This research proposal is aimed at elucidating the mechanism of lymphomagenesis by the slow transforming murine retroviruses. It focuses on the understanding of the tissue-specificity of the diseases caused by these retroviruses. Included in these studies are experiments to further our understanding of the role that the long terminal repeat (LTR) sequences play in this specificity and to identify the cell population(s) which is involved in the genesis of thymic lymphomas in mice. The LTR which will be characterized is that of the MCF13 murine leukemia virus, which causes thymic lymphomas. Analysis of the contribution of MCF13 LTR sequences to this tissue specificity will depend on the generation of a fine deletion map. Small deletions involving only a few nucleotides will be created by the method of oligonucleotide site-directed mutagenesis. These deletions will include nucleotide sequences which are involved in protein binding in the enhancer element and regions upstream and downstream of this element. Protein binding sites will be identified by the electrophoretic mobility shift assay in conjunction with footprinting analysis by DNAaseI nuclease and copper-phenanthroline chemical cleavages. Once sequence motifs important for tissue-specific transcription are identified, their combinatorial interactions with each other and with repressor elements will be examined. The identification of tissues and cell-types which have MCF13 LTR activity will be identified with the use of transgenic mice. The expression of different marker genes whose transcription is dependent on MCF13 LTR activity will be monitored in both prenatal and postnatal animals by RNA analysis. This analysis will be performed by primer extension assays. The phenotype of the cells which express MCF 13 LTR activity will be identified by using fluorescent antibodies specific for T cell antigens, such as Thy1, Lyt-2, L3T4, and MEL-14, and analysis by flow cytometry.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA044166-08
Application #
3186749
Study Section
Experimental Virology Study Section (EVR)
Project Start
1979-04-01
Project End
1994-08-31
Budget Start
1993-01-01
Budget End
1994-08-31
Support Year
8
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of Washington
Department
Type
Schools of Medicine
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Yoshimura, Fayth K; Luo, Xixia; Zhao, Xiaoqing et al. (2008) Up-regulation of a cellular protein at the translational level by a retrovirus. Proc Natl Acad Sci U S A 105:5543-8
Zhao, Xiaoqing; Yoshimura, Fayth K (2008) Expression of murine leukemia virus envelope protein is sufficient for the induction of apoptosis. J Virol 82:2586-9
Yoshimura, Fayth K; Luo, Xixia (2007) Induction of endoplasmic reticulum stress in thymic lymphocytes by the envelope precursor polyprotein of a murine leukemia virus during the preleukemic period. J Virol 81:4374-7
Nanua, Suparna; Yoshimura, Fayth K (2004) Mink epithelial cell killing by pathogenic murine leukemia viruses involves endoplasmic reticulum stress. J Virol 78:12071-4
Nanua, Suparna; Yoshimura, Fayth K (2004) Differential cell killing by lymphomagenic murine leukemia viruses occurs independently of p53 activation and mitochondrial damage. J Virol 78:5088-96
Yoshimura, F K; Wang, T (2001) Role of the LTR region between the enhancer and promoter in mink cell focus-forming murine leukemia virus pathogenesis. Virology 283:121-31
Yoshimura, F K; Wang, T; Nanua, S (2001) Mink cell focus-forming murine leukemia virus killing of mink cells involves apoptosis and superinfection. J Virol 75:6007-15
Yoshimura, F K; Wang, T; Yu, F et al. (2000) Mink cell focus-forming murine leukemia virus infection induces apoptosis of thymic lymphocytes. J Virol 74:8119-26
Yoshimura, F K; Wang, T; Cankovic, M (1999) Sequences between the enhancer and promoter in the long terminal repeat affect murine leukemia virus pathogenicity and replication in the thymus. J Virol 73:4890-8
Chen, H; Yoshimura, F K (1998) Spacing between the enhancer and promoter of the long terminal repeat of a murine leukaemia retrovirus is required for transcriptional activation in T cells. J Gen Virol 79 ( Pt 5):1101-4

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