COVID-19 researchGene: HDAC6
Evidence Summary from Illumina curation team (Alison Coffey and Julie Taylor): Histone deacetylase 6 (HDAC6) is a unique cytoplasmic deacetylase that regulates various important biological processes by preventing protein aggregation and deacetylating different non-histone substrates. Growing evidence has indicated a dual role for HDAC6 in viral infection and pathogenesis: HDAC6 may represent a host defence mechanism against viral infection by modulating microtubule acetylation, triggering antiviral immune response and stimulating protective autophagy, or it may be hijacked by the virus to enhance proinflammatory response (Zheng et al, 2017). HDAC6 promotes the aggresome/autophagic degradation of the viral polyprotein Pr55Gag to inhibit HIV-1 production and infection (Hernández et al, 2019). Depletion of HDAC6 expression (in vitro) led to impaired antiviral responses against RNA viruses, but not against DNA viruses. HDAC6 knockout mice were highly susceptible to RNA virus infections compared to wildtype mice (Choi et al, 2016). Overexpression of Hdac6 enhances resistance to virus infection in embryonic stem cells and in mice (Wang et al, 2015).
PMID: 27959772 - Zheng et al. (2017) (Review) This review highlights current data illustrating the complexity and importance of HDAC6 in viral pathogenesis.
HDAC6 has both proviral and antiviral effects. HDAC6 can inhibit infection of both RNA and DNA virus by modulating microtubule (MT) cytoskeleton and stimulating selective autophagy and restrict viral diffusion by triggering antiviral immune response. However, RNA viruses can also utilize HDAC6-mediated aggresome pathway or proinflammatory response to facilitate viral pathogenesis (Fig 1 and Table 1)
• HDAC6 triggers antiviral gene expression upon RNA virus infection (Fig 3a)
• HDAC6 interacts with Vif or A3G and competes for Vif–A3G interaction through its BUZ domain, impairs the incorporation of Vif into nascent virions and finally controls HIV-1 infectiveness (Fig 4)
• HDAC6 facilitates viral uncoating and pathogenesis (Fig 5)
Findings support exploration of a potential therapeutic role for restricting viral pathogenesis by targeting HDAC6.
PMID: 31736889: Hernández et al. (2019) - HIV Nef is a central auxiliary protein in HIV infection and pathogenesis. Results from the study indicate that HDAC6 promotes the aggresome/autophagic degradation of the viral polyprotein Pr55Gag to inhibit HIV-1 production
• HIV-1 Nef viral protein induces HDAC6 Degradation (Enzyme degradation by recombinant HIV-1 Nef in HEK-293T cells in both endogenous and over expressed HDAC6 is shown in Fig 1)
• Mutated Nef protein Nef-PPAA did not promote HDAC6 degradation (Figure 3A, quantified in Figure 3B). This fact may indicate that this motif is involved in Nef-mediated HDAC6 interaction and/or processing, or that a conformational change in the mutated viral protein abrogates the degradative activity observed with the wt-Nef (Figures 1–3)
• Nef assures viral production and infection by targeting HDAC6, stabilizing Pr55Gag and Vif, thereby facilitating Pr55Gag location and aggregation at plasma membrane, and subsequent virus production and infection capacity (events summarized by schematic illustrations in Figure 10)
PMID: 26746851: Choi et al. (2016) - HDAC6 plays an important role in the antiviral immune response by producing IFNs and proinflammatory cytokines in responses to foreign RNA viruses.
HDAC6+/+ and HDAC6-/- mice were intravenously infected with vesicular stomatitis virus (VSV, Indiana strain). Results show that
• HDAC6-/- mice are more susceptible to VSV-Indiana infection than HDAC6+/+ mice and showed significantly decreased survival rate (Fig 1A)
• Virus titers were significantly higher and IFN-b and IL-6 production was markedly lower in HDAC6-/- mice than in HDAC6+/+ mice (Fig 1D and E)
• Role of HDAC6 in cytokine induction by poly(I:C), which is a synthetic double-stranded RNA (dsRNA): Intravenous injection of poly(I:C) caused the rapid and robust induction of IFN-b and IL-6 in HDAC6+/+ mice; however, induction of these cytokines was significantly reduced in HDAC6-/-mice (Fig 1F).
• HDAC6 deficiency reduces the innate immune response on mouse macrophage and mouse embryonic fibroblast (Fig 3)
• HDAC6 and RIG-I transiently interact in response to RNA viral infection (Fig 5A and B) and HDAC6 regulates the binding of RIG-I to 50 pppdsRNA by deacetylating RIG-I (Fig 5G)
PMID: 25482409 Wang et al. (2015) - This is another study that provides a proof of principle of antivirus function by Hdac6 in vivo. HDAC6 overexpression significantly enhances resistance to avian H5N1 virus infection and extends the survival rate in Hdac6tg mice (transgenic) (Fig 2). Also, ES cells overexpressing Hdac6 displayed resistance to infection by adenovirus at high titers (Fig 1).
Created: 28 May 2020, 3:32 p.m. | Last Modified: 28 May 2020, 3:32 p.m.
Panel Version: 0.349
Identified through an OMIM search for potential viral susceptibility genes, and subsequently triaged/reviewed by Illumina curation team.
Created: 28 May 2020, 12:36 p.m. | Last Modified: 28 May 2020, 12:36 p.m.
Panel Version: 0.336
gene: HDAC6 was added gene: HDAC6 was added to COVID-19 research. Sources: Expert list,OMIM,Expert Review Green Mode of inheritance for gene: HDAC6 was set to Unknown