Interferon-gamma (IFNG) is a pleiotropic cytokine that modulates both innate and adaptive immune networks; it is the most potent activator of macrophages and a signature cytokine of activated T lymphocytes. Though IFNG is now appreciated to have a multitude of roles in immune modulation and broad-spectrum pathogen defense, it was originally discovered, and named, as a secretory factor that interferes with viral replication. In contrast to the prototypical type I interferons produced by any cells upon viral infection, only specific subsets of immune cells can produce IFNG upon infection or stimulation with antigen or mitogen. Still, virtually all cells can respond to both types of interferons. This makes IFNG a versatile anti-microbial cytokine and also gives it a unique position in the antiviral defense system. The goal of this review is to highlight the direct antiviral mechanisms of IFNG, thereby clarifying its antiviral function in the effective control of viral infections.
Antiviral Agents ; Defense Mechanisms ; Interferon Type I ; Interferon-gamma* ; Interferons ; Macrophages ; T-Lymphocytes

We investigated the possibility of producing chicken alpha interferon (ChIFN-alpha) in transgenic plants. The cDNA encoding ChIFN-alpha was introduced into lettuce (Lactuca sativa L.) plants by using an agro-infiltration transient expression system. The ChIFN-alpha gene was correctly transcribed and translated in the lettuce plants according to RT-PCR and ELISA assays. Recombinant protein exhibited antiviral activity in vitro by inhibition of vesicular stomatitis virus (VSV) replication on chicken embryonic fibroblast (CEF). The results demonstrate that biologically active avian cytokine with potential pharmaceutical applications could be expressed in transgenic lettuce plants and that it is possible to generate interferon protein in forage plants for preventing infectious diseases of poultry.
Animals ; Chickens ; Interferon Type I ; biosynthesis ; Interferon-alpha ; genetics ; Lettuce ; genetics ; Plants, Genetically Modified ; genetics ; Recombinant Proteins

Hydrophobic interaction chromatography was used to separate correctly refolded and mis-refolded consensus interferon. The effects of ligand types, salt concentration, pH and flow rate were investigated. The best result could be obtained by using Butyl Sepharose 4 Fast Flow, 0.8 mol/L of ammonium sulfate, pH 8.3 and 90cm/h of linear flow rate. Reverse-phase HPLC analysis showed the purity of the pooled fraction was as high as 99.6%. The specific activity of purified consensus interferon was 2.3 x 10(9) IU/mg, The mass recovery of targeth protein was 36.7%.
Chromatography, Liquid ; methods ; Hydrophobic and Hydrophilic Interactions ; Interferon Type I ; chemistry ; isolation & purification ; Interferon-alpha ; Protein Conformation ; Protein Folding ; Recombinant Proteins

The effect of induction temperature on aggregation of consensus interferon-alpha expressed by Pichia pastoris was investigated. The cell growth and cIFN level were analyzed and compared when Pichia pastoris was grown at 30,25,20 degrees C during induction phase, using 5.0L fermentor. The result suggested that the cell growth was not affected much under the different induction temperature, but the protein level declined markedly with the decrease of the induction temperature. The total protein ammount induced at 20 degrees C was 67.8 percent of that at 30 degrees C. SDS-PAGE and native-PAGE as well as Western blotting analysis were further conducted. The electrophoresis results revealed that cIFN formed aggregates after secreted into media when protein was induced at 30 degrees C but this problem can be restored by decreasing the induction temperature to 20 degrees C. cIFN monomer in supernatant arrived at 570mg/L and bioactivity of fermentation broth reached 1.05 x 10(9) IU/mL at 20 degrees C of induction temperature. The amount of cIFN monomer and bioactivity in supernatant elevated 7.2 and 38.7 times, respectively, when the induction temperature was controlled at 20 degrees C instead of conventional 30 degrees C.
Fermentation ; Humans ; Interferon Type I ; biosynthesis ; genetics ; Interferon-alpha ; Pichia ; genetics ; growth & development ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; Temperature

Toll-like receptor 9 binds to DNA from bacteria or viruses and activates a signaling pathway that leads to the induction of proinflammatory cytokines and type I interferon. Adaptor complex AP-3 was required for TLR9 trafficking and the production of type I interferon but not for proinflammatory cytokines. This suggests that TLR9 signaling is regulated by the subcellular localization of the receptor.
Bacteria ; Cytokines ; DNA ; Interferon Type I ; Toll-Like Receptor 9 ; Toll-Like Receptors

Dendritic cells(DC) are specialized antigen-presenting cells that prime naive T cells to induce initial immune responses. The immature DC capture and process antigens in the periphery, then emigrate to lymphoid organs. There they complete their maturation by upregulating HLA-I, II molecules, costimulatory molecules (eg. CD80, CD86) and adhesive molecules (eg. CD50, CD54, CD58). More studies showed that in vitro only interferons type I (IFN-alpha, beta) accelerate DC maturation in a dose-dependent manner. The DC induced by IFN type I highly express HLA-A, B, C, HLA-DR, costimulatory molecules and adhesive molecules, and they express enhancing effect of T-cells stimulatory activity in vitro. Progress of research in this field was summarized in this paper.
Cells, Cultured ; Dendritic Cells ; drug effects ; immunology ; physiology ; Humans ; Immunophenotyping ; Interferon Type I ; pharmacology

Ubiquitin-specific protease(USP), which belongs to cysteine protease, is an important member of the deubiquitinating enzyme family(DUB). USP plays an important role in the immune response against viral infections, in which it can regulate the production of type I interferon through various ways to initiate or weaken the antiviral immune response. USP2b, USP3, USP18, USP25, UL36USP and HAUSP play a role of antivirus; while USP4, USP13, USP15 and USP17 negatively regulate antiviral immune response. In this article we review the recent progress on roles of USP family in antiviral immune response.
Humans ; Interferon Type I ; immunology ; Ubiquitin-Specific Proteases ; immunology ; Virus Diseases ; immunology

Interferons (IFNs) are cytokines playing an important role in immune responses. Interferons are classified into two distinct types according to specific interferon receptors(IFNR). Type I IFNs include IFN-α and IFN-β, whereas IFN-γ is type II IFN. It is well known that type I IFNs have important roles in the host defense against viruses through activation of interferon receptor A (IFNAR). However, many recent studies have also demonstrated that type I IFNs have effects on immune responses to bacterial infection. This review focuses on the immune regulation of type I IFN-mediated signal pathways in bacterial infections such as Listeria monocytogenes, Streptococcus, Mycobacterium tuberculosis, Bacillus anthracis, Legionella, Pseudomonas aeruginosa and others.
Animals ; Bacterial Infections ; immunology ; Humans ; Immunity, Innate ; Interferon Type I ; immunology ; Signal Transduction

Plasmacytoid dendritic cells (pDCs) are a unique subset of cells with different functional characteristics compared to classical dendritic cells. The pDCs are critical for the production of type I IFN in response to microbial and self-nucleic acids. They have an important role for host defense against viral pathogen infections. In addition, pDCs have been well studied as a critical player for breaking tolerance to self-nucleic acids that induce autoimmune disorders such as systemic lupus erythematosus. However, pDCs have an immunoregulatory role in inducing the immune tolerance by generating Tregs and various regulatory mechanisms in mucosal tissues. Here, we summarize the recent studies of pDCs that focused on the functional characteristics of gut pDCs, including interactions with other immune cells in the gut. Furthermore, the dynamic role of gut pDCs will be investigated with respect to disease status including gut infection, inflammatory bowel disease, and cancers.
Dendritic Cells ; Immune Tolerance ; Inflammatory Bowel Diseases ; Interferon Type I ; Lupus Erythematosus, Systemic ; Mucous Membrane

Type I interferon (IFN) is considered as a bridge between innate and adaptive immunity. Proper activation or inhibition of type I IFN signaling is essential for host defense against pathogen invasion, tumor cell proliferation, and overactive immune responses. Due to intricate and diverse chemical structures, natural products and their derivatives have become an invaluable source inspiring innovative drug discovery. In addition, some natural products have been applied in clinical practice for infection, cancer, and autoimmunity over thousands of years and their promising curative effects and safety have been well-accepted. However, whether these natural products are primarily targeting type I IFN signaling and specific molecular targets involved are not fully elucidated. In the current review, we thoroughly summarize recent advances in the pharmacology researches of natural products for their type I IFN activity, including both agonism/activation and antagonism/inhibition, and their potential application as therapies. Furthermore, the source and chemical nature of natural products with type I IFN activity are highlighted and their specific molecular targets in the type I IFN pathway and mode of action are classified. In conclusion, natural products possessing type I IFN activity represent promising therapeutic strategies and have a bright prospect in the treatment of infection, cancer, and autoimmune diseases.
Biological Products/therapeutic use* ; Immunity, Innate ; Signal Transduction ; Interferon Type I/metabolism*