MPYS/STING-Mediated TNF-α, Not Type I IFN, Is Essential for the Mucosal Adjuvant Activity of (3′–5′)-Cyclic-Di-Guanosine-Monophosphate In Vivo

Innate immunity is the front-line defense against infectious microorganisms, including viruses and bacteria. Type I interferons are pleiotropic cytokines that perform antiviral, antiproliferative, and immunomodulatory functions in cells. The cGAS–STING pathway, comprising the main DNA sensor cyclic guanosine monophosphate/adenosine monophosphate synthase (cGAS) and stimulator of IFN genes (STING), is a major pathway that mediates immune reactions and is involved in the strong induction of type I IFN production, which can fight against microbial infections. Autophagy is an evolutionarily conserved degradation process that is required to maintain host health and facilitate capture and elimination of invading pathogens by the immune system. Mounting evidence indicates that autophagy plays an important role in cGAS–STING signaling pathway-mediated type I IFN production. This review briefly summarizes the research progress on how autophagy regulates the cGAS–STING pathway, regulating type I IFN production, with a particular focus on the crosstalk between autophagy and cGAS–STING signaling during infection by pathogenic microorganisms.

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Innate triggering and antiviral effector functions of activin A

10.1101/2021.03.23.436626 ◽

2021 ◽

Author(s):

Kinda Al-Hourani ◽

Narayan Ramamurthy ◽

Emanuele Marchi ◽

Ruth M Eichinger ◽

Lian N Lee ◽

...

Keyword(s):

Viral Infection ◽

Influenza A ◽

Mononuclear Cells ◽

Human Peripheral Blood ◽

Activin A ◽

Type I ◽

Type I Ifn ◽

Effector Functions

First-line defence against viral infection is contingent upon rapid detection of conserved viral structural and genomic motifs by germline-encoded pattern recognition receptors, followed by activation of the type I IFN system and establishment of an intracellular antiviral state. Novel antiviral functions of bone morphogenetic protein and related activin cytokines, acting in conjunction with, and independently of, type I IFN, have recently been described. Activin A mediates multiple innate and adaptive immune functions, including antiviral effects. However, how such effects are mediated and how activin might be triggered by viral infection have not been defined. Here we addressed this in vivo and in vitro, in humans and mice. Transcriptomic analyses delineated strikingly congruent patterns of gene regulation in hepatocytes stimulated with recombinant activin A and IFNα in vitro. Activin A mRNA, encoded by INHBA, is induced upon activation of RIG-I, MDA5 and TLR7/8 viral nucleic acid sensors in vitro, across multiple cell lines and in human peripheral blood mononuclear cells. In vivo, infection of mice with influenza A also upregulated Inhba mRNA in the lung; this local upregulation of Inhba is retained in MAVS knockout mice, indicating a role for non-RIG-I-like receptors in its induction. Activin induction and signalling were also detectable in patients with chronic viral hepatitis. Together, these data suggest Activin A is triggered in parallel with type I IFN responses and can trigger related antiviral effector functions. This model has implications for the development of targeted antiviral therapies, in addition to revealing novel facets of activin biology.

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Revisiting the role of IRF3 in inflammation and immunity by conditional and specifically targeted gene ablation in mice

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1803936115 ◽

2018 ◽

Vol 115 (20) ◽

pp. 5253-5258 ◽

Cited By ~ 19

Author(s):

Hideyuki Yanai ◽

Shiho Chiba ◽

Sho Hangai ◽

Kohei Kometani ◽

Asuka Inoue ◽

...

Keyword(s):

Immune Cell ◽

Cell Types ◽

Type I ◽

Type I Ifn ◽

Cell Type ◽

Gene Ablation ◽

Cell Type Specific

IFN regulatory factor 3 (IRF3) is a transcription regulator of cellular responses in many cell types that is known to be essential for innate immunity. To confirm IRF3’s broad role in immunity and to more fully discern its role in various cellular subsets, we engineered Irf3-floxed mice to allow for the cell type-specific ablation of Irf3. Analysis of these mice confirmed the general requirement of IRF3 for the evocation of type I IFN responses in vitro and in vivo. Furthermore, immune cell ontogeny and frequencies of immune cell types were unaffected when Irf3 was selectively inactivated in either T cells or B cells in the mice. Interestingly, in a model of lipopolysaccharide-induced septic shock, selective Irf3 deficiency in myeloid cells led to reduced levels of type I IFN in the sera and increased survival of these mice, indicating the myeloid-specific, pathogenic role of the Toll-like receptor 4–IRF3 type I IFN axis in this model of sepsis. Thus, Irf3-floxed mice can serve as useful tool for further exploring the cell type-specific functions of this transcription factor.

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Autophagy Contributes to Host Immunity and Protection against Zika Virus Infection via Type I IFN Signaling

Mediators of Inflammation ◽

10.1155/2020/9527147 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15 ◽

Cited By ~ 1

Author(s):

Yuyi Huang ◽

Yujie Wang ◽

Shuhui Meng ◽

Zhuohang Chen ◽

Haifan Kong ◽

...

Keyword(s):

Virus Infection ◽

Cell Line ◽

Zika Virus ◽

Fetal Brain ◽

Host Immunity ◽

Type I ◽

Type I Ifn ◽

Zikv Infection

Recent studies have indicated that the Zika virus (ZIKV) has a significant impact on the fetal brain, and autophagy is contributing to host immune response and defense against virus infection. Here, we demonstrate that ZIKV infection triggered increased LC3 punctuation in mouse monocyte-macrophage cell line (RAW264.7), mouse microglial cell line (BV2), and hindbrain tissues, proving the occurrence of autophagy both in vitro and in vivo. Interestingly, manual intervention of autophagy, like deficiency inhibited by 3-MA, can reduce viral clearance in RAW264.7 cells upon ZIKV infection. Besides, specific siRNA strategy confirmed that autophagy can be activated through Atg7-Atg5 and type I IFN signaling pathway upon ZIKV infection, while knocking down of Atg7 and Atg5 effectively decreased the ZIKV clearance in phagocytes. Furthermore, we analyzed that type I IFN signaling could contribute to autophagic clearance of invaded ZIKV in phagocytes. Taken together, our findings demonstrate that ZIKV-induced autophagy is favorable to activate host immunity, particularly through type I IFN signaling, which participates in host protection and defense against ZIKV infection.

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Rhesus Macaque Rhadinovirus Encodes a Viral Interferon Regulatory Factor To Disrupt Promyelocytic Leukemia Nuclear Bodies and Antagonize Type I Interferon Signaling

Journal of Virology ◽

10.1128/jvi.02147-18 ◽

2019 ◽

Vol 93 (6) ◽

Cited By ~ 1

Author(s):

Laura K. Springgay ◽

Kristin Fitzpatrick ◽

Byung Park ◽

Ryan D. Estep ◽

Scott W. Wong

Keyword(s):

Immune Response ◽

Rhesus Macaque ◽

Promyelocytic Leukemia ◽

Nuclear Bodies ◽

Type I ◽

Type I Ifn ◽

Regulatory Factors ◽

Successful Infection ◽

Promyelocytic Leukemia Nuclear Bodies

ABSTRACTInterferon (IFN) production and the subsequent induction of IFN-stimulated genes (ISGs) are highly effective innate strategies utilized by cells to protect against invading pathogens, including viruses. Critical components involved in this innate process are promyelocytic leukemia nuclear bodies (PML-NBs), which are subnuclear structures required for the development of a robust IFN response. As such, PML-NBs serve as an important hurdle for viruses to overcome to successfully establish an infection. Both Kaposi’s sarcoma-associated herpesvirus (KSHV) and the closely related rhesus macaque rhadinovirus (RRV) are unique for encoding viral homologs of IFN regulatory factors (termed vIRFs) that can manipulate the host immune response by multiple mechanisms. All four KSHV vIRFs inhibit the induction of IFN, while vIRF1 and vIRF2 can inhibit ISG induction downstream of the IFN receptor. Less is known about the RRV vIRFs. RRV vIRF R6 can inhibit the induction of IFN by IRF3; however, it is not known whether any RRV vIRFs inhibit ISG induction following IFN receptor signaling. In our present study, we demonstrate that the RRV vIRF R12 aids viral replication in the presence of the type I IFN response. This is achieved in part through the disruption of PML-NBs and the inhibition of robust ISG transcription.IMPORTANCEKSHV and RRV encode a unique set of homologs of cellular IFN regulatory factors, termed vIRFs, which are hypothesized to help these viruses evade the innate immune response and establish infections in their respective hosts. Our work elucidates the role of one RRV vIRF, R12, and demonstrates that RRV can dampen the type I IFN response downstream of IFN signaling, which would be important for establishing a successful infectionin vivo.

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Essential Role of Host Double-Stranded DNA Released from Dying Cells by Cationic Liposomes for Mucosal Adjuvanticity

Vaccines ◽

10.3390/vaccines8010008 ◽

2019 ◽

Vol 8 (1) ◽

pp. 8

Author(s):

Rui Tada ◽

Akihiro Ohshima ◽

Yuya Tanazawa ◽

Akari Ohmi ◽

Saeko Takahashi ◽

...

Keyword(s):

Essential Role ◽

Cationic Liposome ◽

Cationic Liposomes ◽

Mucosal Vaccine ◽

Nasal Administration ◽

Adjuvant Activity ◽

Mucosal Adjuvant ◽

Double Stranded Dna ◽

Dying Cells

Infectious disease remains a substantial cause of death. To overcome this issue, mucosal vaccine systems are considered to be a promising strategy. Yet, none are approved for clinical use, except for live-attenuated mucosal vaccines, mainly owing to the lack of effective and safe systems to induce antigen-specific immune responses in the mucosal compartment. We have reported that intranasal vaccination of an antigenic protein, with cationic liposomes composed of 1,2-dioleoyl-3-trimethylammonium-propane and 3β-[N-(N′,N′-dimethylaminoethane)-carbamoyl], induced antigen-specific mucosal and systemic antibody responses in mice. However, precise molecular mechanism(s) underlying the mucosal adjuvant effects of cationic liposomes remain to be uncovered. Here, we show that a host double-stranded DNA (dsDNA), released at the site of cationic liposome injection, plays an essential role for the mucosal adjuvanticity of the cationic liposome. Namely, we found that nasal administration of the cationic liposomes induced localized cell death, at the site of injection, resulting in extracellular leakage of host dsDNA. Additionally, in vivo DNase I treatment markedly impaired OVA-specific mucosal and systemic antibody production exerted by cationic liposomes. Our report reveals that host dsDNA, released from local dying cells, acts as a damage-associated molecular pattern that mediates the mucosal adjuvant activity of cationic liposomes.

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hCD46 receptor is not required for measles vaccine Schwarz strain replication in vivo: Type-I IFN is the species barrier in mice

Virology ◽

10.1016/j.virol.2018.08.014 ◽

2018 ◽

Vol 524 ◽

pp. 151-159 ◽

Cited By ~ 1

Author(s):

M. Mura ◽

C. Ruffié ◽

E. Billon-Denis ◽

C. Combredet ◽

J.N. Tournier ◽

...

Keyword(s):

Type I ◽

Type I Ifn ◽

Measles Vaccine ◽

Species Barrier

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Cyclophosphamide induces type I interferon and augments the number of CD44hi T lymphocytes in mice: implications for strategies of chemoimmunotherapy of cancer

Blood ◽

10.1182/blood.v95.6.2024 ◽

2000 ◽

Vol 95 (6) ◽

pp. 2024-2030 ◽

Cited By ~ 149

Author(s):

Giovanna Schiavoni ◽

Fabrizio Mattei ◽

Tiziana Di Pucchio ◽

Stefano M. Santini ◽

Laura Bracci ◽

...

Keyword(s):

T Cells ◽

T Lymphocytes ◽

Adoptive Immunotherapy ◽

Messenger Rna ◽

Type I ◽

Type I Ifn ◽

Term Survival ◽

Spleen Lymphocytes

Abstract In a previous study, we reported that a single injection of cyclophosphamide (CTX) in tumor-bearing mice resulted in tumor eradication when the animals were subsequently injected with tumor-sensitized lymphocytes. Notably, CTX acted by inducing bystander effects on T cells, and the response to the combined CTX/adoptive immunotherapy regimen was inhibited in mice treated with antibodies to mouse interferon (IFN)–/β. In the present study, we have investigated whether CTX induced the expression of type I IFN, and we have characterized the CTX effects on the phenotype of T cells in normal mice. CTX injection resulted in an accumulation of type I IFN messenger RNA in the spleen of inoculated mice, at 24 to 48 hours, that was associated with IFN detection in the majority of the animals. CTX also enhanced the expression of the Ly-6C on spleen lymphocytes. This enhancement was inhibited in mice treated with anti–type I IFN antibodies. Moreover, CTX induced a long-lasting increase in in vivo lymphocyte proliferation and in the percentage of CD44hiCD4+ and CD44hiCD8+T lymphocytes. These results demonstrate that CTX is an inducer of type I IFN in vivo and enhances the number of T cells exhibiting the CD44hi memory phenotype. Since type I IFN has been recently recognized as the important cytokine for the in vivo expansion and long-term survival of memory T cells, we suggest that induction of this cytokine may explain at least part of the immunomodulatory effects observed after CTX treatment. Finally, these findings provide a new rationale for combined treatments with CTX and adoptive immunotherapy in cancer patients.

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