The goal of this project is to better understand the effects of host cells and other co-factors on human retroviral replication and pathogenesis. Highly active combination antiviral drug therapy (HAART) holds promise to convert productive HIV infections into a chronic, non-viremic, non-progressive condition. However, in some patients, limited but continuous viral production has been observed and, in others, latently infected long-lived peripheral T cells which can be reactivated during a normal immune response have been identified in HAART-treated HIV infected individuals. In developing long term therapy for HIV infected individuals it will be necessary to control viral production from and/or eradicate these latent reservoirs through adjuvant therapies like immunotherapy. We have previously identified two mechanisms which activate expression of latent HIV provirus: immune activation, which requires contact between latently infected cells and uninfected activated CD4+ cells, and hypomethylation. We have recently demonstrated that acute HIV infection increases the cellular capacity to methylate genes. Increased DNA methyltransferase (DNMT) activity in HIV infected cells can result in an increase in the latent reservoir through methylation of the HIV LTR and the subsequent silencing of viral gene expression. In addition, increased DNMT activity can result in aberrant methylation of cellular genes including, interferon-gamma (IFN-gamma). This hypermethylation of IFN-gamma results in decreased production of IFN-gamma, decreased type 1 immune response and increased spread of cell free virions. In attempting to understand the role of methylation in the regulation of viral and gene regulation, we have made progress in several areas. First, HIV proviral integration is not necessary for HIV infection to increase the cellular capacity to methylate genes. Second, DNMT-1 but not DNMT3a and DNMT3b are increased during HIV infection of lymphoid cells. Third, in some (49/96) patients on long-term HAART, CD4+ T cells have greatly diminished ability to produce IFN-gamma which can be restored through hypomethylation of IFN-gamma promoter, using hypomethylating drugs. Bisulfite genomic sequencing of this promoter has shown that the IFN-gamma promoter can remain hypermethylated during HAART therapy. Fourth, using a newly developed array based assay (differential methylation hybridization), we have found that CD4+ T lymphocytes from HIV infected individuals have several CpG islands which are more extensively methylated than normal controls. We have identified one of these genes as the p16(Ink4a) gene indicating that CpG islands, normally hypomethylated, can be hypermethlated after HIV infection. Since DNMT1 is the DNMT that is predominantly upregulated following HIV infection and recent evidence suggests that, in addition to its enzymatic function, it can form complexes with other proteins including transcriptional factors such as Tat or Vpr can tether to complexes containing DNMT-1 dysregulate transcription control in a novel manner. Although largely unknown, the cellular events triggered by HTLV-1 infection in the lymphoproliferative process are of major importance to the establishment of leukemia. We have recently characterized an infectious clone of HTLV-1 as well as a susceptible expressing cell line to study the molecular interactions of this infectious clone. The HTLV-1 surface unit of the envelope has been fused to the Ig molecule and is being used to study the regulation of the HIV-1 receptor. This project was formerly Z01 CM 09251-12 LLB. AIDS Title: Negative Regulation of HIV replication - Pathogenic Effects

Agency
National Institute of Health (NIH)
Institute
Division of Basic Sciences - NCI (NCI)
Type
Intramural Research (Z01)
Project #
1Z01BC010252-06
Application #
6559127
Study Section
(LLB)
Project Start
Project End
Budget Start
Budget End
Support Year
6
Fiscal Year
2001
Total Cost
Indirect Cost
Name
Basic Sciences
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Takenouchi, Norihiro; Jones, Kathryn S; Lisinski, Ivonne et al. (2007) GLUT1 is not the primary binding receptor but is associated with cell-to-cell transmission of human T-cell leukemia virus type 1. J Virol 81:1506-10
Jones, Kathryn S; Fugo, Kazunori; Petrow-Sadowski, Cari et al. (2006) Human T-cell leukemia virus type 1 (HTLV-1) and HTLV-2 use different receptor complexes to enter T cells. J Virol 80:8291-302
Jones, Kathryn S; Akel, Salem; Petrow-Sadowski, Cari et al. (2005) Induction of human T cell leukemia virus type I receptors on quiescent naive T lymphocytes by TGF-beta. J Immunol 174:4262-70
Ruscetti, Francis W; Akel, Salem; Bartelmez, Stephen H (2005) Autocrine transforming growth factor-beta regulation of hematopoiesis: many outcomes that depend on the context. Oncogene 24:5751-63
Jones, Kathryn S; Petrow-Sadowski, Cari; Bertolette, Daniel C et al. (2005) Heparan sulfate proteoglycans mediate attachment and entry of human T-cell leukemia virus type 1 virions into CD4+ T cells. J Virol 79:12692-702
Polianova, Maria T; Ruscetti, Francis W; Pert, Candace B et al. (2005) Chemokine receptor-5 (CCR5) is a receptor for the HIV entry inhibitor peptide T (DAPTA). Antiviral Res 67:83-92
Wielgosz, Matthew M; Rauch, Daniel A; Jones, Kathryn S et al. (2005) Cholesterol dependence of HTLV-I infection. AIDS Res Hum Retroviruses 21:43-50
Puri, Anu; Rawat, Satinder S; Lin, Han-Ming Joseph et al. (2004) An inhibitor of glycosphingolipid metabolism blocks HIV-1 infection of primary T-cells. AIDS 18:849-58
Taub, Dennis D; Mikovits, Judy A; Nilsson, Gunnar et al. (2004) Alterations in mast cell function and survival following in vitro infection with human immunodeficiency viruses-1 through CXCR4. Cell Immunol 230:65-80
Finnegan, Catherine M; Rawat, Satinder S; Puri, Anu et al. (2004) Ceramide, a target for antiretroviral therapy. Proc Natl Acad Sci U S A 101:15452-7

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