Dotted line shows limit of detection

By | November 13, 2021

Dotted line shows limit of detection. degree to which each virus does this, and their capacity to antagonize IFN activity and its complex effects, are key in determining transmission mechanism, host range, and disease pathogenesis. Like other viruses, lentiviruses also antagonize specific host proteins or pathways that would otherwise suppress infection. Lentiviruses typically do this through accessory gene function. For example, HIV-1 antagonizes IFN-induced restriction LYN-1604 factors through accessory genes encoding Vif (APOBEC3G/H), Vpu (tetherin), and Nef (tetherin/SERINC3/5) reviewed in?Foster et al., 2017; Sumner et al., 2017. The HIV-1 accessory protein Vpr interacts with and manipulates many LYN-1604 proteins including its cofactor DCAF1 (Zhang et al., 2001), karyopherin alpha 1 (KPNA1, importin ) (Miyatake et al., 2016), the host enzyme UNG2 (Wu et al., 2016) as well as HTLF (Lahouassa et al., 2016; Yan et al., 2019), SLX4 (Laguette et al., 2014), and CCDC137 (Zhang and Bieniasz, 2020). Indeed, Vpr has been shown to significantly change infected cell protein profiles, affecting the level of hundreds of proteins in proteomic LYN-1604 studies, likely indirectly in most cases, consistent with manipulation of central mechanisms in cell biology (Greenwood et al., 2019). Vpr has also been shown to both enhance (Liu et al., 2014; Liu et al., 2013; Vermeire et al., 2016) or decrease NF-B activation (Harman et al., 2015; Trotard et al., 2016) in different contexts and act as a cofactor for HIV-1 nuclear entry, particularly in macrophages (Vodicka et al., 1998). However, despite this work, the mechanistic details of Vpr promotion of HIV replication are poorly understood and many studies seem contradictory. This is partly because the mechanisms of Vpr-dependent enhancement of HIV-1 replication are context dependent, and cell type specific, although most studies agree that Vpr is definitely more important for replication in macrophages than in T cells or PBMC (Connor et al., 1995; Dedera et al., 1989; Fouchier et al., 1998; Hattori et al., 1990; Mashiba et al., 2015). Manipulation of sponsor Mapkap1 innate immune mechanisms by Vpr to facilitate replication in macrophages has been suggested by numerous studies, although there has been no obvious mechanistic model or understanding how particular Vpr target proteins link to innate immune manipulation (Harman et al., 2015; Liu et al., 2014; Okumura et al., 2008; Trotard et al., 2016; Vermeire et al., 2016). Many viruses have been shown to manipulate innate immune activation by focusing on transcription element nuclear access downstream of PRR. For example, Japanese encephalitis computer virus NS5 focuses on KPNA2, 3, and 4 to prevent IRF3 and NF-?B nuclear translocation (Ye et al., 2017). Hantaan computer virus nucleocapsid protein inhibits NF-?B p65 translocation by targeting KPNA1, -2, and -4 (Taylor et al., 2009). Most recently, vaccinia computer virus protein A55 was shown to interact with KPNA2 to disturb its connection with NF-?B (Pallett et al., 2019). Hepatitis C computer virus NS3/4A protein restricts IRF3 and NF-B translocation by cleaving KPNB1 (importin-) (Gagn et al., 2017). HIV-1 Vpr has also been linked to Karyopherins and manipulation of nuclear import. Vpr has been shown to interact with a variety of mouse (Miyatake et al., 2016), candida (Vodicka et al., 1998) and human being karyopherin proteins including human being KPNA1, 2, and 5 (Nitahara-Kasahara et al., 2007). Indeed, the structure of a C-terminal Vpr peptide (residues 85C96) has been solved in complex with mouse importin 2 (Miyatake et al., 2016). Here, we?demonstrate that Vpr inhibits innate immune activation downstream of a variety of viral and non-viral PAMPs by inhibiting nuclear transport of IRF3 and NF-?B by KPNA1. We confirm Vpr connection with KPNA1 by co-immunoprecipitation and link Karyopherin binding and inhibition of innate immunity by showing that Vpr prevents connection between KPNA1 and IRF3/NF-?B after illness of THP-1 cells with HIV-GFP -Vpr or HIV-GFP +Vpr in the indicated MOI. (D) Percentage of THP-1 cells infected by HIV-GFP -Vpr or HIV-GFP +Vpr in (C). (E) Collapse induction of after illness of THP-1 cells with HIV-GFP -Vpr, HIV-GFP +Vpr, or HIV-1 particles lacking Vpr and genome, at indicated doses measured by reverse transcriptase SG-PERT assay. (F) Percentage of THP-1 cells infected by HIV-GFP viruses in (E). (G) Collapse induction of after illness of unmodified control, cGAS-/-or MAVS-/- THP-1 knock out cells with HIV-GFP lacking Vpr (0.3 RT U/ml). (H) Percentage illness of control, cGAS-/-or MAVS-/- THP-1 knock?out cells infected with HIV-GFP at indicated doses of RT (SG-PERT). (BCH) Data are indicated as means??SD (n?=?3) with two-way.