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Bui KC, Nguyen TML, Riebold M, Xing J, Bhuria V, Nguyen LT, Le HS, Velavan TP, Wilkens L, Malek NP, Bozko P, Plentz RR. Role of adiponectin signaling in cholangiocarcinoma. Z Gastroenterol 2018. [DOI: 10.1055/s-0038-1668968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- KC Bui
- Medical University Hospital, Department of Internal Medicine I, Tübingen, Deutschland
- Vietnam Military Medical University, Department of Pathophysiology, Hanoi, Vietnam
- Medical University Hospital, Institute of Tropical Medicine, Tübingen, Deutschland
| | - TML Nguyen
- Medical University Hospital, Department of Internal Medicine I, Tübingen, Deutschland
- Vietnam Military Medical University, Department of Biochemistry, Hanoi, Vietnam
- Vietnamese-German Center of Excellence in Medical Research, Hanoi, Vietnam
| | - M Riebold
- Medical University Hospital, Department of Internal Medicine I, Tübingen, Deutschland
| | - J Xing
- Medical University Hospital, Department of Internal Medicine I, Tübingen, Deutschland
| | - V Bhuria
- Medical University Hospital, Department of Internal Medicine I, Tübingen, Deutschland
| | - LT Nguyen
- Vietnam Military Medical University, Department of Pathophysiology, Hanoi, Vietnam
| | - HS Le
- Vietnamese-German Center of Excellence in Medical Research, Hanoi, Vietnam
- 108 Military Central Hospital, Hanoi, Vietnam
| | - TP Velavan
- Medical University Hospital, Institute of Tropical Medicine, Tübingen, Deutschland
- Vietnamese-German Center of Excellence in Medical Research, Hanoi, Vietnam
| | - L Wilkens
- Hannover Regional Hospital, Institute of Pathology, Hannover, Deutschland
| | - NP Malek
- Medical University Hospital, Department of Internal Medicine I, Tübingen, Deutschland
| | - P Bozko
- Medical University Hospital, Department of Internal Medicine I, Tübingen, Deutschland
| | - RR Plentz
- Medical University Hospital, Department of Internal Medicine I, Tübingen, Deutschland
- Bremen-Nord Hospital, Department of Internal Medicine II, Bremen, Deutschland
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Sy BT, Nguyen HM, Toan NL, Song LH, Tong HV, Wolboldt C, Binh VQ, Kremsner PG, Velavan TP, Bock CT. Identification of a natural intergenotypic recombinant hepatitis delta virus genotype 1 and 2 in Vietnamese HBsAg-positive patients. J Viral Hepat 2015; 22:55-63. [PMID: 24548489 DOI: 10.1111/jvh.12228] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [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: 11/08/2013] [Accepted: 01/02/2014] [Indexed: 12/18/2022]
Abstract
Hepatitis D virus (HDV) infection is acquired as a co- /superinfection of Hepatitis B virus (HBV) and can modulate the pathophysiology of chronic hepatitis B and related liver diseases including hepatocellular carcinoma. Among the eight distinct HDV genotypes reported, relatively few studies have attempted to investigate the prevalence of HDV mixed genotypes and RNA recombination of HDV. With a recorded prevalence of 10-20% HBV infection in Vietnam, this study investigated the HDV variability, HDV genotypes and HDV recombination among twenty-one HDV isolates in Vietnamese HBsAg-positive patients. HDV subgenomic and full-length genome sequences were obtained using newly established HDV-specific RT-PCR techniques. The nucleotide homology was observed from 74.6% to 99.4% among the investigated full-length genome of the HDV isolates. We observed HDV genotype 1 and HDV genotype 2 in the investigated Vietnamese patients. Although no HDV genotype mixtures were observed, we report here a newly identified recombinant of HDV genotypes (HDV 1 and HDV 2). The identified recombinant HDV isolate C03 revealed sequence homology to both HDV genotype 1 (nt1 to nt907) and HDV genotype 2 (nt908 to nt1675; HDAg coding region) with a breakpoint at nt908. Our findings demonstrate the prevalence of intergenotypic recombination between HDV genotypes 1 and 2 in a Vietnamese HBsAg-positive patient. Extended investigation on the distribution and prevalence of HDV, HDV mixed genotypes and recombinant HDV genotypes in a larger Vietnamese population offers vital insights into understanding of the micro-epidemiology of HDV and subsequent pathophysiology in chronic HBV- /HDV-related liver diseases.
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Affiliation(s)
- B T Sy
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany; Vietnam Military Medical University, Ha Noi, Viet Nam
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Messias-Reason IJT, van Tong H, Velavan TP. Analysis of polymorphic sites in the promoter of the nitric oxide synthase 2 gene in Brazilian patients with leprosy. Int J Immunogenet 2014; 41:231-5. [PMID: 24495190 DOI: 10.1111/iji.12108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 11/26/2013] [Accepted: 12/19/2013] [Indexed: 12/01/2022]
Abstract
Leprosy is one of the most neglected infectious tropical diseases of the skin and the nerves caused by the intracellular pathogen Mycobacterium leprae. The inducible NOS isoform encoded by NOS2A plays a vital role in host defence against bacterial infections. The functional promoter polymorphisms in NOS2A are associated with various autoimmune and infectious diseases. We investigated the association of NOS2A variants with progression of leprosy in a Brazilian cohort including 221 clinically classified patients and 103 unrelated healthy controls. We observed a novel variant ss528838018A/G in the promoter region at position -6558. The other functional variants were observed with low frequency of minor allele (<0.005). NOS2A promoter variant (-954G/C) was not observed in Brazilian populations, and the new observed promoter variant (ss528838018A/G) as well as other promoter variants were not associated with any clinical forms of leprosy in the Brazilian populations.
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Affiliation(s)
- I J T Messias-Reason
- Laboratório de Imunopatologia Molecular, Departamento de Patologia Médica, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, Brazil
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Tong HV, Toan NL, Song LH, Bock CT, Kremsner PG, Velavan TP. Hepatitis B virus-induced hepatocellular carcinoma: functional roles of MICA variants. J Viral Hepat 2013; 20:687-98. [PMID: 24010643 DOI: 10.1111/jvh.12089] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [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: 09/01/2012] [Accepted: 01/01/2013] [Indexed: 01/05/2023]
Abstract
Hepatitis B virus infection is a high-risk factor for hepatocellular carcinoma. The human major histocompatibility complex class I chain-related gene A (MICA) is a ligand of the NKG2D receptor that modulates the NK and T-cell-mediated immune responses and is associated with several diseases. This study determined the effects of MICA polymorphisms during HBV infection and HBV-induced HCC. We conducted a case-controlled study in a Vietnamese cohort and genotyped ten functional MICA polymorphisms including the microsatellite motif in 552 clinically classified hepatitis B virus patients and 418 healthy controls. The serum soluble MICA levels (sMICA) were correlated with MICA variants and liver enzyme levels. We demonstrated a significant contribution of MICA rs2596542G/A promoter variant and nonsynonymous substitutions MICA-129Met/Val, MICA-251Gln/Arg, MICA-175Gly/Ser, triplet repeat polymorphism and respective haplotypes with HBV-induced HCC and HBV persistence. The circulating sMICA levels in HBV patient groups were elevated significantly compared with healthy controls. A significant contribution of studied MICA variants to sMICA levels was also observed. The liver enzymes alanine amino transferase (ALT), aspartate transaminase (AST), total bilirubin and direct bilirubin were positively correlated with sMICA levels suggesting sMICA as a biomarker for liver injury. We conclude that MICA polymorphisms play a crucial role in modulating innate immune responses, tumour surveillance and regulate disease susceptibility during HBV infection.
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Affiliation(s)
- H V Tong
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
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Shinde V, Marcinek P, Rani DS, Sunder SR, Arun S, Jain S, Nath I, Thangaraj K, Velavan TP, Valluri VL. Genetic evidence of TAP1 gene variant as a susceptibility factor in Indian leprosy patients. Hum Immunol 2013; 74:803-7. [PMID: 23395648 DOI: 10.1016/j.humimm.2013.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 12/07/2012] [Accepted: 01/14/2013] [Indexed: 02/08/2023]
Abstract
The heterodimeric transporter associated with antigen processing (TAP) gene loci is known to play a vital role in immune surveillance. We investigated a possible association of gene polymorphisms both in TAP1 and TAP2 in a cohort of clinically classified leprosy patients (n=222) and in ethnically matched controls (n=223). The TAP1 and TAP2 genes were genotyped for four single nucleotide polymorphisms TAP1 (rs1057141 Iso333Val and rs1135216 Asp637Gly) and TAP2 (rs2228396 Ala565Thr and rs241447 Ala665Thr) by direct sequencing and ARMS-PCR. The minor allele of TAP1 637G contributes to an increased risk to leprosy compared to controls (OR: 1.68, 95% CI 1.2-2.36, P=0.0057). An increased risk for the variant minor allele of the TAP1 637G to multibacillary (BL+LL) or paucibacillary (BT+TT) infections was also observed [multibacillary vs. controls (OR: 1.56, 95% CI 1.07-2.28, P=0.054); paucibacillary vs. controls (OR: 1.92, 95% CI 1.21-3.01, P=0.013)]. In the dominant model, the genotypes of the TAP1 rs1135216AG+GG additionally contributed to an increased risk. Overall our findings demonstrate that the TAP1 gene variant (rs1135216 Asp637Gly) influences the susceptibility to clinically classified leprosy patients in Indian population.
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Abstract
Human host encounters a wide array of parasites; however, the crucial aspect is the failure of the host immune system to clear these parasites despite antigen recognition. In the recent past, a new immunological concept has emerged, which provides a framework to better understand several aspects of host susceptibility to parasitic infection. It is widely believed that parasites are able to modulate the magnitude of effector responses by inducing regulatory T cell (Tregs) population and several studies have investigated whether this cell population plays a role in balancing protective immunity and pathogenesis during parasite infection. This review discusses the several mechanism of Treg-mediated immunosuppression in the human host and focuses on the functional role of Tregs and regulatory gene polymorphisms in infectious diseases.
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Affiliation(s)
- T P Velavan
- Institute for Tropical Medicine, University of Tübingen, 72074 Tübingen, Germany.
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Hoang TV, Toan NL, Song LH, Ouf EA, Bock CT, Kremsner PG, Kun JFJ, Velavan TP. Ficolin-2 levels and FCN2 haplotypes influence hepatitis B infection outcome in Vietnamese patients. PLoS One 2011; 6:e28113. [PMID: 22140517 PMCID: PMC3222672 DOI: 10.1371/journal.pone.0028113] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 11/01/2011] [Indexed: 01/16/2023] Open
Abstract
Human Ficolin-2 (L-ficolins) encoded by FCN2 gene is a soluble serum protein that plays an important role in innate immunity and is mainly expressed in the liver. Ficolin-2 serum levels and FCN2 single nucleotide polymorphisms were associated to several infectious diseases. We initially screened the complete FCN2 gene in 48 healthy individuals of Vietnamese ethnicity. We genotyped a Vietnamese cohort comprising of 423 clinically classified hepatitis B virus patients and 303 controls for functional single nucleotide polymorphisms in the promoter region (-986G>A, -602G>A, -4A>G) and in exon 8 (+6424G>T) by real-time PCR and investigated the contribution of FCN2 genotypes and haplotypes to serum Ficolin-2 levels, viral load and liver enzyme levels. Haplotypes differed significantly between patients and controls (P = 0.002) and the haplotype AGGG was found frequently in controls in comparison to patients with hepatitis B virus and hepatocellular carcinoma (P = 0.0002 and P<0.0001) conferring a protective effect. Ficolin-2 levels differed significantly between patients and controls (p<0.0001). Patients with acute hepatitis B had higher serum Ficolin-2 levels compared to other patient groups and controls.The viral load was observed to be significantly distributed among the haplotypes (P = 0.04) and the AAAG haplotype contributed to higher Ficolin-2 levels and to viral load. Four novel single nucleotide polymorphisms in introns (-941G>T, -310G>A, +2363G>A, +4882G>A) and one synonymous mutation in exon 8 (+6485G>T) was observed. Strong linkage was found between the variant -986G>A and -4A>G. The very first study on Vietnamese cohort associates both Ficolin-2 serum levels and FCN2 haplotypes to hepatitis B virus infection and subsequent disease progression.
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Affiliation(s)
- Tong V Hoang
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.
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Hanel SA, Velavan TP, Kremsner PG, Kun JFJ. Novel and functional regulatory SNPs in the promoter region of FOXP3 gene in a Gabonese population. Immunogenetics 2011; 63:409-15. [PMID: 21472440 DOI: 10.1007/s00251-011-0524-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Accepted: 01/21/2011] [Indexed: 12/13/2022]
Abstract
Parasites exert a selection pressure on their hosts and are accountable for driving diversity within gene families and immune gene polymorphisms in a host population. The overwhelming response of regulatory T cells during infectious challenges directs the host immune system to lose the ability to mount parasite specific T cell responses. The underlying idea of this study is that regulatory single nucleotide polymorphism (SNPs) can cause significant changes in gene expression in functional immune genes. We identified and investigated regulatory SNPs in the promoter region of the FOXP3 gene in a group of Gabonese individuals exposed to a variety of parasitic infections. We identified two novel and one promoter variants in 40 individual subjects. We further validated these promoter variants for their allelic gene expression using transient transfection assays. Two promoter variants, -794 (C/G) and the other variant -734/-540 (C/T) revealed a significant higher expression of the reporter gene at basal level in comparison to the major allele. The identification of SNPs that modify function in the promoter regions could provide a basis for studying parasite susceptibility in association studies.
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Affiliation(s)
- Susanne A Hanel
- Institute for Tropical Medicine, University of Tübingen, Wilhelmstrasse 27, 72074 Tübingen, Germany
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Velavan TP, Bechlars S, Huang X, Kremsner PG, Kun JFJ. Novel regulatory SNPs in the promoter region of the TNFRSF18 gene in a Gabonese population. Braz J Med Biol Res 2011; 44:418-20. [PMID: 21445534 DOI: 10.1590/s0100-879x2011007500036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Accepted: 03/10/2011] [Indexed: 11/21/2022] Open
Abstract
Parasites are accountable for driving diversity within immune gene families. We identified and investigated regulatory single nucleotide polymorphisms (SNPs) in the promoter regions of the tumor necrosis factor receptor superfamily member 18 (TNFRSF18) gene by direct sequencing in a group of male Gabonese individuals exposed to a wide array of parasitic diseases such as malaria, filariasis and schistosomiasis. Two new promoter variants were identified in 40 individuals. Both novel variants were heterozygous and were linked to SNP #rs3753344 (C/T), which has been described. One of the SNP variants (ss2080581728) was close to the general transcription factor site, the TATA box. We further validated these new promoter variants for their allelic gene expression using transient transfection assays. One new promoter variant with two base changes (C/T - ss2080581728/rs3753344) displayed an altered expression of the marker gene. Both novel variants remained less active at the non-induced state in comparison to the major allele. The allele frequencies observed in this study were consistent with data for other African populations. The detection and analysis of these human immune gene polymorphisms contribute to a better understanding of the interaction between host-parasite and expression of Treg activity.
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Affiliation(s)
- T P Velavan
- Institute for Tropical Medicine, University of Tübingen, Germany.
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Velavan TP, Boldt ABW, Tomiuk J, Seibold F, Schoepfer AM, Flogerzi B, Müller S, Abad-Grau MDM, Kremsner PG, Kun JFJ. Variant alleles of the mannose binding lectin 2 gene (MBL2) confer heterozygote advantage within Crohn's families. Scand J Gastroenterol 2010; 45:1129-30. [PMID: 20443743 DOI: 10.3109/00365521.2010.485324] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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