1,723,059 research outputs found
Immunomodulatory Function of Interleukin 28B During Primary Infection With Cytomegalovirus
No full textBackground. Feedback mechanisms between interferons α and λ (IFNs) may be affected by single nucleotide polymorphisms (SNP) in interleukin 28B (IL-28B; IFN-λ3) promoter region and may influence cytomegalovirus (CMV) replication. Methods. We associated IL-28B SNPs with the risk of CMV replication after transplantation. Next, we examined the effect of IL-28B genotypes on IL-28B, and IFN-stimulated gene (ISG) expression, and CMV replication in human foreskin fibroblast (HFF) and peripheral blood mononuclear cells (PBMCs). Results. Transplant recipients with an IL-28B SNP (rs8099917) had significantly less CMV replication (P = .036). Both HFF-cells and PBMCs with a SNP showed lower IL-28B expression during infection with CMV, but higher "antiviral” ISG expression (eg, OAS1). Fibroblasts with a SNP had a 3-log reduction of CMV replication at day 4 (P = .004). IL-28B pretreatment induced ISG expression in noninfected fibroblasts, but a relative decrease of ISG expression could be observed in CMV-infected fibroblasts. The inhibitory effects of IL-28B could be abolished by siRNA or antagonistic peptides against the IL-28 receptor. In fibroblasts, inhibition of IL-28 signaling resulted in an increase of ISG expression and 3-log reduction of CMV-replication (P = .01). Conclusions. We postulate that IL-28B may act as a key regulator of ISG expression during primary CMV infection. IL-28B SNPs may be associated with higher antiviral ISG expression, which results in better replication contro
Immunomodulatory Function of Interleukin 28B during primary infection with cytomegalovirus
No full textFeedback mechanisms between interferons alpha and lambda (IFNs) may be affected by single nucleotide polymorphisms (SNP) in interleukin 28B (IL-28B; IFN-lambda3) promoter region and may influence cytomegalovirus (CMV) replication. We associated IL-28B SNPs with the risk of CMV replication after transplantation. Next, we examined the effect of IL-28B genotypes on IL-28B, and IFN-stimulated gene (ISG) expression, and CMV replication in human foreskin fibroblast (HFF) and peripheral blood mononuclear cells (PBMCs). Transplant recipients with an IL-28B SNP (rs8099917) had significantly less CMV replication (P = .036). Both HFF-cells and PBMCs with a SNP showed lower IL-28B expression during infection with CMV, but higher "antiviral" ISG expression (eg, OAS1). Fibroblasts with a SNP had a 3-log reduction of CMV replication at day 4 (P = .004). IL-28B pretreatment induced ISG expression in noninfected fibroblasts, but a relative decrease of ISG expression could be observed in CMV-infected fibroblasts. The inhibitory effects of IL-28B could be abolished by siRNA or antagonistic peptides against the IL-28 receptor. In fibroblasts, inhibition of IL-28 signaling resulted in an increase of ISG expression and 3-log reduction of CMV-replication (P = .01). We postulate that IL-28B may act as a key regulator of ISG expression during primary CMV infection. IL-28B SNPs may be associated with higher antiviral ISG expression, which results in better replication control
Estimating the net contribution of interleukin-28B variation to spontaneous hepatitis C virus clearance
No full textThe identification of associations between interleukin-28B (IL-28B) variants and the spontaneous clearance of hepatitis C virus (HCV) raises the issues of causality and the net contribution of host genetics to the trait. To estimate more precisely the net effect of IL-28B genetic variation on HCV clearance, we optimized genotyping and compared the host contributions in multiple- and single-source cohorts to control for viral and demographic effects. The analysis included individuals with chronic or spontaneously cleared HCV infections from a multiple-source cohort (n = 389) and a single-source cohort (n = 71). We performed detailed genotyping in the coding region of IL-28B and searched for copy number variations to identify the genetic variant or haplotype carrying the strongest association with viral clearance. This analysis was used to compare the effects of IL-28B variation in the two cohorts. Haplotypes characterized by carriage of the major alleles at IL-28B single-nucleotide polymorphisms (SNPs) were highly overrepresented in individuals with spontaneous clearance versus those with chronic HCV infections (66.1% versus 38.6%, P = 6 × 10(-9) ). The odds ratios for clearance were 2.1 [95% confidence interval (CI) = 1.6-3.0] and 3.9 (95% CI = 1.5-10.2) in the multiple- and single-source cohorts, respectively. Protective haplotypes were in perfect linkage (r(2) = 1.0) with a nonsynonymous coding variant (rs8103142). Copy number variants were not detected. CONCLUSION: We identified IL-28B haplotypes highly predictive of spontaneous HCV clearance. The high linkage disequilibrium between IL-28B SNPs indicates that association studies need to be complemented by functional experiments to identify single causal variants. The point estimate for the genetic effect was higher in the single-source cohort, which was used to effectively control for viral diversity, sex, and coinfections and, therefore, offered a precise estimate of the net host genetic contribution
Genetic variation of the IL-28B promoter affecting gene expression.
No full textThe current standard of care for the treatment of chronic hepatitis C is pegylated interferon-α (PEG-IFNα) and ribavirin (RBV). The treatment achieves a sustained viral clearance in only approximately 50% of patients. Recent whole genome association studies revealed that single nucleotide polymorphisms (SNPs) around IL-28B have been associated with response to the standard therapy and could predict treatment responses at approximately 80%. However, it is not clear which SNP is most informative because the genomic region containing significant SNPs shows strong linkage disequilibrium. We focused on SNPs in close proximity to the IL-28B gene to evaluate the function of each and identify the SNP affecting the IL-28B expression level most. The structures of IL-28A/B from 5' to 3'-UTR were determined by complete cDNA cloning. Both IL-28A and 28B genes consisted of 6 exons, differing from the CCDS data of NCBI. Two intron SNPs and a nonsynonymous SNP did not affect IL-28B gene function and expression levels but a SNP located in the proximal promoter region influenced gene expression. A (TA) dinucleotide repeat, rs72258881, located in the promoter region was discovered by our functional studies of the proximal SNPs upstream of IL-28B; the transcriptional activity of the promoter increased gradually in a (TA)(n) length-dependent manner following IFN-α and lipopolysaccharide stimulation. Healthy Japanese donors exhibited a broad range of (TA) dinucleotide repeat numbers from 10 to 18 and the most prevalent genotype was 12/12 (75%), differing from the database (13/13). However, genetic variation of IL-28A corresponding to that of IL-28B was not detected in these Japanese donors. These findings suggest that the dinucleotide repeat could be associated with the transcriptional activity of IL-28B as well as being a marker to improve the prediction of the response to interferon-based hepatitis C virus treatment
FIGURES 28a, 28b in The Nearctic Ecclisomyia species (Trichoptera: Limnephilidae)
No full textFIGURES 28a, 28b. Ecclisomyia maculosa Banks, female pupa, apical process. 28a, dorsal; 28b, ventral.Published as part of Givens, Donald R., 2018, The Nearctic Ecclisomyia species (Trichoptera: Limnephilidae), pp. 201-259 in Zootaxa 4413 (2) on page 236, DOI: 10.11646/zootaxa.4413.2.1, http://zenodo.org/record/122734
Lin-28B expression promotes transformation and invasion in human hepatocellular carcinoma
No full text許多microRNA (miRNA) 於人類癌症中常受抑制，如let-7 miRNA 家族。let-7 miRNA 家族除了調節癌細胞的自體更新(self-renewal)及腫瘤形成能力(tumorigenecity)外，於胚胎發育中也扮演重要角色。最近研究發現RNA結合蛋白(RNA-binding protein) Lin-28及Lin-28B會透過let-7的前趨物(precursor)於末端之尿嘧啶化(uridylation)並使之分解，以致let-7生合成減少。在肝癌細胞中，我們發現只有Lin-28B會高度表現，而Lin-28並沒有此現象。此外，Lin-28B較常表現於高度表現α胎兒蛋白並且分級(grade)較高的肝癌。於肝癌細胞株中，Hep3B及HCC36所表現的Lin-28B量最多，因此我們選擇這兩株細胞株為研究之用。我們利用RNA干擾的方式將其Lin-28B 敲減(knockdown)。利用轉殖Lin-28B載體，使Lin-28B過度表現於HA22T。Lin-28B被knockdown的細胞株Hep3B及HCC36在體外增生的速度降低。Lin-28B敲減的Hep3B細胞株在免疫不全小鼠(NOD/SCID mice)生成腫瘤的速率也下降。相反地，Lin-28B過度表現的HA22T細胞生長速度較快，且生成腫瘤的能力也較高。我們也發現過度表現Lin-28B的HA22T會引起上皮-間質轉化(Epithelial-mesenchymal transition)，而使其侵犯(invasion)及移動(migration)能力皆提高。由於Lin-28B與let-7 miRNA的密切關係，我們以大規模即時PCR陣列(Large-scale real-time PCR array)進一步研究，分析顯示Lin-28B所調節最主要的miRNA是let-7/mir-98家族。Lin-28B過度表現會使let-7所抑制的基因c-myc及HMGA2表現量增加； Lin-28B過度表現也會使受let-7控制的第一型類胰島素成長因子受體(IGF1R)表現量上升。我們的研究結果顯示，透過共同抑制let-7/mir-98家族及許多致癌基因途徑，Lin-28B於肝癌腫瘤形成及轉移扮演著重要的角色。In human cancers, multiple members of microRNAs (miRNA) are often repressed, such as the let-7 family miRNA. The let-7 family regulates self-renewal and tumorigenicity of cancer cells, and plays critical roles in embryonic development. The RNA binding proteins Lin-28 and Lin-28B are recently demonstrated to negatively regulate let-7 biogenesis by inducing terminal uridylation and degradation of the let-7 precursors. In this study, we showed that in hepatocellular carcinoma (HCC), only Lin-28B but not Lin-28 was highly expressed. Lin-28B expression in HCC was more frequently found in high grade tumors with high α-fetoprotein levels. Among the HCC cell lines, Hep3B and HCC36 expressed higher levels of Lin-28B than the other cell lines, and were chosen for gene knockdown of Lin-28B. HA22T cell line which had very low level or undetectable Lin-28B, was chosen for ectopic expression of Lin-28B. Knockdown of Lin-28B by RNA interference in the Hep3B and HCC36 led to suppressed proliferation in vitro and reduced in vivo tumor growth in NOD/SCID mice. In contrast, overexpression of Lin-28B in HA22T enhanced proliferation and tumorigenecity. Moreover, overexpression of Lin-28B induced epithelial-mesenchymal transition in HA22T cells, accompanied by increased invasion and migration capacity. To further delineate the role of Lin-28B in the expression of miRNA family, we did a large-scale real-time PCR array analysis. The results revealed that only let-7/mir-98 family members were regulated by Lin-28B. Lin-28B overexpression enhanced the expression of the known let-7 targets c-myc and HMGA2. In this study, we also found that Lin-28B enhanced the expression of type 1 insulin-like growth factor receptor (IGF1R) in a let-7-dependent manner. These findings highlight the important role for Lin-28B in tumor formation and invasion in HCC, through coordinated repression of the let-7/mir-98 family and induction of multiple oncogenic pathways
Polimorfismo de nucleotídeo único da il-28b rs12979860 e il-28b rs8099917 e infecção do citomegalovírus em pacientes submetidos a transplante de células-tronco hematopoiéticas
Full text linkOrientadora: Profa. Dra. Sonia Mara RaboniDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Saúde, Programa de Pós-Graduação em Medicina Interna e Ciências da Saúde. Defesa : Curitiba, 11/09/2018Inclui referênciasResumo: Introdução: A infecção pelo Citomegalovírus (CMV) após o Transplante de Células Tronco Hematopoiéticas (TCTH) ocorre em até 80% dos pacientes e impacta em aumento de mortalidade não relacionada a recidiva. A principal estratégia para redução do risco de doença pelo CMV é a terapia preemptiva, que consiste no monitoramento periódico e início precoce de antiviral. Apesar de eficaz, esta estratégia possui efeitos tóxicos e aumento nos custos. Estudos recentes sugerem que Polimorfismos de Nucleotídeo Único (PNU) da IL-28B modulam a infecção do CMV, o que poderia orientar o uso racional da terapia preemptiva. Objetivos: Identificar os genótipos dos PNU da IL-28B rs12979860 e IL-28B rs8099917 em pacientes submetidos à TCTH e associação com infecção do CMV. Métodos: Estudo analítico, observacional, longitudinal, prospectivo, não intervencionista. Foram avaliados os PNU descritos e correlacionados com a incidência de infecção e cinética viral do CMV e com a incidência de outras virais além de fúngicas e bacterianas. Os dados foram coletados do prontuário do paciente. Resultados: Os genótipos C/T (49,6%) da IL- 28B rs12979860 e o T/T (76,7%) da IL-28B rs8099917 foram os mais comuns. Não houve diferença significativa entre os grupos que tiveram infecção ou não do CMV quanto aos polimorfismos ou às variáveis estudadas. Os genótipos contendo alelos menores tanto da IL-28B rs12979869 quanto da IL-28B rs8099917 apresentaram uma menor progressão ao pico de antigenemia (p<0,05). O genótipo de alelo maior do receptor da IL-28B rs8099917 foi relacionado a menor incidência de infecção fúngica invasiva. Conclusão: O achado de uma menor progressão ao pico sugere que o alelo menor pode conferir uma melhor resposta imunológica após a infecção pelo CMV. Pode haver impacto, também, nas infecções fúngicas nesse contexto. Mais trabalhos são necessários para confirmar esses achados.Abstract: Introduction: Cytomegalovirus Infection after Hematopoietic Stem Cell Transplantation (HSCT) occurs in 60-80% of patients and impacts in higher nonrelapse- mortality. The main strategy for CMV disease prevention is preemptive therapy, which consists of periodic monitoring and early initiation of antiviral therapy. Although effective, this strategy has toxic effects and increased costs. Recent studies suggest that IL-28B Single Nucleotide Polymorphisms (SNP) modulate CMV infection, which could guide the rational use of preemptive therapy. Objectives: To identify the IL-28B SNP rs12979860 and IL-28B rs8099917 genotypes in patients undergoing HSCT and study their association with CMV infection. Methods: Analytical, observational, longitudinal, prospective, noninterventional study. To describe the SNU genotypes and correlated with CMV's infection incidence viral kinetics and with other viral infections incidence besides bacterial and fungal infections. Data were collected from patient's chart. Results: The IL-28B rs12979860 C/T(49.6%) and IL-28B rs8099917 T/T (76.7%) genotypes were the most common. There was no significant difference between groups with and without CMV infection regarding the SNP or variables studied. Genotypes containing minor alleles of both IL-28B rs12979869 and IL-28B rs8099917 showed a slower progression to the antigenemia peak (p <0.05). Recipient IL-28B rs8099917 genotype containing major alleles was related to lower incidence of invasive fungal infection. Conclusion: The finding of a smaller progression to the peak suggests that the minor allele may confer a better immune response after CMV infection in HSCT subjects. There may also be impact on fungal infections. More studies are needed to confirm these findings
IL28B, HLA-C, and KIR variants additively predict response to therapy in chronic Hepatitis C virus infection in a European cohort: A cross-sectional study
Full text linkBackground
To date, drug response genes have not proved as useful in clinical practice as was anticipated at the start of the genomic era. An exception is in the treatment of chronic hepatitis C virus (HCV) genotype 1 infection with pegylated interferon-alpha and ribavirin (PegIFN/R). Viral clearance is achieved in 40%–50% of patients. Interleukin 28B (IL28B) genotype predicts treatment-induced and spontaneous clearance. To improve the predictive value of this genotype, we studied the combined effect of variants of IL28B with human leukocyte antigen C (HLA-C), and its ligands the killer immunoglobulin-like receptors (KIR), which have previously been implicated in HCV viral control.
Methods and Findings
We genotyped chronic hepatitis C (CHC) genotype 1 patients with PegIFN/R treatment-induced clearance (n = 417) and treatment failure (n = 493), and 234 individuals with spontaneous clearance, for HLA-C C1 versus C2, presence of inhibitory and activating KIR genes, and two IL28B SNPs, rs8099917 and rs12979860. All individuals were Europeans or of European descent. IL28B SNP rs8099917 “G” was associated with absence of treatment-induced clearance (odds ratio [OR] 2.19, p = 1.27×10−8, 1.67–2.88) and absence of spontaneous clearance (OR 3.83, p = 1.71×10−14, 2.67–5.48) of HCV, as was rs12979860, with slightly lower ORs. The HLA-C C2C2 genotype was also over-represented in patients who failed treatment (OR 1.52, p = 0.024, 1.05–2.20), but was not associated with spontaneous clearance. Prediction of treatment failure improved from 66% with IL28B to 80% using both genes in this cohort (OR 3.78, p = 8.83×10−6, 2.03–7.04). There was evidence that KIR2DL3 and KIR2DS2 carriage also altered HCV treatment response in combination with HLA-C and IL28B.
Conclusions
Genotyping for IL28B, HLA-C, and KIR genes improves prediction of HCV treatment response. These findings support a role for natural killer (NK) cell activation in PegIFN/R treatment-induced clearance, partially mediated by IL28B
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