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Diez AF, Leroux LP, Chagneau S, Plouffe A, Gold M, Chaparro V, Jaramillo M. Toxoplasma gondii inhibits the expression of autophagy-related genes through AKT-dependent inactivation of the transcription factor FOXO3a. mBio 2023; 14:e0079523. [PMID: 37387601 PMCID: PMC10470550 DOI: 10.1128/mbio.00795-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 05/15/2023] [Indexed: 07/01/2023] Open
Abstract
The intracellular parasite Toxoplasma gondii induces host AKT activation to prevent autophagy-mediated clearance; however, the molecular underpinnings are not fully understood. Autophagy can be negatively regulated through AKT-sensitive phosphorylation and nuclear export of the transcription factor Forkhead box O3a (FOXO3a). Using a combination of pharmacological and genetic approaches, herein we investigated whether T. gondii hinders host autophagy through AKT-dependent inactivation of FOXO3a. We found that infection by type I and II strains of T. gondii promotes gradual and sustained AKT-dependent phosphorylation of FOXO3a at residues S253 and T32 in human foreskin fibroblasts (HFF) and murine 3T3 fibroblasts. Mechanistically, AKT-sensitive phosphorylation of FOXO3a by T. gondii required live infection and the activity of PI3K but was independent of the plasma membrane receptor EGFR and the kinase PKCα. Phosphorylation of FOXO3a at AKT-sensitive residues was paralleled by its nuclear exclusion in T. gondii-infected HFF. Importantly, the parasite was unable to drive cytoplasmic localization of FOXO3a upon pharmacological blockade of AKT or overexpression of an AKT-insensitive mutant form of FOXO3a. Transcription of a subset of bona fide autophagy-related targets of FOXO3a was reduced during T. gondii infection in an AKT-dependent fashion. However, parasite-directed repression of autophagy-related genes was AKT-resistant in cells deficient in FOXO3a. Consistent with this, T. gondii failed to inhibit the recruitment of acidic organelles and LC3, an autophagy marker, to the parasitophorous vacuole upon chemically or genetically induced nuclear retention of FOXO3a. In all, we provide evidence that T. gondii suppresses FOXO3a-regulated transcriptional programs to prevent autophagy-mediated killing. IMPORTANCE The parasite Toxoplasma gondii is the etiological agent of toxoplasmosis, an opportunistic infection commonly transmitted by ingestion of contaminated food or water. To date, no effective vaccines in humans have been developed and no promising drugs are available to treat chronic infection or prevent congenital infection. T. gondii targets numerous host cell processes to establish a favorable replicative niche. Of note, T. gondii activates the host AKT signaling pathway to prevent autophagy-mediated killing. Herein, we report that T. gondii inhibits FOXO3a, a transcription factor that regulates the expression of autophagy-related genes, through AKT-dependent phosphorylation. The parasite's ability to block the recruitment of the autophagy machinery to the parasitophorous vacuole is impeded upon pharmacological inhibition of AKT or overexpression of an AKT-insensitive form of FOXO3a. Thus, our study provides greater granularity in the role of FOXO3a during infection and reinforces the potential of targeting autophagy as a therapeutic strategy against T. gondii.
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Affiliation(s)
- Andres Felipe Diez
- Institut National de la Recherche Scientifique (INRS)—Centre Armand-Frappier Santé Biotechnologie (AFSB), Laval, Québec, Canada
| | - Louis-Philippe Leroux
- Institut National de la Recherche Scientifique (INRS)—Centre Armand-Frappier Santé Biotechnologie (AFSB), Laval, Québec, Canada
| | - Sophie Chagneau
- Institut National de la Recherche Scientifique (INRS)—Centre Armand-Frappier Santé Biotechnologie (AFSB), Laval, Québec, Canada
| | - Alexandra Plouffe
- Institut National de la Recherche Scientifique (INRS)—Centre Armand-Frappier Santé Biotechnologie (AFSB), Laval, Québec, Canada
| | - Mackenzie Gold
- Institut National de la Recherche Scientifique (INRS)—Centre Armand-Frappier Santé Biotechnologie (AFSB), Laval, Québec, Canada
| | - Visnu Chaparro
- Institut National de la Recherche Scientifique (INRS)—Centre Armand-Frappier Santé Biotechnologie (AFSB), Laval, Québec, Canada
| | - Maritza Jaramillo
- Institut National de la Recherche Scientifique (INRS)—Centre Armand-Frappier Santé Biotechnologie (AFSB), Laval, Québec, Canada
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Du Y, Hu Z, Luo Y, Wang HY, Yu X, Wang RF. Function and regulation of cGAS-STING signaling in infectious diseases. Front Immunol 2023; 14:1130423. [PMID: 36825026 PMCID: PMC9941744 DOI: 10.3389/fimmu.2023.1130423] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 01/24/2023] [Indexed: 02/10/2023] Open
Abstract
The efficacious detection of pathogens and prompt induction of innate immune signaling serve as a crucial component of immune defense against infectious pathogens. Over the past decade, DNA-sensing receptor cyclic GMP-AMP synthase (cGAS) and its downstream signaling adaptor stimulator of interferon genes (STING) have emerged as key mediators of type I interferon (IFN) and nuclear factor-κB (NF-κB) responses in health and infection diseases. Moreover, both cGAS-STING pathway and pathogens have developed delicate strategies to resist each other for their survival. The mechanistic and functional comprehension of the interplay between cGAS-STING pathway and pathogens is opening the way for the development and application of pharmacological agonists and antagonists in the treatment of infectious diseases. Here, we briefly review the current knowledge of DNA sensing through the cGAS-STING pathway, and emphatically highlight the potent undertaking of cGAS-STING signaling pathway in the host against infectious pathogenic organisms.
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Affiliation(s)
- Yang Du
- Department of Medicine, and Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Research Center of Medical Sciences, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, China
| | - Zhiqiang Hu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Yien Luo
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, China
| | - Helen Y. Wang
- Department of Medicine, and Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Department of Pediatrics, Children’s Hospital, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Xiao Yu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Lab of Single Cell Technology and Application, Southern Medical University, Guangzhou, Guangdong, China
| | - Rong-Fu Wang
- Department of Medicine, and Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Department of Pediatrics, Children’s Hospital, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
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Expression and Localization of Fas-Associated Factor 1 in Testicular Tissues of Different Ages and Ovaries at Different Reproductive Cycle Phases of Bos grunniens. Animals (Basel) 2023; 13:ani13030340. [PMID: 36766229 PMCID: PMC9913830 DOI: 10.3390/ani13030340] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023] Open
Abstract
Fas-associated factor 1 (FAF1), a member of the Fas family, is involved in biological processes such as apoptosis, inflammation, cell proliferation and proteostasis. This study aimed to explore the biological role of FAF1 in testicular tissue at different ages (juveniles (1 and 2 years old), adults (3, 4, 6, and 7 years old) and old-aged animals (11 years old)) and ovaries during different reproductive cycle phases (follicular, luteal, and pregnancy phases). FAF1 mRNA, relative protein expression and protein expression localization were determined in testes and ovaries using real-time quantification, WB and immunohistochemistry (IHC), respectively. Real-time quantification of testis tissues showed that the relative expression of FAF1 mRNA in testis tissues at 3, 4 and 7 years of age was significantly higher than of those in other ages, and in ovarian tissues was significantly higher in luteal phase ovaries than those in follicular and pregnancy phase ovaries; follicular phase ovaries were the lowest. WB of testis tissues showed that the relative protein expression of FAF1 protein was significantly higher at 11 and 7 years of age; in ovarian tissue, the relative protein expression of FAF1 protein was significantly higher in follicular phase ovaries than in luteal and pregnancy phase ovaries, and lowest in luteal phase ovaries. The relative protein expression of FAF1 at 3, 4 and 7 years of age was the lowest. IHC showed that FAF1 was mainly expressed in spermatozoa, spermatocytes, spermatogonia and supporting cells; in ovarian tissue, FAF1 was expressed in ovarian germ epithelial cells, granulosa cells, cumulus cells and luteal cells. The IHC results showed that FAF1 mRNA and protein were significantly differentially expressed in testes of different ages and ovarian tissues of different reproductive cycle phases, revealing the significance of FAF1 in the regulation of male and female B. grunniens reproductive physiology. Furthermore, our results provide a basis for the further exploration of FAF1 in the reproductive physiology of B. grunniens.
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Abstract
Innate immunity acts as the first line of defense against pathogen invasion. During Toxoplasma gondii infection, multiple innate immune sensors are activated by invading microbes or pathogen-associated molecular patterns (PAMPs). However, how inflammasome is activated and its regulatory mechanisms during T. gondii infection remain elusive. Here, we showed that the infection of PRU, a lethal type II T. gondii strain, activates inflammasome at the early stage of infection. PRU tachyzoites, RNA and soluble tachyzoite antigen (STAg) mainly triggered the NLRP3 inflammasome, while PRU genomic DNA (gDNA) specially activated the AIM2 inflammasome. Furthermore, mice deficient in AIM2, NLRP3, or caspase-1/11 were more susceptible to T. gondii PRU infection, and the ablation of inflammasome signaling impaired antitoxoplasmosis immune responses by enhancing type I interferon (IFN-I) production. Blockage of IFN-I receptor fulfilled inflammasome-deficient mice competent immune responses as WT mice. Moreover, we have identified that the suppressor of cytokine signaling 1 (SOCS1) is a key negative regulator induced by inflammasome-activated IL-1β signaling and inhibits IFN-I production by targeting interferon regulatory factor 3 (IRF3). In general, our study defines a novel protective role of inflammasome activation during toxoplasmosis and identifies a critical regulatory mechanism of the cross talk between inflammasome and IFN-I signaling for understanding infectious diseases. IMPORTANCE As a key component of innate immunity, inflammasome is critical for host antitoxoplasmosis immunity, but the underlying mechanisms are still elusive. In this study, we found that inflammasome signaling was activated by PAMPs of T. gondii, which generated a protective immunity against T. gondii invasion by suppressing type I interferon (IFN-I) production. Mechanically, inflammasome-coupled IL-1β signaling triggered the expression of negative regulator SOCS1, which bound to IRF3 to inhibit IFN-I production. The role of IFN-I in anti-T. gondii immunity is little studied and controversial, and here we also found IFN-I is harmful to host antitoxoplasmosis immunity by using knockout mice and recombinant proteins. In general, our study identifies a protective role of inflammasomes to the host during T. gondii infection and a novel mechanism by which inflammasome suppresses IFN-I signaling in antitoxoplasmosis immunity, which will likely provide new insights into therapeutic targets for toxoplasmosis and highlight the cross talk between innate immune signaling in infectious diseases prevention.
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Du F, Sun H, Sun F, Yang S, Tan H, Li X, Chai Y, Jiang Q, Han D. Knockdown of TANK-Binding Kinase 1 Enhances the Sensitivity of Hepatocellular Carcinoma Cells to Molecular-Targeted Drugs. Front Pharmacol 2022; 13:924523. [PMID: 35747750 PMCID: PMC9209752 DOI: 10.3389/fphar.2022.924523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 04/25/2022] [Indexed: 12/25/2022] Open
Abstract
The protein kinase, TANK-binding kinase 1 (TBK1), not only regulates various biological processes but also functions as an important regulator of human oncogenesis. However, the detailed function and molecular mechanisms of TBK1 in hepatocellular carcinoma (HCC), especially the resistance of HCC cells to molecular-targeted drugs, are almost unknown. In the present work, the role of TBK1 in regulating the sensitivity of HCC cells to molecular-targeted drugs was measured by multiple assays. The high expression of TBK1 was identified in HCC clinical specimens compared with paired non-tumor tissues. The high level of TBK1 in advanced HCC was associated with a poor prognosis in patients with advanced HCC who received the molecular-targeted drug, sorafenib, compared to patients with advanced HCC patients and a low level of TBK1. Overexpression of TBK1 in HCC cells induced their resistance to molecular-targeted drugs, whereas knockdown of TBK1 enhanced the cells’ sensitivity to molecular-targeted dugs. Regarding the mechanism, although overexpression of TBK1 enhanced expression levels of drug-resistance and pro-survival-/anti-apoptosis-related factors, knockdown of TBK1 repressed the expression of these factors in HCC cells. Therefore, TBK1 is a promising therapeutic target for HCC treatment and knockdown of TBK1 enhanced sensitivity of HCC cells to molecular-targeted drugs.
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Affiliation(s)
- Fengxia Du
- Department of Pharmacy, Medical Support Center of PLA General Hospital, Beijing, China
| | - Huiwei Sun
- Department of Infectious Diseases, Fifth Medical Center of Chinese PLA General Hospital, Institute of Infectious Diseases, Beijing, China
| | - Fang Sun
- Department of Infectious Diseases, Fifth Medical Center of Chinese PLA General Hospital, Institute of Infectious Diseases, Beijing, China
| | - Shiwei Yang
- Organ Transplant Center and Department of Hepatobiliary Surgery, China-Japan Friendship Hospital, Beijing, China
| | - Haidong Tan
- Organ Transplant Center and Department of Hepatobiliary Surgery, China-Japan Friendship Hospital, Beijing, China
| | - Xiaojuan Li
- Department of Infectious Diseases, Fifth Medical Center of Chinese PLA General Hospital, Institute of Infectious Diseases, Beijing, China
| | - Yantao Chai
- Department of Infectious Diseases, Fifth Medical Center of Chinese PLA General Hospital, Institute of Infectious Diseases, Beijing, China
| | - Qiyu Jiang
- Department of Infectious Diseases, Fifth Medical Center of Chinese PLA General Hospital, Institute of Infectious Diseases, Beijing, China
- *Correspondence: Dongdong Han, ; Qiyu Jiang,
| | - Dongdong Han
- Organ Transplant Center and Department of Hepatobiliary Surgery, China-Japan Friendship Hospital, Beijing, China
- *Correspondence: Dongdong Han, ; Qiyu Jiang,
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Gao FF, Quan JH, Choi IW, Lee YJ, Jang SG, Yuk JM, Lee YH, Cha GH. FAF1 downregulation by Toxoplasma gondii enables host IRF3 mobilization and promotes parasite growth. J Cell Mol Med 2021; 25:9460-9472. [PMID: 34464509 PMCID: PMC8500981 DOI: 10.1111/jcmm.16889] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 07/30/2021] [Accepted: 08/09/2021] [Indexed: 01/27/2023] Open
Abstract
Fas‐associated factor 1 (FAF1) has gained a reputation as a member of the FAS death‐inducing signalling complex. However, the role of FAF1 in the immunity response is not fully understood. Here, we report that, in the human retinal pigment epithelial (RPE) cell line ARPE‐19 cells, FAF1 expression level was downregulated by Toxoplasma gondii infection, and PI3K/AKT inhibitors reversed T. gondii‐induced FAF1 downregulation. In silico analysis for the FAF1 promoter sequence showed the presence of a FOXO response element (FRE), which is a conserved binding site for FOXO1 transcription factor. In accordance with the finding, FOXO1 overexpression potentiated, whereas FOXO1 depletion inhibited intracellular FAF1 expression level. We also found that FAF1 downregulation by T. gondii is correlated with enhanced IRF3 transcription activity. Inhibition of PI3K/AKT pathway with specific inhibitors had no effect on the level of T. gondii‐induced IRF3 phosphorylation but blocked IRF3 nuclear import and ISGs transcription. These results suggest that T. gondii can downregulate host FAF1 in PI3K/AKT/FOXO1‐dependent manner, and the event is essential for IRF3 nuclear translocation to active the transcription of ISGs and thereby T. gondii proliferation.
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Affiliation(s)
- Fei-Fei Gao
- Brain Korea 21 FOUR Project for Medical Science, Chungnam National University, Daejeon, Korea.,Department of Medical Science and Department of Infection Biology, Chungnam National University, Daejeon, Korea
| | - Juan-Hua Quan
- Department of Gastroenterology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - In-Wook Choi
- Department of Medical Science and Department of Infection Biology, Chungnam National University, Daejeon, Korea
| | - Yeon-Jae Lee
- Brain Korea 21 FOUR Project for Medical Science, Chungnam National University, Daejeon, Korea.,Department of Medical Science and Department of Infection Biology, Chungnam National University, Daejeon, Korea
| | - Seul-Gi Jang
- Brain Korea 21 FOUR Project for Medical Science, Chungnam National University, Daejeon, Korea.,Department of Medical Science and Department of Infection Biology, Chungnam National University, Daejeon, Korea
| | - Jae-Min Yuk
- Brain Korea 21 FOUR Project for Medical Science, Chungnam National University, Daejeon, Korea.,Department of Medical Science and Department of Infection Biology, Chungnam National University, Daejeon, Korea
| | - Young-Ha Lee
- Brain Korea 21 FOUR Project for Medical Science, Chungnam National University, Daejeon, Korea.,Department of Medical Science and Department of Infection Biology, Chungnam National University, Daejeon, Korea
| | - Guang-Ho Cha
- Department of Medical Science and Department of Infection Biology, Chungnam National University, Daejeon, Korea
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