title: Stabilized human TRIM5α protects human T cells from HIV-1 infection.
abstract: Rhesus (rh) but not human (hu) TRIM5α potently restricts human immunodeficiency virus (HIV)-1 infection. It is not clear why huTRIM5α fails to effectively block HIV infection, but it is thought to have a lower affinity for the viral core. Using primary human CD4 T cells, we investigated the ability of huTRIM5α, rhTRIM5α, and the huTRIM5αR323-332 B30.2/SPRY patch-mutant to form cytoplasmic bodies, postulated as key components of the HIV-1 restriction apparatus. Both rhTRIM5α and huTRIM5αR323-332 formed pronounced cytoplasmic bodies, whereas cytoplasmic bodies in T cells overexpressing huTRIM5α were present but more difficult to detect. As expression of all three TRIM5α orthologs was similar at the RNA level, we next investigated the role of protein stability in conferring TRIM5α-mediated HIV-1 restriction. Both steady-state and pulse-chase experiments revealed that the huTRIM5α protein was much less stable than rhTRIM5α, and this difference correlated with higher self-ubiquitination activity. Using a stabilized form of huTRIM5α in which the steady-state expression level was more similar to rhTRIM5α, we observed comparable HIV-1 restriction activity in multi-round HIV-1 challenge assays. Lastly, primary human CD4 T cells expressing a stabilized huTRIM5α were protected from HIV-1-mediated destruction in vivo, indicating that efforts to stabilize huTRIM5α should have significant long-term therapeutic value.
authors.affiliation: Department of Microbiology, University of Pennsylvania, Pennsylvania, PA, USA; Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, USA.
authors.forename: Max W
authors.initials: MW
authors.lastname: Richardson
authors.affiliation: Department of Cancer Biology, University of Pennsylvania, Pennsylvania, PA, USA; Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, USA.
authors.forename: Lili
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Cancer Biology, University of Pennsylvania, Pennsylvania, PA, USA; Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, USA.
authors.forename: Frances
authors.initials: F
authors.lastname: Xin
authors.affiliation: Department of Cancer Biology, University of Pennsylvania, Pennsylvania, PA, USA; Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, USA.
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Microbiology, University of Pennsylvania, Pennsylvania, PA, USA; Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA, USA. Electronic address: rileyj@exchange.upenn.edu.
authors.forename: James L
authors.initials: JL
authors.lastname: Riley
mesh_terms: D000818:Animals; D000090103:Antiviral Restriction Factors; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism* / Q000637:transplantation / Q000821:virology; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D004195:Disease Models, Animal; D015658:HIV Infections / Q000378:metabolism / Q000517:prevention & control*; D015497:HIV-1 / Q000254:growth & development / Q000276:immunology*; D006801:Humans; D008253:Macaca mulatta; D051379:Mice; D055550:Protein Stability; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D012313:RNA / Q000378:metabolism; D000070584:Tripartite Motif Proteins; D044767:Ubiquitin-Protein Ligases; D054875:Ubiquitination
chemical_list: D000090103:Antiviral Restriction Factors; D002352:Carrier Proteins; D011506:Proteins; D000070584:Tripartite Motif Proteins; D012313:RNA; C477346:TRIM5 protein, human; C482587:TRIM5(alpha) protein, rhesus monkey; D044767:Ubiquitin-Protein Ligases