Mammary Tumor Virus, Mouse: The type species of BETARETROVIRUS commonly latent in mice. It causes mammary adenocarcinoma in a genetically susceptible strain of mice when the appropriate hormonal influences operate.Tumor Virus Infections: Infections produced by oncogenic viruses. The infections caused by DNA viruses are less numerous but more diverse than those caused by the RNA oncogenic viruses.Retroviridae Infections: Virus diseases caused by the RETROVIRIDAE.RNA Viruses: Viruses whose genetic material is RNA.Oncogenic Viruses: Viruses that produce tumors.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Mammary Neoplasms, Experimental: Experimentally induced mammary neoplasms in animals to provide a model for studying human BREAST NEOPLASMS.Vaccinia virus: The type species of ORTHOPOXVIRUS, related to COWPOX VIRUS, but whose true origin is unknown. It has been used as a live vaccine against SMALLPOX. It is also used as a vector for inserting foreign DNA into animals. Rabbitpox virus is a subspecies of VACCINIA VIRUS.RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.Virus Cultivation: Process of growing viruses in live animals, plants, or cultured cells.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Receptors, Virus: Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.Virus Diseases: A general term for diseases produced by viruses.Antigens, Viral: Substances elaborated by viruses that have antigenic activity.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Simian virus 40: A species of POLYOMAVIRUS originally isolated from Rhesus monkey kidney tissue. It produces malignancy in human and newborn hamster kidney cell cultures.Viral Proteins: Proteins found in any species of virus.Genes, Viral: The functional hereditary units of VIRUSES.Influenza A Virus, H1N1 Subtype: A subtype of INFLUENZA A VIRUS with the surface proteins hemagglutinin 1 and neuraminidase 1. The H1N1 subtype was responsible for the Spanish flu pandemic of 1918.Virus Shedding: The expelling of virus particles from the body. Important routes include the respiratory tract, genital tract, and intestinal tract. Virus shedding is an important means of vertical transmission (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).Avian leukosis virus: The type species of ALPHARETROVIRUS producing latent or manifest lymphoid leukosis in fowl.Plant Viruses: Viruses parasitic on plants higher than bacteria.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.DNA Viruses: Viruses whose nucleic acid is DNA.Defective Viruses: Viruses which lack a complete genome so that they cannot completely replicate or cannot form a protein coat. Some are host-dependent defectives, meaning they can replicate only in cell systems which provide the particular genetic function which they lack. Others, called SATELLITE VIRUSES, are able to replicate only when their genetic defect is complemented by a helper virus.Cell Line, Tumor: A cell line derived from cultured tumor cells.Tumor Markers, Biological: Molecular products metabolized and secreted by neoplastic tissue and characterized biochemically in cells or body fluids. They are indicators of tumor stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids.Measles virus: The type species of MORBILLIVIRUS and the cause of the highly infectious human disease MEASLES, which affects mostly children.Tumor Necrosis Factor-alpha: Serum glycoprotein produced by activated MACROPHAGES and other mammalian MONONUCLEAR LEUKOCYTES. It has necrotizing activity against tumor cell lines and increases ability to reject tumor transplants. Also known as TNF-alpha, it is only 30% homologous to TNF-beta (LYMPHOTOXIN), but they share TNF RECEPTORS.Avian Sarcoma Viruses: Group of alpharetroviruses (ALPHARETROVIRUS) producing sarcomata and other tumors in chickens and other fowl and also in pigeons, ducks, and RATS.Orthomyxoviridae Infections: Virus diseases caused by the ORTHOMYXOVIRIDAE.Virus Assembly: The assembly of VIRAL STRUCTURAL PROTEINS and nucleic acid (VIRAL DNA or VIRAL RNA) to form a VIRUS PARTICLE.Respiratory Syncytial Viruses: A group of viruses in the PNEUMOVIRUS genus causing respiratory infections in various mammals. Humans and cattle are most affected but infections in goats and sheep have also been reported.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Influenza A Virus, H5N1 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 5 and neuraminidase 1. The H5N1 subtype, frequently referred to as the bird flu virus, is endemic in wild birds and very contagious among both domestic (POULTRY) and wild birds. It does not usually infect humans, but some cases have been reported.Sindbis Virus: The type species of ALPHAVIRUS normally transmitted to birds by CULEX mosquitoes in Egypt, South Africa, India, Malaya, the Philippines, and Australia. It may be associated with fever in humans. Serotypes (differing by less than 17% in nucleotide sequence) include Babanki, Kyzylagach, and Ockelbo viruses.Tumor Burden: The total amount (cell number, weight, size or volume) of tumor cells or tissue in the body.Respiratory Syncytial Virus Infections: Pneumovirus infections caused by the RESPIRATORY SYNCYTIAL VIRUSES. Humans and cattle are most affected but infections in goats and sheep have been reported.West Nile virus: A species of FLAVIVIRUS, one of the Japanese encephalitis virus group (ENCEPHALITIS VIRUSES, JAPANESE). It can infect birds and mammals. In humans, it is seen most frequently in Africa, Asia, and Europe presenting as a silent infection or undifferentiated fever (WEST NILE FEVER). The virus appeared in North America for the first time in 1999. It is transmitted mainly by CULEX spp mosquitoes which feed primarily on birds, but it can also be carried by the Asian Tiger mosquito, AEDES albopictus, which feeds mainly on mammals.Rabies virus: The type species of LYSSAVIRUS causing rabies in humans and other animals. Transmission is mostly by animal bites through saliva. The virus is neurotropic multiplying in neurons and myotubes of vertebrates.Hepatitis B virus: The type species of the genus ORTHOHEPADNAVIRUS which causes human HEPATITIS B and is also apparently a causal agent in human HEPATOCELLULAR CARCINOMA. The Dane particle is an intact hepatitis virion, named after its discoverer. Non-infectious spherical and tubular particles are also seen in the serum.Antiviral Agents: Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.Influenza A Virus, H3N2 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 3 and neuraminidase 2. The H3N2 subtype was responsible for the Hong Kong flu pandemic of 1968.Neoplasms, Experimental: Experimentally induced new abnormal growth of TISSUES in animals to provide models for studying human neoplasms.Rauscher Virus: A strain of MURINE LEUKEMIA VIRUS associated with mouse tumors similar to those caused by the FRIEND MURINE LEUKEMIA VIRUS. It is a replication-competent murine leukemia virus. It can act as a helper virus when complexing with a defective transforming component, RAUSCHER SPLEEN FOCUS-FORMING VIRUS.Yaba monkey tumor virus: The type species of YATAPOXVIRUS, a tumor-producing DNA virus discovered in monkeys in Yaba, Nigeria. It has been found to produce histiocytomas in monkeys and humans.Mice, Inbred BALB CAlpharetrovirus: A genus of the family RETROVIRIDAE with type C morphology, that causes malignant and other diseases in wild birds and domestic fowl.Epstein-Barr Virus Infections: Infection with human herpesvirus 4 (HERPESVIRUS 4, HUMAN); which may facilitate the development of various lymphoproliferative disorders. These include BURKITT LYMPHOMA (African type), INFECTIOUS MONONUCLEOSIS, and oral hairy leukoplakia (LEUKOPLAKIA, HAIRY).Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Gammaretrovirus: A genus of RETROVIRIDAE comprising endogenous sequences in mammals, related RETICULOENDOTHELIOSIS VIRUSES, AVIAN, and a reptilian virus. Many species contain oncogenes and cause leukemias and sarcomas.Cell Transformation, Neoplastic: Cell changes manifested by escape from control mechanisms, increased growth potential, alterations in the cell surface, karyotypic abnormalities, morphological and biochemical deviations from the norm, and other attributes conferring the ability to invade, metastasize, and kill.Mice, Inbred C57BLHepatitis C: INFLAMMATION of the LIVER in humans caused by HEPATITIS C VIRUS, a single-stranded RNA virus. Its incubation period is 30-90 days. Hepatitis C is transmitted primarily by contaminated blood parenterally, and is often associated with transfusion and intravenous drug abuse. However, in a significant number of cases, the source of hepatitis C infection is unknown.Influenza, Human: An acute viral infection in humans involving the respiratory tract. It is marked by inflammation of the NASAL MUCOSA; the PHARYNX; and conjunctiva, and by headache and severe, often generalized, myalgia.Gene Expression Regulation, Viral: Any of the processes by which cytoplasmic factors influence the differential control of gene action in viruses.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Transfection: The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.Vero Cells: A CELL LINE derived from the kidney of the African green (vervet) monkey, (CERCOPITHECUS AETHIOPS) used primarily in virus replication studies and plaque assays.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Retroviridae: Family of RNA viruses that infects birds and mammals and encodes the enzyme reverse transcriptase. The family contains seven genera: DELTARETROVIRUS; LENTIVIRUS; RETROVIRUSES TYPE B, MAMMALIAN; ALPHARETROVIRUS; GAMMARETROVIRUS; RETROVIRUSES TYPE D; and SPUMAVIRUS. A key feature of retrovirus biology is the synthesis of a DNA copy of the genome which is integrated into cellular DNA. After integration it is sometimes not expressed but maintained in a latent state (PROVIRUSES).Cercopithecus aethiops: A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.Vesicular stomatitis Indiana virus: The type species of VESICULOVIRUS causing a disease symptomatically similar to FOOT-AND-MOUTH DISEASE in cattle, horses, and pigs. It may be transmitted to other species including humans, where it causes influenza-like symptoms.Wilms Tumor: A malignant kidney tumor, caused by the uncontrolled multiplication of renal stem (blastemal), stromal (STROMAL CELLS), and epithelial (EPITHELIAL CELLS) elements. However, not all three are present in every case. Several genes or chromosomal areas have been associated with Wilms tumor which is usually found in childhood as a firm lump in a child's side or ABDOMEN.Repetitive Sequences, Nucleic Acid: Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).Neutralization Tests: The measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Tumor Suppressor Protein p53: Nuclear phosphoprotein encoded by the p53 gene (GENES, P53) whose normal function is to control CELL PROLIFERATION and APOPTOSIS. A mutant or absent p53 protein has been found in LEUKEMIA; OSTEOSARCOMA; LUNG CANCER; and COLORECTAL CANCER.Virus Activation: The mechanism by which latent viruses, such as genetically transmitted tumor viruses (PROVIRUSES) or PROPHAGES of lysogenic bacteria, are induced to replicate and then released as infectious viruses. It may be effected by various endogenous and exogenous stimuli, including B-cell LIPOPOLYSACCHARIDES, glucocorticoid hormones, halogenated pyrimidines, IONIZING RADIATION, ultraviolet light, and superinfecting viruses.Orthomyxoviridae: A family of RNA viruses causing INFLUENZA and other diseases. There are five recognized genera: INFLUENZAVIRUS A; INFLUENZAVIRUS B; INFLUENZAVIRUS C; ISAVIRUS; and THOGOTOVIRUS.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Cell Transformation, Viral: An inheritable change in cells manifested by changes in cell division and growth and alterations in cell surface properties. It is induced by infection with a transforming virus.RNA-Directed DNA Polymerase: An enzyme that synthesizes DNA on an RNA template. It is encoded by the pol gene of retroviruses and by certain retrovirus-like elements. EC 2.7.7.49.Moloney murine leukemia virus: A strain of Murine leukemia virus (LEUKEMIA VIRUS, MURINE) arising during the propagation of S37 mouse sarcoma, and causing lymphoid leukemia in mice. It also infects rats and newborn hamsters. It is apparently transmitted to embryos in utero and to newborns through mother's milk.Virion: The infective system of a virus, composed of the viral genome, a protein core, and a protein coat called a capsid, which may be naked or enclosed in a lipoprotein envelope called the peplos.Nucleic Acid Hybridization: Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)DNA Virus InfectionsProviruses: Duplex DNA sequences in eukaryotic chromosomes, corresponding to the genome of a virus, that are transmitted from one cell generation to the next without causing lysis of the host. Proviruses are often associated with neoplastic cell transformation and are key features of retrovirus biology.Simian immunodeficiency virus: Species of the genus LENTIVIRUS, subgenus primate immunodeficiency viruses (IMMUNODEFICIENCY VIRUSES, PRIMATE), that induces acquired immunodeficiency syndrome in monkeys and apes (SAIDS). The genetic organization of SIV is virtually identical to HIV.Promoter Regions, Genetic: DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.Hemagglutinin Glycoproteins, Influenza Virus: Membrane glycoproteins from influenza viruses which are involved in hemagglutination, virus attachment, and envelope fusion. Fourteen distinct subtypes of HA glycoproteins and nine of NA glycoproteins have been identified from INFLUENZA A VIRUS; no subtypes have been identified for Influenza B or Influenza C viruses.Herpesvirus 4, Human: The type species of LYMPHOCRYPTOVIRUS, subfamily GAMMAHERPESVIRINAE, infecting B-cells in humans. It is thought to be the causative agent of INFECTIOUS MONONUCLEOSIS and is strongly associated with oral hairy leukoplakia (LEUKOPLAKIA, HAIRY;), BURKITT LYMPHOMA; and other malignancies.Genes, Tumor Suppressor: Genes that inhibit expression of the tumorigenic phenotype. They are normally involved in holding cellular growth in check. When tumor suppressor genes are inactivated or lost, a barrier to normal proliferation is removed and unregulated growth is possible.Parainfluenza Virus 1, Human: A species of RESPIROVIRUS also called hemadsorption virus 2 (HA2), which causes laryngotracheitis in humans, especially children.Virus Latency: The ability of a pathogenic virus to lie dormant within a cell (latent infection). In eukaryotes, subsequent activation and viral replication is thought to be caused by extracellular stimulation of cellular transcription factors. Latency in bacteriophage is maintained by the expression of virally encoded repressors.Mice, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.Hepacivirus: A genus of FLAVIVIRIDAE causing parenterally-transmitted HEPATITIS C which is associated with transfusions and drug abuse. Hepatitis C virus is the type species.Viral Plaque Assay: Method for measuring viral infectivity and multiplication in CULTURED CELLS. Clear lysed areas or plaques develop as the VIRAL PARTICLES are released from the infected cells during incubation. With some VIRUSES, the cells are killed by a cytopathic effect; with others, the infected cells are not killed but can be detected by their hemadsorptive ability. Sometimes the plaque cells contain VIRAL ANTIGENS which can be measured by IMMUNOFLUORESCENCE.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.RNA Virus InfectionsGenetic Vectors: DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.Virus Integration: Insertion of viral DNA into host-cell DNA. This includes integration of phage DNA into bacterial DNA; (LYSOGENY); to form a PROPHAGE or integration of retroviral DNA into cellular DNA to form a PROVIRUS.Satellite Viruses: Defective viruses which can multiply only by association with a helper virus which complements the defective gene. Satellite viruses may be associated with certain plant viruses, animal viruses, or bacteriophages. They differ from satellite RNA; (RNA, SATELLITE) in that satellite viruses encode their own coat protein.Mammary Glands, Animal: MAMMARY GLANDS in the non-human MAMMALS.Carcinoid Tumor: A usually small, slow-growing neoplasm composed of islands of rounded, oxyphilic, or spindle-shaped cells of medium size, with moderately small vesicular nuclei, and covered by intact mucosa with a yellow cut surface. The tumor can occur anywhere in the gastrointestinal tract (and in the lungs and other sites); approximately 90% arise in the appendix. It is now established that these tumors are of neuroendocrine origin and derive from a primitive stem cell. (From Stedman, 25th ed & Holland et al., Cancer Medicine, 3d ed, p1182)Hepatitis A virus: A species in the genus HEPATOVIRUS containing one serotype and two strains: HUMAN HEPATITIS A VIRUS and Simian hepatitis A virus causing hepatitis in humans (HEPATITIS A) and primates, respectively.Mumps virus: The type species of RUBULAVIRUS that causes an acute infectious disease in humans, affecting mainly children. Transmission occurs by droplet infection.Hepatitis B: INFLAMMATION of the LIVER in humans caused by a member of the ORTHOHEPADNAVIRUS genus, HEPATITIS B VIRUS. It is primarily transmitted by parenteral exposure, such as transfusion of contaminated blood or blood products, but can also be transmitted via sexual or intimate personal contact.Sendai virus: The type species of RESPIROVIRUS in the subfamily PARAMYXOVIRINAE. It is the murine version of HUMAN PARAINFLUENZA VIRUS 1, distinguished by host range.Inclusion Bodies, Viral: An area showing altered staining behavior in the nucleus or cytoplasm of a virus-infected cell. Some inclusion bodies represent "virus factories" in which viral nucleic acid or protein is being synthesized; others are merely artifacts of fixation and staining. One example, Negri bodies, are found in the cytoplasm or processes of nerve cells in animals that have died from rabies.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Dengue: An acute febrile disease transmitted by the bite of AEDES mosquitoes infected with DENGUE VIRUS. It is self-limiting and characterized by fever, myalgia, headache, and rash. SEVERE DENGUE is a more virulent form of dengue.DNA Primers: Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.HIV Infections: Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).Mammary Neoplasms, Animal: Tumors or cancer of the MAMMARY GLAND in animals (MAMMARY GLANDS, ANIMAL).Tumor Suppressor Proteins: Proteins that are normally involved in holding cellular growth in check. Deficiencies or abnormalities in these proteins may lead to unregulated cell growth and tumor development.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.T-Lymphocytes: Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.Simplexvirus: A genus of the family HERPESVIRIDAE, subfamily ALPHAHERPESVIRINAE, consisting of herpes simplex-like viruses. The type species is HERPESVIRUS 1, HUMAN.Dexamethasone: An anti-inflammatory 9-fluoro-glucocorticoid.Semliki forest virus: A species of ALPHAVIRUS isolated in central, eastern, and southern Africa.Neuroendocrine Tumors: Tumors whose cells possess secretory granules and originate from the neuroectoderm, i.e., the cells of the ectoblast or epiblast that program the neuroendocrine system. Common properties across most neuroendocrine tumors include ectopic hormone production (often via APUD CELLS), the presence of tumor-associated antigens, and isozyme composition.Virus Attachment: The binding of virus particles to receptors on the host cell surface. For enveloped viruses, the virion ligand is usually a surface glycoprotein as is the cellular receptor. For non-enveloped viruses, the virus CAPSID serves as the ligand.Fluorescent Antibody Technique: Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Brain Neoplasms: Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.HeLa Cells: The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.Cytopathogenic Effect, Viral: Visible morphologic changes in cells infected with viruses. It includes shutdown of cellular RNA and protein synthesis, cell fusion, release of lysosomal enzymes, changes in cell membrane permeability, diffuse changes in intracellular structures, presence of viral inclusion bodies, and chromosomal aberrations. It excludes malignant transformation, which is CELL TRANSFORMATION, VIRAL. Viral cytopathogenic effects provide a valuable method for identifying and classifying the infecting viruses.Enzyme-Linked Immunosorbent Assay: An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.Respirovirus Infections: Infections with viruses of the genus RESPIROVIRUS, family PARAMYXOVIRIDAE. Host cell infection occurs by adsorption, via HEMAGGLUTININ, to the cell surface.BK Virus: A species of POLYOMAVIRUS apparently infecting over 90% of children but not clearly associated with any clinical illness in childhood. The virus remains latent in the body throughout life and can be reactivated under certain circumstances.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Respiratory Syncytial Virus, Human: The type species of PNEUMOVIRUS and an important cause of lower respiratory disease in infants and young children. It frequently presents with bronchitis and bronchopneumonia and is further characterized by fever, cough, dyspnea, wheezing, and pallor.Chikungunya virus: A species of ALPHAVIRUS causing an acute dengue-like fever.Mice, Inbred C3HAntigens, Viral, Tumor: Those proteins recognized by antibodies from serum of animals bearing tumors induced by viruses; these proteins are presumably coded for by the nucleic acids of the same viruses that caused the neoplastic transformation.West Nile Fever: A mosquito-borne viral illness caused by the WEST NILE VIRUS, a FLAVIVIRUS and endemic to regions of Africa, Asia, and Europe. Common clinical features include HEADACHE; FEVER; maculopapular rash; gastrointestinal symptoms; and lymphadenopathy. MENINGITIS; ENCEPHALITIS; and MYELITIS may also occur. The disease may occasionally be fatal or leave survivors with residual neurologic deficits. (From Joynt, Clinical Neurology, 1996, Ch26, p13; Lancet 1998 Sep 5;352(9130):767-71)Cowpox virus: A species of ORTHOPOXVIRUS that is the etiologic agent of COWPOX. It is closely related to but antigenically different from VACCINIA VIRUS.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Tumor Microenvironment: The milieu surrounding neoplasms consisting of cells, vessels, soluble factors, and molecules, that can influence and be influenced by, the neoplasm's growth.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Adenocarcinoma: A malignant epithelial tumor with a glandular organization.Mosaic Viruses: Viruses which produce a mottled appearance of the leaves of plants.Viral Load: The quantity of measurable virus in a body fluid. Change in viral load, measured in plasma, is sometimes used as a SURROGATE MARKER in disease progression.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Avian myeloblastosis virus: A species of ALPHARETROVIRUS causing anemia in fowl.Leukemia Virus, Feline: A species of GAMMARETROVIRUS causing leukemia, lymphosarcoma, immune deficiency, or other degenerative diseases in cats. Several cellular oncogenes confer on FeLV the ability to induce sarcomas (see also SARCOMA VIRUSES, FELINE).JC Virus: A species of POLYOMAVIRUS, originally isolated from the brain of a patient with progressive multifocal leukoencephalopathy. The patient's initials J.C. gave the virus its name. Infection is not accompanied by any apparent illness but serious demyelinating disease can appear later, probably following reactivation of latent virus.DNA, Neoplasm: DNA present in neoplastic tissue.Liver Neoplasms: Tumors or cancer of the LIVER.Epitopes: Sites on an antigen that interact with specific antibodies.CD8-Positive T-Lymphocytes: A critical subpopulation of regulatory T-lymphocytes involved in MHC Class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-LYMPHOCYTES, CYTOTOXIC) and CD8+ suppressor T-lymphocytes.Capsid: The outer protein protective shell of a virus, which protects the viral nucleic acid.Chick Embryo: The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.Viruses, Unclassified: Viruses whose taxonomic relationships have not been established.Host-Pathogen Interactions: The interactions between a host and a pathogen, usually resulting in disease.Haplorhini: A suborder of PRIMATES consisting of six families: CEBIDAE (some New World monkeys), ATELIDAE (some New World monkeys), CERCOPITHECIDAE (Old World monkeys), HYLOBATIDAE (gibbons and siamangs), CALLITRICHINAE (marmosets and tamarins), and HOMINIDAE (humans and great apes).Influenza A virus: The type species of the genus INFLUENZAVIRUS A that causes influenza and other diseases in humans and animals. Antigenic variation occurs frequently between strains, allowing classification into subtypes and variants. Transmission is usually by aerosol (human and most non-aquatic hosts) or waterborne (ducks). Infected birds shed the virus in their saliva, nasal secretions, and feces.Betaretrovirus: A genus of the family RETROVIRIDAE consisting of viruses with either type B or type D morphology. This includes a few exogenous, vertically transmitted and endogenous viruses of mice (type B) and some primate and sheep viruses (type D). MAMMARY TUMOR VIRUS, MOUSE is the type species.Superantigens: Microbial antigens that have in common an extremely potent activating effect on T-cells that bear a specific variable region. Superantigens cross-link the variable region with class II MHC proteins regardless of the peptide binding in the T-cell receptor's pocket. The result is a transient expansion and subsequent death and anergy of the T-cells with the appropriate variable regions.Antigens, Neoplasm: Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Bluetongue virus: The type species of ORBIVIRUS causing a serious disease in sheep, especially lambs. It may also infect wild ruminants and other domestic animals.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Neoplasms: New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.Culture Techniques: Methods of maintaining or growing biological materials in controlled laboratory conditions. These include the cultures of CELLS; TISSUES; organs; or embryo in vitro. Both animal and plant tissues may be cultured by a variety of methods. Cultures may derive from normal or abnormal tissues, and consist of a single cell type or mixed cell types.Recombination, Genetic: Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.TritiumCross Reactions: Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.Neoplasm Metastasis: The transfer of a neoplasm from one organ or part of the body to another remote from the primary site.Herpesvirus 1, Human: The type species of SIMPLEXVIRUS causing most forms of non-genital herpes simplex in humans. Primary infection occurs mainly in infants and young children and then the virus becomes latent in the dorsal root ganglion. It then is periodically reactivated throughout life causing mostly benign conditions.Sarcoma, Experimental: Experimentally induced neoplasms of CONNECTIVE TISSUE in animals to provide a model for studying human SARCOMA.Tobacco Mosaic Virus: The type species of TOBAMOVIRUS which causes mosaic disease of tobacco. Transmission occurs by mechanical inoculation.Friend murine leukemia virus: A strain of Murine leukemia virus (LEUKEMIA VIRUS, MURINE) producing leukemia of the reticulum-cell type with massive infiltration of liver, spleen, and bone marrow. It infects DBA/2 and Swiss mice.Terminal Repeat Sequences: Nucleotide sequences repeated on both the 5' and 3' ends of a sequence under consideration. For example, the hallmarks of a transposon are that it is flanked by inverted repeats on each end and the inverted repeats are flanked by direct repeats. The Delta element of Ty retrotransposons and LTRs (long terminal repeats) are examples of this concept.Lymphocytic choriomeningitis virus: The type species of ARENAVIRUS, part of the Old World Arenaviruses (ARENAVIRUSES, OLD WORLD), producing a silent infection in house and laboratory mice. In humans, infection with LCMV can be inapparent, or can present with an influenza-like illness, a benign aseptic meningitis, or a severe meningoencephalomyelitis. The virus can also infect monkeys, dogs, field mice, guinea pigs, and hamsters, the latter an epidemiologically important host.Neovascularization, Pathologic: A pathologic process consisting of the proliferation of blood vessels in abnormal tissues or in abnormal positions.DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.CD4-Positive T-Lymphocytes: A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.Myxoma virus: The type species of LEPORIPOXVIRUS causing infectious myxomatosis, a severe generalized disease, in rabbits. Tumors are not always present.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Viremia: The presence of viruses in the blood.Transplantation, Heterologous: Transplantation between animals of different species.Sarcoma Viruses, Murine: A group of replication-defective viruses, in the genus GAMMARETROVIRUS, which are capable of transforming cells, but which replicate and produce tumors only in the presence of Murine leukemia viruses (LEUKEMIA VIRUS, MURINE).Lassa virus: A species of ARENAVIRUS, part of the Old World Arenaviruses (ARENAVIRUSES, OLD WORLD), and the etiologic agent of LASSA FEVER. LASSA VIRUS is a common infective agent in humans in West Africa. Its natural host is the multimammate mouse Mastomys natalensis.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Flow Cytometry: Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Spleen: An encapsulated lymphatic organ through which venous blood filters.Antigens, Polyomavirus Transforming: Polyomavirus antigens which cause infection and cellular transformation. The large T antigen is necessary for the initiation of viral DNA synthesis, repression of transcription of the early region and is responsible in conjunction with the middle T antigen for the transformation of primary cells. Small T antigen is necessary for the completion of the productive infection cycle.Virus Physiological Phenomena: Biological properties, processes, and activities of VIRUSES.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Yellow fever virus: The type species of the FLAVIVIRUS genus. Principal vector transmission to humans is by AEDES spp. mosquitoes.Molecular Weight: The sum of the weight of all the atoms in a molecule.Hepatitis B Surface Antigens: Those hepatitis B antigens found on the surface of the Dane particle and on the 20 nm spherical and tubular particles. Several subspecificities of the surface antigen are known. These were formerly called the Australia antigen.Neoplasm Proteins: Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.Receptors, Glucocorticoid: Cytoplasmic proteins that specifically bind glucocorticoids and mediate their cellular effects. The glucocorticoid receptor-glucocorticoid complex acts in the nucleus to induce transcription of DNA. Glucocorticoids were named for their actions on blood glucose concentration, but they have equally important effects on protein and fat metabolism. Cortisol is the most important example.Polyomavirus: A genus of potentially oncogenic viruses of the family POLYOMAVIRIDAE. These viruses are normally present in their natural hosts as latent infections. The virus is oncogenic in hosts different from the species of origin.Leukemia, Experimental: Leukemia induced experimentally in animals by exposure to leukemogenic agents, such as VIRUSES; RADIATION; or by TRANSPLANTATION of leukemic tissues.Disease Progression: The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.Dengue Virus: A species of the genus FLAVIVIRUS which causes an acute febrile and sometimes hemorrhagic disease in man. Dengue is mosquito-borne and four serotypes are known.Neuraminidase: An enzyme that catalyzes the hydrolysis of alpha-2,3, alpha-2,6-, and alpha-2,8-glycosidic linkages (at a decreasing rate, respectively) of terminal sialic residues in oligosaccharides, glycoproteins, glycolipids, colominic acid, and synthetic substrate. (From Enzyme Nomenclature, 1992)Gene Products, gag: Proteins coded by the retroviral gag gene. The products are usually synthesized as protein precursors or POLYPROTEINS, which are then cleaved by viral proteases to yield the final products. Many of the final products are associated with the nucleoprotein core of the virion. gag is short for group-specific antigen.

Immunohistochemical expression of mdm2 and p21WAF1 in invasive cervical cancer: correlation with p53 protein and high risk HPV infection. (1/2725)

AIM: To investigate the immunocytochemical staining pattern of mdm2 and p21WAF1 proteins in invasive cervical cancer and to determine its relation with the expression of p53 and with the high risk HPV infection. METHODS: Immunocytochemistry for p53, mdm2, and p21WAF1 was performed in 31 paraffin embedded sections of invasive cervical cancer. The results were assessed by image analysis, evaluating for each protein the optical density of the immunostained area, scored as percentage of the total nuclear area. The presence of high risk human papillomavirus (HPV) infection was detected by using the polymerase chain reaction. RESULTS: Immunostaining for both mdm2 and p21WAF1 was correlated with p53 expression; however, the correlation between p53 and mdm2 (R = 0.49; p < 0.01) was more significant than between p53 and p21WAF1 (R = 0.31; p < 0.05); the less stringent correlation between p53 and p21WAF1 might reflect the p53 independent mechanisms of p21WAF1 induction. Similar average levels of p53, mdm2, and p21WAF1 immunostaining were found in the presence or absence of high risk HPV-DNA, without significant differences between the two groups. CONCLUSIONS: These data suggest that mdm2 and p21WAF1 proteins are expressed in invasive cervical cancer and that their immunocytochemical staining pattern is not abrogated by the presence of high risk HPV genomic sequences.  (+info)

Microsatellite instability, Epstein-Barr virus, mutation of type II transforming growth factor beta receptor and BAX in gastric carcinomas in Hong Kong Chinese. (2/2725)

Microsatellite instability (MI), the phenotypic manifestation of mismatch repair failure, is found in a proportion of gastric carcinomas. Little is known of the links between MI and Epstein-Barr virus (EBV) status and clinicopathological elements. Examination of genes mutated through the MI mechanism could also be expected to reveal important information on the carcinogenic pathway. Seventy-nine gastric carcinomas (61 EBV negative, 18 EBV positive) from local Hong Kong Chinese population, an intermediate-incidence area, were examined. Eight microsatellite loci, inclusive of the A10 tract of type II transforming growth factor beta receptor (TbetaR-II), were used to evaluate the MI status. MI in the BAX and insulin-like growth factor II receptor (IGF-IIR) genes were also examined. High-level MI (>40% unstable loci) was detected in ten cases (12.7%) and low-level MI (1-40% unstable loci) in three (3.8%). High-level MI was detected in two EBV-associated cases (11%) and the incidence was similar for the EBV-negative cases (13%). The high-level MIs were significantly associated with intestinal-type tumours (P = 0.03) and a more prominent lymphoid infiltrate (P = 0.04). Similar associations were noted in the EBV-positive carcinomas. The high-level MIs were more commonly located in the antrum, whereas the EBV-associated carcinomas were mostly located in body. Thirteen cardia cases were negative for both high-level MI and EBV. All patients aged below 55 were MI negative (P = 0.049). Of the high-level MIs, 80% had mutation in TbetaR-II, 40% in BAX and 0% in IGF-IIR. Of low-level MIs, 33% also had TbetaR-II mutation. These mutations were absent in the MI-negative cases. Of three lymphoepithelioma-like carcinomas, two cases were EBV positive and MI negative, one case was EBV negative but with high-level MI. In conclusion, high-level MIs were present regardless of the EBV status, and were found in a particular clinicopathological subset of gastric carcinoma patient. Inactivation of important growth regulatory genes observed in these carcinomas confirms the importance of MI in carcinogenesis.  (+info)

Association of simian virus 40 with a central nervous system lesion distinct from progressive multifocal leukoencephalopathy in macaques with AIDS. (3/2725)

The primate polyomavirus SV40 is known to cause interstitial nephritis in primary infections and progressive multifocal leukoencephalopathy (PML) upon reactivation of a latent infection in SIV-infected macaques. We now describe a second central nervous system manifestation of SV40: a meningoencephalitis affecting cerebral gray matter, without demyelination, distinct from PML. Meningoencephalitis appears also to be a primary manifestation of SV40 infection and can be seen in conjunction with SV40-induced interstitial nephritis and pneumonitis. The difference in the lesions of meningoencephalitis and PML does not appear to be due to cellular tropism, as both oligodendrocytes and astrocytes are infected in PML and meningoencephalitis, as determined by in situ hybridization or immunohistochemistry for SV40 coupled with immunohistochemistry for cellular determinants. This is further supported by examination of SV40 nucleic acid sequences from the ori-enhancer and large-T-antigen regions, which reveals no tissue-or lesion-specific variation in SV40 sequences.  (+info)

Lymphomatoid granulomatosis following autologous stem cell transplantation. (4/2725)

Lymphomatoid granulomatosis (LYG) is a rare angio-destructive lymphoproliferative disorder (LPD) of uncertain etiology, with prominent pulmonary involvement. Recent studies indicate that LYG is an Epstein-Barr virus (EBV)-associated B cell LPD with large numbers of background reactive T lymphocytes (T cell-rich B cell lymphoma). Although the disease frequently, but not exclusively, occurs in various immunodeficiency states, it has not been reported in association with the transient immunosuppression following autologous bone marrow/peripheral stem cell transplantation (ABM/PSCT). We describe a patient who developed lymphomatoid granulomatosis of the lung approximately 2 weeks after high-dose chemotherapy and autologous peripheral stem cell transplantation for multiple myeloma. Although molecular studies showed no evidence of EBV genome in the biopsy material, the serologic profile with high IgM titers was suggestive of primary EBV infection. Complete radiologic remission occurred following reconstitution of the patient's immune response after a 2-week course of ganciclovir treatment. Despite the apparently low frequency of LPD (both LYG and EBV-associated post-transplant lymphoma) in the ABMT setting, we believe that it should be considered in the differential diagnosis of patients whose clinical course following ABMT is complicated by fevers, in the absence of an identifiable infectious process.  (+info)

Cervicovaginal human papillomavirus infection in human immunodeficiency virus-1 (HIV)-positive and high-risk HIV-negative women. (5/2725)

BACKGROUND: Human papillomavirus (HPV) infection is associated with precancerous cervical squamous intraepithelial lesions commonly seen among women infected with human immunodeficiency virus-1 (HIV). We characterized HPV infection in a large cohort of HIV-positive and HIV-negative women participating in the Women's Interagency HIV Study to determine the prevalence of and risk factors for cervicovaginal HPV infection in HIV-positive women. METHODS: HIV-positive (n = 1778) and HIV-negative (n = 500) women were tested at enrollment for the presence of HPV DNA in a cervicovaginal lavage specimen. Blood samples were tested for HIV antibody status, level of CD4-positive T cells, and HIV RNA load (copies/mL). An interview detailing risk factors was conducted. Univariate and multivariate analyses were performed. RESULTS: Compared with HIV-negative women, HIV-positive women with a CD4+ cell count of less than 200/mm3 were at the highest risk of HPV infection, regardless of HIV RNA load (odds ratio [OR] = 10.13; 95% confidence interval [CI] = 7.32-14.04), followed by women with a CD4+ count greater than 200/mm3 and an HIV RNA load greater than 20,000 copies/mL (OR = 5.78; 95% CI = 4.17-8.08) and women with a CD4+ count greater than 200/mm3 and an HIV RNA load less than 20,000 copies/mL (OR = 3.12; 95% CI = 2.36-4.12), after adjustment for other factors. Other risk factors among HIV-positive women included racial/ethnic background (African-American versus Caucasian, OR = 1.64; 95% CI = 1.19-2.28), current smoking (yes versus no; OR = 1.55; 95% CI = 1.20-1.99), and younger age (age < 30 years versus > or = 40 years; OR = 1.75; 95% CI = 1.23-2.49). CONCLUSIONS: Although the strongest risk factors of HPV infection among HIV-positive women were indicators of more advanced HIV-related disease, other factors commonly found in studies of HIV-negative women, including racial/ethnic background, current smoking, and age, were important in HIV-positive women as well.  (+info)

Risk factors for abnormal anal cytology in young heterosexual women. (6/2725)

Although anal cancers are up to four times more common in women than men, little is known about the natural history of anal human papillomavirus (HPV) infections and HPV-related anal lesions in women. This study reports on the prevalence of and risks for anal cytological abnormalities over a 1-year period in a cohort of young women participating in a study of the natural history of cervical HPV infection. In addition to their regularly scheduled sexual behavior interviews and cervical testing, consenting women received anal HPV DNA and cytological testing. Anal cytology smears were obtained from 410 women whose mean age was 22.5 +/- 2.5 years at the onset of the study. Sixteen women (3.9%) were found to have abnormal anal cytology: 4 women had low-grade squamous intraepithelial lesions (SILs) or condyloma; and 12 women had atypical cells of undetermined significance. Factors found to be significantly associated with abnormal anal cytology were a history of anal sex [odds ratio (OR), 6.90; 95% confidence interval (CI), 1.7-47.2], a history of cervical SILs (OR, 4.13; 95% CI, 1.3-14.9), and a current anal HPV infection (OR, 12.28; 95% CI, 3.9-43.5). The strong association between anal intercourse and the development of HPV-induced SILs supports the role of sexual transmission of HPV in anal SILs. Young women who had engaged in anal intercourse or had a history of cervical SILs were found to be at highest risk.  (+info)

Persistently high Epstein-Barr virus (EBV) loads in peripheral blood lymphocytes from patients with chronic active EBV infection. (7/2725)

Chronic active Epstein-Barr virus infection (CAEBV) is a severe illness with unusual EBV activation that persists for years, and its pathogenesis is largely unknown. After the creation of an accurate and reproducible polymerase chain reaction system to quantify EBV DNA, virus loads in peripheral blood lymphocytes (PBL) were determined in 54 children: 15 with CAEBV, 16 with infectious mononucleosis (IM), and 23 healthy children. Children with CAEBV and those with IM had high virus loads. Lower loads were detected in 47% of seropositive healthy donors. There were two distinct differences between children with CAEBV and those with IM: The former had greater viral replication (10(3)-10(7) copies/2.5x10(5) PBL) than those with IM, and viral replication declined in children with IM whereas active replication persisted for years in subjects with CAEBV. Persisting high virus loads are a possible diagnostic criterion for CAEBV. EBV loads may enable classification and prognosis of EBV infections.  (+info)

B cell response after MMTV infection: extrafollicular plasmablasts represent the main infected population and can transmit viral infection. (8/2725)

The immune response to mouse mammary tumor virus (MMTV) relies on the presentation of an MMTV-encoded superantigen by infected B cells to superantigen-specific T cells. The initial extrafollicular B cell differentiation involved the generation of B cells expressing low levels of B220. These B220low B cells corresponded to plasmablasts that expressed high levels of CD43 and syndecan-1 and were CD62 ligand- and IgD-. Viral DNA was detected nearly exclusively in these B220low B cells by PCR, and retroviral type-A particles were observed in their cytoplasm by electron microscopy. An MMTV transmission to the offspring was also achieved after transfer of B220low CD62 ligand- CD43+ plasmablasts into noninfected females. These data suggest that B220low plasmablasts, representing the bulk of infected B cells, are capable of sustaining viral replication and may be involved in the transmission of MMTV.  (+info)

  • Thus, the metabolic plasticity of cancer cells is illustrated under conditions frequently established for solid tumors in vivo , such as aglycemia plus hypoxia. (frontiersin.org)
  • CNS tumors are the most common solid tumors in children and adolescents," explains Keith Okamoto, one of the study's lead authors. (eurekalert.org)
  • Although Hodgkin's lymphoma (HL) can be considered a successful paradigm of modern treatment strategies, about 15-20% of patients with advanced-stage HL still die following relapse or progressive disease and a similar proportion of patients are over-treated, 1 , 2 leading to treatment-related late sequelae including solid tumors and end-organ dysfunction. (haematologica.org)
  • Most of these replicating oncolytic viruses specifically target solid tumors [ 4 ], which is a significant advantage over the use of conventional chemo- and radiotherapy. (biomedcentral.com)
  • However, although B cells present antigen to experienced T cells, they are inefficient at inducing immune responses by naïve T cells ( 9 , 10 ), as would occur when cognate T cells first encounter Sag during MMTV infection. (asm.org)
  • Thus, several groups have tested whether DCs, which are professional antigen-presenting cells, participate in MMTV Sag presentation to cognate T cells and thereby initiate virus infection. (asm.org)
  • 2004) Toxoplasma gondii antigen-pulsed-dendritic cell-derived exosomes induce a protective immune response against T. gondii infection. (springer.com)
  • Colino J, Snapper CM (2007) Dendritic cell-derived exosomes express a Streptococcus pneumoniae capsular polysaccharide type 14 cross-reactive antigen that induces protective immunoglobulin responses against pneumococcal infection in mice. (springer.com)
  • The large T antigen regulates the life cycle of the virus as well as stimulates the cell cycle of the host cell. (aacrjournals.org)
  • Immortalization of swine umbilical vein endothelial cells (SUVECs) with the simian virus 40 large-T antigen. (semanticscholar.org)
  • The T cell receptor (TCR) repertoires of cytotoxic responses to the immunodominant and subdominant HLA A11-restricted epitopes in the Epstein-Barr virus (EBV) nuclear antigen-4 were investigated in four healthy virus carriers. (nih.gov)
  • 10. Transforming activity of bovine leukemia virus and properties of tumor-associated antigen on bovine lymphosarcoma. (indigo.ca)
  • Tumor will focus on the DNA viruses in the human population that are associated with cancers. (worldcat.org)
  • Thus far, a strong link between some RNA and DNA viruses and various cancers in humans has been established and the transforming activity of several of the viruses in cell culture and their oncogenecity in experimental animals has been well documented. (biomedsearch.com)
  • The acknowledgment that viruses are potent biological factors in driving many cancers have seen a dramatic upsurge in recent years in large part to the success of the human papilloma virus vaccine against invasive cervical carcinomas and followed by the awarding of the noble prize in medicine in 2008 to Dr. Harald zurHausen who identified the link between papilloma virus and cervical cancers. (indigo.ca)
  • Over the last few years there have been some volumes addressing different aspects of viruses and cancers and to some extent focusing on the DNA viruses, more specifically the human DNA viruses. (indigo.ca)
  • We will also cover other known oncogenic viruses associated cancers in other mammals in addition to humans. (indigo.ca)
  • HPV DNA has been detected in tumor tissues of head and neck cancer ( 3 , 4 ), oral cancer ( 5 ), esophageal cancer ( 6 , 7 ), and some skin cancers ( 8 , 9 ), as well as lung cancer ( 10 , 11 ). (aacrjournals.org)
  • However, HPV DNA was not detectable by regular PCR in one earlier study ( 18 ) and a survey of HPV16 virus-like particle antibodies in patients with epithelial cancers also failed to provide an association between HPV and colorectal cancer ( 19 ), challenging the association of colorectal cancers with HPVs. (aacrjournals.org)
  • The World Health Organization 's International Agency for Research on Cancer estimated that in 2002, infection caused 17.8% of human cancers, with 11.9% caused by one of seven viruses. (wikipedia.org)
  • A minority of persons (or animals) will go on to develop cancers after infection. (wikipedia.org)
  • Relman and Fredericks have described the difficulties in applying Koch's postulates to virus-induced cancers. (wikipedia.org)
  • Because foreign virus antigens are expressed in these tumors, persons who are immunosuppressed such as AIDS or transplant patients are at higher risk for these types of cancers. (wikipedia.org)
  • 12% of all human cancers are caused by virus infections. (icgeb.org)
  • It has now been established that infection with human papillomavirus (HPV) is necessary for the development of most cervical cancers. (aacrjournals.org)
  • The majority of risk associated with HSV-2 was confined to HPV-negative tumors, indicating a possible separate pathway to disease that may account for 5-10% of invasive cervical cancers. (aacrjournals.org)
  • Another avenue of research conducted in Essani's laboratory has been to create a recombinant tanapox virus that can mobilize the body's immune system to fight cancers. (wmich.edu)
  • Papillomaviruses (PVs) were the first viruses recognized to cause tumors and cancers in mammalian hosts by Shope, nearly a century ago ( Shope and Hurst, 1933 ). (frontiersin.org)
  • Despite effective vaccines and screening, HPV infection and morbidity remain a significant worldwide burden, with HPV infections and HPV-related cancers expected increase through 2040. (frontiersin.org)
  • Although HPVs have long-recognized roles in tumorigenesis and cancers, our understanding of the molecular mechanisms by which these viruses interact with cells and usurp cellular processes to initiate infections and produce progeny virions is limited. (frontiersin.org)
  • BALB/c mice develop other cancers later in life including reticular neoplasms, primary lung tumors, and renal tumors. (jax.org)
  • This is the first time it has been shown," explains co-lead study author Dr. Adel Samson, who is a medical oncologist at the University of Leeds, "that a therapeutic virus is able to pass through the brain-blood barrier, and that opens up the possibility [that] this type of immunotherapy could be used to treat more people with aggressive brain cancers. (medicalnewstoday.com)
  • Cancers of the brain and other tissues located in the central nervous system (CNS) occur because abnormal cells in those tissues grow out of control and form tumors. (medicalnewstoday.com)
  • Effective treatment of solid cancers by tumor-directed DC-vaccines still remains a challenge in clinical oncology. (ebscohost.com)
  • More recently, it has been demonstrated that clearance of virus from the central nervous system is dependent upon the presence of both CD4+ and CD8+ cells that recognize viral antigens in the context of H-2D gene products (7). (springer.com)
  • Although mammary epithelial cells are the ultimate targets of MMTV, the virus utilizes components of the host immune system to establish infection. (asm.org)
  • Previous studies indicated that dendritic cells play a role in MMTV infection. (asm.org)
  • Here we show that dendritic cells are the first cells to be infected by MMTV in vivo and that they are capable of producing infectious virus that can be transmitted to other cell types. (asm.org)
  • Moreover, upon contact with the virus, dendritic cells became more mature and migrated in response to the chemokine macrophage inflammatory protein 3β. (asm.org)
  • Finally, we demonstrate that targeted ablation of dendritic cells in vivo dramatically attenuated MMTV infection. (asm.org)
  • These data indicate that MMTV infection of dendritic cells is critical to initial propagation of the virus in vivo. (asm.org)
  • These infected B cells were thought to present the virus-encoded superantigen (Sag) to T cells expressing Sag-specific T-cell receptor (TCR) Vβ chains, resulting in their stimulation. (asm.org)
  • T-cell stimulation results in the subsequent amplification of infection, through inducing the proliferation of infected B cells and the recruitment of additional infection-competent target cells. (asm.org)
  • B cells are clearly required to establish high-level infection, since immunoglobulin μ knockout mice that lack B cells do not support long-term MMTV infection ( 7 ). (asm.org)
  • In addition, DCs can be infected by MMTV and can present Sag to T cells, suggesting their involvement in the early phase of infection ( 5 , 24 , 38 ). (asm.org)
  • 3D melanoma cultures were established by placing tumor cells on the surface of a Matrigel matrix, which was followed by the growth of tumor cells on the matrix surface and invasion of the Matrigel matrix by some tumor cells to form multicellular tumor spheroids within the matrix. (asm.org)
  • When established 3D melanoma cultures were inoculated with HSV-1 by placing virus on the surface of cultures, virus infection caused extensive death of melanoma cells growing on the surface of the 3D matrix and significantly decreased the number of tumor cell spheroids within the matrix. (asm.org)
  • However, HSV-1 infection did not lead to a complete destruction of tumor cells in the 3D cultures during a 17-day observation period and, surprisingly, HSV-1 infection promoted the growth of some melanoma cells within the matrix as determined by the significantly increased size of residual viable multicellular tumor spheroids in virus-inoculated 3D cultures at 17 days after virus inoculation. (asm.org)
  • These findings suggest that although HSV-1 oncolytic virotherapy may cause extensive tumor cell killing, it may also be associated with the unintended promotion of the growth of some tumor cells. (asm.org)
  • Our observations reported here suggest that potential dangers of HSV-1 oncolytic therapy include promotion of growth of some tumor cells. (asm.org)
  • Furthermore, our findings raise the possibility that HSV-1 infection of neoplastic cells during natural infections or vaccinations may promote the growth of tumors. (asm.org)
  • Oncolytic HSV-1 therapy is dependent upon virus replication in tumor cells and is augmented by host antiviral and infection-induced antitumor immune responses ( 1 , 3 - 6 ). (asm.org)
  • In T-VEC, deletions of wild-type γ 34.5 and α 47 viral genes promote targeting tumor cells over nonneoplastic cells and enhance the body's natural antitumor response ( 7 ). (asm.org)
  • While TNF-alpha induced comparable IkappaB-alpha degradation and NFkappaB activation in mock-infected and DENV-2-infected cells early in infection, later in infection and co-inciding with TNF-alpha-induced cell death, TNF-alpha-stimulated IkappaB-alpha degradation and NFkappaB activation was reduced. (monash.edu)
  • Tumor Necrosis Factor-Mediated Survival of CD169 Cells Promotes Immune Activation during Vesicular Stomatitis Virus Infection. (helmholtz-hzi.de)
  • Exosomal content of cells varies with the cell type that produces them as well as environmental factors that alter the normal state of the cell such as viral infection. (springer.com)
  • While numerous viruses can infect various cell types of the CNS and elicit damaging neuropathologies, few have been studied for their exosomal composition, content, and function on recipient cells. (springer.com)
  • Some of the more recent studies including HIV-1, HTLV-1, and EBV-infected B cells indicate that exosomes from these infections contain viral miRNAs, viral transactivators, and a host of cytokines that can control the course of infection. (springer.com)
  • In addition, the in vitro EBOV infection of peripheral blood mononuclear cells (PBMC) resulted in strong cytokine/chemokine induction, a marked increase in lactate dehydrogenase (LDH) activity, and an increase in the number of apoptotic lymphocytes examined by electron microscopy. (utmb.edu)
  • In situ PCR detection of the tumor tissues confirmed the presence of HPV DNA in tumor cells. (aacrjournals.org)
  • Organized into five parts encompassing 36 chapters, this book begins with an overview of both the in vivo and in vitro behavior of metastatic tumor cells. (elsevier.com)
  • Integration of viral DNA into host DNA was first discerned for the prophage of the temperate bacteriophage lambda by Andre Lwoff in 1950 and for the simian DNA virus SV40 in cultured mammalian cells in 1968 [ 8 ]. (royalsocietypublishing.org)
  • After initial inoculation, the virus replicates in nasopharyngeal epithelial cells. (medscape.com)
  • The T lymphocytes are cytotoxic to the Epstein-Barr virus-infected B cells and eventually reduce the number of Epstein-Barr virus-infected B lymphocytes to less than 1 per 10 6 circulating B cells. (medscape.com)
  • After acute Epstein-Barr virus infection, latently infected lymphocytes and epithelial cells persist and are immortalized. (medscape.com)
  • During latent infection, the virus is present in the lymphocytes and oropharyngeal epithelial cells as episomes in the nucleus. (medscape.com)
  • Simian virus 40 (SV40) is a monkey virus that was introduced in the human population by contaminated poliovaccines, produced in SV40-infected monkey cells, between 1955 and 1963. (greenmedinfo.com)
  • These chromosome alterations may hit genes important in oncogenesis and generate genetic instability in tumor cells. (greenmedinfo.com)
  • The clastogenic activity of Tag, which fixes the chromosome damage in the infected cells, may explain the low viral load in SV40-positive human tumors and the observation that Tag is expressed only in a fraction of tumor cells. (greenmedinfo.com)
  • Elimination of B-RAF in oncogenic C-RAF-expressing alveolar epithelial type II cells reduces MAPK signal intensity and lung tumor growth. (nih.gov)
  • Firstly, this is because viruses cannot truly be isolated in pure culture-even stringent isolation techniques cannot exclude undetected contaminating viruses with similar density characteristics, and viruses must be grown on cells. (wikipedia.org)
  • A new study shows that the virus, known for killing cells. (eurekalert.org)
  • The findings suggest that the lethal power of the virus - known for infecting and killing cells in the brains of fetuses, causing babies to be born with tiny, misshapen heads - could be directed at malignant cells in the brain. (eurekalert.org)
  • We showed that Zika virus can kill the kind of glioblastoma cells that tend to be resistant to current treatments and lead to death," said Michael S. Diamond, MD, PhD, the Herbert S. Gasser Professor of Medicine at Washington University School of Medicine and the study's co-senior author. (eurekalert.org)
  • Zika virus specifically targets and kills neuroprogenitor cells. (eurekalert.org)
  • In collaboration with co-senior authors Diamond and Milan G. Chheda, MD, of Washington University School of Medicine, and Jeremy N. Rich, MD, of UC San Diego, Zhu tested whether the virus could kill stem cells in glioblastomas removed from patients at diagnosis. (eurekalert.org)
  • The standard treatment kills the bulk of the tumor cells but often leaves the stem cells intact to regenerate the tumor. (eurekalert.org)
  • Zika virus attacks the stem cells but bypasses the greater part of the tumor. (eurekalert.org)
  • The idea of injecting a virus notorious for causing brain damage into people's brains seems alarming, but Zika may be safer for use in adults because its primary targets - neuroprogenitor cells - are rare in the adult brain. (eurekalert.org)
  • The fetal brain, on the other hand, is loaded with such cells, which is part of the reason why Zika infection before birth produces widespread and severe brain damage, while natural infection in adulthood causes mild symptoms. (eurekalert.org)
  • The researchers conducted additional studies of the virus using brain tissue from epilepsy patients and showed that the virus does not infect noncancerous brain cells. (eurekalert.org)
  • As an additional safety feature, the researchers introduced two mutations that weakened the virus's ability to combat the cell's defenses against infection, reasoning that the mutated virus still would be able to grow in tumor cells - which have a poor antiviral defense system - but would be eliminated quickly in healthy cells with a robust antiviral response. (eurekalert.org)
  • In this review we will focus on how DNA viruses alter the glucose metabolism of transformed cells. (hindawi.com)
  • The viral genes transcribed or expressed in infected cells modulate the physiological machinery of cells that leads to cell transformation and development of tumor. (hindawi.com)
  • In 1960, Sweet and Hilleman discovered a new virus in cultures of kidney cells of rhesus monkeys, producing vaccines to poliovirus [ 3 ]. (hindawi.com)
  • In their life cycle, viruses replicate, inducing the cytopathic effect in the host cells and forming new viral particles. (hindawi.com)
  • Herpesviruses are able to establish persistent infection transforming the host cells. (hindawi.com)
  • It is well known that tumor cells differ from normal cells by glucose metabolism. (hindawi.com)
  • The virus was tested against the most aggressive brain tumor - glioblastoma multiforme, which originates in the glial cells that surround and support neurons. (eurekalert.org)
  • Since 2004 scientists have found that brain tumors are driven by haywire stem cells that replicate themselves, differentiate into other types of cells, and bear protein markers like normal stem cells. (eurekalert.org)
  • So we decided to test Delta-24-RGD against glioma stem cells and tumors grown from them. (eurekalert.org)
  • We have to be cautious, because an animal model doesn't fully represent humans, but the tumors grown by these stem cells closely resemble the tumors we see in our patients, which is an exciting finding in itself. (eurekalert.org)
  • To overcome this inhibition, we generated a novel recombinant myxoma virus (vPD1), which inhibits the PD1/PDL1 pathway specifically within the tumor microenvironment by secreting a soluble form of PD1 from infected cells. (aacrjournals.org)
  • To overcome this increased toxicity, while maintaining an improved response rate, we generated a recombinant oncolytic myxoma virus (MYXV) designed to inhibit the PD1/PDL1 pathway specifically within the local tumor microenvironment by secreting a soluble form of PD1 from infected cells. (aacrjournals.org)
  • Unlike cells, which contain all the structures needed for growth and reproduction, viruses are composed of only an outer coat (capsid), the genome, and, in some cases, a few enzymes. (encyclopedia.com)
  • The article is called "Zika virus selectively kills aggressive human embryonal CNS tumor cells in vitro and in vivo" and was published online this Thursday. (eurekalert.org)
  • The tumor cells are modified to emit light, which can be picked up with a specific equipment, producing a colored signal in the place where the tumors are. (eurekalert.org)
  • Concentrations of one viral particle per ten cells were sufficient to infect and kill cells derived from AT/RT and medulloblastoma tumors. (eurekalert.org)
  • In addition, the virus showed high specificity for this type of cells. (eurekalert.org)
  • The virus did not infect tumor cells indiscriminately," explains Okamoto. (eurekalert.org)
  • It is quite specific for tumor cells of the nervous system. (eurekalert.org)
  • The researchers also tested in vitro the functionality of viruses formed in tumor cells after infection. (eurekalert.org)
  • Our results suggest Zika has an even greater affinity with central nervous system tumor cells than with healthy neural stem cells [the virus's main targets in the brains of fetuses exposed during pregnancy]. (news-medical.net)
  • When it infects tumor cells, it swiftly destroys them,' Okamoto said. (news-medical.net)
  • According to Okamoto, these tumor cells with stem cell-like characteristics have been observed in various kinds of solid tumor including those that affect the central nervous system. (news-medical.net)
  • Our research and studies by other groups have shown that Zika virus causes microcephaly because it infects and destroys neural stem cells in the fetus, preventing the formation of new neurons. (news-medical.net)
  • So we had the idea of investigating whether the virus also attacked tumor stem cells in the central nervous system,' he said. (news-medical.net)
  • The neural stem cells that undergo these alterations give rise to tumor cells at a later stage. (news-medical.net)
  • The researchers performed a dose escalation study, adding steadily larger amounts of Zika virus to cultured tumor cells until they found the quantity that promoted infection. (news-medical.net)
  • Using immunofluorescence microscopy they confirmed that the virus had in fact invaded the tumor cells and begun to replicate inside them. (news-medical.net)
  • We observed that small amounts of Zika were sufficient to infect CNS tumor cells,' Okamoto said. (news-medical.net)
  • The second experiment consisted of comparing Zika's capacity to infect healthy neural stem cells obtained from induced pluripotent stem cells (adult cells reprogrammed in the laboratory to behave like stem cells) with its infection of CNS tumor stem cells. (news-medical.net)
  • We infected both cell types in vitro and found tumor stem cells to be even more susceptible to destruction by Zika than healthy neural stem cells,' Okamoto said. (news-medical.net)
  • In this same experiment, we exposed mature neurons differentiated from human neural stem cells to Zika and found that they weren't infected or destroyed by the virus. (news-medical.net)
  • This is very good news, since our specific goal is to destroy tumor cells,' Zatz noted. (news-medical.net)
  • The neural stem cells used in the experiment, she explained, were obtained during a previous study conducted by the group with pairs of discordant twins - cases in which only one twin was affected by the virus although both had been equally exposed during pregnancy. (news-medical.net)
  • 6 These malignant cells are, however, greatly outnumbered by the reactive cells in the tumor microenvironment. (haematologica.org)
  • The stimulatory factor sends a signal to attract white blood cells into the tumor, Dr. Ollila explained, thereby inducing the body's activated immune system to kill the metastatic melanoma cells. (facs.org)
  • HTLV-I and HTLV-II infection can also be confirmed by amplification of viral sequences by polymerase chain reaction (PCR) from peripheral blood mononuclear cells. (inchem.org)
  • In ATLL, the virus is clonally integrated into the tumour cells. (inchem.org)
  • Humoral immunity to infection depends upon two layers of protection: pre-existing antibodies expressed by long-lived plasma cells and a stable population of rapidly reactive memory B cells (MBCs). (washington.edu)
  • and the cytotoxicity and receptor binding activities of the TNF are unaffected or enhanced on tumor cells. (google.co.uk)
  • We recently reported that selective systemic delivery of suicide genes such as herpes simplex virus thymidine kinase ( HSVtk ) to tumor endothelial cells through a novel targeted adeno-associated virus/phage vector leads to suppression of tumor growth. (aacrjournals.org)
  • We show that there is a heterotypic "bystander" effect between endothelial cells expressing the HSVtk suicide gene and tumor cells. (aacrjournals.org)
  • Treatment of cocultures of HSVtk -transduced endothelial cells and non- HSVtk -transduced tumor cells with ganciclovir results in the death of both endothelial and tumor cells. (aacrjournals.org)
  • Blocking of this effect by 18α-glycyrrhetinic acid indicates that gap junctions between endothelial and tumor cells are largely responsible for this phenomenon. (aacrjournals.org)
  • It is based on the correction of pathologic gene expression patterns (e.g. by the transfer of tumor suppressor genes) or on the delivery of cytotoxic genes that directly or indirectly kill tumor cells irrespective of its gene expression. (aacrjournals.org)
  • This "bystander effect" may potentially overcome the requirement for all malignant cells to be transduced to achieve meaningful tumor regression ( 2 , 5 ). (aacrjournals.org)
  • Given the estimates that up of 100 tumor cells are sustained by a single endothelial cell ( 7 ), vascular gene targeting might minimize or overcome this problem. (aacrjournals.org)
  • Indoleamine-2,3-dioxygenase (IDO) is expressed in response to interferon γ (IFN γ ) and has been linked to both antiviral functions and to the immune escape of tumor cells. (hindawi.com)
  • We observed that IFN γ treatment of human glioblastoma cells induced the expression of IDO and that this expression was quelled by infection with both wild-type and JD0G viruses. (hindawi.com)
  • The role of IDO in inhibiting virus replication and the connection of this protein to the escape of tumor cells from immune surveillance suggest that IDO downregulation by HSV infection may enhance the oncolytic activity of vectors such as JD0G. (hindawi.com)
  • The tumor vasculature in infected tumor areas remained functional and the endothelial cells were not infected. (biomedcentral.com)
  • The immunohistochemical analysis of infected tumors displayed intense infiltration of MHCII-positive cells and colocalization of tumor vessels with MHCII + /CD31 + vascular leukocytes. (biomedcentral.com)
  • However, GI-101A tumor growth analysis upon VACV-infection in either immunosuppressed nude mice (MHCII + -cell depleted) or in immune-deficient mouse strains (T-, B-, NK-cell-deficient) revealed that neither MHCII-positive immune cells nor T-, B-, or NK cells contributed significantly to VACV-mediated tumor regression. (biomedcentral.com)
  • Moreover, viruses induce local inflammation at sites of infection leading to local remodeling of the infected tissue such as activation of the vasculature and local recruitment of immune cells. (biomedcentral.com)
  • Rb normally guards against both the proliferation of cancerous cells and against viral infection. (medindia.net)
  • So the virus has an easier time invading tumours and replicating in its cells. (medindia.net)
  • The paper shows that Delta-24-RGD forces tumour cells to devour themselves until they die. (medindia.net)
  • Cells normally employ autophagy temporarily to survive when nutrients are short, to recycle components to form new organelles, or to fend off viral or bacterial infection. (medindia.net)
  • Antibody-drug conjugates (ADCs) are intended to bind to specific positive target antigens and eradicate only tumor cells from an intracellular released payload through the lysosomal protease. (biomedcentral.com)
  • Beth Rogers is the first person in the United States to undergo a trial procedure in which a virus was injected in her brain tumor. (uamshealth.com)
  • Beth Rogers might have been the first person in the United States to be treated as part of a clinical trial that included the injection of a virus into her brain tumor in combination with immunotherapy treatments - but the Hazen resident said she had no fear. (uamshealth.com)
  • The research team led by Fueyo, co-senior author Frederick Lang, M.D., professor in M. D. Anderson's Department of Neurosurgery, and first author Hong Jiang, Ph.D., instructor in neuro-oncology, derived four brain tumor stem cell lines from four specimens of glioblastoma multiforme. (eurekalert.org)
  • The immune response to mouse hepatitis virus: Expression of monocyte procoagulant activity and plasminogen activator during infection in vivo. (springer.com)
  • with the exception of its association with milk, the virus is cell associated in vivo ( 31 ). (asm.org)
  • Finally, this heterotypic bystander effect is accompanied by a suppression of tumor growth in vivo that is independent of primary gene transfer into host-derived tumor vascular endothelium. (aacrjournals.org)
  • Experimental ablation of the immune cell populations by X irradiation (3) , antilymphocyte serum (4) , or infection with frog virus-3 (5) renders resistant A/J mice susceptible. (springer.com)
  • Susceptibility to mouse hepatitis virus strain 3 in Balb/cJ mice: Failure of immune cell proliferation and interleukin 2 production, in: Coronaviruses, Michael M.C. Lai and Stephen A. Stohlman, ed. (springer.com)
  • Activation of the immune coagulation system by murine hepatitis virus strain 3. (springer.com)
  • Initial studies of virus-DC interactions focused predominantly on the outcomes of antiviral immune responses and the control of infection ( 36 ). (asm.org)
  • In particular, DC participation in the immune response to the murine retrovirus mouse mammary tumor virus (MMTV) has been demonstrated. (asm.org)
  • Ebola virus (EBOV) infections are characterized by dysregulation of normal host immune responses. (utmb.edu)
  • Other chapters consider the effects of different soluble immune mediators on tumor cell growth and metastasis. (elsevier.com)
  • Study of human immune responses to malaria parasite infection has been hampered by a lack of small animal models. (pnas.org)
  • Host immune response to the viral infection includes CD8+ T lymphocytes with suppressor and cytotoxic functions, the characteristic atypical lymphocytes found in the peripheral blood. (medscape.com)
  • Applying all of the data and knowledge gained from his research, Essani has focused on how different viruses can harm or benefit the human immune system. (wmich.edu)
  • However, in EBV-associated tumors the antigens are well defined, thus allowing the Ambinder lab to define the epitope-specific cellular immune responses. (hopkinsmedicine.org)
  • TVEC is a genetically modified herpes virus that contains the stimulatory factor known as GM-CSF that increases a tumor-specific immune response. (facs.org)
  • However, for individuals with immune system deficiencies the course of the infection can have serious effects or even be fatal. (tum.de)
  • Virus recognition and response by the innate immune system are critical components of host defense against infection. (washington.edu)
  • Immunological aspects of viral-mediated tumor regression were studied in either immune-deficient mouse strains (T-, B-, NK-cell-deficient) or upon cyclophosphamide-induced immunosuppression (MHCII + -cell depletion) in nude mice. (biomedcentral.com)
  • In fact, CD8 T cell responses in these infections, which are adapted for long-term immune surveillance,have properties that may make them more desirable for long-term anti-tumor immunity. (jimmunol.org)
  • Susceptibility/resistance to mouse hepatitis virus strain 3 and macrophage procoagulant activity are genetically linked and controlled by two non-H-2-linked genes. (springer.com)
  • Conversely, many host genes have been incorporated into large DNA viruses, such as herpesviuses and poxviruses, as well as oncogene-bearing retroviruses. (royalsocietypublishing.org)
  • Moreover, we demonstrated an increased expression of genes involved in leukocyte-endothelial cell interaction in VACV-infected tumors, which orchestrate perivascular inflammatory cell infiltration. (biomedcentral.com)
  • These findings confirm the presence of MMTV in humans, strongly suggest saliva as route in inter-human infection, and support the hypothesis of a viral origin for human breast carcinoma. (oncotarget.com)
  • Human immunodeficiency viruses and human T-cell lymphotropic viruses / views and expert opinions of an IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, Lyon, 11-18 June 1996. (who.int)
  • Humans are the only known reservoir of Epstein-Barr virus. (medscape.com)
  • Epidemiological evidence now suggests that SV40 may be contagiously transmitted in humans by horizontal infection, independent of the earlier administration of SV40-contaminated poliovaccines. (greenmedinfo.com)
  • Detection of SV40 DNA sequences in blood and sperm and of SV40 virions in sewage points to the hematic, sexual, and orofecal routes as means of virus transmission in humans. (greenmedinfo.com)
  • The site of latent infection in humans is not known, but the presence of SV40 in urine suggests the kidney as a possible site of latency, as it occurs in the natural monkey host. (greenmedinfo.com)
  • Molluscum contagiosum only infects humans and is a common infection of children and immunodeficient individuals. (cdc.gov)
  • In order to do this, it will be necessary to obtain the purified virus in larger amounts and produced according to the good cultivation practices required for testing in humans. (eurekalert.org)
  • Murine hepatitis virus strain 3 (MHV-3) produces a strain dependent spectrum of liver disease. (springer.com)
  • Lymphocyte-instructed monocyte induction of the coagulation pathways parallels the induction of hepatitis by the murine hepatitis virus. (springer.com)
  • Immunopathology of mouse hepatitis virus type 3 infection. (springer.com)
  • T-cell mediated clearance of mouse hepatitis virus strain JHM from the central nervous system. (springer.com)
  • 16, 16 dimethyl prostaglandin E2 prevents the development of fulminant hepatitis and blocks the induction of monocyte/macrophage procoagulant activity after murine hepatitis virus strain 3 infection. (springer.com)
  • These two mechanisms differ in their biology and epidemiology: direct tumor viruses must have at least one virus copy in every tumor cell expressing at least one protein or RNA that is causing the cell to become cancerous. (wikipedia.org)
  • Application of the ELISPOT Assay to the Characterization of CD8+ Responses to Epstein-Barr Virus Antigens. (hopkinsmedicine.org)
  • Serological detection of specific reactivity to Gag and Env HTLV-I or HTLV-II antigens, confirmed if necessary by western blot, is indicative of current infection. (inchem.org)
  • Neogenix has created chimeric immunogenic tumor-associated antigens (TAAs) isolated from some of the first vaccines ever tested. (ebscohost.com)
  • Rogers came to UAMS for the procedure when her tumor continued to grow despite two previous surgeries and a combination of chemotherapy and radiation. (uamshealth.com)
  • The standard treatment is aggressive - surgery, followed by chemotherapy and radiation - yet most tumors recur within six months. (eurekalert.org)
  • The findings suggest that Zika infection and chemotherapy-radiation treatment have complementary effects. (eurekalert.org)
  • Frontline anticancer therapies such as chemotherapy and irradiation often slow tumor growth, but tumor regrowth and spread to distant sites usually occurs after the conclusion of treatment. (aacrjournals.org)
  • Solid human and murine tumors often respond well initially to conventional, frontline therapies such as chemotherapy and radiotherapy, leading to the cessation of tumor growth and even tumor shrinkage. (aacrjournals.org)
  • Delta-24-RGD developed by Fueyo and colleagues was tested against the most aggressive brain tumour Glioblastoma multiforme that is highly resistant to radiation and chemotherapy and is also invasive that even surgery never eliminates it almost all the time. (medindia.net)
  • The studies were conducted using human cell lineages derived from two types of embryonic tumors of the central nervous system (CNS): medulloblastoma and atypical teratoid rhabdoid tumor (AT/RT). (eurekalert.org)
  • The experiments were performed with three human tumor cell lines: two derived from medulloblastoma and the third from atypical teratoid/rhabdoid tumor (AT/RT). (news-medical.net)
  • If Zika were used in people, it would have to be injected into the brain, most likely during surgery to remove the primary tumor. (eurekalert.org)
  • However, a major clinical problem is the subsequent regrowth of such tumors-both at the site of the primary tumor and/or distant sites. (aacrjournals.org)
  • We evaluated telomerase activity in seven primary malignant mesothelioma biopsies and matched lung specimens and 20 mesothelioma cell lines and eight corresponding primary tumor cultures. (semanticscholar.org)
  • Other viruses are only carcinogenic when they integrate into the host cell genome as part of a biological accident, such as polyomaviruses and papillomaviruses. (wikipedia.org)
  • Classification of viruses considers the genome characteristics, virion shape and macromolecular composition, and other properties, such as antigenicity and host range. (encyclopedia.com)
  • Similar to the human genome, viruses are used by Essani and many top research universities because of similarities and the ability to manipulate the genome. (wmich.edu)
  • Human papillomaviruses (HPVs) are small, non-enveloped icosahedral viruses of 55 nm containing a circular, ≈8-kb double-stranded DNA genome condensed by cellular histones. (frontiersin.org)
  • The present volume on enzootic bovine leukosis and bovine leukemia virus updates the reader on the disease and its causative agent and includes the nucleotide sequence of the BLV genome as well as data on its integration into the DNA of the tumor cell. (indigo.ca)
  • 9. Sequence analysis of the bovine leukemia virus genome. (indigo.ca)
  • Infectious viruses and carcinogenesis] / V. I. Struck. (who.int)
  • The most common manifestation of primary infection with this organism is acute infectious mononucleosis, a self-limited clinical syndrome that most frequently affects adolescents and young adults. (medscape.com)
  • The search for the etiologic agent of infectious mononucleosis was unsuccessful for many years, partly because researchers did not appreciate that most primary infections are asymptomatic and that most adults are seropositive. (medscape.com)
  • [ 3 ] Henle reported the relationship between acute infectious mononucleosis and Epstein-Barr virus in 1968. (medscape.com)
  • [ 4 ] Subsequently, a large prospective study of students at Yale University firmly established Epstein-Barr virus as the etiologic agent of infectious mononucleosis. (medscape.com)
  • Here, we provide a general overview of the current HPV infection paradigm, the epithelial differentiation-dependent HPV replicative cycle, and review the specifics of how HPVs usurp Rab-related functions during infectious entry. (frontiersin.org)
  • Vaccine intervention against virus-induced tumours / edited by J. M. Goldman and M. A. Epstein. (who.int)
  • This proposed volume will attempt to review and address the major gaps in current knowledge in DNA viruses as well as RNA viruses bringing a historical perspective of where studies began to a more recent molecular approach and vaccine successes in tumor viruses. (indigo.ca)
  • These data suggest that vaccine vectors derived from persistent viruses may perform better than those from acute viruses at mediating anti-tumor protection. (jimmunol.org)
  • In recent years, more attention has been paid to human polyomaviruses, particularly JC virus (JCV), which infects greater than 80% of the human population, due to the ability of this virus to induce a fatal demyelinating disease in the brain, its presence in various tumors of central nervous system (CNS) and non-CNS origin, and the oncogenic potential of this virus in several laboratory animal models. (biomedsearch.com)
  • Infection with Epstein-Barr virus is associated with lymphoproliferative disorders, especially in immunocompromised hosts, and is associated with various tumors, including nasopharyngeal carcinoma and Burkitt lymphoma. (medscape.com)
  • Hsp60 may favor oncogenesis by promoting survival or growth of some tumor cell types. (bireme.br)
  • Finally, it has been demonstrated that MMTV can induce DC maturation and up-regulation of surface expression of the virus entry receptor transferrin receptor 1 (TfR1) via interaction with Toll-like receptor 4 (TLR4) ( 8 ). (asm.org)
  • At the same time, it was also shown that human adenoviruses could induce tumors in newborn hamsters [ 5 ]. (hindawi.com)
  • Some of the H5N1 and H9N2 virus subtypes induce markedly elevated cytokine levels when compared with the seasonal H1N1 virus. (mdpi.com)
  • However, H9N2/G1 did not induce the expression of PP2A indicating that the activation of PP2A is not mediated by p38MAPK in virus-infected PBMac. (mdpi.com)
  • For therapeutic success, knock-down of tumor-specific tolerance appears mandatory before a potent tumor-specific cytotoxic T-cell response can be triggered by DC-vaccinations. (ebscohost.com)
  • So we can actually restore the endogenous antiviral factories which then fight the virus,' says Schreiner. (tum.de)
  • The incidence of ALV-induced tumors was lower in MAB+ chickens than in MAB- chickens, significantly so in one of three trials conducted. (docphin.com)
  • Control animals treated with a similar virus that lacked the vasculostatin gene, on the other hand, survived an average of 26 days and none were tumor-free. (healthcanal.com)
  • To identify the role of single nucleotide polymorphisms (SNPs) of the tumor necrosis factor (TNF) gene in the natural course of 2009 influenza A H1N1 virus infection. (cdc.gov)
  • The -238 A SNP allele of the TNF gene imposes on the course of 2009 H1N1 virus infection and is an independent risk factor for pneumonia. (cdc.gov)
  • Association between tumour necrosis factor gene polymorphisms and the clinical types of patients with chronic hepatitis B virus infection. (cdc.gov)
  • We conducted the present study to investigate the association of MBL gene mutations and TNF-α promoter polymorphism with host''s susceptibility to various courses of HBV infection in Korean. (yonsei.ac.kr)
  • MBL gene codon 54 mutation was not associated with HBV clearance (P=0.132) and progression of HBV infection (P=0.136). (yonsei.ac.kr)
  • This gene was identified by its similarity with mouse fgf3/int-2, a proto-oncogene activated in virally induced mammary tumors in the mouse. (cancerindex.org)
  • Frequent amplification of this gene has been found in human tumors, which may be important for neoplastic transformation and tumor progression. (cancerindex.org)
  • Expression of the DMP1 transcription factor, a cyclin D-binding Myb-like protein, induces growth arrest in mouse embryo fibroblast strains but is devoid of antiproliferative activity in primary diploid fibroblasts that lack the ARF tumor suppressor gene. (pnas.org)
  • Using the tanopox virus as a model for his research, Essani looks at the molecular mechanisms within the viral model that dictate which gene sequences are expressed or kept silent. (wmich.edu)
  • Acyclovir treatment inhibited HSV-1-induced tumor cell killing but did not block the virus infection-induced increase in spheroid size. (asm.org)
  • Our study indicates that HSV-1 infection of 3D tumor cell cultures provides an experimental platform in which mechanisms of HSV-1-mediated promotion of tumor cell growth can be effectively studied. (asm.org)
  • BK virus-associated hemorrhagic cystitis presenting as mural nodules in the urinary bladder after hematopoietic stem cell transplantation. (sickkids.ca)
  • Deficiency of the B cell-activating factor receptor results in limited CD169+ macrophage function during viral infection. (helmholtz-hzi.de)
  • FGF family members possess broad mitogenic and cell survival activities and are involved in a variety of biological processes including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. (cancerindex.org)
  • Emerging roles of DNA tumor viruses in cell proliferation: new insights into genomic instability. (biomedsearch.com)
  • Virus Mediated Cell Proliferation - Jae Jung4. (indigo.ca)
  • Marek's Disease Virus and T cell Lymphomas - Mark Parcells and Robin Morgan14. (indigo.ca)
  • Merkel Cell Polyoma viruses - Jurgen Becker19. (indigo.ca)
  • This book discusses as well the immunobiology and immunopathology of human tumor cell metastasis. (elsevier.com)
  • Hence, loss of ARF limits cell-autonomous tumor surveillance in response to particular oncogenic signals, and animals lacking ARF function, such as those lacking p53, are highly tumor prone ( 20 ). (pnas.org)
  • In 1964, Epstein described the first human tumor virus when he found virus particles in a Burkitt lymphoma cell line. (medscape.com)
  • Vilhelm Ellerman and Olaf Bang, University of Copenhagen, first demonstrated that avian sarcoma leukosis virus could be transmitted after cell-free filtration to new chickens, causing leukemia. (wikipedia.org)
  • Tumor DNA viruses enhance "aerobic" glycolysis upon virus-induced cell transformation, supporting rapid cell proliferation and showing the Warburg effect. (hindawi.com)
  • Hence, they acquire various hallmarks during the process of tumor progression, such as self-sufficiency in growth signals, insensitivity to growth-inhibitory (antigrowth) signals, evasion of programmed cell death (apoptosis), limitless replicative potential, sustained angiogenesis, and tissue invasion and metastases [ 1 ]. (hindawi.com)
  • This virus both induced and maintained antitumor CD8 + T-cell responses within directly treated tumors and proved safer and more effective than combination therapy using unmodified myxoma and systemic αPD1 antibodies. (aacrjournals.org)
  • Viruses have evolved with time and have developed defense systems that can counteract the reactions of the host cell. (wmich.edu)
  • When the tanopox virus enters a cell, it is able to reprogram the cell and dictate new processes to be performed. (wmich.edu)
  • Once tanopox virus has entered the cell, a new protein is produced which is then secreted into the blood stream. (wmich.edu)
  • In the last 20 years, the development of methods to produce virus-like particles (VLPs) and pseudovirions (PsV) along with more physiologically relevant cell- and tissue-based models has facilitated progress in this area. (frontiersin.org)
  • Epitope-dependent selection of highly restricted or diverse T cell receptor repertoires in response to persistent infection by Epstein-Barr virus. (nih.gov)
  • Human T-cell lymphotropic viruses (HTLV-I and HTLV-II), the only known human oncornavirinae , have distinct genetic and structural features. (inchem.org)
  • An adenovirus infection can be potentially life-threatening, especially for children after a stem cell transplant. (tum.de)
  • An infection is particularly dangerous for children following a stem cell transplant. (tum.de)
  • Schreiner and her team are investigating how the virus reproduces in the cell. (tum.de)
  • In order to protect children who undergo stem cell therapy from adenovirus infections, scientists intend to develop new methods for detecting even very small amounts of the viruses in the patient and the donor before the therapy. (tum.de)
  • Moreover, the observed bystander killing is mediated by connexins 43 and 26, which are expressed in endothelial and tumor cell types. (aacrjournals.org)
  • The vasculature of a solid tumor is an attractive target for intervention because the angiogenic endothelium expresses several cell-surface receptors that are essentially absent or barely detectable in normal blood vessels ( 8 , 9 ). (aacrjournals.org)
  • These approaches normally use viruses that cause acute infections, as they provoke potent CD8 T cell responses. (jimmunol.org)
  • Persistent virus vectors have not been used in this setting due to the perception that exhaustion of the T cell response occurs and would lead to poor anti-tumor protection. (jimmunol.org)
  • However, such exhaustion generally only occurs in high-load virus infections, whereas T cell function is intact in lower-load persistent infections. (jimmunol.org)
  • In this report, we show that a persistent gammaherpesvirus vector provides superior protection against melanoma, relative to a nonpersistent mutant of the same virus. (jimmunol.org)
  • However, the detailed mechanisms of p38MAPK activation and TNF-alpha hyperinduction following influenza virus infections are not known. (mdpi.com)
  • Here we hypothesize that protein phosphatases are involved in the regulation of cytokine expressions during influenza virus infection. (mdpi.com)
  • Fueyo and colleagues developed Delta-24-RGD to prey on a molecular weakness in tumors and altered the virus so it could not replicate in normal tissue. (eurekalert.org)
  • The risk associated with smoking was present to a similar extent among women positive and negative for HPV as measured by HPV 16 capsid antibodies and HPV DNA in the tumor tissue (cases). (aacrjournals.org)
  • However, viral colonization triggers hyperpermeability and dilatation of the tumor vessels, which resembled the activated endothelium in wounded tissue. (biomedcentral.com)