and viral spread within the liver. (prnewswire.com)
- Human respiratory syncytial virus (RSV), a leading cause of respiratory tract infections in infants, inhibits type I interferon (IFN)-dependent signalling, as well as IFN synthesis. (microbiologyresearch.org)
Immunity11
- Overall, our work uncovers the contribution of endogenous RNAs to antiviral immunity and demonstrates the importance of this pathway in HIV-1 infection. (pasteur.fr)
- This mechanism could trigger immunity against viruses before they become detectable. (pasteur.fr)
- They showed that the same type of endogenous RNA is involved in triggering innate immunity for different infections, which indicates that this mechanism has been highly conserved during evolution to protect against viral infections. (pasteur.fr)
- The scientists hypothesize that by recognizing endogenous RNA, the cell is able to keep one step ahead of the infection and induce immunity before the virus has replicated enough to be detected directly. (pasteur.fr)
- Anti-HBs appear after exposure to HBsAg and is a marker for immunity following infection or as a result of vaccination. (cdc.gov)
- I'm interested in how viruses engage with these pathways with respect to cellular antiviral immunity, to develop novel avenues for therapeutic intervention. (gla.ac.uk)
- My research focuses on companion animal virology and immunology with a view to understanding disease pathogenesis, correlates of immunity to infection and the development of novel approaches to the diagnosis, prevention and treatment of viral diseases. (gla.ac.uk)
- Resistance depends on the efficient sensing of the infection and mounting of antiviral responses that involve programmed death of infected cells, suppression of viral replication, inflammation and the establishment of adaptive immunity. (frontiersin.org)
- The MDA5 protein plays an important role in innate immunity, the body's early, nonspecific response to foreign invaders (pathogens) such as viruses and bacteria. (medlineplus.gov)
- however, the immune response to HBV vaccine is lower in patients with HIV infection than in uninfected patients, and postvaccination HBsAg must be tested to document immunity. (medscape.com)
- All patients with HBV/HIV coinfection must be assessed for hepatitis A virus (HAV) immunity and vaccinated if negative. (medscape.com)
Ebola16
- Other viruses within the NNS RNA virus order include the deadly Ebola, Hendra, and Nipah viruses (EBOV, HeV, and NiV), as well as the re-emerging measles virus (MeV). (uky.edu)
- ELISA for the detection of previously detected in E. helvum bats antibodies of antibodies to Ebola viruses. (cdc.gov)
- Long- bats, is required to further investigate term survival of an urban fruit bat sero- positive for Ebola and Lagos bat viruses. (cdc.gov)
- Ebola Res- ton virus infection of pigs: clinical signifi - the spleens. (cdc.gov)
- Fruit bats as reservoirs of Ebola virus. (cdc.gov)
- It has shown an efficacy of 97.5% in preventing infection among 90,000 individuals in an active Ebola virus outbreak in the Democratic Republic of the Congo. (medscape.com)
- Patients who have died of Ebola virus disease should be buried promptly and with as little contact as possible. (medscape.com)
- Nucleoside analogue inhibitors of the cell-encoded enzyme S-adenosylhomocysteine hydrolase (SAH) have been shown to inhibit Zaire ebolavirus replication in adult BALB/c mice infected with mouse-adapted Ebola virus. (medscape.com)
- Smith and colleagues found that in rhesus macaques infected with a lethal dose of Ebola virus, treatment with interferon beta early after exposure led to a significant increase in survival time, though it did not reduce mortality significantly. (medscape.com)
- [ 33 ] These findings suggest that early postexposure interferon-beta therapy may be a promising adjunct in the treatment of Ebola virus infection. (medscape.com)
- Equine IgG containing high-titer neutralizing antibodies to Ebola virus protected guinea pigs and baboons but was not effective in protecting infected rhesus monkeys. (medscape.com)
- In May 1995, these diseases came to worldwide attention with an outbreak of Ebola virus near the city of Kikwik, Zaire. (medscape.com)
- Ebola virus. (medscape.com)
- There have been five documented outbreaks of Ebola Reston virus (RESTV) in animals epidemiologically linked to the Philippines. (who.int)
- Ebola Reston virus (RESTV) is one of the six virus has been hypothesized that ongoing, undetected RESTV species of the Ebola virus in the family Filoviridae. (who.int)
- natural infection of Ebola virus in NHPs. (who.int)
Replication14
- Knowledge gaps exist with regard to the mechanisms of viral replication within hepatocytes and disease progression during chronic infection. (lancs.ac.uk)
- Conclusions: High-throughput sequencing has shed new light on the pathways that may regulate HCV replication and associated pathology during chronic infection. (lancs.ac.uk)
- In the life cycle of NNS viruses, viral proteins assume multi-functional roles to optimize their replication and spread. (uky.edu)
- The modified virus fluoresces when it is replicating, allowing researchers to monitor the replication of viruses in thousands of cells at a time. (wikipedia.org)
- One of the antiviral drugs investigated by Cameron (T-1106) causes virus replication to pause and reverse, preventing efficient replication. (wikipedia.org)
- dsRNA could be formed by RNA replication intermediates, by secondary structures in RNA genomes or antigenomes, or by both. (ox.ac.uk)
- During an infection, viral RNA is introduced into the cell cytoplasm so that it can be read and translated into proteins needed for viral replication. (pasteur.fr)
- To counter this replication, human cells express cytoplasmic RIG-I-like receptors, which serve as the first line of defense against viral infections. (pasteur.fr)
- Many human viruses utilise or suppress ubiquitin and ubiquitin-like pathways during infection, enhancing their replication. (gla.ac.uk)
- Our study provides high-resolution structures of medically relevant FluPol A , as well as insights into the replication mechanisms of the viral RNA genome. (nature.com)
- Interferons assist the immune response by inhibiting viral replication within host cells, activating natural killer cells, increasing antigen presentation to lymphocytes, and inducing the resistance of host cells to viral infection. (wikidoc.org)
- Specifically, we are interested in uncovering common strategies used by positive-strand RNA viruses to facilitate virus replication or limit host responses to infection. (tigem.it)
- In HHV-1 and HHV-2 oral infections, viral replication within the oral epithelium may cause lysis of epithelial cells, with vesicle formation. (medscape.com)
- Prior to the initiation of ART, all patients who test positive for hepatitis B surface antigen (HBsAg) should be tested for hepatitis B virus (HBV) deoxyribonucleic acid (DNA) using a quantitative assay to determine the level of HBV replication. (medscape.com)
Detectable1
- Individuals with persistent HCV and detectable HCV RNA during early chronic infection (one year [±4 months] postinfection) were included. (ox.ac.uk)
Zika24
- Infection during pregnancy with Zika virus, a mosquito- (range = 19-73 months), and 33 (30.3%) children with an ASD borne flavivirus, can cause birth defects and neurodevelop- diagnosis also had a family member with an ASD diagnosis. (cdc.gov)
- 2016-March 31, 2018, to women with laboratory evidence ranged from 1.3% to 4.6% among children aged 4 years ( 3 ) of Zika virus infection during pregnancy. (cdc.gov)
- In Puerto Rico, any child who fails a standardized autism- ticipating site for the Autism and Developmental Disabilities specific screening, regardless of Zika virus exposure, receives a Monitoring Network to conduct ASD surveillance among standardized evaluation at Puerto Rico Children with Special children aged 4 and 8 years. (cdc.gov)
- She is involved in developing clinical guidance for healthcare providers caring for pregnant women and women of reproductive age with possible exposure to Zika virus. (cdc.gov)
- Dr. Oduyebo is also involved with the US Zika Pregnancy Registry, and provides technical assistance to support state, tribal, local and territorial health departments collecting information about pregnancy and infant outcomes following laboratory evidence of confirmed or possible Zika virus infection during pregnancy. (cdc.gov)
- Dr. Berry-Bibee is a practicing OB-GYN and a guest researcher at the CDC, currently serving on CDC's Zika Virus Emergency Response on the Pregnancy and Birth Defects Task Force Contraception Access Team. (cdc.gov)
- Researchers, led by scientists at the University of Colorado School of Medicine, have found basic molecular processes used by the Zika virus to "hijack" the cells that it infects and potentially how it makes molecules that are directly linked to disease. (news-medical.net)
- The first of five early stage clinical trials to test the safety and ability of an investigational Zika vaccine candidate called the Zika Purified Inactivated Virus (ZPIV) vaccine to generate an immune system response has begun at the Walter Reed Army Institute of Research Clinical Trial Center in Silver Spring, Maryland. (news-medical.net)
- In a study that could one day help eliminate the tragic birth defects caused by Zika virus, scientists from the Florida campus of The Scripps Research Institute have elucidated how the virus attacks the brains of newborns, information that could accelerate the development of treatments. (news-medical.net)
- A Biosecurity Research Institute study has found important results in the fight against Zika virus: Culex mosquitoes do not appear to transmit Zika virus. (news-medical.net)
- For the first time, abnormal brain development following a Zika infection during pregnancy has been documented experimentally in the offspring of a non-human primate. (news-medical.net)
- Stopping the explosive spread of Zika virus - which can lead to birth defects in babies born to infected mothers - depends on genetic insights gleaned through new tools and models. (news-medical.net)
- The sudden emergence of the Zika virus epidemic in Latin America in 2015-16 has caught the scientific world unawares. (news-medical.net)
- Saint Louis University's Center for Vaccine Development is studying an investigational vaccine for yellow fever, a potentially deadly disease that is spread by the same mosquito that transmits Zika virus. (news-medical.net)
- The rapid development of a safe and effective vaccine to prevent the Zika virus (ZIKV) is a global priority, as infection in pregnant women has been shown to lead to fetal microcephaly and other major birth defects. (news-medical.net)
- This pocket is also found in other human pathogenic viruses transmitted by different mosquitoes, such as the Zika and chikungunya viruses. (pasteur.fr)
- A viral disease transmitted by the bite of Aedes mosquitoes infected with Zika Virus. (bvsalud.org)
- The Zika virus is transmitted to humans through the bite of an infected mosquito of the genus Aedes , mainly Aedes aegypti . (bvsalud.org)
- Transmission associated with blood transfusion is possible, since the RNA of Zika virus was identified in asymptomatic blood donors during a current surge. (bvsalud.org)
- There is strong evidence of a possible association of infection by Zika virus in pregnant women in Brazil and the occurrence of microcephaly in newborn infants. (bvsalud.org)
- About 1 in 5 people infected with the Zika virus become symptomatic. (bvsalud.org)
- Based on the typical clinical features, differential diagnosis for infection by Zika virus is widespread. (bvsalud.org)
- There is no vaccine and no specific antiviral treatment available for the condition of the Zika virus. (bvsalud.org)
- The fact that the species of Aedes mosquitoes that transmit the Zika virus are found throughout the world, it is likely that the outbreak from spreading to other countries. (bvsalud.org)
Presence of viral2
- This publication shows that some immune receptors that detect the presence of viral RNA are also activated by RNA produced by our cells, potentially enabling cells to react more quickly to infection. (pasteur.fr)
- Investigating the presence of viral RNA and the associated inflammatory response in skin biopsies from vaccinated volunteers, this research contributes to understanding the potential connection between rash occurrence and a tetravalent neutralizing antibody response. (uvm.edu)
Symptomatic4
- Parainfluenza virus and human metapneumovirus can produce symptomatic maternal infections however don't trigger intrauterine fetal an infection. (hudsen.org)
- Studies that enrolled ≥ 65-year-old patients who had symptomatic SARS-CoV-2 infection and were treated with favipiravir are discussed here. (springer.com)
- Children under 6 months of age, persons with immune deficiencies or on immunosuppressive or immunomodulatory therapies, persons with allergies to egg proteins, thymus disorders, malignant neoplasms, transplant recipients, and persons with symptomatic HIV infection should not get the Yellow Fever vaccine. (iamat.org)
- Data from studies were extracted into evidence tables on risk of infection, severity of disease and mortality and organized by asymptomatic, pre-symptomatic, symptomatic, recurrent or reinfection, as well as culture versus RT-PCR and sample source (e.g. respiratory, fecal, etc. (canada.ca)
Regulation5
- The present study aimed to explore the regulation of gene expression during chronic HCV infection in liver biopsy samples. (lancs.ac.uk)
- One of these newly uncovered roles for viral matrix proteins involves the regulation of viral RNA synthesis. (uky.edu)
- Besides their canonical roles in translation, tRNAs also originate tRNA-derived small RNAs (tsRNAs), a class of small non-coding RNAs with regulatory functions ranging from translation regulation to gene expression control and cellular stress response. (mdpi.com)
- In the canonical model, IFN regulation, after RNA virus infection, is conducted by IRF-3 and IRF-7. (biomedcentral.com)
- RNA epitranscriptomics: Regulation of infection of RNA and DNA viruses by N 6 -methyladenosine (m 6 A). (bvsalud.org)
Endogenous8
- Y RNAs are conserved endogenous RIG-I ligands across RNA virus infection and are targeted by HIV-1. (pasteur.fr)
- Here, we characterize the landscape of endogenous ligands that engage RIG-I-like receptors (RLRs) upon infection by different RNA viruses. (pasteur.fr)
- It was previously believed that these receptors were only sensitive to viral RNA, but this new study shows that cells are capable of producing endogenous RNA molecules that are also able to activate the receptors. (pasteur.fr)
- The structure of this endogenous RNA mimics viral RNA so that it can be recognized by RIG-I receptors. (pasteur.fr)
- The results of the study also show that endogenous RNAs are always present in cells but that they do not normally bind to RIG-I receptors and are only detected after the onset of a viral infection. (pasteur.fr)
- The detailed mechanisms have not yet been elucidated, but it seems that the presence of the virus interferes in certain cellular biochemical pathways that determine the immunogenicity of endogenous RNAs, in other words their ability to trigger an immune response. (pasteur.fr)
- When the cell is infected, it modifies processes that lead to the expression of endogenous RNAs, making them capable of binding to RIG-I receptors. (pasteur.fr)
- It is therefore an active process in which the host reacts to viral presence in its cells and uses endogenous RNA to induce an immune response. (pasteur.fr)
Interference3
- Antiviral RNA interference responses induced by Semliki Forest virus infection of mosquito cells: characterization, origin, and frequency-dependent functions of virus-derived small interfering RNAs. (ox.ac.uk)
- RNA interference (RNAi) is an important mosquito defense mechanism against arbovirus infection. (ox.ac.uk)
- In particular, the RNA interference (RNAi) pathways are of notable significance for the control of viral infections. (mdpi.com)
Humans10
- In the sylvatic cycle , Yellow Fever is transmitted by mosquitoes that bite infected monkeys passing the infection to humans living in or visiting jungle areas. (iamat.org)
- In the intermediate or savannah cycle , the infection is transmitted to humans via mosquitoes that bite infected monkeys or other humans living or working in jungle border areas in Africa. (iamat.org)
- Rift Valley fever virus, transmitted by mosquitoes, is responsible for outbreaks in livestock in Africa and can also be fatal in humans. (pasteur.fr)
- The virus also causes severe disease in humans who come into contact with contaminated animals or who are bitten by infected mosquitoes, resulting in severe encephalitis and hemorrhagic fever that can prove fatal. (pasteur.fr)
- These results suggest that the innate immune response to viruses differs significantly between pangolins and other mammals, including humans. (frontiersin.org)
- Nonetheless, many other viral infections can affect the oral cavity in humans, either as localized or systemic infections. (medscape.com)
- Chlamydia are bacteria that cause disease in humans, including sexually transmitted infections (STIs), and infections of the eyes and respiratory tract. (msdmanuals.com)
- Nonhuman primates and humans are probably the main reservoirs of the virus, and anthroponotic transmission (man-vector-man) occurs during outbreaks. (bvsalud.org)
- Although RESTV has been identified in humans, there was no death or illness attributed to the infection. (who.int)
- Although three filoviruses have been identified in result in the emergence of more pathogenic viruses in animals in Asia, 3,4 RESTV is the only filovirus isolated humans and/or livestock. (who.int)
Immunogenicity1
- Further, we found that HIV-1 triggered a VPR-dependent downregulation of RNA triphosphatase DUSP11 in vitro and in vivo, inducing a transcriptome-wide change of cellular RNA 5′-triphosphorylation that licenses Y RNA immunogenicity. (pasteur.fr)
Asymptomatic2
Innate3
- The RNA molecules bind to these receptors, triggering defense mechanisms in the innate immune system to tackle the infection. (pasteur.fr)
- This research offers new keys to understanding RNA virus infections and the innate immune response to them. (pasteur.fr)
- Previous research has shown that infection with coronaviruses activates an innate immune response upon sensing of viral RNA by interferon-induced with helicase C domain 1 (IFIH1), also known as MDA5. (frontiersin.org)
Protein14
- For most NNS RNA viruses, the attachment protein is important for the tethering of a viral membrane to host cells, while the fusion protein is responsible for the membrane merger of the virus and host. (uky.edu)
- One of the key players during the course of infection is the matrix protein (M). The matrix protein has been identified as a master regulator of viral infection with most studies focusing on its roles in late-stage infection, during assembly and budding of viral progeny. (uky.edu)
- Interestingly, some recent studies show that the matrix protein has other critical roles in viral infection such as immune modulation and host cell translation antagonism. (uky.edu)
- Phosphorylation of the plant encoded, double-stranded (dsRNA)-dependent protein kinase (pPKR) is significantly enhanced over basal levels during early phases of virus and viroid infection. (elsevierpure.com)
- We now show that virus infection differentially effects pPKR protein levels. (elsevierpure.com)
- However, ribosome-associated pPKR protein levels from virus infected tissues decreased approximately 4-fold relative to levels in extracts from mock inoculated tissues. (elsevierpure.com)
- Langland, J , Langland, L & Roth, D 1998, ' Differential localization and accumulation of the plant double stranded RNA-dependent protein kinase during virus infection ', Plant Physiology and Biochemistry , vol. 36, no. 5, pp. 395-400. (elsevierpure.com)
- In the homologous protein of the chikungunya virus, the scientists pinpointed one of the residues of the recognition pocket as amino acid 226. (pasteur.fr)
- Likewise, Z-DNA-binding protein (ZBP1), which senses both Z-DNA and Z-RNA, has been lost during the evolution of pangolins. (frontiersin.org)
- Stimulation of TLRs (Toll-Like Receptors) by a pathogen induces activation of signal transduction cascades, which leads to translocation of nuclear factor-κB (NF-κB) to the nucleus [ 1 ], activation of interferon regulatory factors 3/7 (IRF3/7) and/or activator protein-1 (AP-1), which cooperate to induce transcription of various cytokines such as alpha/beta interferon (IFN-α/β) to counteract infection [ 2 - 4 ]. (biomedcentral.com)
- In addition to mechanistically delineating the functions of Atlastins in flavivirus infection, we uncovered a novel role for one member of this protein family in cellular retrograde vesicle trafficking. (tigem.it)
- In particular, the protein recognizes a molecule called double-stranded RNA (a chemical cousin of DNA), which certain viruses, including rhinovirus, RSV, and the flu virus, have as their genetic material or produce when they infect cells and copy (replicate) themselves. (medlineplus.gov)
- When the MDA5 protein recognizes pieces of viral RNA inside the cell, it helps turn on the production of immune system proteins called interferons. (medlineplus.gov)
- Deficiency of MDA5 protein activity reduces interferon production in response to RNA-containing viruses. (medlineplus.gov)
Infectious4
- During the infectious cycle, viral surface glycoproteins play critical roles in establishing infection. (uky.edu)
- As an Honorary Consultant in Infectious Diseases, my research focuses on the epidemiology of influenza and other respiratory viruses in the UK and sub-Saharan Africa including COVID-19. (gla.ac.uk)
- Species that tolerate infections can carry a high burden of infectious agents, and therefore may be important reservoirs for transmissions to other species. (frontiersin.org)
- HHV-4, also known as Epstein-Barr virus (EBV), causes the primary infection infectious mononucleosis , and it is implicated in various diseases, such as African Burkitt lymphoma , other immunoproliferative disorders, and nasopharyngeal carcinoma. (medscape.com)
Antivirals3
- Despite their public impact, there are currently very limited available FDA-approved therapeutics and antivirals against NNS RNA viruses. (uky.edu)
- To study the mechanism of action of ribavirin-based antivirals, Cameron developed an analytical assay that could monitor whether ribavirin could incorporate into viral RNA. (wikipedia.org)
- However, it is a last-resort medication to treat the novel or re-emerging influenza viruses that are resistant to certain antivirals, like oseltamivir [ 1 ]. (springer.com)
Mimicking of viral1
- Sensing of Y RNAs was dependent on their mimicking of viral secondary structure and their 5′-triphosphate extremity. (pasteur.fr)
Enterovirus1
- Enterovirus infections affect many parts of the body and may be caused by any of several different viral strains. (msdmanuals.com)
Recurrent infections2
- They may be primary or recurrent infections. (medscape.com)
- Respiratory syncytial virus (RSV) and the influenza (flu) virus may also cause recurrent infections in affected individuals. (medlineplus.gov)
Vitro and in vivo1
- However, influenza A virus (IAV) infection releases virulent pneumococci from biofilms in vitro and in vivo. (lu.se)
Pathogens3
- Exposure to hepatitis viruses has long been recognized as an occupational risk for health care personnel (HCP), and recommendations previously were established for managing occupational exposures to bloodborne pathogens, including hepatitis C virus (HCV) ( 1 ) (Supplementary Figure, https://stacks.cdc.gov/view/cdc/90288 ). (cdc.gov)
- Therefore, tolerance to infections has evolved as an alternative response of many hosts to specific pathogens ( 6 , 7 ). (frontiersin.org)
- Infection with human immunodeficiency virus (HIV) can result in immunosuppression, allowing opportunistic pathogens to cause disease. (medscape.com)
Severe4
- This agreement marks a significant step forward in Atriva's commitment to combating severe RNA virus infections through innovative host-cell-targeting therapies. (bigcountryhomepage.com)
- Together, we aim to address the urgent medical need for safe and effective therapies for patients suffering from severe RNA virus infections. (bigcountryhomepage.com)
- MDA5 deficiency is a disorder of the immune system (immunodeficiency) that leads to recurrent, severe infections of the lungs and airways (respiratory tract) beginning in infancy. (medlineplus.gov)
- A lack of the important early immune response stimulated by interferons leads to severe viral infections in infants with MDA5 deficiency. (medlineplus.gov)
Clinical6
- Improved understanding of natural history of hepatitis C virus (HCV) RNA levels in chronic infection provides enhanced insights into immunopathogenesis of HCV and has implications for the clinical management of chronic HCV infection. (ox.ac.uk)
- Developing high throughput methods for generating and analysing virus genomic sequences from clinical samples. (gla.ac.uk)
- This report establishes new CDC guidance that includes recommendations for a testing algorithm and clinical management for HCP with potential occupational exposure to hepatitis C virus (HCV). (cdc.gov)
- Health care providers can use this guidance to update their procedures for postexposure testing and clinical management of HCP potentially exposed to hepatitis C virus. (cdc.gov)
- Herpesviruses establish latent permanent infections in their hosts, although clinical signs of disease may not be detected. (medscape.com)
- Treatment of HIV infection may improve the virologic, histologic, and clinical evolution of chronic HBV infection. (medscape.com)
Institut Pasteur3
- Scientists from the Institut Pasteur and the CNRS, working with the University of Göttingen, have characterized the mechanism used by the virus to insert one of its envelope proteins into the host cell membrane, thereby enabling it to infect the cell. (pasteur.fr)
- Scientists in the Structural Virology Unit (Institut Pasteur/CNRS) directed by Félix Rey, in collaboration with the University of Göttingen, characterized the mechanism used by the virus to insert one of its surface proteins into the host cell membrane and drive fusion. (pasteur.fr)
- This study offers a further illustration of the power of comparative analyses of viruses that appear very distant, such as bunyaviruses, alphaviruses and flaviviruses, which can result in highly significant findings and reveal shared mechanisms of action ," commented Félix Rey, Head of the Structural Virology Unit (Institut Pasteur/CNRS), where the study was carried out. (pasteur.fr)
High-throughput1
- We applied high-throughput RNA-Seq technology to provide a more complete overview of the interactions between HCV and the host. (lancs.ac.uk)
Serum6
- Qualitative determination of the human antibody directed against hepatitis C virus (anti-HCV) in human serum or plasma is measured using direct solid-phase enzyme immunoassay with the anti-HCV screening ELISA. (cdc.gov)
- characterized by sustained disappearance of serum HCV RNA and normalization of liver enzymes. (cdc.gov)
- Urine and serum samples from patients with confirmed CHIKV infections from an endemic area (Aruba) and from ITM will be analyzed. (clinicaltrials.gov)
- Endpoints: diagnostic sensitivity of CHIKV RT-PCR on urine samples in patients with a confirmed CHIKV infection, comparison of analytical sensitivity (based on Ct-values) with RT-PCR on serum, positivity rates of RT-PCR urine samples over time Ethical issues: Informed consent will be obtained from study participants. (clinicaltrials.gov)
- In 1917, a 12-year-old with features suggestive of MVEV infection recovered after receiving immune serum. (mja.com.au)
- The laboratory diagnosis is usually performed by testing the plasma or serum to detect the virus, viral nucleic acid or virus specific immunoglobulin M and neutralizing antibodies. (bvsalud.org)
Defense1
- Cells therefore have defense mechanisms that they trigger themselves to ward off infection. (pasteur.fr)
Cells13
- Cameron developed a microfluidic device that allowed him to simultaneously monitor thousands of cells infected with viruses. (wikipedia.org)
- Interferons (IFNs) are natural proteins produced by the cells of the immune system of most vertebrates in response to challenges by foreign agents such as viruses , parasites and tumor cells. (wikidoc.org)
- Interferons are produced by a wide variety of cells in response to the presence of double-stranded RNA , a key indicator of viral infection. (wikidoc.org)
- As the original cell dies from the cytolytic RNA virus , these thousands of viruses will infect nearby cells. (wikidoc.org)
- X-chromosome Inactivation silences one X-chromosome in female cells, and this process is initiated and maintained by the long noncoding RNA Xist. (upenn.edu)
- RVF virus spreads in its host by fusing with cell membranes so that it can proliferate and infect other cells. (pasteur.fr)
- Understanding the mechanism used by these viruses for insertion in the cell membrane paves the way for the development of therapeutic agents that target the "pocket" involved in the fusion of viral and cell membranes with the aim of preventing pathogenic arboviruses from entering host cells. (pasteur.fr)
- Our lab employs complementary expertise in molecular virology and cell biology to investigate mechanisms at the interface between viruses and their host cells. (tigem.it)
- Oxidant tone regulates RANTES gene expression in airway epithelial cells infected with respiratory syncytial virus. (microbiologyresearch.org)
- Differential response of dendritic cells to human metapneumovirus and respiratory syncytial virus. (microbiologyresearch.org)
- [ 5 , 6 ] In a localized primary infection, the virus penetrates the mucosal epithelium and invades the cells of the basal layer, where the viral DNA inserts into the host DNA. (medscape.com)
- We used whole-transcriptome shotgun sequencing (RNA-seq) to compare the S. pneumoniae transcriptome in biofilms, bacteria dispersed from biofilms after exposure to IAV, febrile-range temperature, or ATP, and planktonic cells grown at 37°C. Compared with biofilm. (lu.se)
- We used whole-transcriptome shotgun sequencing (RNA-seq) to compare the S. pneumoniae transcriptome in biofilms, bacteria dispersed from biofilms after exposure to IAV, febrile-range temperature, or ATP, and planktonic cells grown at 37°C. Compared with biofilm bacteria, actively dispersed S. pneumoniae, which were more virulent in invasive disease, upregulated genes involved in carbohydrate metabolism. (lu.se)
Influenza viruses2
- RNA viruses, which include influenza viruses , SARS-CoV-2 (which causes COVID-19 ) and HIV , are one of the major threats that the immune system has to deal with. (pasteur.fr)
- Favipiravir (Aviganâ„¢, T-705, 6-fluoro-3-hydroxy-2-pyrazinecarboxamide) was approved in Japan in 2014 against emerging influenza viruses. (springer.com)
Vaccine2
- This dissertation encompasses original research on adaptive immune responses triggered by natural viral infections caused by NoV and SARS-CoV-2, as well as an exploration of the rash side effect associated with the TV003 DENV vaccine through the detection of viral RNA. (uvm.edu)
- 11 It is also possible that prior immunisation with yellow fever virus or JEV vaccine may induce cross-reactive antibodies. (mja.com.au)
Immune responses1
- In summary, this dissertation seeks to address knowledge gaps in the field of immune responses to three distinct RNA viruses, offering insights into the adaptive immune processes triggered by natural viral infections and vaccination, and their implications for the emergence of viral variants. (uvm.edu)
Proteins4
- Although initially thought to be solely a membrane anchor, the transmembrane domains of several viruses have been shown to be important for the functionality of fusion proteins. (uky.edu)
- The matrix proteins of many enveloped viruses have been shown to associate in high order oligomers to form a grid- like array underneath the plasma membrane, where they can induce membrane curvature to allow for the budding of viral particles. (uky.edu)
- Using a limited number of proteins, viruses can subvert host cell processes to suit their needs, often resulting in a complete reorganization of cellular membrane compartments. (tigem.it)
- Our current work is focused on evaluating the roles host membrane proteins have in facilitating positive-strand RNA virus infection. (tigem.it)
Chronic HCV infection1
- This study assessed factors associated with HCV RNA levels during early chronic infection in a population with well-defined early chronic HCV infection. (ox.ac.uk)
Epidemiology1
- In addition, NHANES provides the means to better define the epidemiology of other hepatitis viruses. (cdc.gov)
Genetic6
- He went on to demonstrate that ribavirin works by creating extreme mutation within viruses that forces them into genetic melt down. (wikipedia.org)
- Scientists have identified a new "multicomponent" virus -- one containing different segments of genetic material in separate particles -- that can infect animals, according to research published today in the journal Cell Host & Microbe. (news-medical.net)
- Qualitative RT-PCR for HCV RNA Test to detect HCV RNA by amplification of viral genetic sequences. (cdc.gov)
- Quantitative assays for HCV RNA Tests to detect HCV RNA concentration (viral load) by amplification of viral genetic sequences or by signal amplification. (cdc.gov)
- Another subset of viruses has DNA as their genetic material. (medlineplus.gov)
- The presence of RESTV in pigs poses a possibility of genetic evolution of the virus. (who.int)
Detection1
- characterized by detection of HCV RNA greater than or equal to 6 months after newly acquired infection. (cdc.gov)
Strains2
- HPV infections have received particular attention in recent years, as high-risk strains have been linked to some cases of oral squamous cell carcinoma. (medscape.com)
- Treatment of HBV infection alone without addressing the HIV infection will lead to emergence of HIV strains that are resistant to nucleoside reverse-transcriptase inhibitors (NRTI). (medscape.com)
HMPV2
Immunization1
- New immunization strategies have been developed to eliminate the spread of hepatitis B virus (HBV) and hepatitis A virus (HAV) in the United States. (cdc.gov)
20011
- Afin de définir l'épidémiologie de la maladie, une surveillance sentinelle a été mise en place en 2001 dans cinq hôpitaux de différentes régions du pays. (who.int)
Distinct1
- The 12 distinct enveloped RNA viruses that cause most viral hemorrhagic fever (VHF) cases are members of 4 families: Arenaviridae, Bunyaviridae, Filoviridae, and Flaviviridae. (medscape.com)
Bacteria2
- Microorganisms are tiny living creatures, such as bacteria and viruses. (msdmanuals.com)
- Bejel, yaws (frambesia), and pinta are infections caused by Treponema , which are spiral-shaped bacteria called spirochetes. (msdmanuals.com)
Mechanisms2
- Potential mechanisms of fetal safety from maternal viral infections are additionally mentioned. (hudsen.org)
- Infections usually become less frequent with age in people with MDA5 deficiency, as the body's immune system matures and develops other mechanisms for fighting viruses. (medlineplus.gov)
Insights2
- Here we used deep sequencing of viRNAs and bioinformatic analysis of RNA secondary structures to gain insights into the characteristics and origins of viRNAs. (ox.ac.uk)
- Chapter IV provides insights into the etiology of the rash induced by live attenuated DENV vaccines and challenge viruses. (uvm.edu)
Flavivirus infection1
- Our work places the ER remodeling system as a central component for flavivirus infection and spread. (tigem.it)
Diseases2
- Urban demographic expansion, deforestation and agricultural settlements in peri-urban areas, are known causes of the increase in the probability of concurrent infection of these two diseases. (who.int)
- Diseases caused by RNA VIRUSES. (bvsalud.org)
DsRNA2
- Further, the level of cytosolic-associated pPKR capable of binding to dsRNA declined during early TMV infection events suggesting that vital dsRNA's bind to pPKR in the cytosol during initial phases of pathogenesis. (elsevierpure.com)
- The production of virus-derived small interfering RNAs (viRNAs) from viral double-stranded RNA (dsRNA) is a key event in this host response. (ox.ac.uk)
Virology1
- Studying virus entry using a multidisciplinary toolkit encompassing basic virology, computational/mathematical analysis, structural biology, and advanced microscopy. (gla.ac.uk)
Early chronic infection3
- Factors associated with hepatitis C virus RNA levels in early chronic infection: the InC3 study. (ox.ac.uk)
- Distribution of HCV RNA levels during early chronic infection was compared by selected host and virological factors. (ox.ac.uk)
- In conclusion, this study demonstrated that IFNL4 rs12979860 CC genotype, male sex, HIV co-infection and HCV genotype G2 are associated with high HCV RNA levels in early chronic infection. (ox.ac.uk)
Cellular2
- An immune receptor normally known for identifying viral RNA is also capable of binding to cellular RNA to induce immune defenses. (pasteur.fr)
- My group apply the techniques of elecrton-cryomicroscopy and image analysis to the study of viruses, providing an exciting opportunity to visualise the process of virus infection at cellular scale and at macromoleculr resolution. (gla.ac.uk)
Molecules1
- Transfer RNA (tRNA) molecules contain various post-transcriptional modifications that are crucial for tRNA stability, translation efficiency, and fidelity. (mdpi.com)