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Móvio MI, de Almeida GWC, Martines IDGL, Barros de Lima G, Sasaki SD, Kihara AH, Poole E, Nevels M, Carlan da Silva MC. SARS-CoV-2 ORF8 as a Modulator of Cytokine Induction: Evidence and Search for Molecular Mechanisms. Viruses 2024; 16:161. [PMID: 38275971 PMCID: PMC10819295 DOI: 10.3390/v16010161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/11/2024] [Accepted: 01/14/2024] [Indexed: 01/27/2024] Open
Abstract
Severe cases of SARS-CoV-2 infection are characterized by an immune response that leads to the overproduction of pro-inflammatory cytokines, resulting in lung damage, cardiovascular symptoms, hematologic symptoms, acute kidney injury and multiple organ failure that can lead to death. This remarkable increase in cytokines and other inflammatory molecules is primarily caused by viral proteins, and particular interest has been given to ORF8, a unique accessory protein specific to SARS-CoV-2. Despite plenty of research, the precise mechanisms by which ORF8 induces proinflammatory cytokines are not clear. Our investigations demonstrated that ORF8 augments production of IL-6 induced by Poly(I:C) in human embryonic kidney (HEK)-293 and monocyte-derived dendritic cells (mono-DCs). We discuss our findings and the multifaceted roles of ORF8 as a modulator of cytokine response, focusing on type I interferon and IL-6, a key component of the immune response to SARS-CoV-2. In addition, we explore the hypothesis that ORF8 may act through pattern recognition receptors of dsRNA such as TLRs.
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Affiliation(s)
- Marília Inês Móvio
- Laboratório de Neurogenética, Universidade Federal do ABC (UFABC), São Bernardo do Campo, São Paulo 09606-070, Brazil; (M.I.M.)
| | - Giovana Waner Carneiro de Almeida
- Centro de Ciências Naturais e Humanas (CCNH), Universidade Federal do UFABC (UFABC), São Bernardo do Campo, São Paulo 09606-070, Brazil; (G.W.C.d.A.); (G.B.d.L.); (S.D.S.)
| | - Isabella das Graças Lopes Martines
- Centro de Ciências Naturais e Humanas (CCNH), Universidade Federal do UFABC (UFABC), São Bernardo do Campo, São Paulo 09606-070, Brazil; (G.W.C.d.A.); (G.B.d.L.); (S.D.S.)
| | - Gilmara Barros de Lima
- Centro de Ciências Naturais e Humanas (CCNH), Universidade Federal do UFABC (UFABC), São Bernardo do Campo, São Paulo 09606-070, Brazil; (G.W.C.d.A.); (G.B.d.L.); (S.D.S.)
| | - Sergio Daishi Sasaki
- Centro de Ciências Naturais e Humanas (CCNH), Universidade Federal do UFABC (UFABC), São Bernardo do Campo, São Paulo 09606-070, Brazil; (G.W.C.d.A.); (G.B.d.L.); (S.D.S.)
| | - Alexandre Hiroaki Kihara
- Laboratório de Neurogenética, Universidade Federal do ABC (UFABC), São Bernardo do Campo, São Paulo 09606-070, Brazil; (M.I.M.)
| | - Emma Poole
- Division of Virology, Department of Pathology, Cambridge University, Level 5, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 0QQ, UK
| | - Michael Nevels
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK;
| | - Maria Cristina Carlan da Silva
- Centro de Ciências Naturais e Humanas (CCNH), Universidade Federal do UFABC (UFABC), São Bernardo do Campo, São Paulo 09606-070, Brazil; (G.W.C.d.A.); (G.B.d.L.); (S.D.S.)
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Tuncel B, Kaygusuz S, Sayın Kocakap DB, Aksoy E, Azkur AK. Do CCR5 (CCR5Δ32) and TLR3 (RS5743313) gene polymorphisms prevent chronic hepatitis B infection? J Med Virol 2023; 95:e28376. [PMID: 36478230 DOI: 10.1002/jmv.28376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/07/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022]
Abstract
Hepatitis B virus (HBV) is still a significant health problem in human. HBV severity or sensitivity of patients may be based on the individual genetic factors significantly. The aim of this study is to investigate the association of CCR5 (CCR5Δ32), TLR3 (rs5743313) functional gene polymorphisms, interferon-gamma (IFN-ɣ) level in HBV infection, which are thought to play an important role in innate and acquired immunity in patients who have undergone HBV seroconversion and those who have chronic hepatitis B disease and receive treatment. One hundred patients who are became naturally immune against HBV infection (HBsAg negative, anti-HBc IgG, and anti-HBs IgG positive), and 100 patients with chronic hepatitis B infection (>6 months HBsAg positive) who are receiving oral antiviral therapy were compared for CCR5Δ32, TLR3 (rs5743313) genotypes and serum IFN-ɣ level. It was found that CCR5Δ32 polymorphism (Wt/Δ32 and Δ32/Δ32) was significantly higher in the chronic hepatitis B group (p = 0.048) but not for TLR3 gene polymorphism. However, serum IFN-ɣ level was significantly higher in the HBV seroconversion group (75 ± 89 ng/ml) than in the chronic hepatitis B group (4.35 ± 17.27 ng/ml) (p < 0.001). In conclusion, a higher CCR5Δ32 allele frequency in patients with chronic hepatitis B might be considered as a marker of progression to chronic hepatitis.
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Affiliation(s)
- Burçin Tuncel
- Department of Infectious Diseases and Clinical Microbiology, Faculty of Medicine, Kırıkkale University, Kırıkkale, Türkiye
| | - Sedat Kaygusuz
- Department of Infectious Diseases and Clinical Microbiology, Faculty of Medicine, Kırıkkale University, Kırıkkale, Türkiye
| | | | - Emel Aksoy
- Department of Virology, Faculty of Veterinary Medicine, Kırıkkale University, Kırıkkale, Türkiye
| | - Ahmet Kürşat Azkur
- Department of Virology, Faculty of Veterinary Medicine, Kırıkkale University, Kırıkkale, Türkiye
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Gao Y, Nepal N, Jin SZ. Toll-like receptors and hepatitis C virus infection. Hepatobiliary Pancreat Dis Int 2021; 20:521-529. [PMID: 34419367 DOI: 10.1016/j.hbpd.2021.07.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 07/26/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Hepatitis C virus (HCV) infection is a worldwide issue. However, the current treatment for hepatitis C has many shortcomings. Toll-like receptors (TLRs) are pattern recognition receptors involved in HCV infection, and an increasing number of studies are focusing on the role of TLRs in the progression of hepatitis C. DATA SOURCES We performed a PubMed search up to January 2021 with the following keywords: hepatitis C, toll-like receptors, interferons, inflammation, and immune evasion. We also used terms such as single-nucleotide polymorphisms (SNPs), susceptibility, fibrosis, cirrhosis, direct-acting antiviral agents, agonists, and antagonists to supplement the query results. We reviewed relevant publications analyzing the correlation between hepatitis C and TLRs and the role of TLRs in HCV infection. RESULTS TLRs 1-4 and 6-9 are involved in the process of HCV infection. When the host is exposed to the HCV, TLRs, as important participants in HCV immune evasion, trigger innate immunity to remove the virus and also promote inflammation and liver fibrosis. TLR gene SNPs affect hepatitis C susceptibility, treatment, and prognosis. The contribution of each TLR to HCV is different. Drugs targeting various TLRs are developed and validated, and TLRs can synergize with classic hepatitis C drugs, including interferon and direct-acting antiviral agents, constituting a new direction for the treatment of hepatitis C. CONCLUSIONS TLRs are important receptors in HCV infection. Different TLRs induce different mechanisms of virus clearance and inflammatory response. Although TLR-related antiviral therapy strategies exist, more studies are needed to explore the clinical application of TLR-related drugs.
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Affiliation(s)
- Yang Gao
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Narayan Nepal
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Shi-Zhu Jin
- Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China.
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Seyed-Khorrami SM, Soleimanjahi H, Soudi S, Habibian A. MSCs loaded with oncolytic reovirus: migration and in vivo virus delivery potential for evaluating anti-cancer effect in tumor-bearing C57BL/6 mice. Cancer Cell Int 2021; 21:244. [PMID: 33933086 PMCID: PMC8088007 DOI: 10.1186/s12935-021-01848-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 02/20/2021] [Indexed: 02/07/2023] Open
Abstract
Background and aims Several oncolytic viruses applications have been approved in the clinic or in different phases of clinical trials. However, these methods have some rudimentary problems. Therefore, to enhance the delivery and quality of treatment, considering the advantage of cell carrier-based methods such as Mesenchymal Stem Cells (MSC) have been proposed. This study was designed to evaluate the performance and quality of cancer treatment based on MSCs loaded by oncolytic reovirus in the cancerous C57BL/6 mouse model. Also, we evaluated MSCs migration potency in vitro and in vivo following the oncolytic reovirus infection. Methods C57BL/6 mice were inoculated with TC-1 cell lines and tumors were established in the right flank. Mice were systemically treated with reovirus, MSCs-loaded with reovirus, MSCs, and PBS as a control in separated groups. Effects of infected AD-MSCs with reovirus on tumor growth and penetration in the tumor site were monitored. All groups of mice were monitored for two months in order to therapeutic and anticancer potential. After treatments, tumor size alteration and apoptosis rate, as well as cytokine release pattern was assessed. Results The results of the current study indicated that the effect of reovirus infection on AD-MSCs is not devastating the migration capacity especially in MOI 1 and 5 while intact cells remain. On the other hand, MSCs play an efficient role as a carrier to deliver oncolytic virus into the tumor site in comparison with systemic administration of reovirus alone. Apoptosis intensity relies on viral titration and passing time. Followed by systemic administration, treatment with oncolytic reovirus-infected AD-MSCs and MSCs alone had shown significant inhibition in tumor growth. Also, treatment by reovirus causes an increase in IFN-γ secretion. Conclusion The results of in vitro and in vivo study confirmed the tumor-homing properties of infected AD-MSCs and the significant antitumor activity of this platform. Hence, our results showed that the cell carrier strategy using oncolytic reovirus-loaded AD-MSCs enhanced virus delivery, infiltration, and antitumor activity can be effectively applied in most cancers.
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Affiliation(s)
| | - Hoorieh Soleimanjahi
- Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Sara Soudi
- Department of Immunology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Ala Habibian
- Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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Shiratori T, Imaizumi T, Hirono K, Kawaguchi S, Matsumiya T, Seya K, Tasaka S. ISG56 is involved in CXCL10 expression induced by TLR3 signaling in BEAS-2B bronchial epithelial cells. Exp Lung Res 2020; 46:195-202. [PMID: 32363951 DOI: 10.1080/01902148.2020.1760965] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Purpose and aim of the study: Bronchial epithelial cells play an important role in immune response against viral infections. Toll-like receptor 3 (TLR3) is a pathogen recognition receptor that recognizes viral double-stranded RNA (dsRNA). Activation of TLR3 induces the expression of interferon (IFN)-β, and newly synthesized IFN-β exhibits anti-viral activity by upregulating the expression of IFN-stimulated genes (ISGs). ISG56 encodes a multifunctional protein with tetratricopeptide motifs and is involved in anti-viral reactions through various mechanisms. Expression of chemokines such as CXCL10, which induces leukocyte chemotaxis, is essential for defense against airway microbes. However, regulation of chemokine expression by ISG56 in bronchial epithelial cells has not been fully investigated. The aim of this study was to examine the expression of ISG56 and its role in CXCL10 production in BEAS-2B bronchial epithelial cells treated with dsRNA.Materials and methods: BEAS-2B bronchial epithelial cells were treated with polyinosinic-polycytidylic acid (poly IC), a synthetic TLR3 ligand. The mRNA and protein expression levels of ISG 56 were analyzed by quantitative reverse transcription polymerase chain reaction and western blotting. The effect of knocking down TLR3, IFN-β, and ISG56 was examined using RNA interference. The protein expression of CXCL10 in culture medium was measured using an enzyme-linked immunosorbent assay.Results: Poly IC induced ISG56 expression in a concentration- and time- dependent manner. RNA interference showed that ISG56 induction was inhibited by knockdown of TLR3 or IFN-β and that ISG 56 knockdown decreased CXCL10 expression.Conclusions: ISG56 was induced by poly IC through TLR3/IFN-β axis, and ISG56 may positively regulated CXCL10 expression in BEAS-2B cells. ISG56 may modulate anti-viral innate immunity, at least in part, by regulating the expression of CXCL10 in bronchial epithelial cells.
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Affiliation(s)
- Toshihiro Shiratori
- Department of Respiratory Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Tadaatsu Imaizumi
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Koji Hirono
- Department of Pediatrics, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Shogo Kawaguchi
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Tomoh Matsumiya
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Kazuhiko Seya
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Sadatomo Tasaka
- Department of Respiratory Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
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Modulation of Apoptosis by Cytotoxic Mediators and Cell-Survival Molecules in Sjögren's Syndrome. Int J Mol Sci 2018; 19:ijms19082369. [PMID: 30103522 PMCID: PMC6121505 DOI: 10.3390/ijms19082369] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/08/2018] [Accepted: 08/10/2018] [Indexed: 12/11/2022] Open
Abstract
The pathogenesis of Sjögren’s syndrome (SS) involves multiple factors including genetic background, cell death, and exocrine dysfunction. We here discuss apoptotic control in exocrine glands in SS by showing various pro- and anti-apoptotic pathways. Although the membrane-bound and soluble form of the Fas/Fas ligand system is a leading player with activation of the death domain and caspase 8/3 cleavage, the role of soluble Fas/FasL (including its polymorphism) in apoptosis is controversial. The tumor necrosis factor related apoptosis-inducing ligand (TRAIL)-mediated apoptosis of salivary gland epithelial cells (SGECs) involves a mitochondrial pathway that includes caspase 9 cleavage. The involvement of innate immunity cells such as toll-like receptors (TLRs) has been investigated; TLR2-4 and TLR7-9 are associated with the induction of inflammation in exocrine glands of SS patients. TLR3 has the potential to induce the apoptosis of SS patients’ SGECs. Linkage of epidermal growth factor (EGF) was shown in exocrine glands in SS, and it inhibited the Fas/FasL system with the help of cell-survival factors. TLR3 has dual actions to cause inflammation as well as apoptosis, which are inhibited by EGF. In conclusion, apoptosis in exocrine glands of SS patients is tightly controlled by balance of pro-apoptotic signals and growth factor.
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Lee EY, Lee MW, Wong GCL. Modulation of toll-like receptor signaling by antimicrobial peptides. Semin Cell Dev Biol 2018; 88:173-184. [PMID: 29432957 DOI: 10.1016/j.semcdb.2018.02.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 02/06/2018] [Indexed: 01/05/2023]
Abstract
Antimicrobial peptides (AMPs) are typically thought of as molecular hole punchers that directly kill pathogens by membrane permeation. However, recent work has shown that AMPs are pleiotropic, multifunctional molecules that can strongly modulate immune responses. In this review, we provide a historical overview of the immunomodulatory properties of natural and synthetic antimicrobial peptides, with a special focus on human cathelicidin and defensins. We also summarize the various mechanisms of AMP immune modulation and outline key structural rules underlying the recently-discovered phenomenon of AMP-mediated Toll-like receptor (TLR) signaling. In particular, we describe several complementary studies demonstrating how AMPs self-assemble with nucleic acids to form nanocrystalline complexes that amplify TLR-mediated inflammation. In a broader scope, we discuss how this new conceptual framework allows for the prediction of immunomodulatory behavior in AMPs, how the discovery of hidden antimicrobial activity in known immune signaling proteins can inform these predictions, and how these findings reshape our understanding of AMPs in normal host defense and autoimmune disease.
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Affiliation(s)
- Ernest Y Lee
- Department of Bioengineering, University of California, Los Angeles, CA 90095, United States
| | - Michelle W Lee
- Department of Bioengineering, University of California, Los Angeles, CA 90095, United States
| | - Gerard C L Wong
- Department of Bioengineering, University of California, Los Angeles, CA 90095, United States.
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8
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Lee EY, Takahashi T, Curk T, Dobnikar J, Gallo RL, Wong GCL. Crystallinity of Double-Stranded RNA-Antimicrobial Peptide Complexes Modulates Toll-Like Receptor 3-Mediated Inflammation. ACS NANO 2017; 11:12145-12155. [PMID: 29016111 PMCID: PMC5936640 DOI: 10.1021/acsnano.7b05234] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Double-stranded RNA (dsRNA) induces production of pro-inflammatory cytokines in normal human epidermal keratinocytes (NHEK) by specific binding to endosomal Toll-like receptor-3 (TLR3). Recently, it has been shown that hyperactivation of TLR3 in psoriatic keratinocytes by dsRNA can occur in the presence of human antimicrobial peptide (AMP) LL37. Here, we combine synchrotron X-ray scattering, microscopy, computer simulations, and measurements of NHEK cytokine production to elucidate a previously unanticipated form of specific molecular pattern recognition. LL37 and similar α-helical AMPs can form pro-inflammatory nanocrystalline complexes with dsRNA that are recognized by TLR3 differently than dsRNA alone. dsRNA complexes that activate IL-6 production in NHEK and those that do not are both able to enter cells and co-localize with TLR3. However, the crystallinity of these AMP-dsRNA complexes, specifically the geometric spacing between parallel dsRNA and the repeat number of ordered dsRNA, strongly influences the level of TLR3 activation. Crystalline complexes that present dsRNA at a spacing that matches with the steric size of TLR3 can recruit and engage multiple TLR3 receptors, driving receptor clustering and immune amplification, whereas crystalline complexes that exhibit poor steric matching do not. Reverse-transcription quantitative PCR of IL-6 during siRNA knockdown of TLR3 confirms that cytokine production is due to TLR3: High levels of IL-6 transcription are observed for sterically matched complexes without TLR3 knockdown, whereas such activity is abrogated with TLR3 knockdown.
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Affiliation(s)
- Ernest Y. Lee
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095, United States
| | - Toshiya Takahashi
- Department of Dermatology, University of California, San Diego, La Jolla, CA 92093, United States
| | - Tine Curk
- Beijing National Laboratory for Condensed Matter Physics & CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jure Dobnikar
- Beijing National Laboratory for Condensed Matter Physics & CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Department of Chemistry, University of Cambridge, Cambridge, UK
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- To whom correspondence should be addressed: Gerard C.L. Wong, Department of Bioengineering, University of California, Los Angeles, 4121 Engineering V UCLA Los Angeles, CA 90095. Tel: (310) 794-7684 , Richard L. Gallo, Department of Dermatology, University of California, San Diego, 3350 La Jolla Village Drive, San Diego, CA 92161. , Jure Dobnikar, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
| | - Richard L. Gallo
- Department of Dermatology, University of California, San Diego, La Jolla, CA 92093, United States
- To whom correspondence should be addressed: Gerard C.L. Wong, Department of Bioengineering, University of California, Los Angeles, 4121 Engineering V UCLA Los Angeles, CA 90095. Tel: (310) 794-7684 , Richard L. Gallo, Department of Dermatology, University of California, San Diego, 3350 La Jolla Village Drive, San Diego, CA 92161. , Jure Dobnikar, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
| | - Gerard C. L. Wong
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095, United States
- To whom correspondence should be addressed: Gerard C.L. Wong, Department of Bioengineering, University of California, Los Angeles, 4121 Engineering V UCLA Los Angeles, CA 90095. Tel: (310) 794-7684 , Richard L. Gallo, Department of Dermatology, University of California, San Diego, 3350 La Jolla Village Drive, San Diego, CA 92161. , Jure Dobnikar, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
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Toll-Like Receptor-3 Mediates HIV-1-Induced Interleukin-6 Expression in the Human Brain Endothelium via TAK1 and JNK Pathways: Implications for Viral Neuropathogenesis. Mol Neurobiol 2017; 55:5976-5992. [PMID: 29128906 DOI: 10.1007/s12035-017-0816-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/27/2017] [Indexed: 12/22/2022]
Abstract
HIV-1-associated neurocognitive disorders (HAND) is associated with blood-brain-barrier (BBB) inflammation, and inflammation involves toll-like receptors (TLRs) signaling. It is not known whether primary human brain microvascular endothelial cells (HBMEC), the major BBB component, express TLRs or whether TLRs are involved in BBB dysfunction and HAND. We demonstrate that HBMEC express TLR3, 4, 5, 7, 9, and 10, and TLR3 was the most abundant. HIV-1 and TLR3 activation increased endothelial TLR3 transcription and expression. HIV-1-positive human subjects showed significantly higher TLR3 expression in brain tissues and blood vessels, with higher TLR3 levels in subjects with HAND. HIV-1 and TLR3 activation increased endothelial IL6 expression by 6-to-127-fold (P < 0.001), activated c-jun(serine-63) and SAPK/JNK(Thr183/Tyr185). HIV-1 upregulated IL6 through interleukin-1 receptor-associated-kinase (IRAK)-1/4/TAK1/JNK pathways, via ATP-dependent JNK activation. TLR3 activation upregulated IL6 through TAK1/JNK pathways, via ATP-dependent or -independent JNK activation. HIV-1 and TLR3 activation also upregulated transcription factors associated with IL6 and TAK1/JNK pathways (Jun, CEBPA, STAT1). Blocking TLR3 activation prevented HIV-1- and TLR3 ligands-induced upregulation of these transcription factors, prevented IL6 transcription and expression, c-jun and JNK activation. HIV-1 and TLR3 ligands significantly increased monocytes adhesion and migration through the BBB, and decreased endothelial claudin-5 expression. Blocking TLR3 and JNK activation prevented HIV-1- and TLR3 ligands-induced claudin-5 downregulation, monocytes adhesion and transendothelial migration. These data suggest that viral immune recognition via endothelial TLR3 is involved in endothelial inflammation and BBB dysfunction in HIV/AIDS and HAND. Our data provides novel insights into the molecular basis of these HIV-1- and TLR3-mediated effects.
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Kasumba DM, Hajake T, Oh SW, Kotenko SV, Kato H, Fujita T. A Plant-Derived Nucleic Acid Reconciles Type I IFN and a Pyroptotic-like Event in Immunity against Respiratory Viruses. THE JOURNAL OF IMMUNOLOGY 2017; 199:2460-2474. [DOI: 10.4049/jimmunol.1700523] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 07/23/2017] [Indexed: 12/14/2022]
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Akbal E, Koçak E, Köklü S, Ergül B, Akyürek Ö, Yılmaz FM. Serum Toll-Like Receptor-2, Toll-Like Receptor-4 Levels in Patients with HBeAg-Negative Chronic Viral Hepatitis B. Viral Immunol 2017; 30:278-282. [PMID: 28414577 DOI: 10.1089/vim.2016.0131] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Toll-like receptors (TLRs) may play an important role in hepatitis-B pathogenesis. However, serum TLR-2 and TLR-4 levels and their association with serum liver enzymes, hepatitis B virus (HBV) DNA, quantitative HBsAg levels, and liver biopsy findings, are unknown. A total of naive 40 HBeAg (-) chronic hepatitis B (CHB) patients and 20 healthy control subjects were recruited in this study. Liver tests, HBV DNA, serum TLR-2 and TLR-4, and quantitative HBsAg levels were evaluated among all groups. The relationship among TLR-2, TLR-4, quantitative HBsAg levels and liver tests, and liver histological findings were investigated with correlation analysis. Serum TLR-2 and TLR-4 levels in HBeAg (-) CHB patients were higher than in the control group. There was a positive correlation between serum TLR-2, TLR-4, and HBV DNA and ALT levels. We have further demonstrated that serum TLR-2 levels are correlated with AST and quantitative HBsAg levels. However, TLRs levels were not linked to the liver biopsy findings. TLR can have an important role in hepatitis B pathogenesis. Liver injury in CHB may cause elevated TLR-2 and TLR-4 levels.
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Affiliation(s)
- Erdem Akbal
- 1 Department of Gastroenterology, Florence Nightingale Hospital, Faculty of Medicine, İstanbul Bilim University , İstanbul, Turkey
| | - Erdem Koçak
- 1 Department of Gastroenterology, Florence Nightingale Hospital, Faculty of Medicine, İstanbul Bilim University , İstanbul, Turkey
| | - Seyfettin Köklü
- 2 Department of Gastroenterology, Faculty of Medicine, Hacettepe University , Ankara, Turkey
| | - Bilal Ergül
- 3 Department of Gastroenterology, Kırşehir State Hospital , Kırşehir, Turkey
| | - Ömer Akyürek
- 4 Department of Internal Medicine, Medova Hospital , Konya, Turkey
| | - Fatma Meriç Yılmaz
- 5 Department of Medical Biochemistry, Numune Education and Research Hospital , Ankara, Turkey
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Bhargavan B, Woollard SM, Kanmogne GD. Toll-like receptor-3 mediates HIV-1 transactivation via NFκB and JNK pathways and histone acetylation, but prolonged activation suppresses Tat and HIV-1 replication. Cell Signal 2015; 28:7-22. [PMID: 26569339 DOI: 10.1016/j.cellsig.2015.11.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 11/03/2015] [Accepted: 11/09/2015] [Indexed: 01/13/2023]
Abstract
TLR3 has been implicated in the pathogenesis of several viral infections, including SIV- and HIV-1-induced inflammation and AIDS. However the molecular mechanisms of these TLR3-mediated effects are not known, and it is not known whether HIV interacts with cellular TLR3 to affect disease process. Here we investigate the effects of TLR3 ligands on HIV-1 transactivation using both primary human macrophages and cells containing integrated copies of the HIV-1 promoter. We demonstrate that TLR3 activation induced upregulation of transcription factors such as c-Jun, CCAAT/enhancer-binding protein alpha (CEBPA), signal transducer and activator of transcription (STAT)-1, STAT-2, RELB, and nuclear factor kappa-B1 (NFκB1), most of which are known to regulate the HIV promoter activity. We also demonstrate that TLR3 activation increased HIV-1 transactivation via the c-Jun N-terminal kinase (JNK) and NFκB pathways. This was associated with epigenetic modifications, including decreased histone deacetylase activity, increased histone acetyl transferase (HAT) activity, and increased acetylation of histones H3 and H4 at lysine residues in the nucleosome-0 and nucleosome-1 of the HIV-1 promoter. However, prolonged TLR3 activation decreased HIV-1 transactivation, decreased HAT activity and Tat transcription, and suppressed viral replication. Overall, data suggests that TLR3 can act as viral sensor to mediate viral transactivation, cellular signaling, innate immune response, and inflammation in HIV-infected humans. Our study provides novel insights into the molecular basis for these TLR3-mediated effects.
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Affiliation(s)
- Biju Bhargavan
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5800, USA.
| | - Shawna M Woollard
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5800, USA.
| | - Georgette D Kanmogne
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198-5800, USA.
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Horai Y, Nakamura H, Nakashima Y, Hayashi T, Kawakami A. Analysis of the downstream mediators of toll-like receptor 3-induced apoptosis in labial salivary glands in patients with Sjögren's syndrome. Mod Rheumatol 2015; 26:99-104. [PMID: 25926385 DOI: 10.3109/14397595.2015.1045256] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVES The aim of this study was to clarify the molecular mechanisms elicited by toll-like receptor (TLR)3 in salivary gland cell death in patients with SS. METHODS Expression of TLR3 and its downstream molecules was examined by immunohistochemical analysis, immunofluorescence, Western blot (WB), and antibody dot-blot array in labial salivary glands (LSGs), and cultured primary salivary gland epithelial cells (SGECs) obtained from patients with SS. We also investigated the difference of expression between ducts/alveoli of LSGs and cultured SGECs. RESULTS Phosphorylated Fas-associated protein with death domain (p-FADD) or caspase-8 was not found in ducts or alveoli of LSGs from SS patients and controls. Weak expression of receptor-interacting serine/threonine-protein kinase 3 (RIPK3) was found in SS patients, whereas no staining was observed in LSGs of controls. In contrast to LSGs, stimulation of SGECs with polyinosinic:cytidylic acid (poly I:C) significantly induced the expression of RIPK3, p-FADD, and cleaved caspase-8 by immunofluorescence and RIPK3, p-FADD, and cleaved caspase-3 by WB. However, it was counteracted by epidermal growth factor (EGF). Co-localization of anti-apoptotic molecules hemeoxygenase-2, heat shock protein 27, and p-protein kinase B or p-Akt was induced in EGF-stimulated SGECs. CONCLUSIONS We observed that poly I:C induced apoptosis of SGECs in vitro compared with a relatively low prevalence of apoptosis found in the ducts and alveoli of LSGs in vivo. Thus, we speculate that other counter-regulatory mechanisms, including those induced by EGF, might exist to protect against TLR3-mediated apoptosis of ductal and acinar epithelial cells in vivo.
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Affiliation(s)
- Yoshiro Horai
- a Unit of Translational Medicine, Department of Immunology and Rheumatology , Nagasaki University Graduate School of Biomedical Sciences, Sakamoto , Nagasaki , Japan
| | - Hideki Nakamura
- a Unit of Translational Medicine, Department of Immunology and Rheumatology , Nagasaki University Graduate School of Biomedical Sciences, Sakamoto , Nagasaki , Japan
| | - Yoshikazu Nakashima
- a Unit of Translational Medicine, Department of Immunology and Rheumatology , Nagasaki University Graduate School of Biomedical Sciences, Sakamoto , Nagasaki , Japan
| | - Tomayoshi Hayashi
- b Department of Pathology , Nagasaki Prefectural Shimabara Hospital, Shimabara , Nagasaki , Japan
| | - Atsushi Kawakami
- a Unit of Translational Medicine, Department of Immunology and Rheumatology , Nagasaki University Graduate School of Biomedical Sciences, Sakamoto , Nagasaki , Japan
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Singh D, Vaughan R, Kao CC. LL-37 peptide enhancement of signal transduction by Toll-like receptor 3 is regulated by pH: identification of a peptide antagonist of LL-37. J Biol Chem 2014; 289:27614-24. [PMID: 25092290 PMCID: PMC4183800 DOI: 10.1074/jbc.m114.582973] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 07/24/2014] [Indexed: 12/30/2022] Open
Abstract
LL-37 is a peptide secreted by human epithelial cells that can lyse bacteria, suppress signaling by Toll-like receptor 4 (TLR4), and enhance signaling to double-stranded RNA (dsRNA) by TLR3. How LL-37 interacts with dsRNA to affect signal transduction by TLR3 is not completely understood. We determined that LL-37 binds dsRNA and traffics to endosomes and releases the dsRNA in a pH-dependent manner. Using dynamic light scattering spectroscopy and cell-based FRET experiments, LL-37 was found to form higher order complexes independent of dsRNA binding. Upon acidification LL-37 will dissociate from a larger complex. In cells, LL-37 has a half-live of ∼ 1 h. LL-37 half-life was increased by inhibiting endosome acidification or inhibiting cathepsins, which include proteases whose activity are activated by endosome acidification. Residues in LL-37 that contact poly(I:C) and facilitate oligomerization in vitro were mapped. Peptide LL-29, which contains the oligomerization region of LL-37, inhibited LL-37 enhancement of TLR3 signal transduction. LL-29 prevented LL-37 · poly(I:C) co-localization to endosomes containing TLR3. These results shed light on the requirements for LL-37 enhancement of TLR3 signaling.
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Affiliation(s)
- Divyendu Singh
- From the Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405
| | - Robert Vaughan
- From the Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405
| | - C Cheng Kao
- From the Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405
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15
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Cui G, Wang X, Ye X, Zu J, Zan K, Hua F. Oxygen-glucose deprivation of neurons transfected with toll-like receptor 3-siRNA: Determination of an optimal transfection sequence. Neural Regen Res 2014; 8:3233-40. [PMID: 25206644 PMCID: PMC4146184 DOI: 10.3969/j.issn.1673-5374.2013.34.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 11/07/2013] [Indexed: 12/21/2022] Open
Abstract
Toll-like receptor 3 protein expression has been shown to be upregulated during cerebral ischemia/reperfusion injury in rats. In this study, rat primary cortical neurons were subjected to oxygen-glucose deprivation to simulate cerebral ischemia/reperfusion injury. Chemically synthesized small interfering RNA (siRNA)-1280, -1724 and -418 specific to toll-like receptor 3 were transfected into oxygen-glucose deprived cortical neurons to suppress the upregulation of toll-like receptor 3 protein expression. Western blotting demonstrated that after transfection with siRNA, toll-like receptor 3 protein expression reduced, especially in the toll-like receptor 3-1724 group. These results suggested that siRNA-1724 is an optimal sequence for inhibiting toll-like receptor 3 expression in cortical neurons following oxygen-glucose deprivation.
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Affiliation(s)
- Guiyun Cui
- Department of Neurology, Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, Jiangsu Province, China
| | - Xiaopeng Wang
- Department of Neurology, Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, Jiangsu Province, China
| | - Xinchun Ye
- Department of Neurology, Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, Jiangsu Province, China
| | - Jie Zu
- Department of Neurology, Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, Jiangsu Province, China
| | - Kun Zan
- Department of Neurology, Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, Jiangsu Province, China
| | - Fang Hua
- Department of Neurology, Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, Jiangsu Province, China
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16
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TLR3 plays significant roles against hepatitis B virus. Mol Biol Rep 2014; 41:3279-86. [DOI: 10.1007/s11033-014-3190-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 01/21/2014] [Indexed: 01/30/2023]
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17
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Activation and evasion of antiviral innate immunity by hepatitis C virus. J Mol Biol 2013; 426:1198-209. [PMID: 24184198 DOI: 10.1016/j.jmb.2013.10.032] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 10/22/2013] [Accepted: 10/23/2013] [Indexed: 02/08/2023]
Abstract
Hepatitis C virus (HCV) chronically infects 130-170 million people worldwide and is a major public health burden. HCV is an RNA virus that infects hepatocytes within liver, and this infection is sensed as non-self by the intracellular innate immune response to program antiviral immunity to HCV. HCV encodes several strategies to evade this antiviral response, and this evasion of innate immunity plays a key role in determining viral persistence. This review discusses the molecular mechanisms of how the intracellular innate immune system detects HCV infection, including how HCV pathogen-associated molecular patterns are generated during infection and where they are recognized as foreign by the innate immune system. Further, this review highlights the key innate immune evasion strategies used by HCV to establish persistent infection within the liver, as well as how host genotype influences the outcome of HCV infection. Understanding these HCV-host interactions is key in understanding how to target HCV during infection and for the design of more effective HCV therapies at the immunological level.
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18
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Huang YW, Lin SC, Wei SC, Hu JT, Chang HY, Huang SH, Chen DS, Chen PJ, Hsu PN, Yang SS, Kao JH. Reduced Toll-like receptor 3 expression in chronic hepatitis B patients and its restoration by interferon therapy. Antivir Ther 2013; 18:877-84. [PMID: 23744559 DOI: 10.3851/imp2630] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2013] [Indexed: 12/17/2022]
Abstract
BACKGROUND Toll-like receptor (TLR)3 gene variants may correlate with clinical significance of chronic viral infections including HBV. We aimed to investigate the expression of TLR3 in peripheral blood mononuclear cells (PBMCs) and liver cells of chronic hepatitis B (CHB) patients and its response to pegylated interferon or nucleoside analogue therapy. METHODS We consecutively enrolled 127 CHB patients and 64 hepatitis B surface antigen-negative, anti-HCV-negative healthy individuals as controls. We compared the TLR3 expressions on fresh PBMCs and liver cells from patients and controls, before and during pegylated interferon or nucleoside analogue therapy. RESULTS Compared to controls, patients had a lower TLR3 mean fluorescence intensity (MFI) on PBMCs (mean ± sd 14.61 ± 13.49 versus 9.70 ± 4.61; P < 0.001), independent of age, gender and alanine aminotransferase (ALT; -13.466, 95% CI -17.202, -9.730; P < 0.001). Patients had limited TLR3 stains on Kupffer cells, whereas controls had diffuse stains on Kupffer and hepatocytes. Hepatic TLR3 messenger RNA was lower in patients than controls (0.47 ± 0.30 versus 1-fold). Using pretreatment TLR3 MFI as a referent, among 5 of 12 pegylated-interferon-treated patients with sustained virological response (SVR), TLR3 MFI was restored to a mean of 1.5- to 1.7-folds immediately after treatment. Among seven non-responders or relapsers, TLR3 MFI reduced to a mean of 0.5- to 0.7-fold. Among 10 entecavir-treated patients with on-treatment virological response, TLR3 MFI gradually was restored to a mean of 1.2-folds during 48-week therapy. CONCLUSIONS CHB patients have reduced TLR3 expression on PBMCs, independent of age, gender and ALT, and on liver cells. Patients with pegylated-interferon-induced SVR have a more significant restoration of TLR3 expression than those under entecavir.
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Affiliation(s)
- Yi-Wen Huang
- Liver Center, Cathay General Hospital Medical Center, Taipei, Taiwan
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19
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He X, Jia H, Jing Z, Liu D. Recognition of pathogen-associated nucleic acids by endosomal nucleic acid-sensing toll-like receptors. Acta Biochim Biophys Sin (Shanghai) 2013; 45:241-58. [PMID: 23369718 PMCID: PMC7109797 DOI: 10.1093/abbs/gms122] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Foreign nucleic acids, the essential signature molecules of invading pathogens that act as danger signals for host cells, are detected by endosomal nucleic acid-sensing toll-like receptors (TLRs) 3, 7, 8, 9, and 13. These TLRs have evolved to recognize ‘non-self’ nucleic acids within endosomal compartments and rapidly initiate innate immune responses to ensure host protection through induction of type I interferons, inflammatory cytokines, chemokines, and co-stimulatory molecules and maturation of immune cells. In this review, we highlight our understanding of the recognition of pathogen-associated nucleic acids and activation of corresponding signaling pathways through endosomal nucleic acid-sensing TLRs 3, 7, 8, 9, and 13 for an enormous diversity of pathogens, with particular emphasis on their compartmentalization, intracellular trafficking, proteolytic cleavage, autophagy, and regulatory programs.
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Affiliation(s)
- Xiaobing He
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, CAAS, Lanzhou 730046, China
| | - Huaijie Jia
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, CAAS, Lanzhou 730046, China
| | - Zhizhong Jing
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, CAAS, Lanzhou 730046, China
- Correspondence address. Tel: +86-931-8341979; Fax: +86-931-8340977; E-mail: (Z.J.)/ (D.L.)
| | - Dingxiang Liu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, CAAS, Lanzhou 730046, China
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore
- Correspondence address. Tel: +86-931-8341979; Fax: +86-931-8340977; E-mail: (Z.J.)/ (D.L.)
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20
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Weber M, Gawanbacht A, Habjan M, Rang A, Borner C, Schmidt AM, Veitinger S, Jacob R, Devignot S, Kochs G, García-Sastre A, Weber F. Incoming RNA virus nucleocapsids containing a 5'-triphosphorylated genome activate RIG-I and antiviral signaling. Cell Host Microbe 2013; 13:336-46. [PMID: 23498958 PMCID: PMC5515363 DOI: 10.1016/j.chom.2013.01.012] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 10/12/2012] [Accepted: 01/25/2013] [Indexed: 12/24/2022]
Abstract
Host defense to RNA viruses depends on rapid intracellular recognition of viral RNA by two cytoplasmic RNA helicases: RIG-I and MDA5. RNA transfection experiments indicate that RIG-I responds to naked double-stranded RNAs (dsRNAs) with a triphosphorylated 5' (5'ppp) terminus. However, the identity of the RIG-I stimulating viral structures in an authentic infection context remains unresolved. We show that incoming viral nucleocapsids containing a 5'ppp dsRNA "panhandle" structure trigger antiviral signaling that commences with RIG-I, is mediated through the adaptor protein MAVS, and terminates with transcription factor IRF-3. Independent of mammalian cofactors or viral polymerase activity, RIG-I bound to viral nucleocapsids, underwent a conformational switch, and homo-oligomerized. Enzymatic probing and superresolution microscopy suggest that RIG-I interacts with the panhandle structure of the viral nucleocapsids. These results define cytoplasmic entry of nucleocapsids as the proximal RIG-I-sensitive step during infection and establish viral nucleocapsids with a 5'ppp dsRNA panhandle as a RIG-I activator.
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Affiliation(s)
- Michaela Weber
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Ali Gawanbacht
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
| | - Matthias Habjan
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
| | - Andreas Rang
- Institute of Virology, Helmut-Ruska-Haus, University Hospital Charité, Charité Campus Mitte, Berlin, Germany
| | - Christoph Borner
- Institute of Molecular Medicine, Stefan-Meier-Strasse 17, D-79104 Freiburg, Germany
- Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs University Freiburg, Germany
| | - Anna Mareike Schmidt
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
- Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs University Freiburg, Germany
| | - Sophie Veitinger
- Department of Cell Biology and Cell Pathology, Philipps-University Marburg, Marburg, Germany
| | - Ralf Jacob
- Department of Cell Biology and Cell Pathology, Philipps-University Marburg, Marburg, Germany
| | - Stéphanie Devignot
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Georg Kochs
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
| | - Adolfo García-Sastre
- Department of Microbiology, Mount Sinai School of Medicine, New York, NY-10029, USA
- Department of Medicine, Division of Infectious Diseases, Mount Sinai School of Medicine, New York, NY-10029, USA
- Global Health and Emerging Pathogens Institute, Mount Sinai School of Medicine, New York, NY-10029, USA
| | - Friedemann Weber
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
- Department of Virology, University Freiburg, Hermann-Herder-Strasse 11, D-79008 Freiburg, Germany
- Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs University Freiburg, Germany
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Singh D, Qi R, Jordan JL, San Mateo L, Kao CC. The human antimicrobial peptide LL-37, but not the mouse ortholog, mCRAMP, can stimulate signaling by poly(I:C) through a FPRL1-dependent pathway. J Biol Chem 2013; 288:8258-8268. [PMID: 23386607 DOI: 10.1074/jbc.m112.440883] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
LL-37 is an antimicrobial peptide produced by human cells that can down-regulate the lipopolysaccharide-induced innate immune responses and up-regulate double-stranded (ds) RNA-induced innate responses through Toll-like receptor 3 (TLR3). The murine LL-37 ortholog, mCRAMP, also inhibited lipopolysaccharide-induced responses, but unlike LL-37, it inhibited viral-induced responses in mouse cells. A fluorescence polarization assay showed that LL-37 was able to bind dsRNA better than mCRAMP. In the human lung epithelial cell line BEAS-2B, LL-37, but not mCRAMP, colocalized with TLR3, and the colocalization was increased in the presence of dsRNA. The presence of poly(I:C) increased the accumulation of LL-37 in Rab5 endosomes. Signaling by cells induced with both LL-37 and poly(I:C) was sensitive to inhibitors that affect clathrin-independent trafficking, whereas signaling by poly(I:C) alone was not, suggesting that the LL-37-poly(I:C) complex trafficked to signaling endosomes by a different mechanism than poly(I:C) alone. siRNA knockdown of known LL-37 receptors identified that FPRL1 was responsible for TLR3 signaling induced by LL-37-poly(I:C). These results show that LL-37 and mCRAMP have different activities in TLR3 signaling and that LL-37 can redirect trafficking of poly(I:C) to effect signaling by TLR3 in early endosomes in a mechanism that involves FPRL1.
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Affiliation(s)
- Divyendu Singh
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405-7005
| | - Rongsu Qi
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405-7005
| | - Jarrat L Jordan
- Janssen Pharmaceutical Companies of Johnson & Johnson, Radnor, Pennsylvania 19087
| | - Lani San Mateo
- Janssen Pharmaceutical Companies of Johnson & Johnson, Radnor, Pennsylvania 19087
| | - C Cheng Kao
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405-7005.
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Learning from the messengers: innate sensing of viruses and cytokine regulation of immunity - clues for treatments and vaccines. Viruses 2013; 5:470-527. [PMID: 23435233 PMCID: PMC3640511 DOI: 10.3390/v5020470] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 01/22/2013] [Accepted: 01/23/2013] [Indexed: 12/14/2022] Open
Abstract
Virus infections are a major global public health concern, and only via substantial knowledge of virus pathogenesis and antiviral immune responses can we develop and improve medical treatments, and preventive and therapeutic vaccines. Innate immunity and the shaping of efficient early immune responses are essential for control of viral infections. In order to trigger an efficient antiviral defense, the host senses the invading microbe via pattern recognition receptors (PRRs), recognizing distinct conserved pathogen-associated molecular patterns (PAMPs). The innate sensing of the invading virus results in intracellular signal transduction and subsequent production of interferons (IFNs) and proinflammatory cytokines. Cytokines, including IFNs and chemokines, are vital molecules of antiviral defense regulating cell activation, differentiation of cells, and, not least, exerting direct antiviral effects. Cytokines shape and modulate the immune response and IFNs are principle antiviral mediators initiating antiviral response through induction of antiviral proteins. In the present review, I describe and discuss the current knowledge on early virus–host interactions, focusing on early recognition of virus infection and the resulting expression of type I and type III IFNs, proinflammatory cytokines, and intracellular antiviral mediators. In addition, the review elucidates how targeted stimulation of innate sensors, such as toll-like receptors (TLRs) and intracellular RNA and DNA sensors, may be used therapeutically. Moreover, I present and discuss data showing how current antimicrobial therapies, including antibiotics and antiviral medication, may interfere with, or improve, immune response.
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Qi R, Singh D, Kao CC. Proteolytic processing regulates Toll-like receptor 3 stability and endosomal localization. J Biol Chem 2012; 287:32617-29. [PMID: 22865861 PMCID: PMC3463343 DOI: 10.1074/jbc.m112.387803] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 07/30/2012] [Indexed: 11/06/2022] Open
Abstract
Toll-like receptors (TLRs) 3, 7, and 9 are innate immune receptors that recognize nucleic acids from pathogens in endosomes and initiate signaling transductions that lead to cytokine production. Activation of TLR9 for signaling requires proteolytic processing within the ectodomain by endosome-associated proteases. Whether TLR3 requires similar proteolytic processing to become competent for signaling remains unclear. Herein we report that human TLR3 is proteolytically processed to form two fragments in endosomes. Unc93b1 is required for processing by transporting TLR3 through the Golgi complex and to the endosomes. Proteolytic cleavage requires the eight-amino acid Loop1 within leucine-rich repeat 12 of the TLR3 ectodomain. Proteolytic cleavage is not required for TLR3 signaling in response to poly(I:C), although processing could modulate the degree of response toward viral double-stranded RNAs, especially in mouse cells. Both the full-length and cleaved fragments of TLR3 can bind poly(I:C) and are present in endosomes. However, although the full-length TLR3 has a half-life in HEK293T cells of 3 h, the cleaved fragments have half-lives in excess of 7 h. Inhibition of TLR3 cleavage by either treatment with cathepsin inhibitor or by a mutation in Loop1 decreased the abundance of TLR3 in endosomes targeted for lysosomal degradation.
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Affiliation(s)
- Rongsu Qi
- From the Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47401
| | - Divyendu Singh
- From the Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47401
| | - C. Cheng Kao
- From the Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47401
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24
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Lai Y, Adhikarakunnathu S, Bhardwaj K, Ranjith-Kumar CT, Wen Y, Jordan JL, Wu LH, Dragnea B, San Mateo L, Kao CC. LL37 and cationic peptides enhance TLR3 signaling by viral double-stranded RNAs. PLoS One 2011; 6:e26632. [PMID: 22039520 PMCID: PMC3198786 DOI: 10.1371/journal.pone.0026632] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 09/29/2011] [Indexed: 12/23/2022] Open
Abstract
Background Toll-like Receptor 3 (TLR3) detects viral dsRNA during viral infection. However, most natural viral dsRNAs are poor activators of TLR3 in cell-based systems, leading us to hypothesize that TLR3 needs additional factors to be activated by viral dsRNAs. The anti-microbial peptide LL37 is the only known human member of the cathelicidin family of anti-microbial peptides. LL37 complexes with bacterial lipopolysaccharide (LPS) to prevent activation of TLR4, binds to ssDNA to modulate TLR9 and ssRNA to modulate TLR7 and 8. It synergizes with TLR2/1, TLR3 and TLR5 agonists to increase IL8 and IL6 production. This work seeks to determine whether LL37 enhances viral dsRNA recognition by TLR3. Methodology/Principal Findings Using a human bronchial epithelial cell line (BEAS2B) and human embryonic kidney cells (HEK 293T) transiently transfected with TLR3, we found that LL37 enhanced poly(I:C)-induced TLR3 signaling and enabled the recognition of viral dsRNAs by TLR3. The presence of LL37 also increased the cytokine response to rhinovirus infection in BEAS2B cells and in activated human peripheral blood mononuclear cells. Confocal microscopy determined that LL37 could co-localize with TLR3. Electron microscopy showed that LL37 and poly(I:C) individually formed globular structures, but a complex of the two formed filamentous structures. To separate the effects of LL37 on TLR3 and TLR4, other peptides that bind RNA and transport the complex into cells were tested and found to activate TLR3 signaling in response to dsRNAs, but had no effect on TLR4 signaling. This is the first demonstration that LL37 and other RNA-binding peptides with cell penetrating motifs can activate TLR3 signaling and facilitate the recognition of viral ligands. Conclusions/Significance LL37 and several cell-penetrating peptides can enhance signaling by TLR3 and enable TLR3 to respond to viral dsRNA.
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Affiliation(s)
- Yvonne Lai
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, United States of America.
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