African Swine Fever Virus MGF360-14L Negatively Regulates Type I Interferon Signaling by Targeting IRF3

African swine fever (ASF) is a devastating infectious disease caused by African swine fever virus (ASFV). The ASFV genome encodes multiple structural and non-structural proteins that contribute to evasion of host immunity. In this study, we determined that the viral non-structural protein MGF360-14L inhibits interferon-β (IFN-β) promoter activity induced by cGAS-STING signaling. MGF360-14L was also found to downregulate expression of the IRF3 protein and promote its degradation through ubiquitin-meditated proteolysis. Moreover, MGF360-14L was shown to interact with and destabilize IRF3 by facilitating E3 ligase TRIM21-mediated K63-linked ubiquitination of IRF3. Overall, our study revealed that MGF360-14L promotes degradation of IRF3 through TRIM21, thereby inhibiting type I interferon production. These findings provide new insights into the mechanisms underlying ASFV immune evasion.

STING-Mediated Interferon Induction by Herpes Simplex Virus 1 Requires the Protein Tyrosine Kinase Syk

The innate immune response to virus infection leads to interferon production and inhibition of viral replication. STING, an ER-bound protein, mediates such a response to cytoplasmic cellular or microbial DNA.

ABCC1/MRP1 exports cGAMP and modulates cGAS-dependent immunity

The DNA sensor cyclic GMP-AMP synthase (cGAS) is important for antiviral and anti-tumor immunity. cGAS generates cyclic GMP-AMP (cGAMP), a diffusible cyclic dinucleotide that activates the antiviral response through the adapter protein Stimulator of Interferon Genes (STING). cGAMP is negatively charged and cannot passively cross cell membranes, but recent advances have established a role for extracellular cGAMP as an “immunotransmitter” that can be imported into cells. However, the mechanism by which cGAMP exits cells remains unknown. Here, we identify ABCC1/MRP1 as an ATP-dependent cGAMP exporter that influences STING signaling and type I interferon production. We demonstrate that ABCC1 deficiency exacerbates cGAS-dependent autoimmunity in the Trex1-/- mouse model of Aicardi-Goutières syndrome. These studies identify ABCC1-mediated cGAMP export as a key regulatory mechanism of the cGAS-STING pathway.

Herpes Simplex Virus Type 1 Infection Disturbs the Mitochondrial Network, Leading to Type I Interferon Production through the RNA Polymerase III/RIG-I Pathway

Herpes simplex virus 1 (HSV-1) impairs the mitochondrial network through the viral protein UL12.5. This leads to the fusion of mitochondria and simultaneous release of mitochondrial DNA (mtDNA) in a mouse model.

The Production and characterization of Polyclonal Antibodies Against Interferon Alpha in Mice

The polyclonal antibodies are used extensively for research purposes in many areas of biology, such as immunoprecipitation, histochemistry, enzyme linked immunosorbent assays (ELISA), diagnosis of disease and western blots. Typically, an animal’s immune system will generate a large group of antibodies that recognize several epitopes of a particular antigen. Interferon alpha plays an important role in immune response activation and therefore is of interest in studies related to autoimmune diseases. In this paper the production of antibodies against interferon was studied in order to quantify interferon production to analyze interferon levels in autoimmune disorders in the future. For the antibody production, one month old laboratory grade mice were injected with interferon alpha in combination with a Freund’s complete adjuvant for a course of five weeks after which the antibodies were obtained in mouse serum. Confirmation of the production of anti-interferon alpha antibodies was carried out by the Elisa, immune dot blot and western blot analysis. An interferon alpha of approximately 20.5-21.5 KDa was detected in immunedot blot test. These antibodies may be produced in these mouse models commercially and could be used in future for treatment of autoimmune diseases by managing the interferon levels in the patients. Copyright(c) The Authors