Human T-cell leukemia virus (HTLV-1) infects about 20 million individuals worldwide and is the etiological agent of an adult T-cell leukemia/lymphoma (ATLL), and can also result in an inflammatory disease syndrome called HTLV-1-associated myelopathy (HAM)/tropical spastic paraparesis (TSP). Prevalence rates for HTLV-1 infection in the general population are greater than 1% in the Caribbean Basin, Central Africa, and South Japan. HTLV-1 is notorious for being difficult to study in cell culture, which ha prohibited a rigorous analysis of how these viruses replicate in cells, including the steps involved in retrovirus assembly. The details for how retrovirus particle assembly occurs are poorly understood even for other more tractable retroviral systems. Using a tractable model system, state-of-the-art biophysical approaches, and an interdisciplinary research team, we have made novel observations that form the basis for this proposal. In this application, we propose to investigate questions related to HTLV-1 particle size, Gag stoichiometry in particles, and HTLV-1 Gag interactions in living cells using multiple experimental approaches. In particular, we will apply cryo-electron microscopy/tomography (cryo-EM/ET), total internal reflection fluorescence (TIRF) microscopy, and the novel single-molecule technology of fluorescence fluctuation spectroscopy (FFS) to investigate questions related to 1) particle size and Gag stoichiometry, 2) Gag targeting to membrane, and, 3) HTLV-1 particle biogenesis. The results from these proposed studies should provide further insight into fundamental aspects of HTLV-1 and retrovirus particle assembly, which may aid in developing therapeutics.

Public Health Relevance

Human T-cell leukemia virus type 1 (HTLV-1) is a cancer-causing human retrovirus that infects about 20 million individuals worldwide, with prevalence rates greater than 1% in certain regions. Fundamental studies of HTLV-1 assembly will lead to detailed information about these processes that will be useful for a better understanding of how these viruses replicate in cells. Such information may inform new therapeutic strategies.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM098550-02
Application #
8537954
Study Section
Virology - A Study Section (VIRA)
Program Officer
Sakalian, Michael
Project Start
2012-09-28
Project End
2016-05-31
Budget Start
2013-06-01
Budget End
2014-05-31
Support Year
2
Fiscal Year
2013
Total Cost
$272,754
Indirect Cost
$89,404
Name
University of Minnesota Twin Cities
Department
Dentistry
Type
Schools of Dentistry
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Fogarty, Keir H; Berk, Serkan; Grigsby, Iwen F et al. (2014) Interrelationship between cytoplasmic retroviral Gag concentration and Gag-membrane association. J Mol Biol 426:1611-24