AIDS and Cancer Virus Program

Biography

Dr. Ott received his Ph.D. in molecular biology in 1987 from the State University of New York at Stony Brook. He began studying retroviruses as a postdoctoral fellow in the laboratory of Dr. Alan Rein at the Frederick National Laboratory for Cancer Research. After working on retroviral-mediated human gene therapy in private industry, Dr. Ott joined the AIDS and Cancer Virus Program in 1993 and was named the head of the Retrovirus-Cell Interaction Section in 1999.

Research Description

The Retrovirus-Cell Interaction Section seeks to study HIV-1 assembly from the perspective of both the virus and the cell. While retroviral structural proteins can assemble in vitro into particles, cellular proteins and components such as host RNAs and membranes play critical roles within the cell during viral assembly, release, and infection. To better understand the host cell contribution to HIV-1 biology, we examine the interactions between cellular components and HIV-1 during virion assembly and their impact on the assembly process and viral replication using a variety of methods. A second project in our Section uses retroviral vectors to engineer T cells and pursue HIV/SIV biology and immunology questions, especially examining the basis of differential infection susceptibility of CD4+ T cells and the role of T cells in suppression of viral replication in the rhesus macaque/SIV model system.

Since the cellular proteins that are incorporated into virions can provide clues to virus-cell interactions, we isolate and identify the host proteins present both inside and on the surface of HIV-1 virions that are produced from both primary CD4+ T cells and macrophages. One obstacle to these studies is the presence of proteins that contaminate even highly purified virion preparations. To overcome this complication, we have developed complementary methods that remove these irrelevant proteins and produce high purity virus preparations suitable for biochemical and cellular studies. Biochemical and mass spectrometric sequencing analyses of these virions allow us to detect the cellular proteins that are in the virion, i.e. those both on the surface of and inside virus particles. Analyses of virions produced from primary macrophages and CD4+ T cells have found a large number cellular proteins in HIV-1 particles, many with potential roles in the viral replication cycle. (Our database and protocols are available by following the http://ncifrederick.cancer.gov/research/avp/ link underneath my address.) After identification of these proteins, we carry out follow up studies that examine provocative candidates to determine their importance in HIV-1 replication, especially those that might be involved in assembly. In addition to our protein/assembly studies, we examine the critical roles Gag-RNA and Gag-membrane binding play in HIV-1 assembly. To accomplish these goals, our Section uses a variety of methods in our studies, including protein analyses, molecular biology, virology, and cell biology techniques.

A second project uses retroviruses as tools to modify and modulate primary cells for various virological and immunological studies. Our most widely used system immortalizes specific T cells, while maintaining primary cell phenotypes. Our system has been used both within the program by many investigators around the world to study primary human and simian antigen-specific T cells. Current projects include RNAi suppression of T cell effector functions, differential susceptibility of T cells to HIV-1 and SIV, and T cell engineering using vectors that express α/β TCR complexes, growth factors/cytokines, and T cell homing receptors.

Key Collaborators

• The other ACVP sections
• Ettore Appella, CCR, NCI
• Thomas Hope, Northwestern University
• Ganjam Kaplana, Albert Einstein University
• Ulrich Schubert, University of University of Erlangen-Nuremberg, Germany.

Recent Publications

1. Votteler J, Neumann L, Hahn S, Hahn F, Rauch P, Schmidt K, Studtrucker N, Solbak SMO, Fossen T, Henklein P, Ott DE, Holland G, Bannert N, Schubert U: Highly conserved serine residue 40 in HIV-1 p6 regulates capsid processing and virus core assembly. Retrovirology 16:8-11, 2011. PMID: 21324168
2. Barsov EV: Telomerase and primary T cells: Biology and immortalization for adoptive immunotherapy. Immunotherapy 3(3):407-421, 2011. PMID: 21395382
3. Minang JT, Trivett MT, Barsov EV, Del Prete GQ, Trubey CM, Thomas JA, Gorelick RJ, Piatak M Jr, Ott DE, Ohlen C: TCR triggering transcriptionally downregulates CCR5 expression on rhesus macaque CD4+ T cells with no measurable effect on susceptibility to SIV infection. Virology 409(1):132-140, 2011. Epub 2010 Oct 28. PMID: 21035160
4. Minang JT, Trivett MT, Bolton DL, Trubey CM, Estes JD, Li Y, Smedley J, Pung R, Rosati M, Jalah R, Pavlakis GN, Felber BK, Piatak M Jr, Roederer M, Lifson JD, Ott D, Ohlen C: Distribution, persistence and efficacy of adoptively transferred central and effector memory-derived autologous SIV-specific CD8+ T cell clones in rhesus macaques during acute infection. J Immunol 184(1):315-326, 2010. Epub 2009 Nov 30. PMID: 19949091.
5. Miller Jenkins LM, Ott DE, Hayashi R, Coren LV, Wang D, Xu Q, Schito ML, Inman JK, Appella DH, Appella E. Small-molecule inactivation of HIV-1 NCp7 by repetitive intracellular acyl transfer. Nat Chem Biol 6(12):887-889, 2010. Epub 2010 Oct 17. PMID: 20953192
6. Ott DE: Purification of HIV-1 virions by subtilisin digestion or CD45 immunoaffinity depletion for biochemical studies. Methods Mol Biol 485:15-25, 2009.
7. Ott DE, Coren LV, Shatzer T: The nucleocapsid region of HIV-1 Gag assists in the coordination of assembly and gag processing: Role for RNA-Gag binding in the early stages of assembly. J Virol 83:7718-7727, 2009.
8. Sorin M, Cano J, Davies KP, Mathew S, Shi X, Wu X, Cheng GSW, Ott D, Kalpana GV: Recruitment of a SAP18-HDAC1 complex into HIV-1 virions and its requirement for viral replication. PLoS Pathog 5(6):e1000463, 2009.
9. Minang JT, Trivett MT, Coren LV, Barsov EV, Piatak MJr, Ott DE, Ohlen C: Nef-mediated MHC class I down-regulation unmasks clonal differences in virus suppression by SIV-specific CD8+ T cells independent of IFN-gamma and CD107a responses. Virology 391:130-139, 2009.
10. Gousset K, Ablan SD, Coren LV, Ono A, Soheilian F, Nagashima K, Ott DE, Freed EO: Real-time visualization of HIV-1 GAG trafficking in infected macrophages. PLoS Pathogens 4:1-14, 2008.
11. Minang JT, Barsov EV, Yuan F, Trivett MT, Piatak M, Lifson JD, Ott DE, Ohlen C: Efficient inhibition of SIV replication in rhesus CD4+ T-cell clones by autologous immortalized SIV-specific CD8+ T-cell clones. Virology 372:430-441, 2008.
12. Coren LV, Shatzer T, Ott DE: CD45 immunoaffinity depletion of vesicles from Jurkat T cells demonstrates that "exosomes" contain CD45: no evidence for a distinct exosome/HIV-1 budding pathway. Retrovirology 5:64, 2008.
13. Ott DE: Cellular proteins detected in HIV-1. Rev Med Virol 18:159-175, 2008.
14. Chan R, Uchil PD, Jin J, Shui G, Ott DE, Mothes W, Wenk MR: Retroviruses human immunodeficiency virus and murine leukemia virus are enriched in phosphoinositides. J Virol 82:11228-11238, 2008.
15. Thomas JA, Ott DE, Gorelick RJ: Efficiency of HIV-1 postentry infection processes: Evidence against disproportionate numbers of defective virions. J Virol 81:4367-4370, 2007.
16. Coren LV, Thomas JA, Chertova EN, Sowder RC, II, Gagliardi TD, Gorelick RJ, Ott DE: Mutational analysis of the C-terminal gag cleavage sites in human immunodeficiency virus type 1. J Virol 81:10047-10054, 2007.
17. Andersen H, Barsov EV, Trivett MT, Trubey CM, Giavedoni LD, Lifson JD, Ott DE, Ohlen C: Transduction with human telomerase reverse transcriptase immortalizes a rhesus macaque CD8+ T cell clone with maintenance of surface marker phenotype and function. AIDS Res Hum Retroviruses 23:456-465, 2007.
18. Xu H, Chertova E, Chen J, Ott DE, Roser JD, Hu W-S, Pathak VK: Stoichiometry of the antiviral protein APOBEC3G in HIV-1 virions. Virology 360:247-256, 2007.
19. Melar M, Ott DE, Hope TJ: Physiological levels of virion-associated HIV-1 envelope induce coreceptor-dependent calcium flux. J Virol 81:1773-1785, 2007.

Staffing

• Eugene Barsov, M.D., Ph.D., Visiting Scientist
• Lori V. Coren, Research Associate II

Reagents available to share:

Antisera to HIV, EIAV, MuLV; hTERT Tcell-immortalizing retroviral vectors, please contact Dr. David Ott