R01 HL42103 - Dorothea Zucker-Franklin - New York University, New York, NY
This investigator utilized fresh marrow from HIV-infected individuals to determine whether injury to the megakaryocyte and the myeloid lineages in AIDS were due to immune complexes or to inhibitory factors related to the infection or the virus itself. Inhibitory substances were tested in vitro on colonies from normal bone marrow.
This grant was supported from 1990 to 1995.
Currently, the interaction of HIV and HTLV with dendritic cells (DC) in vitro is being addressed. A method has been established which permits in vitro generation of DC from CD34+ hematopoietic progenitors isolated from cord blood. DC have been co-cultured with HIV as well as with HTLV-l and ll-infected cell lines. To date, the impression has been that there is a preferential association of these retroviruses with DC, but no DC support of viral proliferation has yet been observed. The principal investigator has observed that practically all patients with mycosis fungoides have tax and/or pol proviral in their freshly isolated blood mononuclear cells and skin biopsies. The significance of this concerns the alarming high increase of HTLV infection among the same population at risk of being infected with HIV and the reports that AIDS patients have a more rapid downhill course, if they are also infected with HTLV.
RO1 HL42125 - Jean-Pierre Sommadossi - University of Alabama, Birmingham, AL
The objective of this research was to continue ongoing studies on the mechanism by which pyrimidine nucleoside analog active against HIV (such as 3'azido-3'-deoxythymidine and its congeners) exert toxicity on bone marrow and other cells. Elicitation of these mechanisms may permit the development of a combination therapy with modulating agents that protect or reverse host toxicity without impairment of the anti-HIV activity of the drug under scrutiny. This project had two major aims: (1) the description of the biochemical and molecular mechanism responsible for the effects of AZT and its metabolite, 3'-amino-3'-deoxythymidine (AMT), in human marrow cells, and (2) the detailed characterization of the enzymatic reduction of AZT to AMT in human hepatocytes with the evaluation of potential drug-drug interactions through the cytochrome P-450 pathway.
This grant was being supported from 1993 to 1997.
Studies attempted to elucidate the molecular and biochemical mechanism(s) responsible for effects of AZT and AMT in an array of toxic target sites, such as bone marrow and other cells. Examination of drug-drug interaction which may lead to an enhancement of AMT were investigated in human hepatocytes in culture. The major effect was observed with methadone with a substantial decrease in AZT glucuronidation which may lead to an increased AMT formation. Understanding the mechanism(s) by which pyrimidine nucleoside analogs active against HIV and possibly catabolites exert toxicity on bone marrow and other cells increases the potential to develop selective combination therapy to reverse or protect against host toxicity without impairment of anti-HIV activity.
R01 HL42107 - David W. Golde - Sloan-Kettering Inst. for Cancer Res., NY, NY
The goals of this study were to understand common steps in the pathways of cytokine signaling for HIV proviral activation and virus replication in blood cells and to develop effective inhibitory strategies. Specific aims are: (1) to elucidate pathways involved in cytokine signaling for HIV activation in hematopoietic cells, (2) to develop strategies for inhibiting cytokine-mediated HIV activation and preventing release from latency, and (3) to test gene transfer strategies to inhibit viral replication in myelomonocytic cells.
This grant was being supported from 1988 to 1997.
Progress continues in the effort to understand the signaling pathways in cell that activate HIV. The cytokine tumor necrosis factor (TNF) is an important stimulator of virus production. The investigators are defining how TNF signals for stimulating viral reproduction in order to define new targets for intervention. Also, it has been demonstrated that virus-infected cells accumulate more vitamin C than normal cells. This may be an important potential target for therapeutic intervention. By effectively modulating oxidative and reductive forces in the cell with ascorbate, it may be possible to decrease viral production or actually kill virus-infected cells.
R01 HL13336 - Simon Karpatkin - New York University, New York, NY
This grant focused on the role of idiotype-anti-idiotype complexes in the peripheral destruction of platelets in HIV-1-related immunologic thrombocytopenic purpura (ITP). These studies could help us understand the basic immunologic pathophysiology of HIV-1 infection as well as assist in devising clinical strategies for the treatment and/or eradication of HIV-1-ITP.
This grant is being supported from 1992 to 1996.
This study documented monomenic anti-platelet IgG in an autoimmune platelet disorder using F(ab1)2 binding, affinity purification, salivation binding and Scbtchanel analysis.
R01 HL42283 - Brian Davis - Medical Research Institute, San Francisco, CA
This group studyed the effect of HIV-1 isolates and HIV viral proteins on the in vitro proliferation and differentiation potential of purified marrow CD34+ cells. Four HIV isolates were exposed to normal CD34+ cells. The IRC-3 and HTLV-111b isolates induced a decreased proliferation/ survival of CD34+ cells in IL-3-containing liquid culture, as well as a decrease in CFU-GM and BFU-E colony formation. By contrast, LAV' and pNL4-3 isolates had no effect upon the biological activity of CD34+ cells, as measured in the same assays. Second, certain isolates, even when present in the same concentration as HTL-111b and ICR-3 isolates, are unable to induce CD34+ cell defects. Studies have focused on generating a hematopoietic cell line model system for studying the inhibitory effect of HIV on CD34+ primary bone marrow cells; in particular they have focused on what renders CD34+ cells unable to proliferate and differentiate. Results obtained during the past year have demonstrated that brief exposure of HIV-1 isolates to KG-1 cells induces significant death after a lag period of 7-10 days. This effect does not involve productive HIV-1 infection and occurs for a variety of HIV-1 isolates.
This grant was supported from 1988 to 1993.
Among the most important observations made during support of this proposal are the following: (1) Exposure of HIV-1 to CD34+ hematopoietic cells rarely gives rise to productive infection. This data supports the feasibility of novel treatment modalities for HIV, involving reinfusion of purified CD34+ autologous bone marrow cells along with anti-virals following marrow ablative therapy to destroy virus and virus-infected cells. Conferring resistance to HIV by gene transfer into CD34+ prior to infusion could protect progeny hematopoietic cell from virus infection; (2) HIV-1 triggers apoptotic cell death of CD34+ hematopoietic progenitor cells. These data strongly suggest that HIV-1, and or free gp120 in the presence of anti-gp120 antibody, through direct interaction with CD34+ stem/progenitor cells, could play a direct role in the pathogenesis of peripheral blood cytopenias.
R01 HL42674 - Ronald Hoffman - Indiana University, Indianapolis, IN
This investigator studied the consequences of HIV-1 infection on both human hematopoietic progenitor cells and stem cells. In addition, he examined the effect of two other viral pathogens, cytomegalovirus and the human parvovirus B19, on hematopoiesis.
This grant was supported from 1989 to 1993.
Dr. Hoffman and colleagues clearly demonstrated that the most primitive hematopoietic progenitor cell is not infected by HIV-1. Rather hematopoietic cells that are likely to be infected with this virus are at the progenitor cell level. This observation has clinical implication in that it raises the possibility that peripheral hematologic stem cell autotransplants might be utilized at some time in combination with effective antiviral therapy for the treatment of HIV-1 infected patients.