Simian virus 40 (SV40) contains an essential protein, large tumor antigen (Tag), which assists in viral replication and causes cell transformation and immortalization. Our laboratory has examined plasmid DNA, expressing SV40 Tag under two different promoters, for use in potential cancer vaccination strategies. One plasmid, pSV3-neo, failed to induce SV40 Tag antibody, produced a weak cell-mediated response, and only partial protection in murine experimental tumor challenge systems. The second plasmid, pCMV-Tag, induced antibodies to SV40 Tag, produced a robust cell-mediated response, and invoked complete tumor immunity in vivo. The induction of CD4+ and CD8+ T cell responses following plasmid DNA immunization and tumor cell challenge reflected a type 1 cytokine secretion profile. Our hypothesis for this differential immune response is that pCMV-Tag exhibits a higher level of transgene expression due to a more efficient promoter. We determined that pCMV-Tag levels of SV40 Tag mRNA and protein expression were higher when compared to pSV3-neo. A threshold amount of SV40 Tag may be required to stimulate antibody production and provide complete systemic tumor immunity.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.virol.2004.08.041 | DOI Listing |
Biochem Biophys Res Commun
January 2025
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan; Department of Chemistry, Graduate School of Science, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan; Faculty of Engineering and Graduate School of Engineering, Gifu University, Yanagido 1-1, Gifu, 501-1193, Japan. Electronic address:
Importin α is a crucial player in the nucleocytoplasmic transport of nuclear localization signal (NLS)-containing cargo proteins and is suggested to bind to DNA directly. We hypothesized that importin α, after binding to DNA, may move along DNA via sliding or hopping. We investigated the movement dynamics of importin αs fused to AcGFP along DNA using single-molecule fluorescence microscopy and single-tethered DNA arrays.
View Article and Find Full Text PDFJ Immunother Cancer
October 2024
Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
Background: Immune checkpoint blockade (ICB) therapies are an important treatment for patients with advanced cancers; however, only a subset of patients with certain types of cancer achieve durable remission. Cancer vaccines are an attractive strategy to boost patient immune responses, but less is known about whether and how immunization can induce long-term tumor immune reprogramming and arrest cancer progression. We developed a clinically relevant genetic cancer mouse model in which hepatocytes sporadically undergo oncogenic transformation.
View Article and Find Full Text PDFJ Food Sci
December 2024
College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, P. R. China.
The mammary gland, crucial for milk production in mammals, presents challenges for in vitro study due to its complex structure and limited cell lifespan. We addressed this by introducing the SV40 large T antigen into primary mammary epithelial cells (MECs) from sheep, creating an immortalized T-tag MEC line. This line, stable for over 50 passages, maintained typical epithelial cell morphology during long-term culture.
View Article and Find Full Text PDFJ Virol
October 2024
Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, USA.
Unlabelled: The mechanism used by polyomavirus and other viral SF3 helicases to unwind DNA at replication forks remains unknown. Using AlphaFold2, we have determined the structure of a representative SF3 helicase, the SV40 T-antigen (T-ag). This model has been analyzed in terms of the features of T-ag required for helicase activity, particularly the proximity of the T-ag origin binding domain (OBD) to the replication fork and the distribution of basic residues on the surface of the OBD that are known to play roles in DNA unwinding.
View Article and Find Full Text PDFCancers (Basel)
August 2024
Department of Nutrition, University of North Carolina, Chapel Hill, NC 27599, USA.
Obesity is an established risk and progression factor for triple-negative breast cancer (TNBC), but preclinical studies to delineate the mechanisms underlying the obesity-TNBC link as well as strategies to break that link are constrained by the lack of tumor models syngeneic to obesity-prone mouse strains. C3(1)/SV40 T-antigen (C3-TAg) transgenic mice on an FVB genetic background develop tumors with molecular and pathologic features that closely resemble human TNBC, but FVB mice are resistant to diet-induced obesity (DIO). Herein, we sought to develop transplantable C3-TAg cell lines syngeneic to C57BL/6 mice, an inbred mouse strain that is sensitive to DIO.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!