• viruses
  • The C-terminal portion of the STag protein is distinct from LTag but shares an additional ~100 residues with middle tumor antigen in those viruses that express it, such as murine polyomavirus. (wikipedia.org)
  • Viruses lacking a viral envelope often have complex mechanisms for entry into the host cell. (wikipedia.org)
  • Lastly, biologic effects include the viruses' ability to affect the activity of antigens and immunologlobulins in the host cell. (wikipedia.org)
  • Chronic infections have similar cellular effects as acute cytocidal infections but there is a limited number of progeny and viruses involved in transformation. (wikipedia.org)
  • Most MCV viruses found in MCC tumors, however, have at least two mutations that render the virus nontransmissible: 1) The virus is integrated into the host genome in a monoclonal fashion and 2) The viral T antigen has truncation mutations that leave the T antigen unable to initiate DNA replication needed to propagate the virus. (wikipedia.org)
  • Gammaherpesviruses are of primary interest due to the two human viruses, EBV and KSHV and the diseases they cause.The gammaherpesviruses replicate and persist in lymphoid cells but some are capable of undergoing lytic replication in epithelial or fibroblast cells. (wikipedia.org)
  • Viruses that establish lifelong latent infections must ensure that the viral genome is maintained within the latently infected cell throughout the life of the host, yet at the same time must also be capable of avoiding elimination by the immune surveillance system especially must avoid being detected by host CD8+ cytotoxic T lymphocytes (CTLs). (wikipedia.org)
  • However, in general virus-cell interactions are mediated by commonly occurring molecules on the cell surface, and therefore are likely not a major contributor to individual viruses' observed cell-type tropism. (wikipedia.org)
  • After binding to molecules on the cell surface, the virion is endocytosed and enters the endoplasmic reticulum - a behavior unique among known non-enveloped viruses - where the viral capsid structure is likely to be disrupted by action of host cell disulfide isomerase enzymes. (wikipedia.org)
  • Viruses offer an efficient means of delivering genes into cells, which they evolved to do, and are thus of great use as experimental tools. (wikipedia.org)
  • This danger can be avoided by the use of viruses which lack key genes, and which are thus unable to replicate after entering a cell. (wikipedia.org)
  • tumors
  • These TAAs have facilitated the analysis of T cell responses to tumors and are promising targets for immunotherapeutic strategies. (aacrjournals.org)
  • Furthermore, these miRs enable tumors to evade NK and T cell cytotoxicity. (aacrjournals.org)
  • The three genes in the early region express the large, middle, and small tumor antigens (LT, MT, ST) and are sufficient for inducing tumors. (wikipedia.org)
  • Cells with transforming infections undergo immortalization and inherit the genetic material to produce tumors. (wikipedia.org)
  • Approximately 80% of Merkel cell carcinoma (MCC) tumors have been found to be infected with MCV. (wikipedia.org)
  • Evidence that MCV is the cause for most MCC tumors comes from studies in which T antigen oncoproteins from the virus are inhibited. (wikipedia.org)
  • The large T antigen possesses a helicase motif needed for virus replication that is deleted in MCC tumors. (wikipedia.org)
  • Eight of 10 Merkel cell carcinoma tumors initially tested were found to be infected with MCV. (wikipedia.org)
  • In these tumors, the virus has integrated into the cancer cell genome and can no longer freely replicate. (wikipedia.org)
  • This observation is in contrast to the skin tumors, which carry substantial viral loads. (wikipedia.org)
  • Vitro
  • A distinction between direct ex vivo T cell responses and in vitro -generated T cell responses is provided because in vitro stimulation results in quantitative and functional changes of T cell responses. (aacrjournals.org)
  • As a consequence, HEK 293 cells should not be used as an in vitro model of typical kidney cells. (wikipedia.org)
  • molecules
  • antigen-antibody reaction the reversible binding of antigen to homologous antibody by the formation of weak bonds between antigenic determinants on antigen molecules and antigen binding sites on immunoglobulin molecules. (thefreedictionary.com)
  • They regulate the killing function of these cells by interacting with major histocompatibility (MHC) class I molecules, which are expressed on all nucleated cell types. (wikipedia.org)
  • Most KIRs are inhibitory, meaning that their recognition of MHC molecules suppresses the cytotoxic activity of their NK cell. (wikipedia.org)
  • Only a limited number of KIRs are activating, meaning that their recognition of MHC molecules activates the cytotoxic activity of their cell. (wikipedia.org)
  • Inhibitory receptors recognize self-MHC class I molecules on target self cells, causing the activation of signaling pathways that stop the cytolytic function of NK cells. (wikipedia.org)
  • According to the missing-self hypothesis, inhibitory KIR receptors recognize the downregulation of MHC class I molecules in virally-infected or transformed self cells, leading these receptors to stop sending the inhibition signal, which then leads to the lysis of these unhealthy cells. (wikipedia.org)
  • Activating receptors recognize ligands that indicate host cell aberration, including induced-self antigens (which are markers of infected self cells and include MICA, MICB, and ULBP, all of which are related to MCH class 1 molecules), altered-self antigens (MHC class I antigens laden with foreign peptide), and/or non-self (pathogen encoded molecules). (wikipedia.org)
  • Transformation can also affect the cytoskeleton and change in the quantity of signal molecules. (wikipedia.org)
  • The main function of MHC molecules is to bind to antigens derived from pathogens and display them on the cell surface for recognition by the appropriate T-cells. (wikipedia.org)
  • MHC molecules mediate interactions of leukocytes, also called white blood cells (WBCs), which are immune cells, with other leukocytes or with body cells. (wikipedia.org)
  • In a cell, protein molecules of the host's own phenotype or of other biologic entities are continually synthesized and degraded. (wikipedia.org)
  • By interacting with CD4 molecules on surfaces of helper T cells, MHC class II mediates establishment of specific immunity (also called acquired immunity or adaptive immunity). (wikipedia.org)
  • By interacting with CD8 molecules on surfaces of cytotoxic T cells, MHC class I mediates destruction of infected or malignant host cells, the aspect of specific immunity termed cellular immunity. (wikipedia.org)
  • virally
  • KIR receptors can distinguish between major histocompatibility (MHC) class I allelic variants, which allows them to detect virally infected cells or transformed cells. (wikipedia.org)
  • Because natural killer cells target virally infected host cells and tumor cells, inhibitory KIR receptors are important in facilitating self-tolerance. (wikipedia.org)
  • Cells that have been virally transformed can be differentiated from untransformed cells through a variety of growth, surface, and intracellular observations. (wikipedia.org)
  • nuclear
  • Illicit dmage to host via: Cell Lysis, production of toxic substances, cellular transformation, indirect production of toxic substances, and host cell alterations (nuclear and cytoplasmic). (coursehero.com)
  • Cytopathic Effects, often include a change in cell's morphology such as fusion with adjacent cells to form polykaryocytes as well as the synthesis of nuclear and cytoplasmic inclusion bodies. (wikipedia.org)
  • This unstructured linker region also contains a nuclear localization sequence, which triggers the host cell to transport the protein from the cytoplasm where is it translated to the nucleus where it performs its replication-related functions. (wikipedia.org)
  • genomes
  • In such infections, persistence appears to be due to the stability of histone-associated viral genomes in nonrep-licating cells marked by occasional episodes of low level viral replication as a result of an immune crisis or other events that lead to changes in the transcriptional environment of the host cell. (americorpshealth.biz)
  • In this strategy of virus replication, persistence is a consequence of the continued replication of cells bearing viral genomes! (americorpshealth.biz)
  • Further, clonal pattern of MCV insertions into MCC cell genomes indicates that the virus was present in the Merkel cell before it underwent cancerous transformation. (wikipedia.org)
  • A comprehensive study of the genomes and transcriptomes of HEK 293 and five derivative cell lines compared the HEK 293 transcriptome with that of human kidney, adrenal, pituitary and central nervous tissue. (wikipedia.org)
  • interaction
  • MHC interacts with TCR and its co-receptors to optimize binding conditions for the TCR-antigen interaction, in terms of antigen binding affinity and specificity, and signal transduction effectiveness. (wikipedia.org)
  • for example, the JC virus is believed to require interaction with the 5HT2A receptor and the Merkel cell virus with heparan sulfate. (wikipedia.org)
  • mechanisms
  • Understanding the mechanisms and behavior of natural TAA-specific T cells could provide crucial information for rational development of more efficient T cell-directed immunotherapy. (aacrjournals.org)
  • It is unclear how exactly having the HLA-B27 tissue type increases the risk of ankylosing spondylitis and other associated inflammatory diseases, but mechanisms involving aberrant antigen presentation or T cell activation have been hypothesized. (wikipedia.org)
  • specificity
  • Virotherapy using conditionally replicating adenoviruses (CRAds) exploits their oncolytic potential combined with specificity for cancer cells, while somatic tissues remain unharmed. (openwetware.org)
  • clonal
  • Quantification of T-cell receptor (TCR) chain families can be utilized for detection of clonal T-cell populations. (biomedcentral.com)
  • The method was tested by serial dilutions of clonal T-cells in mononuclear cells from healthy volunteers. (biomedcentral.com)
  • T-cell mediated immune responses are characterized by activation and subsequent clonal expansion of antigen-specific cells. (biomedcentral.com)
  • Pathmanathan R, Prasad U, Sadler R, Flynn K, Raab-Traub N. Clonal proliferations of cells infected with Epstein-Barr virus in preinvasive lesions related to nasopharyngeal carcinoma. (medscape.com)
  • infects
  • Poliovirus-wild type infects intestinal cells/neurons Note: Most virus gain entry to the body via the respiratory pathway (lungs). (coursehero.com)
  • receptors
  • Killer-cell immunoglobulin-like receptors (KIRs), are a family of type I transmembrane glycoproteins expressed on the plasma membrane of natural killer (NK) cells and a minority of T cells. (wikipedia.org)
  • Natural killer cell cytolysis of target cells and cytokine production is controlled by a balance of inhibitory and activating signals, which are facilitated by NK cell receptors. (wikipedia.org)
  • NK cell inhibitory receptors are part of either the immunoglobulin-like (IgSF) superfamily or the C-type lectin-like receptor (CTLR) superfamily. (wikipedia.org)
  • KIR and CD94 (CTLR) receptors are expressed by 5% of peripheral blood T cells. (wikipedia.org)
  • MHC is also the chaperone for intracellular peptides that are complexed with MHCs and presented to T cell receptors (TCRs) as potential foreign antigens. (wikipedia.org)
  • nucleus
  • A possible interpretation is that, due to the damage caused by resveratrol to the plasma membrane, the transfer of the virus from the endoplasmic reticulum to the nucleus, may be hindered thus inhibiting the production of viral DNA. (biomedcentral.com)
  • genetic
  • It is vastly more common in certain regions of East Asia and Africa than elsewhere, with viral, dietary and genetic factors implicated in its causation. (wikipedia.org)
  • pathogen
  • It was the first example of a human viral pathogen discovered using unbiased metagenomic next-generation sequencing with a technique called digital transcriptome subtraction. (wikipedia.org)
  • nasopharyngeal
  • Greene MH, Fraumeni JF, Hoover R. Nasopharyngeal cancer among young people in the United States: racial variations by cell type. (medscape.com)
  • Plasma Epstein-Barr viral deoxyribonucleic acid quantitation complements tumor-node-metastasis staging prognostication in nasopharyngeal carcinoma. (medscape.com)
  • Nasopharyngeal carcinoma (NPC) is caused by a combination of factors: viral, environmental influences, and heredity. (wikipedia.org)
  • The mechanism by which EBV alters nasopharyngeal cells is being elucidated to provide a rational therapeutic target. (wikipedia.org)
  • adenovirus
  • HEK 293 cells were generated in 1973 by transformation of cultures of normal human embryonic kidney cells with sheared adenovirus 5 DNA in Alex van der Eb's laboratory in Leiden, the Netherlands. (wikipedia.org)
  • the transformation by adenovirus was performed by Frank Graham, a post-doc in van der Eb's lab. (wikipedia.org)
  • However, the original adenovirus transformation was inefficient, suggesting that the cell that finally produced the HEK 293 line may have been unusual in some fashion. (wikipedia.org)
  • Graham and coworkers provided evidence that HEK 293 cells and other human cell lines generated by adenovirus transformation of human embryonic kidney cells have many properties of immature neurons, suggesting that the adenovirus preferentially transformed a neuronal lineage cell in the original kidney culture. (wikipedia.org)
  • Given the location of the adrenal gland (adrenal means "next to the kidney"), a few adrenal cells could plausibly have appeared in an embryonic kidney derived culture, and could be preferentially transformed by adenovirus. (wikipedia.org)
  • histocompatibility
  • Recognition of Major Histocompatibility Complex class I (MHC-I) bound peptide is mediated by the dimeric transmembrane T-cell receptor (TCR) composed of an α - and a β -chain in the majority of cases. (biomedcentral.com)
  • helicase
  • Coordinated actions of the OBD and helicase regions result in physical manipulation of the viral genome, melting the DNA double helix at the origin of replication and unwinding the circular DNA chromosome in a bidirectional fashion. (wikipedia.org)