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Tadayon Z, Shahzadeh Fazeli SA, Gholijani N, Daryabor G. Toll-like receptor 9 (TLR9) genetic variants rs187084 and rs352140 confer protection from Behcet's disease among Iranians. BMC Rheumatol 2024; 8:13. [PMID: 38481344 PMCID: PMC10938651 DOI: 10.1186/s41927-024-00382-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/21/2024] [Indexed: 03/17/2024] Open
Abstract
BACKGROUND Behcet's disease (BD) is a multisystem and multifactorial autoimmune disease characterized by relapsing episodes of oral aphthae, genital ulcers, and ocular and skin lesions. Toll-like receptor 9 (TLR9) has pro-inflammatory roles and its genetic variants might be involved in the pathogenesis of inflammatory diseases. METHODS: Two hundred five BD patients and 207 age and sex-matched healthy controls were evaluated for TLR9 single nucleotide polymorphisms - 1486 T/C (rs187084) and + 2848:G/A (rs352140) using polymerase chain reaction-restriction fragment length polymorphism (RFLP-PCR). RESULTS Healthy individuals had a significantly higher frequency of rs187084 AG and AG + GG genotypes than BD patients (p = 0.02 and p = 0.018; respectively). Of interest, healthy males had a significantly higher frequency of rs187084 AG + GG genotype and G allele than male BD patients (p = 0.035 and p = 0.045; respectively). However, rs187084 AG genotype and G allele frequencies were significantly higher in male patients with genital aphthous (p = 0.01 and p = 0.046; respectively). Furthermore, a significantly higher frequency of rs352140 CT and TT + CT genotypes was detected in healthy individuals than in BD patients (p = 0.01, and p = 0.032; respectively). Such results were also seen in healthy females than female patients (p = 0.001, and p = 0.004; respectively). Haplotype analysis revealed a significantly higher frequency of A-C and G-C haplotypes among patients and healthy subjects, respectively (p = 0.002 and p = 0.000; respectively). CONCLUSION Our data suggested that rs187084 AG and AG + GG genotypes and rs352140 CT and TT + CT genotypes protect Iranian individuals from BD but rs187084 AG genotype and G allele predispose male BD individuals to genital aphthous. However, additional studies are required to verify these results.
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Affiliation(s)
- Zahra Tadayon
- Department of Molecular and Cellular Biology, Faculty of Basic Sciences and Advanced Technologies in Biology, University of Science and Culture, ACECR, Tehran, Iran
| | | | - Nasser Gholijani
- Autoimmune Disease Research Center, School of Medicine, Shiraz University of Medical Sciences, PO Box: 71345-1583, Shiraz, Iran
| | - Gholamreza Daryabor
- Autoimmune Disease Research Center, School of Medicine, Shiraz University of Medical Sciences, PO Box: 71345-1583, Shiraz, Iran.
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Huo C, Tian H, Rao H, Zeng B, Li D, Li Z, Li Y. Genetic diversity of Toll-like receptor 9 in swamp eels (Monopterus albus). J Fish Biol 2023; 102:1149-1156. [PMID: 36879356 DOI: 10.1111/jfb.15366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 02/28/2023] [Indexed: 05/13/2023]
Abstract
The swamp eel, Monopterus albus, is an important aquaculture species in Asia (mainly China) whose production has seriously suffered from infectious diseases. In spite of the critical requirement for aquaculture practices, to date there is scant information on its immune defence. Here, the genetic characteristics of Toll-like receptor 9 (TLR9), which plays crucial roles in the initiation of host defence against microbial invasion, were analysed. It exhibits a striking lack of genetic variation resulting from a recent demographic bottleneck. A comparison with the homologue of M. javanensis revealed that replacement but not silent differences have nonrandomly accumulated in the coding sequences at the early stage following their split from a common ancestor. Furthermore, the replacements relevant to the type II functional divergence have mainly occurred in structural motifs mediating ligand recognition and receptor homodimerization. These results provide hints to understand the diversity-based strategy of TLR9 in the arms race against pathogens. Furthermore, the findings reported here give credence to the importance of basic immunology knowledge, especially for the key elements, in genetic engineering and breeding for disease resistance in the eel and other fishes.
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Affiliation(s)
- Caifei Huo
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, People's Republic of China
| | - Haifeng Tian
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, People's Republic of China
| | - Han Rao
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, People's Republic of China
| | - Bo Zeng
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, People's Republic of China
- Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, Sichuan Agricultural University, Chengdu, People's Republic of China
- Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu, People's Republic of China
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, People's Republic of China
| | - Debing Li
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, People's Republic of China
| | - Zhong Li
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, People's Republic of China
| | - Yan Li
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, People's Republic of China
- Key Laboratory of Livestock and Poultry Multi-omics, Ministry of Agriculture and Rural Affairs, Sichuan Agricultural University, Chengdu, People's Republic of China
- Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu, People's Republic of China
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, People's Republic of China
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Liu H, Yang M, Tang X, Liu J, Zheng L, Xu D, Chi C, Lv Z. Molecular insights of a novel fish Toll-like receptor 9 homologue in Nibea albiflora to reveal its function as PRRs. Fish Shellfish Immunol 2021; 118:321-332. [PMID: 34555530 DOI: 10.1016/j.fsi.2021.09.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 08/29/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
Toll-like receptors (TLRs) are an important class of molecules involved in non-specific immunity, and they are also the bridge connecting between non-specific immunity and specific immunity. As a vital member of TLR family TLR9 can be activated by bacterial DNA and induce the production of inflammatory cytokines. In this study, a full length of TLR9 homologue of 3677 bp in Nibea albiflora (named as NaTLR9, GenBank accession no: MN125017.1) was characterized, and its ORF was 3180 bp encoding 1059 amino acid residues with a calculated molecular weight of 121.334 kDa (pI = 6.29). Several leucine-rich repeated sequences (LRR domain) and conservative TIR domain were found in NaTLR9, which was mainly expressed in dendritic cells and macrophages. The phylogenetic and synteny analysis further revealed high sequence identity of NaTLR9 with its counterparts of other teleost, confirming their correct nomenclature and conservative during evolution as an important pattern recognition receptor. The NaTLR9-TIR-pEGFP-N1 fusion protein showed green fluorescence and mainly distributed in the cytoplasm. After co-transfection of NaTLR9-TIR-pEGFP-N1 and NaMyD88-pDsRED-Monomer-N1, green fluorescence obviously overlapped with red and changed into yellowish-green, which suggested that there might be the interaction between homologous NaTLR9-TIR and MyD88. Based on this result the pCDNA3.1-NaTLR9-TIR-flag and pcMV-NaMyD88-TIR-Myc plasmids were co-transfected into 293T cells for the immunoprecipitation test. According to Western blot, TLR9 and MyD88 protein could interact with each other. Furthermore, NaTLR9 was ubiquitously expressed in all the investigated tissues, most abundantly in head kidney, followed by stomach, spleen, liver and gill, but lower in muscle. The vitro immune stimulation experiments revealed that Pseudomonas plecoglossicida and polyinosinic-polycytidylic acid [Poly (I:C)] induced higher levels of NaTLR9 mRNA expression with the peaks of 9.52 times at 2 h and 39.91 times at 24 h compared with the control group respectively. The functional domains (LRRs and TIR, named NaTLR9-TIR and NaTLR9-LRR respectively) of NaTLR9 were expressed and purified, the recombinant proteins both could bind three kinds of typical aquatic pathogenic bacteria (Vibrio. parahaemolyticus, Vibrio alginolyticus, and Vibrio harveyi), which showed that NaTLR9 could couple to bacteria by its function domains. The aforementioned results indicated that NaTLR9 played a significant role in the defense against pathogenic bacteria infection in innate immune response of sciaenidae fish, which may provide some further understandings of the regulatory mechanisms in the teleostean innate immune system.
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Affiliation(s)
- Huihui Liu
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China.
| | - Meijun Yang
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China
| | - Xiuqin Tang
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China
| | - Jiaxin Liu
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China
| | - Libing Zheng
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China
| | - Dongdong Xu
- Marine Fishery Institute of Zhejiang Province, Key Lab of Mariculture and Enhancement of Zhejiang Province, Zhoushan, 316100, PR China
| | - Changfeng Chi
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China
| | - Zhenming Lv
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China
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Camelliti S, Le Noci V, Bianchi F, Storti C, Arnaboldi F, Cataldo A, Indino S, Jachetti E, Figini M, Colombo MP, Balsari A, Gagliano N, Tagliabue E, Sfondrini L, Sommariva M. Macrophages Impair TLR9 Agonist Antitumor Activity through Interacting with the Anti-PD-1 Antibody Fc Domain. Cancers (Basel) 2021; 13:4081. [PMID: 34439233 DOI: 10.3390/cancers13164081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 07/26/2021] [Accepted: 08/03/2021] [Indexed: 12/24/2022] Open
Abstract
Simple Summary We evaluated the contribution of macrophages to the effect of combinatorial immunotherapeutic treatments based on TLR9 stimulation (with CpG-ODNs) and PD-1 blockade in an ovarian cancer preclinical model. We observed a strong reduction in the antitumor efficacy of a TLR9 agonist upon anti-PD-1 antibody administration. Specifically, we found that TLR9-stimulated macrophages, through interacting with the fragment crystallizable (Fc) domain of the anti-PD-1 antibody, acquire an immunoregulatory phenotype leading to dampening of CpG-ODN antitumor effect. Since the stimulation of macrophage TLRs can be achieved not only by synthetic agonists but also by molecules present in the tumor microenvironment, the data we are presenting may represent another possible mechanism of anti-PD-1 antibody therapy resistance. Indeed, it is possible that when delivered as a monotherapy, anti-PD-1 antibody Fc domain may interact with macrophages in which TLR signaling has already been triggered by endogenous ligands, mirroring the biological effects described in the present study. Abstract Background. A combination of TLR9 agonists and an anti-PD-1 antibody has been reported to be effective in immunocompetent mice but the role of innate immunity has not yet been completely elucidated. Therefore, we investigated the contribution of the innate immune system to this combinatorial immunotherapeutic regimens using an immunodeficient mouse model in which the effector functions of innate immunity can clearly emerge without any interference from T lymphocytes. Methods. Athymic mice xenografted with IGROV-1 human ovarian cells, reported to be sensitive to TLR9 agonist therapy, were treated with cytosine–guanine (CpG)-oligodeoxynucleotides (ODNs), an anti-PD-1 antibody or their combination. Results. We found that PD-1 blockade dampened CpG-ODN antitumor activity. In vitro studies indicated that the interaction between the anti-PD-1 antibody fragment crystallizable (Fc) domain and macrophage Fc receptors caused these immune cells to acquire an immunoregulatory phenotype, contributing to a decrease in the efficacy of CpG-ODNs. Accordingly, in vivo macrophage depletion abrogated the detrimental effect exerted by the anti-PD-1 antibody. Conclusion. Our data suggest that if TLR signaling is active in macrophages, coadministration of an anti-PD-1 antibody can reprogram these immune cells towards a polarization state able to negatively affect the immune response and eventually promote tumor growth.
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Maynard SK, Marshall JD, MacGill RS, Yu L, Cann JA, Cheng LI, McCarthy MP, Cayatte C, Robbins SH. Vaccination with synthetic long peptide formulated with CpG in an oil-in-water emulsion induces robust E7-specific CD8 T cell responses and TC-1 tumor eradication. BMC Cancer 2019; 19:540. [PMID: 31170937 PMCID: PMC6555006 DOI: 10.1186/s12885-019-5725-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 05/16/2019] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Despite considerable efforts at developing therapeutic vaccines for cancer, clinical translation of preclinical successes has been challenging, largely due to the difficulty of inducing strong and sustained cytotoxic T lymphocyte (CTL) responses in patients. Several peptide-based cancer vaccines have failed to show sustainable tumor regression in the clinic, possibly because of a lack of optimization of both the adjuvant and antigen components of the preparations. Here, we aimed to develop and optimize a vaccine format utilizing a synthetic long peptide (SLP) containing the human papilloma virus 16 (HPV16) E7 antigen, with a centrally located defined MHC class I epitope, and evaluate its immunogenicity and efficacy in combination with various adjuvant formulations. METHODS E731-73 SLP was tested alone or in combination with toll-like receptor (TLR)3, TLR4, TLR7/8 and TLR9 agonists and formulated in oil-in-water (o/w) or water-in-oil (w/o) emulsions to determine a vaccine format inducing a robust CD8 T cell response in murine models. Once a lead vaccine format was determined, we examined its ability to inhibit tumor growth in the murine TC-1 model that expresses HPV16 E7 antigen. RESULTS We identified the TLR9 agonist CpG formulated in a squalene-based o/w emulsion as the most potent adjuvant, inducing the expansion of multifunctional antigen specific CD8 T cells with cytolytic potential. We also demonstrated that SLP E731-73 + CpG + o/w emulsion vaccine can provide prophylactic and more importantly, therapeutic benefit in the TC-1 murine tumor model. CONCLUSIONS Our results demonstrate that the novel vaccine format E7 SLP + CpG delivered in an o/w emulsion holds potential for the promotion of strong CTL responses and tumor eradication and encourages further development of peptide/adjuvant vaccines in cancer immunotherapy strategies.
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Affiliation(s)
| | | | | | - Li Yu
- Statistical Sciences, MedImmune, Gaithersburg, MD, USA
| | - Jennifer A Cann
- Translational Sciences (Pathology), MedImmune, Gaithersburg, MD, USA
| | - Lily I Cheng
- Translational Sciences (Pathology), MedImmune, Gaithersburg, MD, USA
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Ringelstein-Harlev S, Avivi I, Fanadka M, Horowitz NA, Katz T. Chronic lymphocytic leukemia cells acquire regulatory B-cell properties in response to TLR9 and CD40 activation. Cancer Immunol Immunother 2018; 67:739-748. [PMID: 29450641 PMCID: PMC11028082 DOI: 10.1007/s00262-018-2128-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 02/09/2018] [Indexed: 10/18/2022]
Abstract
Circulating chronic lymphocytic leukemia (CLL) cells share phenotypic features with certain subsets of regulatory B-cells (Bregs). The latter cells have been reported to negatively regulate immune cell responses, mostly by provision of IL-10. The purpose of the current study was to identify and delineate Breg properties of CLL cells. B-cells and T-cells were obtained from the peripheral blood of untreated CLL patients diagnosed according to the 2008 Guidelines of the International Workshop on Chronic Lymphocytic Leukemia. Co-culture assays were used to examine the ability of CLL cells to suppress autologous T-cell immune responses. IL-10 potency of CLL cells was assessed following stimulation with activators of the toll-like receptor 9 (TLR9) or CD40 and was correlated with the inhibitory activity of the cells. TLR9-activated CLL cells were found to increase the frequency of CD4+CD25hiFOXp3+ regulatory T-cells (Tregs) and to inhibit autologous CD4+ T-cell proliferation. This signaling cascade proved to control IL-10 generation in CLL cells, which in turn promoted the inhibition of T-cell proliferation by CLL cells. However, CD40 activation of CLL cells, while exhibiting a similar ability to augment Treg frequency, did not either affect IL-10 generation or T-cell proliferation. In conclusion, CLL cells demonstrate a unique clonal quality of adopting Breg properties which promote modulation of T-cell characteristics. TLR9 appears to be a potent activator of regulatory abilities in CLL cells, possibly contributing to preferential immune escape of TLR9-responsive cells.
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Affiliation(s)
- Shimrit Ringelstein-Harlev
- Department of Hematology and Bone Marrow Transplantation, Rambam Health Care Campus, 8, Ha'Aliya Street, 3109601, Haifa, Israel.
| | - Irit Avivi
- Department of Hematology and Bone Marrow Transplantation, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Mona Fanadka
- Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa, Israel
| | - Netanel A Horowitz
- Department of Hematology and Bone Marrow Transplantation, Rambam Health Care Campus, 8, Ha'Aliya Street, 3109601, Haifa, Israel
- Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa, Israel
| | - Tami Katz
- Department of Hematology and Bone Marrow Transplantation, Rambam Health Care Campus, 8, Ha'Aliya Street, 3109601, Haifa, Israel
- Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa, Israel
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Cohen M, Volpin G, Meir T, Klein E, Katz R, Assaf M, Pollack S. Possible association of Toll-like receptor 9 polymorphisms with cytokine levels and posttraumatic symptoms in individuals with various types of orthopaedic trauma: early findings. Injury 2013; 44:1625-9. [PMID: 23953621 DOI: 10.1016/j.injury.2013.07.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 07/05/2013] [Accepted: 07/13/2013] [Indexed: 02/02/2023]
Abstract
BACKGROUND Although TLR9 polymorphisms may be associated with cytokine dysregulation, its role in regulation of cytokines due to bodily trauma or in relation to acute stress symptoms or posttraumatic stress symptoms (ASS/PTS) has not been evaluated. AIMS To assess serum cytokine levels and levels of ASS and PTS in relation to four common TLR9 single-nucleotide polymorphisms (SNPs) in individuals with various types of orthopaedic trauma. METHODS Forty-eight accident-injured individuals, aged 20-60 years were studied. Serum cytokine levels and TLR9 SNPS (1486T/C, 1237T/C, 1174G/A and 2848G/A) were assessed together with intensity of ASS and PTS symptoms. RESULTS Statistically significant higher serum levels of IL-12 and IL-1β (p<.05) were found in individuals heterozygous for TLR9-1237 (TC) than in individuals expressing the most common TLR9-1237 type (TT), while differences in levels of IL-6 were not significant. Also, marginally significant levels of IL-6 were found in individuals expressing the common TLR9-1174 (GG) compared with individuals homozygous (AA) or heterozygous (GA) for this SNP. They also had non-significant higher intensity of ASS symptoms. A trend of higher PTS levels in individuals expressing the most common type TLR9-1174 (GG) was found, contrary to homozygous (AA) and heterozygous individuals (GA). CONCLUSIONS The results of this pilot study suggest that accident-injured individuals with certain TLR9 polymorphisms express higher levels of pro-inflammatory cytokines (IL-1β, IL-6 and IL-12). The associations of TLR9 SNPSs with increased risk of ASS or PTS should be further studied in larger groups of such patients.
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Affiliation(s)
- Miri Cohen
- Department of Gerontology and School of Social Work, Faculty of Social Welfare and Health Sciences, University of Haifa, Mount Carmel, Haifa, Israel.
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Tu Z, Zhang P, Li H, Niu J, Jin X, Su L. Cross-linking of CD81 by HCV-E2 protein inhibits human intrahepatic plasmacytoid dendritic cells response to CpG-ODN. Cell Immunol. 2013;284:98-103. [PMID: 23954883 DOI: 10.1016/j.cellimm.2013.07.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/18/2013] [Accepted: 07/23/2013] [Indexed: 12/17/2022]
Abstract
Plasmacytoid dendritic cells (pDCs) are reported to be defective in HCV-infected patients, the mechanisms of which remain poorly understood. We isolated liver derived mononuclear cells (LMNCs) and pDCs from normal liver tissues of benign tumor dissections and liver transplant donors. Isolated pDCs and LMNCs were cultured with precoated HCV envelop protein E2 (HCV-E2) or anti-CD81 mAb in the presence of CpG-ODN. Our results show that cross-linking of CD81 by either HCV-E2 or anti-CD81 mAb inhibits IFN-α secretion in CpG-induced pDCs; down-regulates HLA-DR, CD80 and CD86 expression in pDCs; and suppresses CpG-ODN induced proliferation and survival of pDCs. The blockade of CD81 by soluble anti-CD81 antibody restores pDCs response to CpG-ODN. These results suggest that HCV E2 protein interacts with CD81 to inhibit pDC maturation, activation, and IFN-α production, and may thereby contribute to the impaired innate anti-viral immune response in HCV infection.
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Abstract
Unmethylated cytosine-phosphate-guanosine (CpG) oligodeoxynucleotides (ODNs) are recognized by Toll-like receptor 9 (TLR9) found in antigen-presenting cells and B cells and can activate the immune system. Using CpG ODNs as an adjuvant has been found to be effective for treating infectious diseases, cancers, and allergies. Because natural ODNs with only a phosphodiester backbone are easily degraded by nuclease (deoxyribonuclease [DNase]) in serum, CpG ODNs with a phosphorothioate backbone have been studied for clinical application. CpG ODNs with a phosphorothioate backbone have raised concern regarding undesirable side effects; however, several CpG ODNs with only a phosphodiester backbone have been reported to be stable in serum and to show an immunostimulatory effect. In recent years, research has been conducted on delivery systems for CpG ODNs using nanoparticles (NPs). The advantages of NP-based delivery of CpG ODN include (1) it can protect CpG ODN from DNase, (2) it can retain CpG ODN inside the body for a long period of time, (3) it can improve the cellular uptake efficiency of CpG ODN, and (4) it can deliver CpG ODN to the target tissues. Because the target cells of CpG ODN are cells of the immune system and TLR9, the receptor of CpG ODN is localized in endolysosomes, CpG ODN delivery systems are required to have qualities different from other nucleic acid drugs such as antisense DNA and small interfering RNA. Studies until now have reported various NPs as carriers for CpG ODN delivery. This review presents DNase-resistant CpG ODNs with various structures and their immunostimulatory effects and also focuses on delivery systems of CpG ODNs that utilize NPs. Because CpG ODNs interact with TLR9 and activate both the innate and the adaptive immune system, the application of CpG ODNs for the treatment of cancers, infectious diseases, and allergies holds great promise.
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Affiliation(s)
- Nobutaka Hanagata
- Nanotechnology Innovation Station, National Institute for Materials Science, Tsukuba, Ibaraki, Japan.
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