Authors
Kim, KyusikFaculty Advisor
Jeremy LubanAcademic Program
Interdisciplinary Graduate ProgramUMass Chan Affiliations
Program in Molecular MedicineDocument Type
Doctoral DissertationPublication Date
2020-07-17Keywords
HIV-1Cyclophilin A
TRIM5α
Restriction factor
HIV-1 capsid
Host-virus interaction
Primary human blood cells
Microbiology
Virology
Metadata
Show full item recordAbstract
The abundant cellular protein Cyclophilin A (CypA) was found to bind to HIV-1 capsid (CA) in 1993. Since that time, several complementary methods, including disruption of the binding interface by cyclosporine A, CA mutants, and CypA mutants, have been used to demonstrate that CypA acts within human target cells to promote HIV-1 infection. In contrast, in cells from non-human primates, CypA in target cells decreases HIV-1 infectivity, and it does so by promoting TRIM5α-mediated restriction. Using human cancer cell lines and the genetic methods available at the time, attempts to obtain evidence that CypA inhibits HIV-1 restriction by the human TRIM5α ortholog, let alone that human TRIM5α restricts HIV-1, were unsuccessful. Here we revisit the question of the mechanism by which CypA increases HIV-1 infectivity by exploiting lentiviral vectors optimized for primary human blood cells that serve as HIV-1 targets. Disruption of CA−CypA interaction is demonstrated to render HIV-1 vulnerable to endogenous human TRIM5α-mediated recognition and restriction, which occur prior to completion of reverse transcription. Identical findings were acquired with single-cycle vectors or with replication-competent viruses. Consistently, a previously identified, cyclosporine-resistant CA mutation A92E is also shown to confer resistance against restriction by human TRIM5α. Therefore, the results presented in this thesis reveal that HIV-1 exploits a host protein CypA bound to its CA to evade potent restriction by human TRIM5α. This finding not only answers a long-standing question regarding the role of CypA in HIV-1 infection, but also may reinvigorate the development of CypA inhibitors for treatment of HIV-1.DOI
10.13028/hptw-yg49Permanent Link to this Item
http://hdl.handle.net/20.500.14038/31314Rights
Licensed under a Creative Commons licenseDistribution License
http://creativecommons.org/licenses/by/4.0/ae974a485f413a2113503eed53cd6c53
10.13028/hptw-yg49
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Except where otherwise noted, this item's license is described as Licensed under a Creative Commons license