NEMO is a key component of NF-κB- and IRF-3-dependent TLR3-mediated immunity to herpes simplex virus.

St Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY10065, USA.
The Journal of allergy and clinical immunology (Impact Factor: 12.05). 06/2011; 128(3):610-7.e1-4. DOI: 10.1016/j.jaci.2011.04.059
Source: PubMed

ABSTRACT Children with germline mutations in Toll-like receptor 3 (TLR3), UNC93B1, TNF receptor-associated factor 3, and signal transducer and activator of transcription 1 are prone to herpes simplex virus-1 encephalitis, owing to impaired TLR3-triggered, UNC-93B-dependent, IFN-α/β, and/or IFN-λ-mediated signal transducer and activator of transcription 1-dependent immunity.
We explore here the molecular basis of the pathogenesis of herpes simplex encephalitis in a child with a hypomorphic mutation in nuclear factor-κB (NF-κB) essential modulator, which encodes the regulatory subunit of the inhibitor of the Iκβ kinase complex.
The TLR3 signaling pathway was investigated in the patient's fibroblasts by analyses of IFN-β, IFN-λ, and IL-6 mRNA and protein levels, by quantitative PCR and ELISA, respectively, upon TLR3 stimulation (TLR3 agonists or TLR3-dependent viruses). NF-κB activation was assessed by electrophoretic mobility shift assay and interferon regulatory factor 3 dimerization on native gels after stimulation with a TLR3 agonist.
The patient's fibroblasts displayed impaired responses to TLR3 stimulation in terms of IFN-β, IFN-λ, and IL-6 production, owing to impaired activation of both NF-κB and IRF-3. Moreover, vesicular stomatitis virus, a potent IFN-inducer in human fibroblasts, and herpes simplex virus-1, induced only low levels of IFN-β and IFN-λ in the patient's fibroblasts, resulting in enhanced viral replication and cell death, as reported for UNC-93B-deficient fibroblasts.
Herpes simplex encephalitis may occur in patients carrying NF-κB essential modulator mutations, due to the impairment of NF-κB- and interferon regulatory factor 3-dependent-TLR3-mediated antiviral IFN production.

  • [Show abstract] [Hide abstract]
    ABSTRACT: TLR3 is a receptor for dsRNA, which is generated during most viral infections. However, other cellular processes may also produce dsRNA and there are other receptors for dsRNA. The role of TLR3 in protective immunity to viruses has been investigated in mice and humans with genetically impaired TLR3 responses. TLR3-deficient mice responded to experimental challenge with 16 different viruses in various ways. They were susceptible to eight viruses, normally resistant to three other viruses, and their survival rates were higher than those of wild-type mice following infection with four other viruses. Conflicting results were obtained for the other virus tested. These data are difficult to understand in terms of a simple pattern based on virus structure or tissue tropism. Surprisingly, the known human patients with inborn errors of the TLR3 pathway have remained healthy or developed encephalitis in the course of natural primary infection with HSV-1. These patients display no clear susceptibility to other infections, including viral infections, such as other forms of viral encephalitis and other HSV-1 diseases in particular. This restricted susceptibility to viruses seems to result from impaired TLR3-dependent IFN-α/β production by central nervous system (CNS)-resident non-hematopoietic cells infected with HSV-1. These studies neatly illustrate the value of combining genetic studies of experimental infections in mice and natural infections in humans, to elucidate the biological function of host molecules in protective immunity.
    Current opinion in immunology 01/2013; · 10.88 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Research over the past decade has revealed how NF-κB essential modulator (NEMO; also known as IKKγ) regulates the IKKα-IKKβ signalling axis in the innate immune system. The discovery that NEMO is a polyubiquitin-binding protein and that the IKK complex is modulated by other protein kinases that are themselves controlled by polyubiquitin chains has provided a deeper molecular understanding of the non-degradative roles of ubiquitylation. New mechanistic insights of NEMO and related polyubiquitin-binding proteins have become a paradigm for how the interplay between phosphorylation and ubiquitylation controls cell signalling networks in health and disease.
    Nature Reviews Molecular Cell Biology 08/2013; · 37.16 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The focus of this article will be to examine the role of common herpesviruses as a component of the microbiome of atopic patients and to review clinical observations suggesting that atopic patients might be predisposed to more severe and atypical herpes-related illness because their immune response is biased toward a TH2 cytokine profile. Human populations are infected with 8 herpesviruses, including herpes simplex virus HSV1 and HSV2 (also termed HHV1 and HHV2), varicella zoster virus (VZV or HHV3), EBV (HHV4), cytomegalovirus (HHV5), HHV6, HHV7, and Kaposi sarcoma-associated herpesvirus (termed KSV or HHV8). Herpesviruses are highly adapted to lifelong infection of their human hosts and thus can be considered a component of the human "microbiome" in addition to their role in illness triggered by primary infection. HSV1 and HSV2 infection and reactivation can present with more severe cutaneous symptoms termed eczema herpeticum in the atopic population, similar to the more severe eczema vaccinatum, and drug reaction with eosinophilia and systemic symptoms syndrome (DRESS) is associated with reactivation of HSV6 and possibly other herpesviruses in both atopic and nonatopic patients. In this review evidence is reviewed that primary infection with herpesviruses may have an atypical presentation in the atopic patient and conversely that childhood infection might alter the atopic phenotype. Reactivation of latent herpesviruses can directly alter host cytokine profiles through viral expression of cytokine-like proteins, such as IL-10 (EBV) or IL-6 (cytomegalovirus and HHV8), viral encoded and secreted siRNA and microRNAs, and modulation of expression of host transcription pathways, such as nuclear factor κB. Physicians caring for allergic and atopic populations should be aware of common and uncommon presentations of herpes-related disease in atopic patients to provide accurate diagnosis and avoid unnecessary laboratory testing or incorrect diagnosis of other conditions, such as drug allergy or autoimmune disease. Antiviral therapy and vaccines should be administered promptly when indicated clinically.
    The Journal of allergy and clinical immunology 04/2013; · 12.05 Impact Factor

Full-text (2 Sources)

Available from
May 19, 2014