RESUMO
Ubiquitin-specific peptidase 25 (USP25) is one of the best-characterized deubiquitinating enzymes and plays a vital regulatory role in various biological processes, especially in cancer development and immune regulation. However, the exact role of USP25 and its underlying mechanisms in macrophage activation and immunogenicity during Mycobacterium tuberculosis infection remain unclear. In this study, we found that M tuberculosis infection induced USP25 expression in human and mouse macrophages. In particular, USP25 expression is elevated in multiple cell types, especially monocytes, in patients with tuberculosis. Additionally, USP25 deficiency in macrophages and mice resulted in compromised immunity against M tuberculosis infection, accompanied by reduced expressions of various proinflammatory cytokines and chemokines. Mechanistically, USP25 in macrophages promoted the activation of the ERK signaling pathway through deubiquitination and stabilization of B-Raf and C-Raf. These findings collectively suggest the critical roles of USP25 in M tuberculosis infection and its potential as a therapeutic target.
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Autoreactive CD4+ T helper cells are critical players that orchestrate the immune response both in multiple sclerosis (MS) and in other neuroinflammatory autoimmune diseases. Ubiquitination is a posttranslational protein modification involved in regulating a variety of cellular processes, including CD4+ T cell differentiation and function. However, only a limited number of E3 ubiquitin ligases have been characterized in terms of their biological functions, particularly in CD4+ T cell differentiation and function. In this study, we found that the RING finger protein 213 (RNF213) specifically promoted regulatory T (Treg) cell differentiation in CD4+ T cells and attenuated autoimmune disease development in an FOXO1-dependent manner. Mechanistically, RNF213 interacts with Forkhead Box Protein O1 (FOXO1) and promotes nuclear translocation of FOXO1 by K63-linked ubiquitination. Notably, RNF213 expression in CD4+ T cells was induced by IFN-ß and exerts a crucial role in the therapeutic efficacy of IFN-ß for MS. Together, our study findings collectively emphasize the pivotal role of RNF213 in modulating adaptive immune responses. RNF213 holds potential as a promising therapeutic target for addressing disorders associated with Treg cells.
Assuntos
Diferenciação Celular , Proteína Forkhead Box O1 , Interferon beta , Linfócitos T Reguladores , Ubiquitina-Proteína Ligases , Ubiquitinação , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Animais , Proteína Forkhead Box O1/metabolismo , Proteína Forkhead Box O1/genética , Camundongos , Humanos , Interferon beta/metabolismo , Camundongos Endogâmicos C57BL , Núcleo Celular/metabolismo , Esclerose Múltipla/imunologia , Esclerose Múltipla/metabolismo , Esclerose Múltipla/genética , Esclerose Múltipla/patologia , Transporte Ativo do Núcleo Celular , Feminino , Camundongos Knockout , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Encefalomielite Autoimune Experimental/genética , Células HEK293RESUMO
[This corrects the article DOI: 10.1371/journal.ppat.1011480.].
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Ubiquitination is an important protein modification that regulates diverse biological processes, including CD4+ T cell differentiation and functions. However, the function of most E3 ubiquitin ligases in CD4+ T cell differentiation and CD4+ T cell-mediated pathological diseases remains unclear. In this study, we find that tripartite motif-containing motif 11 (TRIM11) specifically negatively regulates regulatory T (Treg) cell differentiation in CD4+ T cells and promotes autoimmune disease development in an AIM2-dependent manner. Mechanistically, TRIM11 interacts with absent in melanoma 2 (AIM2) and promotes the selective autophagic degradation of AIM2 by inducing AIM2 ubiquitination and binding to p62 in CD4+ T cells. AIM2 attenuates AKT and FOXO1 phosphorylation, MYC signaling, and glycolysis, thereby promoting the stability of Treg cells during experimental autoimmune encephalomyelitis (EAE). Our findings suggest that TRIM11 serves as a potential target for immunotherapeutic intervention for dysregulated immune responses that lead to autoimmunity and cancers.
Assuntos
Encefalomielite Autoimune Experimental , Melanoma , Linfócitos T Reguladores , Animais , Diferenciação Celular , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transdução de Sinais/fisiologia , Linfócitos T Reguladores/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteína Sequestossoma-1/metabolismo , Autofagia/genética , Autofagia/fisiologiaRESUMO
Deubiquitinating enzymes (DUBs) regulate antiviral immune response through targeting DNA sensor signaling pathway members. As one of the DNA sensors, interferon (IFN)-γ inducible protein 16 (IFI16) play a major role in response to virus infections through activating the canonical STING/TBK-1/IRF3 signaling pathway. Only a few studies discuss the function of DUBs in IFI16-mediated antiviral response. Ubiquitin-specific protease 12 (USP12), which is one of the major members of the USP family, participates in various biological functions. However, whether USP12 regulates the nucleic acid sensor to modulate antiviral immune responses has not yet been elucidated. In this study, we found that knockout or knockdown of USP12 impaired the HSV-1-induced expressions of IFN-ß, CCL-5, IL-6, and downstream interferon-stimulated genes (ISGs). Moreover, USP12 deficiency increased HSV-1 replication and host susceptibility to HSV-1 infection. Mechanistically, USP12 inhibited the proteasome-dependent degradation of IFI16 through its deubiquitinase activity, thereby maintaining IFI16 stability and promoting IFI16-STING-IRF3- and p65-mediated antiviral signaling. Overall, our findings demonstrate an essential role of USP12 in DNA-sensing signaling and contribute to the understanding of deubiquitination-mediated regulation of innate antiviral responses.
Assuntos
Herpes Simples , Herpesvirus Humano 1 , Humanos , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Herpesvirus Humano 1/fisiologia , Interferons/metabolismo , Antivirais/metabolismo , Imunidade Inata , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismoRESUMO
Background: CD4+ T cells play an important role in body development and homeostasis. Quantitative and functional changes in CD4+ T cells result in abnormal immune responses, which lead to inflammation, cancer, or autoimmune diseases, such as multiple sclerosis (MS). Ubiquitination plays an essential role in the differentiation and functioning of CD4+ T cells. However, the function of several E3 ubiquitin ligases in CD4+ T cell differentiation and T cell-mediated pathological diseases remains unclear. Methods: RNA sequencing data were analyzed to identify the E3 ubiquitin ligases that participate in the pathogenesis of MS. Furthermore, conditional knockout mice were generated. Specifically, flow cytometry, qPCR, western blot, CO-IP and cell transfer adoptive experiments were performed. Results: In this study, we identified The RING finger 157 (RNF157) as a vital regulator of CD4+ T cell differentiation; it promoted Th1 differentiation but attenuated Th17 differentiation and CCR4 and CXCR3 expressions in CD4+ T cells, thereby limiting experimental autoimmune encephalomyelitis development. Mechanistically, RNF157 in CD4+ T cells targeted HDAC1 for K48-linked ubiquitination and degradation. Notably, RNF157 expression was significantly decreased and showed a significant negative correlation with RORγt expression in patients with MS. Conclusions: Our study highlights the critical role of RNF157 in regulating CD4+ T cell functions in autoimmune diseases and suggests RNF157 as a potential target in adaptive immune responses against MS and other autoimmune disorders.
Assuntos
Encefalomielite Autoimune Experimental , Esclerose Múltipla , Camundongos , Animais , Autoimunidade , Ubiquitinação , Encefalomielite Autoimune Experimental/metabolismo , Esclerose Múltipla/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Diferenciação Celular , Camundongos Knockout , Linfócitos T CD4-Positivos , Ubiquitinas/metabolismo , Camundongos Endogâmicos C57BLRESUMO
Innate immune signaling in macrophages during viral infection is regulated by ISGylation, the covalent attachment of the ubiquitin-like protein interferon-stimulated gene 15 (ISG15) to protein targets. Here, we explored the role of ISGylation in the macrophage response to infection with Mycobacterium tuberculosis. In human and mouse macrophages, the E3 ubiquitin ligases HERC5 and mHERC6, respectively, mediated the ISGylation of the phosphatase PTEN, which promoted its degradation. The decreased abundance of PTEN led to an increase in the activity of the PI3K-AKT signaling pathway, which stimulated the synthesis of proinflammatory cytokines. Bacterial growth was increased in culture and in vivo when human or mouse macrophages were deficient in the major E3 ISG15 ligase. The findings expand the role of ISGylation in macrophages to antibacterial immunity and suggest that HERC5 signaling may be a candidate target for adjunct host-directed therapy in patients with tuberculosis.
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Fosfatidilinositol 3-Quinases , Ubiquitina-Proteína Ligases , Animais , Humanos , Camundongos , Antibacterianos , Citocinas/metabolismo , Interferons , Peptídeos e Proteínas de Sinalização Intracelular/genética , PTEN Fosfo-Hidrolase/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinas/metabolismoRESUMO
The balance between inflammatory T helper type 17 (Th17) and immunosuppressive regulatory T (Treg) cells is critical for maintaining immune homeostasis in the human body and is tightly regulated under healthy conditions. An increasing number of studies have reported that deubiquitinases (DUBs) play a vital role in regulating Th17- and Treg-cell differentiation. However, the biological functions of only a small fraction of DUBs in Th17- and Treg-cell differentiation are well defined. In this study, we identified ubiquitin-specific peptidase 1 (USP1) as a vital regulator of CD4+ T-cell differentiation. USP1 promoted Th17-cell differentiation but attenuated Treg-cell differentiation, thereby promoting the development of inflammatory diseases. Mechanistically, USP1 in CD4+ T cells enhanced the activity of RORγt but promoted the proteasomal degradation of Foxp3 through deubiquitination and stabilization of TAZ in vitro and in vivo. Notably, ML323, a specific inhibitor of the USP1/UAF1 deubiquitinase complex, inhibited Th17-cell differentiation and promoted Treg-cell differentiation in vitro and in vivo, indicating that ML323 might be a promising candidate for the treatment of diseases associated with an imbalance between Th17 and Treg cells. Our study highlights the critical role of USP1 in regulating adaptive immune responses and suggests that USP1 might be a drug target for the treatment of diseases associated with an imbalance between Th17 and Treg cells.
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Linfócitos T Reguladores , Células Th17 , Humanos , Diferenciação Celular , Fatores de Transcrição , Proteases Específicas de UbiquitinaRESUMO
The relative abundance of myeloid-derived suppressor cells (MDSCs) compared to cytotoxic T cells determines the outcomes of diseases and the efficacy of immunotherapy. Ubiquitin-specific peptidase 12 (USP12), a member of the USP family of deubiquitinases, targets multiple signalling pathways and regulates diverse biological processes, including cell proliferation and survival. It is well known that ubiquitylation is an important mechanism for regulating the immune response. However, it is unclear whether USP12 regulates tumour growth by influencing MDSCs. In the present study, we reported that USP12 deficiency decreased infiltration and impaired the suppressor function of monocytic (M)-MDSCs, resulting in increased CD8+ T-cell response and decelerated tumour growth. USP12-knockout M-MDSCs were less potent in inhibiting the proliferation of CD8+ T cells and their ability to secrete IFN-γ. Furthermore, USP12 deficiency inhibited the suppressor function of M-MDSCs by downregulating the negative regulatory molecules inducible nitric oxide synthase and PD-L1, through deubiquitinating and stabilizing p65. Our results suggest that USP12 is a positive regulator of M-MDSCs and may serve as a potential target for antitumor therapy.
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Células Supressoras Mieloides , Neoplasias , Humanos , Linfócitos T CD8-Positivos , Transdução de Sinais , Proliferação de Células , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/metabolismoRESUMO
Chronic inflammation develops when the immune system is unable to clear a persistent insult. Unresolved chronic inflammation leads to immunosuppression to maintain the internal homeostatic conditions, which is mediated primarily by myeloid-derived suppressor cells (MDSCs). Toll-like receptors 2 (TLR2) has an important role in chronic inflammation and can be activated by a vast number and diversity of TLR2 ligands, for example Pam2CSK4. However, the regulatory effect of TLR2 signaling on MDSCs in chronic inflammation remains controversial. This study demonstrated that heat-killed Mycobacterium bovis BCG-induced pathology-free chronic inflammation triggered suppressive monocytic MDSCs (M-MDSCs) that expressed TLR2. Activation of TLR2 signaling by Pam2CSK4 treatment enhanced immunosuppression of M-MDSCs by upregulating inducible nitric oxide synthase (iNOS) activity and nitric oxide (NO) production partly through signal transducer and activator of transcription 3 (STAT3) activation. Thus, TLR2 has a fundamental role in promoting the MDSC-mediated immunosuppressive environment during chronic inflammation and might represent a potentially therapeutic target in chronic inflammation disease.
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BACKGROUND: As deubiquitinases (DUBs), ubiquitin C-terminal hydrolase (UCH)-L1 has been shown to play a crucial role in regulating diverse biological processes. However, its function in macrophage polarization remains unclear. METHODS: We performed in vivo and in vitro experiments to investigate the role of ubiquitin carboxyl-terminal hydrolase L1 (UCHL1), a kind of DUBs, in macrophage differentiation by using UCHL1-deficiency mice. RESULTS: We demonstrated that LPS stimulation induced UCHL1 expression in macrophages. The deficiency of UCHL1 expression decreased the expression of CD80 and CD86 but increased the expression of CD206. The expression of TNF-α, IL-6, iNOS, and IL-10 was downregulated, while that of Arg1, Ym1, and Fizz1 was upregulated in UCHL1 deficient macrophages. Moreover, we observed that UCHL1 promoted the degradation of p110α through autophagy, but paradoxically increased the activity of AKT, thereby promoting polarization of macrophages into pro-inflammatory states. CONCLUSION: In this study, we identified UCHL1 as a positive regulator of M1 macrophage polarization. Our findings may help in developing therapeutic interventions for the treatment of inflammatory diseases and pathogenic infections.
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Deubiquitinases (DUBs) regulate diverse biological processes and represent a novel class of drug targets. However, the biological function of only a small fraction of DUBs, especially in adaptive immune response regulation, is well-defined. In this study, we identified DUB ubiquitin-specific peptidase 12 (USP12) as a critical regulator of CD4+ T cell activation. USP12 plays an intrinsic role in promoting the CD4+ T cell phenotype, including differentiation, activation, and proliferation. Although USP12-deficient CD4+ T cells protected mice from autoimmune diseases, the immune response against bacterial infection was subdued. USP12 stabilized B cell lymphoma/leukemia 10 (BCL10) by deubiquitinating, and thereby activated the NF-κB signaling pathway. Interestingly, this USP12 regulatory mechanism was identified in CD4+ T cells, but not in CD8+ T cells. Our study results showed that USP12 activated CD4+ T cell signaling, and targeting USP12 might help develop therapeutic interventions for treating inflammatory diseases or pathogen infections.