8 results on '"Hong-Guang Guo"'
Search Results
2. Tumorigenesis by Human Herpesvirus 8 vGPCR Is Accelerated by Human Immuodeficiency Virus Type 1 Tat
- Author
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Marvin S. Reitz, Mariola Sadowska, Shibani Pati, Man Charurat, and Hong-Guang Guo
- Subjects
Male ,viruses ,Chemokine CXCL2 ,medicine.disease_cause ,Chemokine receptor ,Mice ,Gammaherpesvirinae ,Transgenes ,Phosphorylation ,NF-kappa B ,virus diseases ,Nuclear Proteins ,Drug Synergism ,Transfection ,DNA-Binding Proteins ,Cell Transformation, Neoplastic ,Gene Products, tat ,Herpesvirus 8, Human ,Female ,Receptors, Chemokine ,tat Gene Products, Human Immunodeficiency Virus ,Chemokines ,Cell type ,Immunology ,Mice, Nude ,Mice, Transgenic ,Biology ,Protein Serine-Threonine Kinases ,Microbiology ,Virus ,Herpesviridae ,Virology ,Cell Line, Tumor ,Proto-Oncogene Proteins ,medicine ,Animals ,Sarcoma, Kaposi ,NFATC Transcription Factors ,biology.organism_classification ,Molecular biology ,Mice, Inbred C57BL ,Cell culture ,Insect Science ,HIV-1 ,Pathogenesis and Immunity ,Carcinogenesis ,Proto-Oncogene Proteins c-akt ,Neoplasm Transplantation ,Transcription Factors - Abstract
Human herpesvirus 8 (HHV-8), also called Kaposi's sarcoma (KS) herpesvirus, can cause KS but is inefficient. Untreated human immunodeficiency virus type 1 (HIV-1) coinfection is a powerful risk factor. The HHV-8 chemokine receptor, vGPCR (ORF74), activates NF-κB and NF-AT, and their levels of activation are synergistically increased by HIV-1 Tat. Transgenic vGPCR mice develop KS-like tumors. A cell line derived from one such tumor expresses vGPCR and forms tumors in nude mice. Here we show that transfection of DNA encoding HIV-1tat(but not a transactivation-defective mutant) into these tumor cells increases NF-κB and NF-AT activation levels and accelerates tumor formation. Tumorigenesis was also accelerated when Tat DNA was transfected into normal cells and the transfected cells were mixed with the tumor cells and injected into a single site. Tumorigenesis was also increased when the two cell types were injected at separate sites, suggesting that tumorigenesis is accelerated by Tat through soluble factors.
- Published
- 2004
3. Tumorigenesis by Human Herpesvirus 8 vGPCR Is Accelerated by Human Immuodeficiency Virus Type 1 Tat.
- Author
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Hong-Guang Guo, Pati, Shibani, Sadowska, Mariola, Charurat, Man, and Reitz, Marvin
- Subjects
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HERPESVIRUSES , *HIV , *CARCINOGENESIS , *CHEMOKINES , *TRANSGENIC mice , *GENETIC mutation - Abstract
Human herpesvirus 8 (HHV-8), also called Kaposi's sarcoma (KS) herpesvirus, can cause KS but is inefficient. Untreated human immunodeficiency virus type 1 (HIV-1) coinfection is a powerful risk factor. The HHV-8 chemokine receptor, vGPCR (ORF74), activates NF-κB and NF-AT, and their levels of activation, are synergistically increased by HIV-1 Tat. Transgenic vGPCR mice develop KS-like tumors. A cell line derived from one such tumor expresses vGPCR and forms tumors in nude mice. Here we show that transfection of DNA encoding HIV-1 tat (but not a transactivation-defective mutant) into these tumor cells increases NF-κB and NF-AT activation levels and accelerates tumor formation. Tumorigenesis was also accelerated when Tat DNA was transfected into normal cells and the transfected cells were mixed with the tumor cells and injected into a single site. Tumorigenesis was also increased when the two cell types were injected at separate sites, suggesting that tumorigenesis is accelerated by Tat through soluble factors. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
4. Kaposi's Sarcoma-Like Tumors in a Human Herpesvirus 8 ORF74 Transgenic Mouse.
- Author
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Hong-Guang Guo, Sadowska, Mariola, Reid, William, Tschachler, Erwin, Hayward, Gary, and Reitz, Marvin
- Subjects
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KAPOSI'S sarcoma , *TUMORS , *HERPESVIRUSES - Abstract
The product of human herpesvirus 8 (HHV-8) open reading frame 74 (ORF74) is related structurally and functionally to cellular chemokine receptors. ORF74 activates several cellular signaling pathways in the absence of added ligands, and NIH 3T3 cells expressing ORF74 are tumorigenic in nude mice. We have generated a line of transgenic (Tg) mice with ORF74 driven by the simian virus 40 early promoter. A minority (approximately 30%) of the Tg mice, including the founder, developed tumors resembling Kaposi's sarcoma (KS) lesions, which occurred most typically on the tail or legs. The tumors were highly vascularized, had a spindle cell component, expressed VEGF-C mRNA, and contained a majority of CD31[sup +] cells. CD31 and VEGF-C are typically expressed in KS. Tumors generally (but not always) occurred at single sites and most were relatively indolent, although several mice developed large visceral tumors. ORF74 was expressed in a minority of cells in the Tg tumors and in a few other tissues of mice with tumors; mice without tumors did not express detectable ORF74 in any tissues tested. Cell lines established from tumors expressed ORF74 in a majority of cells, expressed VEGF-C mRNA, and were tumorigenic in nude mice. The resultant tumors grew rapidly, metastasized, and continued to express ORF74. Cell lines established from these secondary tumors also expressed ORF74 and were tumorigenic. These data strongly suggest that ORF74 plays a role in the pathology of KS and confirm and extend previous findings on the tumorigenic potential of ORF74. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
5. A Bcl-2 homolog encoded by Kaposi sarcoma-associated virus, human herpesvirus 8, inhibits...
- Author
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Cheng, Emily H.-Y., Nicholas, John, Bellows, David S., Hayward, Gary S., Hong-Guang Guo, Reitz, Marvin S., and Hardwick, J. Marie
- Subjects
VIRAL proteins ,HERPESVIRUSES ,KAPOSI'S sarcoma - Abstract
Identifies a novel viral Bcl-2 homolog, designated KSbcl-2, from human herpesvirus 8 (HHV8) or Kaposi sarcoma-associated herpesvirus. Encoding of a bcl-2 homolog by HHV8; Inhibition of Sindbis virus-induced apoptosis by the overexpression of KSbcl-2; Expression of KSbcl-2 during the lytic viral replication cycle.
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- 1997
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6. Novel organizational features, captured cellular genes, and strain variability within the genome...
- Author
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Nicholas, John, Zong, Jian-Chao, Alcendor, Donald J., Ciufo, Dolores M., Poole, Lynn J., Sarisky, Robert T., Chuang-Jiun Chiou, Zhang, Xiaoqun, Wan, Xiaoyu, Hong-Guang Guo, Reitz, Marvin S., and Hayward, Gary S.
- Subjects
HERPESVIRUS genetics - Abstract
Presents information on a study which focused on the genome characteristics of gamma herpesviruses (KSHV) and its gentic aspects. Information on the availibility of five distinct gamma herpesviruses to assist in the completion of genomic deoxyribonucleic acid (DNA) sequences; Features of the KSHV; Methodology used to conduct the study; Discussion on the results from the study.
- Published
- 1998
7. Expression of human herpesvirus 8-encoded cyclin D in Kaposi's sarcoma spindle cells.
- Author
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Davis, Monica A., Blasig, Cornelia, Sturzl, Michael, Schreier, Anneliese, Hong-Guang Guo, Reitz, Marvin, Opalenik, Susan R., Browning, Philip J., Davis, M A, Stürzl, M A, Blasig, C, Schreier, A, Guo, H G, Reitz, M, Opalenik, S R, and Browning, P J
- Subjects
GENE expression ,KAPOSI'S sarcoma ,HERPESVIRUSES ,GENETICS - Abstract
Background: Human herpesvirus 8 (HHV-8) DNA sequences have been detected in Kaposi's sarcoma, in primary effusion lymphoma (an unusual high-grade non-Hodgkin's lymphoma seen primarily in patients with acquired immunodeficiency syndrome [AIDS]), and in Castleman's disease (a rare lymphoproliferative disorder); however, proof that HHV-8 is involved in the pathogenesis of these diseases remains to be established. HHV-8 contains a gene, i.e., v-cyclin D, that is a homologue of the cellular cyclin D2 gene, which encodes a protein that promotes passage through G1 phase of the cell cycle. Previous studies have identified v-cyclin D messenger RNA (mRNA) in biopsy specimens of Kaposi's sarcoma. In this study, we isolated a full-length v-cyclin D complementary DNA and characterized the pattern of v-cyclin D mRNA expression in Kaposi's sarcoma.Methods: Standard methods were used to construct and to screen HHV-8 genomic and complementary DNA libraries. Reverse transcription-polymerase chain reaction (RT-PCR) methods and in situ hybridization with RNA probes were used to examine v-cyclin D mRNA expression.Results: RT-PCR demonstrated the presence of v-cyclin D mRNA in biopsy specimens of AIDS-related Kaposi's sarcoma, in early-passage spindle cells from classical (i.e., not AIDS-related) Kaposi's sarcoma, and in spindle cells isolated from the peripheral blood of patients with AIDS-related Kaposi's sarcoma. In situ hybridization indicated that mRNAs for v-cyclin D and kaposin, an HHV-8 latency-associated gene, were present in approximately 1% of the spindle cells in early patch lesions and approximately 60% of the spindle cells in late nodular lesions of Kaposi's sarcoma.Conclusions: Spindle cells of Kaposi's sarcoma, which have been regarded as the tumor cells of this cancer, contain v-cyclin D mRNA. Expression of v-cyclin D protein may be involved in the pathogenesis of Kaposi's sarcoma by promoting cell proliferation. [ABSTRACT FROM AUTHOR]- Published
- 1997
- Full Text
- View/download PDF
8. Alterations in cytotoxic and helper T cell function after infection of T cell clones with human T cell leukemia virus, type I
- Author
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Samuel Broder, Marvin S. Reitz, Robert Yarchoan, Hong-Guang Guo, Hiroaki Mitsuya, and Annette Maluish
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Antigens, Differentiation, T-Lymphocyte ,T cell ,T-cell leukemia ,Retroviridae Proteins ,Gene Products, gag ,chemical and pharmacologic phenomena ,Biology ,Deltaretrovirus ,Interleukin 21 ,Antigen ,HLA Antigens ,medicine ,Cytotoxic T cell ,Humans ,Receptors, Immunologic ,Antigen-presenting cell ,Antibodies, Monoclonal ,Receptors, Interleukin-2 ,General Medicine ,T lymphocyte ,T-Lymphocytes, Helper-Inducer ,Virology ,Clone Cells ,medicine.anatomical_structure ,Immunoglobulin G ,Antigens, Surface ,DNA, Viral ,Clone (B-cell biology) ,Research Article ,Retroviridae Infections ,T-Lymphocytes, Cytotoxic - Abstract
HTLV-I is a transforming human retrovirus that is an etiologic agent of adult T cell leukemia/lymphoma. To investigate the effects of this virus on T cell functions, two OKT3+, OKT4+, OKT8- cytotoxic clones (8.7 and 8.8) specific for allogeneic cells bearing DPw2, a class II histocompatibility antigen, were studied before and after infection with HTLV-I. The clones retained cytotoxic function for up to 70 d after exposure to HTLV-I, even without subsequent antigenic stimulation, but then lost their cytotoxic activity. Prior to infection with HTLV-I, clone 8.8 also lysed OKT3 hybridoma cells; after infection, cytotoxic activity against these OKT3-antibody bearing cells was lost in parallel with the loss of activity against DPw2-bearing target cells. In addition, expression of T3 surface antigen by HTLV-I-infected 8.8 cells was decreased at a time when they lost their cytotoxic activity, possibly contributing to the loss of cytotoxic function. Finally, clone 8.8 could provide help for nonspecific IgG production by autologous B cells when stimulated with irradiated DPw2-bearing non-T cells. After infection with HTLV-I, this helper function became independent of DPw2-stimulation and persisted even when the cytotoxic activity was lost. An OKT4+ T cell clone thus could simultaneously manifest both cytotoxic and helper T cell activities, and these activities were differentially affected after HTLV-I infection.
- Published
- 1986
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