• Simian Virus 40 (SV40) and Mouse Polyoma Virus (PY) are small DNA tumor viruses that have been used extensively to study cellular transformation. (nih.gov)
  • The SV40 early region encodes three tumor antigens, large T (LT), small T (ST) and 17KT that contribute to cellular transformation. (nih.gov)
  • The unique contributions of SV40 LT and ST and PY MT to cellular transformation have provided significant insights into our understanding of tumor suppressors, oncogenes and the process of oncogenesis. (nih.gov)
  • Large (LT), 17KT and Small (ST) of SV40 and PY as well as Middle (MT) T antigens from PY share coding regions. (nih.gov)
  • The N terminal 82 (SV40) and 79 (PY) residues for all T antigens are identical (magenta). (nih.gov)
  • Here, we 'switch' this pathway to a more conventional one by adding a modified poly-lysine to which an optimized nuclear targeting signal, based on that of the SV40 large T-antigen, is linked. (edu.kz)
  • Studies have shown that the combined expression of SV40 large T antigen (T-Ag), hTERT, and H-Ras is able to transform human cells. (elsevier.com)
  • We transduced cells with amphotropic retroviral constructs containing SV40 T antigen, hTERT, and activated H-ras. (elsevier.com)
  • In SV40 and JC virus, STag is not required for viral proliferation, but does improve efficiency. (wikipedia.org)
  • Because of its frequent expression in tumors and high immunogenicity, NY-ESO-1 is an attractive target for cancer immunotherapy and has been used in a series of clinical vaccine trials. (jimmunol.org)
  • Moreover, T antigen did not bind these sequences present in single-stranded RNA. (elsevier.com)
  • Comparison of the sequences of different viral agnoproteins suggests sequence conservation toward the N-terminus with greater variability toward the C-terminus. (wikipedia.org)
  • Cytotoxic T cells were not tolerant or deleted because a tumor antigen-specific cytotoxic T cell response was readily induced in lymphoid tissue by immunization with virus or with tumor cells even in the presence of large tumors. (pnas.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)
  • The result of this is that the virus can reactivate and begin producing large amounts of viral progeny without the host being infected by new outside virus, denoted as the lytic part of the viral life cycle, and stays within the host indefinitely. (wikipedia.org)
  • MHC multimers allow for a previously unattainable level of specificity in antigen-specific T-cell detection and isolation. (wikipedia.org)
  • Hecker, E., 1978, Structure-activity relationships in diterpene esters irritant and cocarcinogenic to mouse skin, in: Carcinogenesis, Vol. 2: Mechanisms of Tumor Promotion and Cocarcinogenesis (T. J. Slaga, A. Sivak, and R. K. Boutwell, eds. (springer.com)
  • Immune effector cells such as lymphocytes, macrophages, dendritic cells, natural killer cells (NK Cell), cytotoxic T lymphocytes (CTL), etc., work together to defend the body against cancer by targeting abnormal antigens expressed on the surface of tumor cells. (wikipedia.org)
  • Dendritic cells can be stimulated to activate a cytotoxic response towards an antigen. (wikipedia.org)
  • Dendritic cells, a type of antigen presenting cell, are harvested from the person needing the immunotherapy. (wikipedia.org)
  • Another cell-based vaccine strategy involves autologous dendritic cells (dendritic cells derived from the patient) to which tumor antigens are added. (wikipedia.org)
  • In this strategy, the antigen-presenting dendritic cells directly stimulate T-cells rather than relying on processing of the antigens by native APCs after the vaccine is delivered. (wikipedia.org)
  • Cells infected with HSV-US12-r.VV, demonstrated a decreased ability of presenting MHC class-I antigens to CD8+ T cells whereas MHC-class-II restricted presentation to CD4+ T cells remained unaffected. (unibas.ch)
  • The observed CTL and lymphoproliferative response indicates that anti-idiotypic B cells termed Jerne cells stimulate both T helper and T cytotoxic cells by virtue of their ability to present recycled or regurgitated peptido-mimics of antigen to T helper cells through class II MHC and de novo synthesized peptido-mimics of antigens to CTLs. (iisc.ac.in)
  • With the availability of sensitive methods, naturally occurring T cells directed against tumor-associated antigens (TAAs) can be frequently detected in cancer patients. (aacrjournals.org)
  • The possible role of TAA-specific T cells in immunosurveillance and tumor escape and the implications for immunological treatment strategies are discussed. (aacrjournals.org)
  • Naturally occurring T cells against TAAs are a common phenomenon in tumor patients. (aacrjournals.org)
  • Surprisingly, the tumor cells were capable of inducing a protective cytotoxic T cell response if transferred as a single-cell suspension. (pnas.org)
  • Tumor growth correlated strictly with ( i ) failure of tumor cells to reach the draining lymph nodes and ( ii ) absence of primed cytotoxic T cells. (pnas.org)
  • Established tumors were rejected by vaccine-induced effector T cells if effector T cells were maintained by prolonged or repetitive vaccination, but not by single-dose vaccination. (pnas.org)
  • Thus, in addition to several other tumor-promoting parameters, some antigenic peripheral sarcomas-and probably carcinomas-may grow not because they anergize or tolerize tumor-specific T cells, but because such tumors are immunologically dealt with as if they were in a so-called immunologically privileged site and are ignored for too long. (pnas.org)
  • It has been postulated that antigen recognition in the absence of signal two-as might occur in peripheral tissues and thus in most carcinomas or sarcomas-renders T (or B) cells nonreactive (anergic) or may delete them ( 10 , 12 , 13 ). (pnas.org)
  • Experimental tumor immunology has often selected successful tumor cells that initiate tumors after injection of few (10-10 4 ) cells. (pnas.org)
  • Thus, "tagged" with these unique viral tumor antigens, cervical cancer cells may be recognized specifically by CTLs. (aacrjournals.org)
  • Epstein-Barr virus (EBV) is associated with several cancers in which the tumor cells express EBV antigens EBNA1 and LMP2. (aacrjournals.org)
  • NK cells provide rapid responses to virus-infected cells, acting at around 3 days after infection , and respond to tumor formation. (wikipedia.org)
  • In contrast to NKT cells, NK cells do not express T-cell antigen receptors (TCR) or pan T marker CD3 or surface immunoglobulins (Ig) B cell receptors , but they usually express the surface markers CD16 (FcγRIII) and CD56 in humans, NK1.1 or NK1.2 in C57BL/6 mice . (wikipedia.org)
  • Immunization of cancer patients with vaccines containing full-length tumor Ags aims to elicit specific Abs and both CD4 + and CD8 + T cells. (jimmunol.org)
  • NK cells also play a role in the adaptive immune response: numerous experiments have demonstrated their ability to readily adjust to the immediate environment and formulate antigen-specific immunological memory, fundamental for responding to secondary infections with the same antigen. (wikipedia.org)
  • Selection of the appropriate adjuvant to activate antigen-presenting cells to stimulate immune responses, is required. (wikipedia.org)
  • In one approach, vaccines contain whole tumor cells, though these vaccines have been less effective in eliciting immune responses in spontaneous cancer models. (wikipedia.org)
  • VP1 molecules possess a surface binding site that interacts with sialic acids attached to glycans, including some gangliosides, on the surfaces of cells to initiate the process of viral infection. (wikipedia.org)
  • Glioblastoma multiforme tumors are characterized by the presence of small areas of necrotizing tissue that are surrounded by anaplastic cells. (wikipedia.org)
  • The viral membrane-anchored surface glycoproteins are responsible for receptor recognition and entry into target cells through membrane fusion. (wikipedia.org)
  • Moreover, in the presence of dying cells, PTX3 restricts the cross presentation of antigens derived from dying cells. (wikipedia.org)
  • When the virus is injected into juvenile hamsters from naive populations, it induces leukemias and lymphomas which are free of virus particles but whose cells contain extra-chromosomal viral DNA. (wikipedia.org)
  • MHC tetramers are used to identify and label specific T-cells by epitope specific binding, allowing the antigen specific immune response to be analyzed in both animal model and in man. (wikipedia.org)
  • MHC tetramers were originally developed using MHC class I molecules for the recognition of cytotoxic T cells, but over the last decade they have allowed for the recognition of CD4 T cells by a wide variety of antigens. (wikipedia.org)
  • MHC pentamers have been used in the detection of antigen-specific CD8+ T cells in flow cytometry, and are cited in over 750 peer reviewed publications , including several in the journals Nature and Science. (wikipedia.org)
  • MHC pentamers can also be used in tissue staining, and in magnetic isolation of antigen-specific T cells. (wikipedia.org)
  • and Adaptive immune response - antigen presenting cells (APCs) display tumor-associated antigens (TAA) and viral-associated antigens (VAA) to educate T-cells to recognize and destroy cancer cells. (wikipedia.org)
  • Reovirus replicates in and eventually kills Ras-activated tumour cells, and as cell death occurs, progeny virus particles are then free to infect surrounding cancer cells. (wikipedia.org)
  • The cells then destroy the tumor cells that express the antigen. (wikipedia.org)
  • These cells are then either pulsed with an antigen or tumor lysate or transfected with a viral vector, causing them to display the antigen. (wikipedia.org)
  • Upon transfusion into the person, these activated cells present the antigen to the effector lymphocytes (CD4+ helper T cells, cytotoxic CD8+ T cells and B cells). (wikipedia.org)
  • This initiates a cytotoxic response against tumor cells expressing the antigen (against which the adaptive response has now been primed). (wikipedia.org)
  • The T cells may already target tumor cells. (wikipedia.org)
  • These T cells, referred to as tumor-infiltrating lymphocytes (TIL), are multiplied using high concentrations of Interleukin-2, anti-CD3 and allo-reactive feeder cells. (wikipedia.org)
  • Genetically engineered T cells are created by harvesting T cells and then infecting the T cells with a retrovirus that contains a copy of a T cell receptor (TCR) gene that is specialised to recognise tumour antigens. (wikipedia.org)
  • Cell-based vaccines include tumor cells or tumor cell lysates. (wikipedia.org)
  • Tumor cells from the patient are predicted to contain the greatest spectrum of relevant antigens, but this approach is expensive and often requires too many tumor cells from the patient to be effective. (wikipedia.org)
  • This indicates that MCV is necessary to maintain the virus-positive tumor cells. (wikipedia.org)
  • Pillars Article: IFNγ and Lymphocytes Prevent Primary Tumour Development and Shape Tumour Immunogenicity. (nih.gov)
  • Using a combination of established cancer cell lines that resemble the patient's tumor can overcome these barriers, but this approach has yet to be effective. (wikipedia.org)
  • Some scientists claim both the innate and adaptive immune systems must be activated to achieve total tumor elimination. (wikipedia.org)
  • Based on both single-arm and randomized phase 2 clinical studies, REOLYSIN also promotes an inflamed tumor phenotype through innate and adaptive immune responses. (wikipedia.org)
  • Inspired by the work of Hilary Koprowski, who developed some of the earliest monoclonal antibodies against tumour antigens and influenza viral antigens, the objective of Centocor was to commercialise monoclonal antibodies for diagnostics and therapeutics. (wikipedia.org)
  • A process called "epitope spreading" or "provoked immunity" may mitigate this weakness, as sometimes an immune response to a single antigen can lead to immunity against other antigens on the same tumor. (wikipedia.org)
  • numerous experiments have demonstrated their ability to readily adjust to the immediate environment and formulate antigen-specific immunological memory , fundamental for responding to secondary infections with the same antigen. (wikipedia.org)
  • In contrast, other TAAs, including most antigens of the MAGE family, do not usually elicit spontaneous T cell responses. (aacrjournals.org)
  • These TAAs have facilitated the analysis of T cell responses to tumors and are promising targets for immunotherapeutic strategies. (aacrjournals.org)
  • They bind viral ligands such as hemagglutinins and hemagglutinin neuraminidases, some bacterial ligands and cellular ligands related with tumour growth such as PCNA . (wikipedia.org)
  • We have shown that NY-ESO-1 is highly immunogenic, inducing spontaneous immune responses in patients with NY-ESO-1-expressing tumor but not in healthy individuals ( 3 ). (jimmunol.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)