Vaccines, Blood & Biologics
HIV Infections and the Safety of the Blood Supply
Principal Investigator: Andrew I. Dayton, MD, PhD
Office / Division / Lab: OBRR / DETTD / LMV
Blood can efficiently transfer diseases from infected donors to uninfected recipients.
We study blood-borne viruses belonging to two classes: retroviruses (Human Immunodeficiency Virus [HIV]) and flaviviruses (West Nile Virus [WNV] and dengue virus [DV]). Our goals are to improve techniques for detecting viruses in blood, reduce transmission of viruses by blood donation, and improve technologies for monitoring virus levels in patients receiving anti-virus therapy. We plan to meet these goals by developing new detection technologies and studying how viruses spread, replicate, and cause disease. These studies are now taking place in our laboratories; depending on the results, our findings could lead to studies in humans.
HIV continually evolves through gene mutations. These mutations can change the virus enough to thwart blood donor screening tests that were designed to identify the original version of the virus. This complicates interpretation of tests that researchers use to predict if a specific variant of HIV will be resistant to a specific anti-viral drug. Therefore, the ability to predict the emergence and/or the biological effects of viral mutations could improve the accuracy of diagnostic and blood donor screening tests for viruses such as HIV WNV, and DV. It could also improve the ability of scientists to monitor the development of resistance to anti-viral drugs in patients with HIV/AIDS.
In addition, improved understanding of how HIV and humans interact with each other will enable researchers to develop improved therapies based on such patient-specific factors such as their genetic makeup. Our laboratory is studying the interactions between HIV and its host (the human it infects). We are trying to understand how the host's natural killer (NK) cells (immune cells that launch the body's early defense against viruses) combat AIDS progression; how HIV can survive (or "hide") in immune cells such as macrophages; and how HIV regulates its own replication and assembles into new viruses that subsequently escape from the infected cell.
Our laboratory is also studying in cultured cells how the female sex hormone estrogen blocks the therapeutic effects of the anti-HIV drug D4T and whether estrogen also blocks the effects of related anti-HIV drugs.
In addition, we are studying the process by which HIV assembles itself into new viruses that can transmit infection.
We study blood-borne and/or bioterrorism viral agents belonging to two classes: retroviruses (primarily Human Immunodeficiency Virus - HIV) and flaviviruses (primarily West Nile Virus [WNV] and dengue virus [DV). Our goals are to 1) improve viral detection; 2) reduce virus transmission; and 3) improve therapeutic monitoring technology. We approach these goals through developing detection technologies, and improving our understanding of viral pathogenesis.
We recently investigated the potential roles of natural killer (NK) cells in AIDS. Starting with peripheral blood mononuclear cells (PBMC) from normal donors, we expanded activated NK cells by co-cultivation with K562-derived stimulator cells expressing IL-15 and 4-1BB ligand (4-1BBL) on the cell surface, with and without IL-18 (also on the cell surface). The expanded NK cells show up-regulated activation markers, secrete high levels of IFN-gamma, and have both direct cell cytotoxicity and ADCC. After we engineered these cells to express the anti-gp120 MAb 2G12, these NK cells showed specifically enhanced cytotoxicity for cells coated with gp120.
Collaborating with outside investigators, we adapted interferometric techniques to detect HIV-1 p24, resulting in a rapid p24 assay with a log better sensitivity than EIA.
In studies funded by the Office of Women’s Health we showed that beta-estradiol (BE) impairs the efficacy of the nucleoside reverse transcriptase inhibitor (NRTI) D4T: in the presence of physiological concentrations of BE, approximately twice as much D4T is required for virus inhibition than is required in the absence of BE. We have observed this effect in primary peripheral blood lymphocytes (PBL) and H9 cells.
Using HPLC and radiolabeled D4T we are now quantifying intracellular concentrations of D4T metabolic intermediates in H9 cells as it is successively phosphorylated to the active form, D4T-PPP in order to determine which step is inhibited by BE. We plan similar experiments for 3H-D4T influx and efflux rates. We also plan to study the ratio of the active metabolite, D4T-PPP to the endogenous pools of dT-PPP, with which it competes. We found that there is more variability in the BE effect in PBL than encountered in our original experiments. However, successive aliquots of cells frozen from any one donation show reproducible results, allowing us to study the mechanism in primary PBL, although at a slower pace than originally anticipated. We have seen BE effects in primary PBL for other NRTI, and are attempting to determine whether the results are consistent among successive aliquots of cells frozen from individual donations.
West Nile Virus (WNV)
Our laboratory developed methods for studying the natural response of host immune system natural killer (NK) cells to viral infection, with emphasis on harnessing these cells for new anti-viral therapies. In early experiments we showed that NK cells are shut down in the host during a WNV infection, eliminating an important immune system defense against this virus. However, we showed in tissue culture that expanded NK cells inhibit WNV replication. Part of this effect is due to IFN-gamma secreted by the NK cells. We are currently trying to determine whether direct cytotoxicity can also play a role.
We are currently attempting to grow large numbers of NK cells modified to combat specific viruses such as HIV and WNV.
Dengue virus (DV)
We are developing mass screening techniques for selecting DV infected cells in order to use shRNA libraries to identify host genes conferring resistance to DV-induced cell death. We are also using binding to sub-genomic regulatory RNAs to identify host genes involved in DV replication.
J Leukoc Biol 2011 Jul;90(1):87-97
Interleukin-12 treatment down-regulates STAT4 and induces apoptosis with increasing ROS production in human natural killer cells.
Lei Y, Zhang H, Zhang M, Dayton A
Retrovirology 2011 Jul 20;8(1):62
Matrin 3 and HIV Rev Regulation of mRNA.
J Gen Virol 2011 Apr;92(Pt 4):796-806
Functional interaction between cellular p100 and the dengue virus 3' UTR.
Lei Y, Huang Y, Zhang H, Yu L, Zhang M, Dayton A
Mol Immunol 2010 Oct;47(16):2604-10
Role of interleukin-18 in human natural killer cell is associated with interleukin-2.
Huang Y, Lei Y, Zhang H, Zhang M, Dayton A
BMC Immunol 2010 Jan 20;11:3
Anti-West Nile virus activity of in vitro expanded human primary natural killer cells.
Zhang M, Daniel S, Huang Y, Chancey C, Huang Q, Lei YF, Grinev A, Mostowski H, Rios M, Dayton A
Transfusion 2009 Jun;49(6):1102-14
Quantitative estimate of the risks and benefits of possible alternative blood donor deferral strategies for men who have had sex with men.
Anderson SA, Yang H, Gallagher LM, O'Callaghan S, Forshee RA, Busch MP, McKenna MT, Williams I, Williams A, Kuehnert MJ, Stramer S, Kleinman S, Epstein J, Dayton AI
J Infect Dis 2008 Nov 1;198(9):1300-8
In Vitro Evaluation of the Protective Role of Human Antibodies to West Nile Virus (WNV) Produced during Natural WNV Infection.
Rios M, Daniel S, Dayton AI, Wood O, Hewlett IK, Epstein JS, Caglioti S, Stramer SL
Retrovirology 2008 Sep 22;5(1):82
Beta-estradiol attenuates the anti-HIV-1 efficacy of Stavudine (D4T) in primary PBL.
Zhang M, Huang Q, Huang Y, Wood O, Yuan W, Chancey C, Daniel S, Rios M, Hewlett I, Clouse KA, Dayton AI
Retrovirology 2008 Feb 1;5:15
Hitting HIV where it hides.
Retrovirology 2006 Aug 30;3:55
Beyond open access: open discourse, the next great equalizer.
J Leukoc Biol 2006 Jun;79(6):1328-38
HIV regulation of the IL-7R: a viral mechanism for enhancing HIV-1 replication in human macrophages in vitro.
Zhang M, Drenkow J, Lankford CS, Frucht DM, Rabin RL, Gingeras TR, Venkateshan C, Schwartzkopff F, Clouse KA, Dayton AI
Transfusion 2006 Apr;46(4):659-67
Monocytes-macrophages are a potential target in human infection with West Nile virus through blood transfusion.
Rios M, Zhang MJ, Grinev A, Srinivasan K, Daniel S, Wood O, Hewlett IK, Dayton AI
J Virol 2005 Nov;79(21):13735-46
Human immunodeficiency virus type 1 Vpr interacts with antiapoptotic mitochondrial protein HAX-1.
Yedavalli VS, Shih HM, Chiang YP, Lu CY, Chang LY, Chen MY, Chuang CY, Dayton AI, Jeang KT, Huang LM
J Biol Chem 2004 Nov 19;279(47):49055-63
Polyarginine inhibits gp160 processing by furin and suppresses productive human immunodeficiency virus type 1 infection.
Kibler KV, Miyazato A, Yedavalli VS, Dayton AI, Jacobs BL, Dapolito G, Kim SJ, Jeang KT
Retrovirology 2004 Oct 29;1(1):35
Within you, without you: HIV-1 Rev and RNA export.