scholarly journals Dendritic cells require a systemic type I interferon response to mature and induce CD4+ Th1 immunity with poly IC as adjuvant

2009 ◽  
Vol 206 (7) ◽  
pp. 1589-1602 ◽  
Author(s):  
M. Paula Longhi ◽  
Christine Trumpfheller ◽  
Juliana Idoyaga ◽  
Marina Caskey ◽  
Ines Matos ◽  
...  
Keyword(s):  
T Cell ◽  
Type I Interferon ◽  
Host Cells ◽  
Interferon Response ◽  
Type I ◽  
Type I Ifn ◽  
Protein Vaccine ◽  
Adaptive Responses ◽  
Cell Repertoire ◽  
Gag Protein

Relative to several other toll-like receptor (TLR) agonists, we found polyinosinic:polycytidylic acid (poly IC) to be the most effective adjuvant for Th1 CD4+ T cell responses to a dendritic cell (DC)–targeted HIV gag protein vaccine in mice. To identify mechanisms for adjuvant action in the intact animal and the polyclonal T cell repertoire, we found poly IC to be the most effective inducer of type I interferon (IFN), which was produced by DEC-205+ DCs, monocytes, and stromal cells. Antibody blocking or deletion of type I IFN receptor showed that IFN was essential for DC maturation and development of CD4+ immunity. The IFN-AR receptor was directly required for DCs to respond to poly IC. STAT 1 was also essential, in keeping with the type I IFN requirement, but not type II IFN or IL-12 p40. Induction of type I IFN was mda5 dependent, but DCs additionally used TLR3. In bone marrow chimeras, radioresistant and, likely, nonhematopoietic cells were the main source of IFN, but mda5 was required in both marrow–derived and radioresistant host cells for adaptive responses. Therefore, the adjuvant action of poly IC requires a widespread innate type I IFN response that directly links antigen presentation by DCs to adaptive immunity.

scholarly journals Hemagglutinin of Influenza A Virus Antagonizes Type I Interferon (IFN) Responses by Inducing Degradation of Type I IFN Receptor 1

2015 ◽  
Vol 90 (5) ◽  
pp. 2403-2417 ◽  
Author(s):  
Chuan Xia ◽  
Madhuvanthi Vijayan ◽  
Curtis J. Pritzl ◽  
Serge Y. Fuchs ◽  
Adrian B. McDermott ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Influenza A Virus ◽  
Influenza A ◽  
Type I Interferon ◽  
Innate Immune ◽  
Host Cells ◽  
Type I ◽  
Type I Ifn ◽  
Type I Ifns ◽  
Ha Protein

ABSTRACTInfluenza A virus (IAV) employs diverse strategies to circumvent type I interferon (IFN) responses, particularly by inhibiting the synthesis of type I IFNs. However, it is poorly understood if and how IAV regulates the type I IFN receptor (IFNAR)-mediated signaling mode. In this study, we demonstrate that IAV induces the degradation of IFNAR subunit 1 (IFNAR1) to attenuate the type I IFN-induced antiviral signaling pathway. Following infection, the level of IFNAR1 protein, but not mRNA, decreased. Indeed, IFNAR1 was phosphorylated and ubiquitinated by IAV infection, which resulted in IFNAR1 elimination. The transiently overexpressed IFNAR1 displayed antiviral activity by inhibiting virus replication. Importantly, the hemagglutinin (HA) protein of IAV was proved to trigger the ubiquitination of IFNAR1, diminishing the levels of IFNAR1. Further, influenza A viral HA1 subunit, but not HA2 subunit, downregulated IFNAR1. However, viral HA-mediated degradation of IFNAR1 was not caused by the endoplasmic reticulum (ER) stress response. IAV HA robustly reduced cellular sensitivity to type I IFNs, suppressing the activation of STAT1/STAT2 and induction of IFN-stimulated antiviral proteins. Taken together, our findings suggest that IAV HA causes IFNAR1 degradation, which in turn helps the virus escape the powerful innate immune system. Thus, the research elucidated an influenza viral mechanism for eluding the IFNAR signaling pathway, which could provide new insights into the interplay between influenza virus and host innate immunity.IMPORTANCEInfluenza A virus (IAV) infection causes significant morbidity and mortality worldwide and remains a major health concern. When triggered by influenza viral infection, host cells produce type I interferon (IFN) to block viral replication. Although IAV was shown to have diverse strategies to evade this powerful, IFN-mediated antiviral response, it is not well-defined if IAV manipulates the IFN receptor-mediated signaling pathway. Here, we uncovered that influenza viral hemagglutinin (HA) protein causes the degradation of type I IFN receptor subunit 1 (IFNAR1). HA promoted phosphorylation and polyubiquitination of IFNAR1, which facilitated the degradation of this receptor. The HA-mediated elimination of IFNAR1 notably decreased the cells' sensitivities to type I IFNs, as demonstrated by the diminished expression of IFN-induced antiviral genes. This discovery could help us understand how IAV regulates the host innate immune response to create an environment optimized for viral survival in host cells.

scholarly journals Hypomethylation of STAT1 and HLA-DRB1 is associated with type-I interferon-dependent HLA-DRB1 expression in lupus CD8+ T cells

2018 ◽  
Author(s):  
Shaylynn Miller ◽  
Patrick Coit ◽  
Elizabeth Gensterblum-Miller ◽  
Paul Renauer ◽  
Nathan C Kilian ◽  
...  
Keyword(s):  
Dna Methylation ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Type I Interferon ◽  
Interferon Response ◽  
Type I ◽  
Mrna Levels ◽  
Healthy Controls ◽  
Genome Wide

AbstractObjectiveWe examined genome-wide DNA methylation changes in CD8+ T cells from lupus patients and controls, and investigated the functional relevance of some of these changes in lupus.MethodsGenome-wide DNA methylation of lupus and age, sex, and ethnicity-matched control CD8+ T cells was measured using the Infinium MethylationEPIC arrays. Measurement of relevant cell subsets was performed via flow cytometry. Gene expression was quantified by qPCR.ResultsLupus CD8+ T cells had 188 hypomethylated CpG sites compared to healthy matched controls. Among the most hypomethylated were sites associated with HLA-DRB1. Genes involved in the type-I interferon response, including STAT1, were also found to be hypomethylated. IFNα upregulated HLA-DRB1 expression on lupus but not control CD8+ T cells. Lupus and control CD8+ T cells significantly increased STAT1 mRNA levels after treatment with IFNα. The expression of CIITA, a key interferon/STAT1 dependent MHC-class II regulator, is induced by IFNα in lupus CD8+ T cells, but not healthy controls. Co-incubation of naïve CD4+ T cells with IFNα-treated CD8+ T cells led to CD4+ T cell activation, determined by increased expression of CD69, in lupus patients but not in healthy controls. This can be blocked by neutralizing antibodies targeting HLA-DR.ConclusionsLupus CD8+ T cells are epigenetically primed to respond to type-I interferon. We describe an HLA-DRB1+ CD8+ T cell subset that can be induced by IFNα in lupus patients. A possible pathogenic role for CD8+ T cells in lupus that is dependent upon a high type-I interferon environment and epigenetic priming warrants further characterization.

scholarly journals Commensal bacteria promote type I interferon signaling to maintain immune tolerance

2021 ◽  
Author(s):  
Adriana Vasquez Ayala ◽  
Kazuhiko Matsuo ◽  
Chia-Yun Hsu ◽  
Marvic Carrillo Terrazas ◽  
Hiutung Chu
Keyword(s):  
Immune Tolerance ◽  
Type I Interferon ◽  
Host Cells ◽  
Type I Interferons ◽  
Type I ◽  
Type I Ifn ◽  
Interferon Signaling ◽  
Mesenteric Lymph Nodes ◽  
Viral Pathogens ◽  
Physiological Processes

Type I interferons (IFN) play essential roles in numerous physiological processes, acting as central coordinators in the host response against pathogens. Upon sensing of microbial ligands, host cells rapidly activate the type I IFN response to prime innate and adaptive immune responses. Recent studies suggest tonic IFN are maintained by commensal microbes and critical in mounting an effective immune response to viral pathogens. Further, emerging developments have extended an immunoregulatory role of type I IFN in the maintenance of immune homeostasis. Yet whether immunomodulatory bacteria from the gut microbiota operate through IFN signaling to promote immune tolerance remains largely unanswered. Here we show that commensal microbes are necessary to maintain type I IFN responses in intestinal tissues. Specifically, Bacteroides fragilis induced type I IFN response in dendritic cells (DCs) and this pathway is necessary for the induction of IL-10-producing Foxp3+ regulatory T cells (Tregs). In addition, we show upregulation of type I IFN related genes in Tregs from mesenteric lymph nodes and colonic lamina propria of mice colonized with B. fragilis. Our findings demonstrate type I interferon signaling plays an important role in microbiota-mediated immune tolerance in the gut.

scholarly journals Pseudorabies Virus dUTPase UL50 Induces Lysosomal Degradation of Type I Interferon Receptor 1 and Antagonizes the Alpha Interferon Response

2017 ◽  
Vol 91 (21) ◽  
Author(s):  
Rui Zhang ◽  
Aotian Xu ◽  
Chao Qin ◽  
Qiong Zhang ◽  
Shifan Chen ◽  
...  
Keyword(s):  
Pseudorabies Virus ◽  
Type I Interferon ◽  
Antiviral Drug ◽  
Ectopic Expression ◽  
Interferon Response ◽  
Type I ◽  
Type I Ifn ◽  
Lysosomal Degradation ◽  
Independent Manner ◽  
Strong Inhibitor

ABSTRACT Alphaherpesviruses that establish persistent infections rely partly on their ability to evade host antiviral responses, notably the type I interferon (IFN) response. However, the mechanisms employed by alphaherpesviruses to avoid this response are not well understood. Pseudorabies virus (PRV) is an economically important pathogen and a useful model system for studying alphaherpesvirus biology. To identify PRV proteins that antagonize type I IFN signaling, we performed a screen by using an IFN-stimulated response element reporter in the swine cell line CRL. Unexpectedly, we identified the dUTPase UL50 as a strong inhibitor. We confirmed that UL50 has the ability to inhibit type I IFN signaling by performing ectopic expression of UL50 in cells and deletion of UL50 in PRV. Mechanistically, UL50 impeded type I IFN-induced STAT1 phosphorylation, likely by accelerating lysosomal degradation of IFN receptor 1 (IFNAR1). In addition, this UL50 activity was independent of its dUTPase activity and required amino acids 225 to 253 in the C-terminal region. The UL50 encoded by herpes simplex virus 1 (HSV-1) also possessed similar activity. Moreover, UL50-deleted PRV was more susceptible to IFN than UL50-proficient PRV. Our results suggest that in addition to its dUTPase activity, the UL50 protein of alphaherpesviruses possesses the ability to suppress type I IFN signaling by promoting lysosomal degradation of IFNAR1, thereby contributing to immune evasion. This finding reveals UL50 as a potential antiviral target. IMPORTANCE Alphaherpesviruses can establish lifelong infections and cause many diseases in humans and animals. Pseudorabies virus (PRV) is a swine alphaherpesvirus that threatens pig production. Using PRV as a model, we found that this alphaherpesvirus could utilize its encoded dUTPase UL50 to induce IFNAR1 degradation and inhibit type I IFN signaling in an enzymatic activity-independent manner. Our finding reveals a mechanism employed by an alphaherpesvirus to evade the immune response and indicates that UL50 is an important viral protein in pathogenesis and is a potential target for antiviral drug development.

scholarly journals HIV/AIDS Vaccine Candidates Based on Replication-Competent Recombinant Poxvirus NYVAC-C-KC Expressing Trimeric gp140 and Gag-Derived Virus-Like Particles or Lacking the Viral Molecule B19 That Inhibits Type I Interferon Activate Relevant HIV-1-Specific B and T Cell Immune Functions in Nonhuman Primates

2017 ◽  
Vol 91 (9) ◽  
Author(s):  
Juan García-Arriaza ◽  
Beatriz Perdiguero ◽  
Jonathan L. Heeney ◽  
Michael S. Seaman ◽  
David C. Montefiori ◽  
...  
Keyword(s):  
T Cell ◽  
Nonhuman Primates ◽  
Type I Interferon ◽  
Interferon Response ◽  
Type I ◽  
Vaccine Candidates ◽  
Aids Vaccine ◽  
Clade C ◽  
Hiv 1 ◽  
Hiv Aids

ABSTRACT The nonreplicating attenuated poxvirus vector NYVAC expressing clade C(CN54) HIV-1 Env(gp120) and Gag-Pol-Nef antigens (NYVAC-C) showed limited immunogenicity in phase I clinical trials. To enhance the capacity of the NYVAC vector to trigger broad humoral responses and a more balanced activation of CD4+ and CD8+ T cells, here we compared the HIV-1-specific immunogenicity elicited in nonhuman primates immunized with two replicating NYVAC vectors that have been modified by the insertion of the K1L and C7L vaccinia virus host range genes and express the clade C(ZM96) trimeric HIV-1 gp140 protein or a Gag(ZM96)-Pol-Nef(CN54) polyprotein as Gag-derived virus-like particles (termed NYVAC-C-KC). Additionally, one NYVAC-C-KC vector was generated by deleting the viral gene B19R, an inhibitor of the type I interferon response (NYVAC-C-KC-ΔB19R). An immunization protocol mimicking that of the RV144 phase III clinical trial was used. Two groups of macaques received two doses of the corresponding NYVAC-C-KC vectors (weeks 0 and 4) and booster doses with NYVAC-C-KC vectors plus the clade C HIV-1 gp120 protein (weeks 12 and 24). The two replicating NYVAC-C-KC vectors induced enhanced and similar HIV-1-specific CD4+ and CD8+ T cell responses, similar levels of binding IgG antibodies, low levels of IgA antibodies, and high levels of antibody-dependent cellular cytotoxicity responses and HIV-1-neutralizing antibodies. Small differences within the NYVAC-C-KC-ΔB19R group were seen in the magnitude of CD4+ and CD8+ T cells, the induction of some cytokines, and the neutralization of some HIV-1 isolates. Thus, replication-competent NYVAC-C-KC vectors acquired relevant immunological properties as vaccine candidates against HIV/AIDS, and the viral B19 molecule exerts some control of immune functions. IMPORTANCE It is of special importance to find a safe and effective HIV/AIDS vaccine that can induce strong and broad T cell and humoral immune responses correlating with HIV-1 protection. Here we developed novel replicating poxvirus NYVAC-based HIV/AIDS vaccine candidates expressing clade C HIV-1 antigens, with one of them lacking the vaccinia virus B19 protein, an inhibitor of the type I interferon response. Immunization of nonhuman primates with these novel NYVAC-C-KC vectors and the protein component gp120 elicited high levels of T cell and humoral immune responses, with the vector containing a deletion in B19R inducing a trend toward a higher magnitude of CD4+ and CD8+ T cell responses and neutralization of some HIV-1 strains. These poxvirus vectors could be considered HIV/AIDS vaccine candidates based on their activation of potential immune correlates of protection.

scholarly journals The NS2 Protein of Human Respiratory Syncytial Virus Suppresses the Cytotoxic T-Cell Response as a Consequence of Suppressing the Type I Interferon Response

2006 ◽  
Vol 80 (12) ◽  
pp. 5958-5967 ◽  
Author(s):  
Alexander Kotelkin ◽  
Igor M. Belyakov ◽  
Lijuan Yang ◽  
Jay A. Berzofsky ◽  
Peter L. Collins ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Type I Interferon ◽  
Human Respiratory Syncytial Virus ◽  
Interferon Response ◽  
Cytotoxic T Cell ◽  
Type I ◽  
Type I Ifn ◽  
Ifn Γ ◽  
Syncytial Virus

ABSTRACT The NS1 and NS2 proteins of human respiratory syncytial virus (HRSV) have been shown to antagonize the type I interferon (IFN) response, an effect subject to host range constraints. We have now found that the HRSV NS2 protein strongly controls IFN induction in mouse cells in vitro, validating the use of the mouse model to study the consequences of these gene deletions on host immunity. We evaluated the effects of deleting the NS1 and/or NS2 gene on the induction of HRSV-specific pulmonary cytotoxic T lymphocytes (CTL) in BALB/c and 129S6 mice in response to intranasal infection with HRSV lacking the NS1 and/or NS2 gene and subsequent challenge with wild-type (wt) HRSV. In mice infected with HRSV lacking the NS2 gene (ΔNS2) or lacking the NS2 gene in combination with the NS1 gene (ΔNS1/2 HRSV), the magnitude of the pulmonary CTL response was substantially elevated compared to that of mice infected with wt HRSV or the ΔNS1 mutant, whether measured by binding of CD8+ cells to an HRSV-specific major histocompatibility complex class I tetramer, by measurement of CD8+ cells secreting gamma interferon (IFN-γ) in response to specific in vitro stimulation, or by a standard chromium release cell-killing assay. In contrast, in STAT1 knockout mice, which lack responsiveness to type I IFN, the level of IFN-γ-secreting CD8+ cells was not significantly different for HRSV lacking the NS2 gene, suggesting that the increase in CTL observed in IFN-responsive mice is type I IFN dependent. Thus, the NS2 protein of HRSV suppresses the CTL component of the adaptive immune response, and this appears to be a consequence of its suppression of type I IFN.

scholarly journals Conidia but Not Yeast Cells of the Fungal Pathogen Histoplasma capsulatum Trigger a Type I Interferon Innate Immune Response in Murine Macrophages

2010 ◽  
Vol 78 (9) ◽  
pp. 3871-3882 ◽  
Author(s):  
Diane O. Inglis ◽  
Charlotte A. Berkes ◽  
Davina R. Hocking Murray ◽  
Anita Sil
Keyword(s):  
Histoplasma Capsulatum ◽  
Type I Interferon ◽  
Respiratory Infections ◽  
Host Cells ◽  
Yeast Cells ◽  
Host Immune System ◽  
Type I ◽  
Type I Ifn ◽  
Murine Bone Marrow ◽  
Reverse Transcription Pcr

ABSTRACT Histoplasma capsulatum is the most common cause of fungal respiratory infections and can lead to progressive disseminated infections, particularly in immunocompromised patients. Infection occurs upon inhalation of the aerosolized spores, known as conidia. Once inside the host, conidia are phagocytosed by alveolar macrophages. The conidia subsequently germinate and produce a budding yeast-like form that colonizes host macrophages and can disseminate throughout host organs and tissues. Even though conidia are the predominant infectious particle for H. capsulatum and are the first cell type encountered by the host during infection, very little is known at a molecular level about conidia or about their interaction with cells of the host immune system. We examined the interaction between conidia and host cells in a murine bone-marrow-derived macrophage model of infection. We used whole-genome expression profiling and quantitative reverse transcription-PCR (qRT-PCR) to monitor the macrophage signaling pathways that are modulated during infection with conidia. Our analysis revealed that type I interferon (IFN)-responsive genes and the beta type I IFN (IFN-β) were induced in macrophages during infection with H. capsulatum conidia but not H. capsulatum yeast cells. Further analysis revealed that the type I IFN signature induced in macrophages in response to conidia is independent of Toll-like receptor (TLR) signaling and the cytosolic RNA sensor MAVS but is dependent on the transcription factor interferon regulatory factor 3 (IRF3). Interestingly, H. capsulatum growth was restricted in mice lacking the type I IFN receptor, indicating that an intact host type I IFN response is required for full virulence of H. capsulatum in mice.

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