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1.
Sci Immunol ; 9(98): eadk2612, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39093956

RESUMO

Aberrant activation of the cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes (cGAS-STING) pathway causes autoimmunity in humans and mice; however, the exact mechanism by which the cGAS-STING pathway initiates adaptive immunity and tissue pathology is still not fully understood. Here, we used a cGAS knockin (KI) mouse model that develops systemic autoimmunity. In the lungs of cGAS-KI mice, blood vessels were enclosed by organized lymphoid tissues that resemble tertiary lymphoid structures (TLSs). Cell-intrinsic cGAS induction promoted up-regulation of CCR5 in CD8+ T cells and led to CCL5 production in vascular endothelial cells. Peripheral CD8+ T cells were recruited to the lungs and produced CXCL13 and interferon-γ. The latter triggered endothelial cell death, potentiated CCL5 production, and was essential for TLS establishment. Blocking CCL5 or CCR5, or depleting CD8+ T cells, impaired TLS formation. cGAS-mediated TLS formation also enhanced humoral and antitumor responses. These data demonstrate that cGAS signaling drives a specialized lymphoid structure that underlies autoimmune tissue pathology.


Assuntos
Linfócitos T CD8-Positivos , Células Endoteliais , Nucleotidiltransferases , Estruturas Linfoides Terciárias , Animais , Nucleotidiltransferases/imunologia , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Camundongos , Células Endoteliais/imunologia , Estruturas Linfoides Terciárias/imunologia , Linfócitos T CD8-Positivos/imunologia , Quimiocina CCL5/imunologia , Quimiocina CCL5/genética , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Transdução de Sinais/imunologia , Receptores CCR5/imunologia , Receptores CCR5/genética , Receptores CCR5/metabolismo , Autoimunidade/imunologia
2.
Oncoimmunology ; 13(1): 2394247, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39206097

RESUMO

Disrupting mitochondrial function in malignant cells is a promising strategy to enhance anticancer immunity. We have recently demonstrated that depriving colorectal cancer cells of serine results in mitochondrial dysfunction coupled with the cytosolic accumulation of mitochondrial DNA and consequent activation of CGAS- and STING-dependent tumor-targeting immune responses.


Assuntos
DNA Mitocondrial , Mitocôndrias , Animais , Humanos , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/patologia , DNA Mitocondrial/metabolismo , DNA Mitocondrial/genética , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Nucleotidiltransferases/genética , Nucleotidiltransferases/imunologia , Nucleotidiltransferases/metabolismo
3.
Front Immunol ; 15: 1403070, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39015575

RESUMO

Background: The cGAS-STING axis-mediated type I interferon pathway is a crucial strategy for host defense against DNA virus infection. Numerous evasion strategies developed by the pseudorabies virus (PRV) counteract host antiviral immunity. To what extent PRV-encoded proteins evade the cGAS-STING signaling pathway is unknown. Methods: Using US2 stably expressing cell lines and US2-deficient PRV model, we revealed that the PRV tegument protein US2 reduces STING protein stability and downregulates STING-mediated antiviral signaling. Results: To promote K48-linked ubiquitination and STING degradation, US2 interacts with the LBD structural domain of STING and recruits the E3 ligase TRIM21. TRIM21 deficiency consistently strengthens the host antiviral immune response brought on by PRV infection. Additionally, US2-deficient PRV is less harmful in mice. Conclusions: Our study implies that PRV US2 inhibits IFN signaling by a new mechanism that selectively targets STING while successfully evading the host antiviral response. As a result, the present study reveals a novel strategy by which PRV evades host defense and offers explanations for why the Bartha-K61 classical vaccine strain failed to offer effective defense against PRV variant strains in China, indicating that US2 may be a key target for developing gene-deficient PRV vaccines.


Assuntos
Herpesvirus Suídeo 1 , Imunidade Inata , Pseudorraiva , Transdução de Sinais , Proteínas do Envelope Viral , Animais , Humanos , Camundongos , Células HEK293 , Herpesvirus Suídeo 1/imunologia , Herpesvirus Suídeo 1/fisiologia , Interações Hospedeiro-Patógeno/imunologia , Evasão da Resposta Imune , Proteínas de Membrana/metabolismo , Proteínas de Membrana/imunologia , Proteínas de Membrana/genética , Nucleotidiltransferases/metabolismo , Nucleotidiltransferases/genética , Nucleotidiltransferases/imunologia , Pseudorraiva/imunologia , Pseudorraiva/virologia , Ribonucleoproteínas/imunologia , Ribonucleoproteínas/metabolismo , Ubiquitinação , Proteínas do Envelope Viral/metabolismo
4.
Signal Transduct Target Ther ; 9(1): 163, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38880789

RESUMO

Chronic obstructive pulmonary disease (COPD) is characterised by persistent airway inflammation even after cigarette smoking cessation. Neutrophil extracellular traps (NETs) have been implicated in COPD severity and acute airway inflammation induced by short-term cigarette smoke (CS). However, whether and how NETs contribute to sustained airway inflammation in COPD remain unclear. This study aimed to elucidate the immunoregulatory mechanism of NETs in COPD, employing human neutrophils, airway epithelial cells (AECs), dendritic cells (DCs), and a long-term CS-induced COPD mouse model, alongside cyclic guanosine monophosphate-adenosine monophosphate synthase and toll-like receptor 9 knockout mice (cGAS--/-, TLR9-/-); Additionally, bronchoalveolar lavage fluid (BALF) of COPD patients was examined. Neutrophils from COPD patients released greater cigarette smoke extract (CSE)-induced NETs (CSE-NETs) due to mitochondrial respiratory chain dysfunction. These CSE-NETs, containing oxidatively-damaged DNA (NETs-DNA), promoted AECs proliferation, nuclear factor kappa B (NF-κB) activation, NF-κB-dependent cytokines and type-I interferons production, and DC maturation, which were ameliorated/reversed by silencing/inhibition of cGAS/TLR9. In the COPD mouse model, blocking NETs-DNA-sensing via cGAS-/- and TLR9-/- mice, inhibiting NETosis using mitoTEMPO, and degrading NETs-DNA with DNase-I, respectively, reduced NETs infiltrations, airway inflammation, NF-κB activation and NF-κB-dependent cytokines, but not type-I interferons due to IFN-α/ß receptor degradation. Elevated NETs components (myeloperoxidase and neutrophil elastase activity) in BALF of COPD smokers correlated with disease severity and NF-κB-dependent cytokine levels, but not type-I interferon levels. In conclusion, NETs-DNA promotes NF-κB-dependent autoimmunity via cGAS/TLR9 in long-term CS exposure-induced COPD. Therefore, targeting NETs-DNA and cGAS/TLR9 emerges as a potential strategy to alleviate persistent airway inflammation in COPD.


Assuntos
Armadilhas Extracelulares , NF-kappa B , Neutrófilos , Nucleotidiltransferases , Doença Pulmonar Obstrutiva Crônica , Receptor Toll-Like 9 , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/imunologia , Doença Pulmonar Obstrutiva Crônica/patologia , Receptor Toll-Like 9/genética , Receptor Toll-Like 9/imunologia , Armadilhas Extracelulares/imunologia , Armadilhas Extracelulares/genética , Nucleotidiltransferases/genética , Nucleotidiltransferases/imunologia , Animais , Humanos , NF-kappa B/genética , NF-kappa B/imunologia , NF-kappa B/metabolismo , Camundongos , Neutrófilos/imunologia , Neutrófilos/patologia , Camundongos Knockout , Autoimunidade/genética , Masculino , DNA/genética , DNA/imunologia , Feminino , Modelos Animais de Doenças , Pessoa de Meia-Idade
5.
Fish Shellfish Immunol ; 151: 109684, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38852788

RESUMO

Singapore grouper iridovirus (SGIV) is a large double-stranded DNA virus that has caused significant economic losses to the grouper aquaculture industry. So far, the structure and function of SGIV proteins have been successively reported. In the present paper, the protein of SGIV VP146 was cloned and identified. VP146 was whole-cell distributed in GS cells. VP146 promoted SGIV replication and inhibited the transcription of interferon-related genes as well as pro-inflammatory cytokines in GS cells. In addition, VP146 was involved in the regulation of the cGAS-STING signaling pathway, and decreased cGAS-STING induced the promoter of ISRE and NF-κB. VP146 interacted with the proteins of cGAS, STING, TBK1, and IRF3 from grouper, but did not affect the binding of grouper STING to grouper TBK1 and grouper IRF3. Interestingly, grouper STING was able to affect the intracellular localization of VP146. Four segment structural domains of grouper STING were constructed, and grouper STING-CTT could affect the intracellular localization of VP146. VP146 had no effect on the self-binding of EcSITNG, nor on the binding of EcSTING to EcTBK1 and EcIRF3. Together, the results demonstrated that SGIV VP146 modulated the cGAS-STING signaling pathway to escape the interferon immune response.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Bass , Iridovirus , Nucleotidiltransferases , Transdução de Sinais , Iridovirus/imunologia , Nucleotidiltransferases/genética , Nucleotidiltransferases/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Transdução de Sinais/imunologia , Bass/genética , Bass/imunologia , Bass/virologia , Linhagem Celular , Baço/citologia , Regulação da Expressão Gênica/imunologia , Replicação Viral/imunologia , Interferons/genética , Interferons/imunologia , Proteínas de Peixes/imunologia , Animais
6.
Adv Sci (Weinh) ; 11(32): e2310108, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38900071

RESUMO

New adjuvants that trigger cellular immune responses are urgently needed for the effective development of cancer and virus vaccines. Motivated by recent discoveries that show activation of type I interferon (IFN-I) signaling boosts T cell immunity, this study proposes that targeting this pathway can be a strategic approach to identify novel vaccine adjuvants. Consequently, a comprehensive chemical screening of 6,800 small molecules is performed, which results in the discovery of the natural compound picrasidine S (PS) as an IFN-I inducer. Further analysis reveals that PS acts as a powerful adjuvant, significantly enhancing both humoral and cellular immune responses. At the molecular level, PS initiates the activation of the cGAS-IFN-I pathway, leading to an enhanced T cell response. PS vaccination notably increases the population of CD8+ central memory (TCM)-like cells and boosts the CD8+ T cell-mediated anti-tumor immune response. Thus, this study identifies PS as a promising candidate for developing vaccine adjuvants in cancer prevention.


Assuntos
Adjuvantes Imunológicos , Imunidade Celular , Adjuvantes Imunológicos/farmacologia , Animais , Camundongos , Imunidade Celular/efeitos dos fármacos , Imunidade Celular/imunologia , Camundongos Endogâmicos C57BL , Nucleotidiltransferases/imunologia , Nucleotidiltransferases/metabolismo , Nucleotidiltransferases/genética , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Interferon Tipo I/imunologia , Humanos , Feminino , Modelos Animais de Doenças , Vacinas Anticâncer/imunologia , Vacinas Anticâncer/farmacologia
7.
Cytokine Growth Factor Rev ; 77: 30-38, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38472042

RESUMO

Pyroptosis, a programmed cell death process, is vital for the immune response against microbial infections and internal danger signals. Recent studies have highlighted the importance of protein palmitoylation, a modification that involves attaching palmitate to cysteine residues, in regulating key proteins involved in pyroptosis. Palmitoylation of cGAS at residue C474 by ZDHHC18 affects its enzymatic activity and DNA binding ability. Similarly, ZDHHC9 promotes cGAS activity through palmitoylation at residues C404/405. NLRP3 palmitoylation at residue C844, mediated by ZDHHC12, impacts its stability and interactions with other proteins, crucial for activating the NLRP3 inflammasome and triggering inflammation. However, the role of ZDHHC5 in NLRP3 palmitoylation remains uncertain due to conflicting findings. Palmitoylation at C88/91 is essential for STING activation and induction of type I interferons. It modulates the formation of multimeric complexes and downstream signaling pathways. GSDMD palmitoylation at C191 is necessary for pore formation and membrane translocation, while GSDME palmitoylation at C407/408 is associated with drug-induced pyroptosis. Moreover, palmitoylation of NOD1 and NOD2 influences their membrane recruitment and immune signaling pathways in response to bacterial peptidoglycans, acting as upstream regulators of pyroptosis. This review summarizes the important roles for palmitoylation in regulating the function of key pyroptosis-related proteins, shedding light on the intricate mechanisms governing immune responses and inflammation.


Assuntos
Lipoilação , Proteína 3 que Contém Domínio de Pirina da Família NLR , Piroptose , Humanos , Animais , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Transdução de Sinais , Inflamassomos/imunologia , Proteínas de Membrana/imunologia , Proteínas de Membrana/metabolismo , Nucleotidiltransferases/metabolismo , Nucleotidiltransferases/imunologia , Inflamação/imunologia , Aciltransferases/imunologia
8.
Nat Commun ; 14(1): 2898, 2023 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-37217469

RESUMO

The DNA sensor cyclic GMP-AMP synthase (cGAS) is critical in host antiviral immunity. Vaccinia virus (VACV) is a large cytoplasmic DNA virus that belongs to the poxvirus family. How vaccinia virus antagonizes the cGAS-mediated cytosolic DNA-sensing pathway is not well understood. In this study, we screened 80 vaccinia genes to identify potential viral inhibitors of the cGAS/Stimulator of interferon gene (STING) pathway. We discovered that vaccinia E5 is a virulence factor and a major inhibitor of cGAS. E5 is responsible for abolishing cGAMP production during vaccinia virus (Western Reserve strain) infection of dendritic cells. E5 localizes to the cytoplasm and nucleus of infected cells. Cytosolic E5 triggers ubiquitination of cGAS and proteasome-dependent degradation via interacting with cGAS. Deleting the E5R gene from the Modified vaccinia virus Ankara (MVA) genome strongly induces type I IFN production by dendritic cells (DCs) and promotes DC maturation, and thereby improves antigen-specific T cell responses.


Assuntos
Células Dendríticas , Nucleotidiltransferases , Vaccinia virus , Proteínas Virais , Camundongos Endogâmicos C57BL , Animais , Camundongos , Camundongos Knockout , Feminino , Nucleotidiltransferases/imunologia , Células Dendríticas/imunologia , Células Dendríticas/virologia , Vaccinia virus/patogenicidade , Fatores de Virulência/imunologia , Ubiquitinação , Proteínas Virais/genética , Proteínas Virais/imunologia , Complexo de Endopeptidases do Proteassoma , Interferon Tipo I/imunologia , Células HEK293 , Humanos , Proteínas de Membrana/imunologia , Linfócitos T/imunologia
9.
J Immunol ; 209(3): 535-547, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35851540

RESUMO

Upon recognition of aberrantly located DNA, the innate immune sensor cyclic GMP-AMP synthase (cGAS) activates stimulator of IFN genes (STING)/IFN regulatory factor (IRF)3-driven antiviral responses. In this study, we characterized the ability of a specific variant of the human cGAS-encoding gene MB21D1, rs610913, to alter cGAS-mediated DNA sensing and viral infection. rs610913 is a frequent G>T polymorphism resulting in a P261H exchange in the cGAS protein. Data from the International Collaboration for the Genomics of HIV suggested that rs610913 nominally associates with HIV-1 acquisition in vivo. Molecular modeling of cGAS(P261H) hinted toward the possibility for an additional binding site for a potential cellular cofactor in cGAS dimers. However, cGAS(wild-type [WT]) or cGAS(P261H)-reconstituted THP-1 cGAS knockout cells shared steady-state expression of IFN-stimulated genes, as opposed to cells expressing the enzymatically inactive cGAS(G212A/S213A). Accordingly, cGAS(WT) and cGAS(P261H) cells were less susceptible to lentiviral transduction and infection with HIV-1, HSV-1, and Chikungunya virus as compared with cGAS knockout or cGAS(G212A/S213A) cells. Upon DNA challenge, innate immune activation appeared to be mildly reduced upon expression of cGAS(P261H) compared with cGAS(WT). Finally, DNA challenge of PBMCs from donors homozygously expressing rs610913 provoked a trend toward a slightly reduced type I IFN response as compared with PBMCs from GG donors. Taken together, the steady-state activity of cGAS maintains a baseline antiviral state rendering cells more refractory to IFN-stimulated gene-sensitive viral infections. rs610913 failed to grossly differ phenotypically from the WT gene, suggesting that cGAS(P261H) and WT cGAS share a similar ability to sense viral infections in vivo.


Assuntos
Imunidade Inata , Viroses , Humanos , DNA Viral/imunologia , Imunidade Inata/genética , Imunidade Inata/imunologia , Nucleotidiltransferases/genética , Nucleotidiltransferases/imunologia , Nucleotidiltransferases/metabolismo , Transdução de Sinais , Viroses/genética , Viroses/imunologia , Viroses/prevenção & controle
10.
EMBO J ; 41(14): e109217, 2022 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-35670106

RESUMO

Varicella-Zoster virus (VZV) causes chickenpox and shingles. Although the infection is associated with severe morbidity in some individuals, molecular mechanisms that determine innate immune responses remain poorly defined. We found that the cGAS/STING DNA sensing pathway was required for type I interferon (IFN) induction during VZV infection and that recognition of VZV by cGAS restricted its replication. Screening of a VZV ORF expression library identified the essential VZV tegument protein ORF9 as a cGAS antagonist. Ectopically or virally expressed ORF9 bound to endogenous cGAS leading to reduced type I IFN responses to transfected DNA. Confocal microscopy revealed co-localisation of cGAS and ORF9. ORF9 and cGAS also interacted directly in a cell-free system and phase-separated together with DNA. Furthermore, ORF9 inhibited cGAMP production by cGAS. Taken together, these results reveal the importance of the cGAS/STING DNA sensing pathway for VZV recognition and identify a VZV immune antagonist that partially but directly interferes with DNA sensing via cGAS.


Assuntos
Herpesvirus Humano 3 , Interferon Tipo I , Nucleotidiltransferases , Proteínas Virais , DNA/metabolismo , Herpesvirus Humano 3/genética , Herpesvirus Humano 3/imunologia , Humanos , Imunidade Inata , Interferon Tipo I/imunologia , Proteínas de Membrana/imunologia , Nucleotidiltransferases/antagonistas & inibidores , Nucleotidiltransferases/imunologia , Proteínas Virais/imunologia
11.
PLoS Pathog ; 18(2): e1010233, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35108342

RESUMO

Schistosomiasis, which is caused by infection with Schistosoma spp., is characterized by granuloma and fibrosis in response to egg deposition. Pattern recognition receptors are important to sense invading Schistosoma, triggering an innate immune response, and subsequently shaping adaptive immunity. Cyclic GMP-AMP synthase (cGAS) was identified as a major cytosolic DNA sensor, which catalyzes the formation of cyclic GMP-AMP (cGAMP), a critical second messenger for the activation of the adaptor protein stimulator of interferon genes (STING). The engagement of STING by cGAMP leads to the activation of TANK-binding kinase 1 (TBK1), interferon regulatory factor 3 (IRF3), and the subsequent type I interferon (IFN) response. cGAS is suggested to regulate infectious diseases, autoimmune diseases, and cancer. However, the function of cGAS in helminth infection is unclear. In this study, we found that Cgas deficiency enhanced the survival of mice infected with S. japonicum markedly, without affecting the egg load in the liver. Consistently, Cgas deletion alleviated liver pathological impairment, reduced egg granuloma formation, and decreased fibrosis severity. In contrast, Sting deletion reduced the formation of egg granulomas markedly, but not liver fibrosis. Notably, Cgas or Sting deficiency reduced the production of IFNß drastically in mice infected with S. japonicum. Intriguingly, intravenous administration of recombinant IFNß exacerbated liver damage and promoted egg granuloma formation, without affecting liver fibrosis. Clodronate liposome-mediated depletion of macrophages indicated that macrophages are the major type of cells contributing to the induction of the type I IFN response during schistosome infection. Moreover, cGAS is important for type I IFN production and phosphorylation of TBK1 and IRF3 in response to stimulation with S. japonicum egg- or adult worm-derived DNA in macrophages. Our results clarified the immunomodulatory effect of cGAS in the regulation of liver granuloma formation during S. japonicum infection, involving sensing schistosome-derived DNA and producing type I IFN. Additionally, we showed that cGAS regulates liver fibrosis in a STING-type I-IFN-independent manner.


Assuntos
Interferon Tipo I/imunologia , Proteínas de Membrana/imunologia , Nucleotidiltransferases/imunologia , Esquistossomose Japônica/imunologia , Esquistossomose/imunologia , Esquistossomose/parasitologia , Animais , Feminino , Imunidade , Fator Regulador 3 de Interferon/metabolismo , Interferon Tipo I/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Nucleotidiltransferases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais
12.
Curr Opin Immunol ; 74: 183-189, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35149240

RESUMO

The cGAS-STING pathway plays a central role in the detection of DNA in the cytosol of mammalian cells and activation of immunity. Although the early evolutionary origin of this pathway in animals has been noted, its ancestral functions have remained elusive so far. We review here new findings in invertebrates establishing a role in sensing and signaling infection, triggering potent transcriptional responses, in addition to autophagy. Results from flies and moths/butterflies point to the importance of STING signaling in antiviral immunity in insects. The recent characterization of cGAS-like receptors in Drosophila reveals the plasticity of this family of pattern-recognition receptors, able to accommodate ligands different from DNA and to produce cyclic dinucleotides beyond 2'3'-cGAMP.


Assuntos
Borboletas , Proteínas de Membrana , Nucleotidiltransferases , Animais , Borboletas/imunologia , Humanos , Imunidade Inata , Proteínas de Membrana/imunologia , Nucleotidiltransferases/imunologia
13.
FASEB J ; 36(2): e22171, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35084749

RESUMO

Toxoplasma gondii is an opportunistic protozoan, which widely infects humans and other warm-blooded animals. The type I interferon (IFN) such as IFN-α/ß is involved in cGAS-STING signaling to resist T. gondii infection. We found in RAW264.7 cells, that T. gondii virulence factor TgROP18I , inhibited IFN-ß production through interacting with interferon regulatory factor 3 (IRF3). Besides, TgROP18I interacted with p62 and Tumor Necrotic Factor Receptor Associated Factor 6 (TRAF6), which resulted in the inhibition of TRAF6-p62 interaction, and phosphorylation of p62. Furthermore, TgROP18I restricted the recruitment of ubiquitin, p62 and microtubule-associated protein light chain 3 (LC3) to the parasitophorous vacuole membrane (PVM) in IFN-γ-stimulated murine cell line L929 cells. In IFN-γ-stimulated human cells, TgROP18I restricted the decoration of PVM with ubiquitin, p62, and LC3, and bound with TRAF2, TRAF6, and p62, respectively. As a result, TgROP18I led to a successful parasitic replication in murine and human cells. Collectively, our study revealed the function of TgROP18I in suppressing host type I interferon responses in T. gondii infection for parasitic immune escape.


Assuntos
Imunidade Inata/imunologia , Proteínas de Membrana/imunologia , Nucleotidiltransferases/imunologia , Transdução de Sinais/imunologia , Toxoplasma/imunologia , Animais , Células COS , Linhagem Celular , Chlorocebus aethiops , Células HEK293 , Humanos , Fator Regulador 3 de Interferon/imunologia , Interferon Tipo I/imunologia , Interferon gama/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Camundongos , Fosforilação/imunologia , Células RAW 264.7 , Fatores de Virulência/imunologia
14.
Front Immunol ; 13: 1010764, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36591278

RESUMO

Introduction: Type I interferon (IFN) plays a vital role in the pathogenesis of systemic lupus erythematosus. Cyclic GMP AMP synthase (cGAS) is a cytosolic DNA sensor that recognizes dsDNA and creates cGAMP to activate STING-mediated type I IFN production. The activation of STING induces lupus disease in Fcgr2b deficient mice through the differentiation of dendritic cells. In contrast, Cgas-deficient mice could be generated more autoantibody production and proteinuria in pristane-induced lupus (PIL). These data suggested that the other dsDNA sensors could be involved in lupus development mechanisms. Methods: This study aimed to identify the cGAS-mediated mechanisms contributing to lupus pathogenesis in PIL. The Cgas-deficient and WT mice were induced lupus disease with pristane and subsequently analyzed autoantibody, histopathology, and immunophenotypes. The lung tissues were analyzed with the expression profiles by RT-PCR and western blot. The bone marrow-derived macrophages were stimulated with inflammasome activators and observed pyroptosis. Results: The Cgas-/- mice developed more severe pulmonary hemorrhage and autoantibody production than WT mice. The activated dendritic cells, IFN-g-, and IL-17a-producing T helper cells, and infiltrated macrophages in the lung were detected in Cgas-/- mice higher than in WT mice. We observed an increase in expression of Aim2, Casp11, and Ifi16 in the lung and serum IL-1a but IL-1b in pristane-injected Cgas-/- mice. The rise of Caspase-11 in the lung of pristane-injected Cgas-/- mice suggested noncanonical inflammasome activation. The activation of AIM2 and NLRP3 inflammasomes in bone marrow-derived macrophages (BMDMs) enhanced the number of dead cells in Cgas-/- mice compared with WT mice. Activation of the inflammasome significantly induced pyroptosis in Cgas-/- BMDMs. The dsDNA level, but not mitochondrial DNA, increased dramatically in pristane-injected Cgas-/- mice suggesting the dsDNA could be a ligand activating inflammasomes. The cGAS agonist-induced BMDM activation in the Cgas-/- mice indicated that the activation of DNA sensors other than cGAS enhanced activated macrophages. Conclusion: These findings suggested that cGAS hampers the unusual noncanonical inflammasome activation through other DNA sensors.


Assuntos
Inflamassomos , Inflamação , Lúpus Eritematoso Sistêmico , Macrófagos , Nucleotidiltransferases , Animais , Camundongos , Autoanticorpos/genética , Autoanticorpos/imunologia , Modelos Animais de Doenças , DNA/genética , DNA/imunologia , Inflamassomos/genética , Inflamassomos/imunologia , Inflamação/genética , Inflamação/imunologia , Lúpus Eritematoso Sistêmico/induzido quimicamente , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/imunologia , Macrófagos/imunologia , Nucleotidiltransferases/deficiência , Nucleotidiltransferases/genética , Nucleotidiltransferases/imunologia
15.
ChemMedChem ; 17(2): e202100671, 2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-34807508

RESUMO

The cGAS-STING pathway discovered ten years ago is an important component of the innate immune system. Activation of cGAS-STING triggers downstream signalling, such as TBK1-IRF3, NF-κB and autophagy, which in turn leads to antipathogen responses, durable antitumour immunity or autoimmune diseases. 2',3'-Cyclic GMP-AMP dinucleotides (2',3'-cGAMP), the key second messengers produced by cGAS, play a pivotal role in cGAS-STING signalling by binding and activating STING. Thus, 2',3'-cGAMP has immunotherapeutic potential, which in turn has stimulated research on the design and synthesis of 2',3'-cGAMP analogues for clinical applications over the past ten years. This review presents the discovery, metabolism, and function of 2',3'-cGAMP in the cGAS-STING innate immune signalling axis. The enzymatic and chemical syntheses of 2',3'-cGAMP analogues as STING-targeting therapeutics are also summarized.


Assuntos
Imunoterapia , Proteínas de Membrana/antagonistas & inibidores , Neoplasias/terapia , Nucleotídeos Cíclicos/farmacologia , Nucleotídeos/farmacologia , Nucleotidiltransferases/antagonistas & inibidores , Humanos , Proteínas de Membrana/imunologia , Modelos Moleculares , Conformação Molecular , Neoplasias/imunologia , Nucleotídeos/síntese química , Nucleotídeos/química , Nucleotídeos Cíclicos/síntese química , Nucleotídeos Cíclicos/química , Nucleotidiltransferases/imunologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia
16.
Protein Cell ; 13(2): 90-101, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34374004

RESUMO

The cyclic GMP-AMP (cGAMP) synthase (cGAS) has been identified as a cytosolic double stranded DNA sensor that plays a pivotal role in the type I interferon and inflammation responses via the STING-dependent signaling pathway. In the past several years, a growing body of evidence has revealed that cGAS is also localized in the nucleus where it is associated with distinct nuclear substructures such as nucleosomes, DNA replication forks, the double-stranded breaks, and centromeres, suggesting that cGAS may have other functions in addition to its role in DNA sensing. However, while the innate immune function of cGAS is well established, the non-canonical nuclear function of cGAS remains poorly understood. Here, we review our current understanding of the complex nature of nuclear cGAS and point to open questions on the novel roles and the mechanisms of action of this protein as a key regulator of cell nuclear function, beyond its well-established role in dsDNA sensing and innate immune response.


Assuntos
Núcleo Celular/imunologia , Imunidade Inata , Nucleotidiltransferases/imunologia , Transdução de Sinais/imunologia , Núcleo Celular/genética , Humanos , Nucleotidiltransferases/genética , Transdução de Sinais/genética
17.
Front Immunol ; 12: 741599, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34899698

RESUMO

cGAS, a DNA sensor in mammalian cells, catalyzes the generation of 2'-3'-cyclic AMP-GMP (cGAMP) once activated by the binding of free DNA. cGAMP can bind to STING, activating downstream TBK1-IRF-3 signaling to initiate the expression of type I interferons. Although cGAS has been considered a traditional DNA-binding protein, several lines of evidence suggest that cGAS is a potential RNA-binding protein (RBP), which is mainly supported by its interactions with RNAs, RBP partners, RNA/cGAS-phase-separations as well as its structural similarity with the dsRNA recognition receptor 2'-5' oligoadenylate synthase. Moreover, two influential studies reported that the cGAS-like receptors (cGLRs) of fly Drosophila melanogaster sense RNA and control 3'-2'-cGAMP signaling. In this review, we summarize and discuss in depth recent studies that identified or implied cGAS as an RBP. We also comprehensively summarized current experimental methods and computational tools that can identify or predict RNAs that bind to cGAS. Based on these discussions, we appeal that the RNA-binding activity of cGAS cannot be ignored in the cGAS-mediated innate antiviral response. It will be important to identify RNAs that can bind and regulate the activity of cGAS in cells with or without virus infection. Our review provides novel insight into the regulation of cGAS by its RNA-binding activity and extends beyond its DNA-binding activity. Our review would be significant for understanding the precise modulation of cGAS activity, providing the foundation for the future development of drugs against cGAS-triggering autoimmune diseases such as Aicardi-Gourtières syndrome.


Assuntos
Imunidade Inata/fisiologia , Nucleotidiltransferases/imunologia , Proteínas de Ligação a RNA/imunologia , Viroses/imunologia , Animais , Humanos
18.
Front Immunol ; 12: 781032, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34858438

RESUMO

The activation of stimulator of interferon genes (STING) signalling pathway has been suggested to promote the immune responses against malignancy. STING is activated in response to the detection of cytosolic DNA and can induce type I interferons and link innate immunity with the adaptive immune system. Due to accretive evidence demonstrating that the STING pathway regulates the immune cells of the tumor microenvironment (TME), STING as a cancer biotherapy has attracted considerable attention. Pancreatic cancer, with a highly immunosuppressive TME, remains fatal cancer. STING has been applied to the treatment of pancreatic cancer through distinct strategies. This review reveals the role of STING signalling on pancreatic tumors and other diseases related to the pancreas. We then discuss new advances of STING in either monotherapy or combination methods for pancreatic cancer immunotherapy.


Assuntos
Imunoterapia/métodos , Proteínas de Membrana/imunologia , Nucleotidiltransferases/imunologia , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/terapia , Humanos , Transdução de Sinais/imunologia
19.
Front Immunol ; 12: 771744, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34868032

RESUMO

Alternative splicing of pre-mRNA increases transcriptome and proteome diversity by generating distinct isoforms that encode functionally diverse proteins, thus affecting many biological processes, including innate immunity. cGAS-STING signaling pathway, whose key molecules also undergo alternative splicing, plays a crucial role in regulating innate immunity. Protein isoforms of key components in the cGAS-STING-TBK1-IRF3 axis have been detected in a variety of species. A chain of evidence showed that these protein isoforms exhibit distinct functions compared to their normal counterparts. The mentioned isoforms act as positive or negative modulators in interferon response via distinct mechanisms. Particularly, we highlight that alternative splicing serves a vital function for the host to avoid the overactivation of the cGAS-STING signaling pathway and that viruses can utilize alternative splicing to resist antiviral response by the host. These findings could provide insights for potential alternative splicing-targeting therapeutic applications.


Assuntos
Lúpus Eritematoso Sistêmico/genética , Proteínas de Membrana/genética , Neoplasias/genética , Nucleotidiltransferases/genética , Viroses/genética , Processamento Alternativo , Animais , Humanos , Lúpus Eritematoso Sistêmico/imunologia , Proteínas de Membrana/imunologia , Neoplasias/imunologia , Nucleotidiltransferases/imunologia , Transdução de Sinais , Viroses/imunologia
20.
Front Immunol ; 12: 795048, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34956229

RESUMO

With the continuous development of immunotherapy, researchers have paid more attention to the specific immune regulatory mechanisms of various immune responses in different diseases. As a novel and vital innate immune signal pathway, the cGAS-STING signal pathway activated by nucleic acid substances, interplays with other immune responses, by which it participates in regulating cancer, autoimmune and inflammatory diseases, microbial and parasitic infectious diseases, and other diseases. With the exception of its role in innate immunity, the growing list of researches demonstrated expanding roles of the cGAS-STING signal pathway in bridging the innate immunity (macrophage polarization) with the adaptive immunity (T lymphocytes differentiation). Macrophages and T lymphocytes are the most representative cells of innate immunity and adaptive immunity, respectively. Their polarization or differentiation are involved in the pathogenesis and progression of various diseases. Here we mainly summarized recent advanced discoveries of how the cGAS-STING signal pathway regulated macrophages polarization and T lymphocytes differentiation in various diseases and vaccine applications, providing a promising direction for the development and clinical application of immunotherapeutic strategies for related diseases.


Assuntos
Imunoterapia/métodos , Proteínas de Membrana/imunologia , Neoplasias/imunologia , Nucleotidiltransferases/imunologia , Animais , Antineoplásicos/farmacologia , Humanos , Proteínas de Membrana/agonistas , Neoplasias/terapia
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