Research Interests:

Cell and molecular biology of HIV and HTLV; Antiviral drug target identification; Antiviral drug resistance; HIV genetic variation, evolution and population genetics; Viral quasispecies; Virus assembly; Evolution of emerging viruses; Paleovirology

The study of retroviruses over the past three decades has led to some of the most important discoveries in biomedical research, and has laid the foundation for biotechnology, cancer research, AIDS research, and human gene therapy. The discovery of reverse transcriptase helped to create the biotechnology industry, the discovery of oncogenes helped to advance our understanding of the genetic basis of cancer, and the discovery of retroviruses in higher animals led to the discovery of human retroviruses that cause cancer (HTLV-1) and AIDS (HIV-1). The creation of retroviral vectors and retrovirus helper cell lines helped to establish the field of gene therapy.

Retroviruses are relatively simple viruses that encode from three to ten genes, but are unusual in that they undergo a step in their life cycle called reverse transcription, which is the synthesis of double-stranded DNA from single-stranded RNA. We are exploring the accuracy of this process in HIV-1 replication and how it influences not only the evolution of HIV-1 variants that are resistant to anti-HIV-1 drugs, but also how it influences the development of an effective AIDS vaccine. We are also exploring how the APOBEC3 proteins impact HIV evolution and drug resistance. A long-term goal of our efforts is to define the molecular determinants for HIV-1 mutation in order to 1) manipulate HIV-1 evolution and improve the efficacy of anti-HIV-1 drugs, and 2) provide the basis for new intervention strategies.

Central steps in the retrovirus life cycle include the recognition of the genomic RNA by the Gag protein, trafficking of Gag and viral RNA to the plasma membrane, Gag oligomerization, and ultimately the biogenesis of virus particles. The details behind how Gag and RNA trafficking as well as virus particle biogenesis occurs is currently being investigated via collaboration by employing highly sophisticated biophysical approaches - including fluorescence spectroscopy methodologies that have single molecule resolution as well as cryoelectron microscopy/tomography. A long term goal of these studies is to develop a better understanding of the detailed steps of Gag oligomerization, viral RNA packaging, and virus biogenesis/virus structure. Such information will ultimately be useful for the discovery of new targets for the rational design of antiviral drugs.

Metabolic disorders associated with highly active antiretroviral therapy (HAART) are becoming increasingly important in the chronically HIV-infected population that has access to therapy.  Clinical observations have revealed a strong correlation between bone density loss in HIV-infected individuals during HAART, particularly in conjunction with the antiretroviral drug tenofovir - a nucleotide analog that inhibits HIV reverse transcriptase.  We are working collaboratively with bone biologists and AIDS clinicians to investigate how HIV-1 infection and tenofovir can cause bone mineral density loss.

Institute for Molecular Virology

The Mansky Lab

Selected Recent Publications:

• Holtz CM, Sadler HA and Mansky LM.  2013.  APOBEC3G cytosine deamination hotspots are defined by both sequence context and single-stranded DNA secondary structure.  Nucleic Acids Research  Epub ahead of print
• Holtz CM, Mansky LM. 2013. Variation of HIV-1 mutation spectra among cell types. J Virol. Epub ahead of print
• Dapp MJ, Patterson, SE, Mansky, LM. 2012. Back to the future: revisiting HIV-1 lethal mutagenesis. Trends in Microbiology. Epub ahead of print
• Dapp MJ, Heineman, RH, Mansky LM. 2012. Interrelationship between HIV-1 fitness and mutation rate. J Mol Biol. Epub ahead of print
• Clouser, CL, Chauhan, J, Bess, MA, Oploo, JL, Zhou, D, Dimick-Gray, S, Mansky, LM, Patterson, SE. 2012. Anti-HIV-1 activity of resveratrol derivatives and synergistic inhibition of HIV-1 by the combination of resveratrol and decitabine. Bioorg Med Chem Lett. 22:6642-6646.
• Dapp MJ, Holtz CM, Mansky LM. 2012. Concomitant lethal mutagenesis of human immunodeficiency virus type 1. J Mol Biol. 419:158-170.
• Clouser CL, Holtz CM, Mullet M, Crankshaw DL, Briggs JE, O’Sullivan MG,
  Patterson SE, Mansky LM. 2012. Activity of a novel combined antiretroviral
  therapy of gemcitabine and decitabine in a mouse model for HIV-1.
  Antimicrobial Agents and Chemotherapy. 56:1942-1948.
• Greggs, WM 3rd, Clouser CL, Patterson SE, Mansky LM. 2012. Discovery of
  drugs that possess activity against feline leukemia virus. Journal of
  General Virology 93:900-905.
• Guenzel CA, Hérate C, Le Rouzic E, Maidou-Peindara P, Sadler HA, Rouyez
  MC, Mansky LM, Benichou S. 2012. Recruitment of the nuclear form of uracil DNA glycosylase into virus particles participates in the full infectivity of HIV-1. J Virol. 86:2533-44.
• Wu K, Chen L, Peng G, Zhou W, Pennell CA, Mansky LM, Geraghty RJ, Li F.
  2011. A virus-binding hot spot on human angiotensin-converting enzyme 2 is
  critical for binding of two different coronaviruses J Virol. 2011
  85:5331-7.
• Fogarty, KH, Zhang, W, Grigsby, IF, Johnson, J, Chen, Y, Mueller, JD and LM Mansky. 2011. New insights into HTLV-1 particle structure, assembly and
  Gag-Gag interactions in living cells. Viruses 3(6):770-93.
• Fogarty, K.H., Johnson, J.L., Grigsby, I.F., MacDonald, P.J., Smith, E.M., Chen, Y., Rawson, J.M., Mansky, L.M., and J.D. Mueller. 2011. Characterization of cytoplasmic Gag-Gag interactions by dual-color z-scan fluorescence fluctuation spectroscopy. Biophysical Journal 100:1587-1595.
• Greggs, W.M., Clouser, C.L., Patterson, S.E., and L.M. Mansky. 2011. Broadening the use of antiretroviral therapy: the case for feline leukemia virus. Therapeutics and Clinical Risk Management 7:115 – 122.
• Clouser, C.L., Holtz, C.M., Mullet, M., Crankshaw, D.L., Briggs, J.E., Chauhan, J., Patterson, S.E., and L.M. Mansky. 2011. Analysis of the ex vivo and in vivo antiretroviral activity of gemcitabine. PLoS One 6:e15840
• Ni, Z., Knorr, D.A., Clouser, C.L., Hexum, M.K., Souther, P., Mansky, L.M., Park, I.-H., and D.S. Kaufman. 2011. Human pluripotent stem cells produce natural killer cells that mediate anti-HIV-1 activity utilizing diverse cellular mechanisms. Journal of Virology 85:43-50
  
• Grigsby, I.F., Zhang, W., Johnson, J.L., Fogarty, K.H., Chen, Y., Rawson, J.M., Crosby, A.J., Mueller, J.D., and L.M. Mansky. 2010.  Biophysical analysis of HTLV-1 particles reveals novel insights into particle morphology and Gag stochiometry.  Retrovirology  7:75
• Dorr, C.R., Yemets, S., Kokomitsyna, O., Krasutsky, P., and L.M. Mansky. 2010.  Triterpene derivatives that inhibit human immunodeficiency virus type 1 replication.  Bioorganic and Medicinal Chemistry Letters  21:542-545
• Sanjuan, R., Nebot, M.R., Chirico, N., Mansky, L.M., and R. Belshaw.  Viral mutation rates.  Journal of Virology 84:9733-9748.
• Clouser, C.L., Patterson, S.E., and L.M. Mansky. 2010. Exploiting drug repositioning for the discovery of a novel HIV combination therapy.  Journal of Virology 84:9301-9309.
• Sadler, H.A., Stenglein, M.D., Harris, R.S., and L.M. Mansky. 2010.  APOBEC3G contributes to HIV-1 variation through sublethal mutagenesis.  Journal of Virology 84:7396-7404.
• Grigsby, I.F., Pham, L., Mansky, L.M., Gopalakrishnan, R., Carlson, A. and Mansky, K.C. 2010.  Tenofovir treatment of primary osteoblasts alters gene expression profiles: implications for bone mineral density loss. Biochemical and Biophysical Research Communications, 394:48-53.
• Grigsby, I.F., Pham, L., Gopalakrishnan, R., Mansky, L.M., and K.C. Mansky.  2010.  Downregulation of Gnas, Got2 and Snord32a following tenofovir exposure of primary osteoclasts.  Biochemical and Biophysical Research Communications  391:1324-1329.
• Grigsby, I.F., Pham, L., Mansky, L.M., Gopalakrishnan, R., and K.C. Mansky. 2009.  Tenofovir-associated bone density loss.  Therapeutics and Clinical Risk Management 6:41-47.
• Dapp, M.D., Clouser, C.L., Patterson, S. and L.M. Mansky. 2009.  5-Azacytidine can induce lethal mutagenesis in human immunodeficiency virus type 1.  Journal of Virology 83:11950-58.
• Chen, Y. Wu, B., Musier-Forsyth, K., Mansky, L.M., and J.D. Mueller. 2009.  Fluorescence fluctuation spectroscopy on viral-like particles reveals variable Gag stoichiometry.  Biophysics Journal 96:1961:1969.
• Nishiguichi, M.K., Hirsch, A.M., deVinney, R., Vendantam, G., Riley, M.A., and L.M. Mansky.  2008. Deciphering evolutionary mechanisms between mutualistic and pathogenic symbioses. Life and Environment  58: 87-106.
• Mbisa J.L., Barr R., Thomas J.A., Vandegraaff N., Dorweiler I.J., Svarovskaia E.S., Brown W.L., Mansky L.M., Gorelick R.J., Harris R.S., Engelman A., Pathak V.K. 2007. Human immunodeficiency virus type 1 cDNAs produced in the presence of APOBEC3G exhibit defects in plus-strand DNA transfer and integration. Journal of Virology 81:7099-7110.
• Hache G., Mansky L.M., and Harris R.S. 2006. Human APOBEC3 proteins, retrovirus restriction, and HIV drug resistance. AIDS Rev. 8:148-57.
• Dorweiler, I.J., Ruone, S.J., Wang, H., Burry, R.W., and L.M. Mansky. 2006. Role of the human T-cell leukemia virus type 1 PTAP motif in Gag targeting and particle release. Journal of Virology 80:3634-3643.
• Chen, R., Yokoyama M., Sato H., Reilly C. Mansky, LM. 2005. Human immunodeficiency virus mutagenesis during antiviral therapy: impact of drug-resistant reverse transcriptase and nucleoside and nonnucleoside reverse transcriptase inhibitors on human immunodeficiency virus type 1 mutation frequencies, Journal of Virology 79:12045-57.
• Jewell, N.A. and L.M. Mansky. 2005. Packaging of heterologous RNAs by a minimal bovine leukemia virus RNA packaging signal into virus particles. Archives of Virology 150:1161-73.
• Jewell, N.A. and L.M. Mansky. 2005. Construction and characterization of deltaretrovirus indicator cell lines. Journal of Virological Methods 123:17-24.
• Chen, R., Quinones-Mateu, M.E., and L.M. Mansky. 2005. HIV-1 mutagenesis during antiretroviral therapy: implications for successful drug treatment. Frontiers in Biosciences 10:743-750.
• Chen, R., Quinones-Mateu, M.E., and L.M. Mansky. 2004. Drug resistance, virus fitness and HIV-1 mutagenesis. Current Pharmaceutical Design 10:4065-4070.
  
• Spidel, J.L., Craven, R.C., Wilson, C.B., Patnaik, A., Wang, H., Mansky, L.M., and J.W. Wills. 2004. Lysines close to the Rous sarcoma virus late domain critical for budding. Journal of Virology 78:10606-10616.
• Chen, R., LeRouzic, E. Kearney, J.A., Mansky, L.M., and S. Benichou. 2004. Vpr-mediated incorporation of UNG2 into HIV-1 particles is required to modulate the virus mutation rate and for replication in macrophages. J. Biol. Chem. 279:28419-25.
• Weiss, K.K., Chen, R., Lee, K., Bambara, R.A., Mansky, L.M., and B. Kim. 2004. A role for dNTP binding of human immunodeficiency virus type 1 reverse transcriptase in viral mutagenesis. Biochemistry 43:4490-4500.
• Wang, H., N. M. Machesky, and L. M. Mansky. 2004. Both the PPPY and PTAP motifs in the human T-cell leukemia virus type 1 Gag protein are required for particle release. Journal of Virology 78:1503-1512.