scholarly journals Synonymous SNPs of viral genes facilitate virus to escape host antiviral RNAi immunity

2018 ◽  
Author(s):  
Xiaobo Zhang ◽  
Yuechao Sun ◽  
Yu Zhang

Synonymous single nucleotide polymorphisms (SNPs) are involved in codon usage preference or mRNA splicing. Up to date, however, the role of synonymous SNPs in immunity remains unclear. To address this issue, the SNPs of white spot syndrome virus (WSSV) were characterized in shrimp in the present study. Our results indicated that there existed synonymous SNPs in the mRNAs of wsv151 and wsv226, two viral genes of WSSV. In the presence of SNP siRNA, wild-type siRNA, wild-type mRNA and SNP mRNA of wsv151 or wsv226, RNAi was significantly suppressed, showing that the synonymous SNPs of wsv151 and wsv226 played negative roles in host siRNA pathway due to mismatch of siRNA with its target. In insect cells, the mismatch, caused by synonymous SNPs of wsv151 or wsv226, between siRNA and its target inhibited the host RNAi. Furthermore, the data revealed that the co-injection of SNP siRNA and wild-type siRNA of wsv151 or wsv226 into WSSV-infected shrimp led to a significant increase of WSSV copies compared with that of SNP siRNA alone or wild-type siRNA alone, indicating that the synonymous SNPs of viral genes could be a strategy of virus escaping host siRNA pathway in shrimp in vivo. Therefore, our study provided novel insights into the underlying mechanism of virus escaping host antiviral RNAi immunity by synonymous SNPs of viral genes.

2013 ◽  
Vol 57 (11) ◽  
pp. 5658-5664 ◽  
Author(s):  
Soo-Jin Yang ◽  
Nagendra N. Mishra ◽  
Aileen Rubio ◽  
Arnold S. Bayer

ABSTRACTSingle nucleotide polymorphisms (SNPs) within themprFopen reading frame (ORF) have been commonly observed in daptomycin-resistant (DAPr)Staphylococcus aureusstrains. Such SNPs are usually associated with a gain-in-function phenotype, in terms of either increased synthesis or enhanced translocation (flipping) of lysyl-phosphatidylglycerol (L-PG). However, it is unclear if suchmprFSNPs are causal in DAPrstrains or are merely a biomarker for this phenotype. In this study, we used an isogenic set ofS. aureusstrains: (i) Newman, (ii) its isogenic ΔmprFmutant, and (iii) several intransplasmid complementation constructs, expressing either a wild-type or point-mutated form of themprFORF cloned from two isogenic DAP-susceptible (DAPs)-DAPrstrain pairs (616-701 and MRSA11/11-REF2145). Complementation of the ΔmprFstrain with singly point-mutatedmprFgenes (mprFS295LormprFT345A) revealed that (i) individual and distinct point mutations within themprFORF can recapitulate phenotypes observed in donor strains (i.e., changes in DAP MICs, positive surface charge, and cell membrane phospholipid profiles) and (ii) these gain-in-function SNPs (i.e., enhanced L-PG synthesis) likely promote reduced DAP binding toS. aureusby a charge repulsion mechanism. Thus, for these two DAPrstrains, the definedmprFSNPs appear to be causally related to this phenotype.


Author(s):  
Lyudmila P. Kuzmina ◽  
Anastasiya G. Khotuleva ◽  
Evgeniy V. Kovalevsky ◽  
Nikolay N. Anokhin ◽  
Iraklij M. Tskhomariya

Introduction. Various industries widely use chrysotile asbestos, which determines the relevance of research aimed at the prevention of asbestos-related diseases. It is promising to assess the role of specific genes, which products are potentially involved in the development and regulation of certain links in the pathogenesis of asbestosis, forming a genetic predisposition to the disease. The study aims to analyze the presence of associations of genetic polymorphism of cytokines and antioxidant enzymes with asbestosis development. Materials and methods. Groups were formed for examination among employees of OJSC "Uralasbest" with an established diagnosis of asbestosis and without lung diseases. For each person included in the study, dust exposure doses were calculated considering the percentage of time spent at the workplace during the shift for the entire work time. Genotyping of single nucleotide polymorphisms of cytokines IL1b (rs16944), IL4 (rs2243250), IL6 (rs1800795), TNFα (rs1800629) and antioxidant enzymes SOD2 (rs4880), GSTP1 (rs1610011), CAT (rs1001179) was carried out. Results. The authors revealed the associations of polymorphic variants A511G IL1b gene (OR=2.457, 95% CI=1.232-4.899) and C47T SOD2 gene (OR=1.705, 95% CI=1.055-2.756) with the development of asbestosis. There was an increase in the T allele IL4 gene (C589T) frequency in persons with asbestosis at lower values of dust exposure doses (OR=2.185, 95% CI=1.057-4.514). The study showed the associations of polymorphism C589T IL4 gene and C174G IL6 gene with more severe asbestosis, polymorphism A313G GSTP1 gene with pleural lesions in asbestosis. Conclusion. Polymorphic variants of the genes of cytokines and antioxidant enzymes, the protein products directly involved in the pathogenetic mechanisms of the formation of asbestosis, contribute to forming a genetic predisposition to the development and severe course of asbestosis. Using the identified genetic markers to identify risk groups for the development and intense period of asbestos-related pathology will optimize treatment and preventive measures, considering the organism's characteristics.


2021 ◽  
Vol 11 (15) ◽  
pp. 6865
Author(s):  
Eun Seon Lee ◽  
Joung Hun Park ◽  
Seong Dong Wi ◽  
Ho Byoung Chae ◽  
Seol Ki Paeng ◽  
...  

The thioredoxin-h (Trx-h) family of Arabidopsis thaliana comprises cytosolic disulfide reductases. However, the physiological function of Trx-h2, which contains an additional 19 amino acids at its N-terminus, remains unclear. In this study, we investigated the molecular function of Trx-h2 both in vitro and in vivo and found that Arabidopsis Trx-h2 overexpression (Trx-h2OE) lines showed significantly longer roots than wild-type plants under cold stress. Therefore, we further investigated the role of Trx-h2 under cold stress. Our results revealed that Trx-h2 functions as an RNA chaperone by melting misfolded and non-functional RNAs, and by facilitating their correct folding into active forms with native conformation. We showed that Trx-h2 binds to and efficiently melts nucleic acids (ssDNA, dsDNA, and RNA), and facilitates the export of mRNAs from the nucleus to the cytoplasm under cold stress. Moreover, overexpression of Trx-h2 increased the survival rate of the cold-sensitive E. coli BX04 cells under low temperature. Thus, our data show that Trx-h2 performs function as an RNA chaperone under cold stress, thus increasing plant cold tolerance.


Author(s):  
Emmanuel Lecorche ◽  
Côme Daniau ◽  
Kevin La ◽  
Faiza Mougari ◽  
Hanaa Benmansour ◽  
...  

Abstract Background Post-surgical infections due to Mycobacterium chimaera appeared as a novel nosocomial threat in 2015, with a worldwide outbreak due to contaminated heater-cooler units used in open chest surgery. We report the results of investigations conducted in France including whole genome sequencing comparison of patient and HCU isolates. Methods We sought M. chimaera infection cases from 2010 onwards through national epidemiological investigations in healthcare facilities performing cardiopulmonary bypass together with a survey on good practices and systematic heater-cooler unit microbial analyses. Clinical and HCU isolates were subjected to whole genome sequencing analyzed with regards to the reference outbreak strain Zuerich-1. Results Only two clinical cases were shown to be related to the outbreak, although 23% (41/175) heater-cooler units were declared positive for M. avium complex. Specific measures to prevent infection were applied in 89% (50/56) healthcare facilities although only 14% (8/56) of them followed the manufacturer maintenance recommendations. Whole genome sequencing comparison showed that the clinical isolates and 72% (26/36) of heater-cooler unit isolates belonged to the epidemic cluster. Within clinical isolates, 5 to 9 non-synonymous single nucleotide polymorphisms were observed, among which an in vivo mutation in a putative efflux pump gene observed in a clinical isolate obtained for one patient under antimicrobial treatment. Conclusions Cases of post-surgical M. chimaera infections were declared to be rare in France, although heater-cooler units were contaminated as in other countries. Genomic analyses confirmed the connection to the outbreak and identified specific single nucleotide polymorphisms, including one suggesting fitness evolution in vivo.


2021 ◽  
Vol 14 (3) ◽  
pp. 235
Author(s):  
Jen-Sheng Pei ◽  
Chao-Chun Chen ◽  
Wen-Shin Chang ◽  
Yun-Chi Wang ◽  
Jaw-Chyun Chen ◽  
...  

The purpose of our study was to investigate whether genetic variations in lncRNA H19 were associated with susceptibility to childhood leukemia. Two hundred and sixty-six childhood leukemia patients and 266 healthy controls were enrolled in Taiwan, and two single nucleotide polymorphisms (SNPs), rs2839698 and rs217727, in H19 were genotyped and analyzed. There was a significant difference in the genotypic distribution of rs2839698 between patients and healthy controls (p = 0.0277). Compared to the wild-type CC genotype, the heterozygous variant CT and homozygous variant TT genotypes were associated with significantly increased risks of childhood leukemia with an adjusted odd ratio (OR) of 1.46 (95% confidence interval (CI), 1.08–2.14, p = 0.0429) and 1.94 (95%CI, 1.15–3.31, p = 0.0169), respectively (pfor tread = 0.0277). The difference in allelic frequencies between childhood leukemia patients and controls was also significant (T versus C, adjusted OR = 1.53, 95%CI, 1.13–1.79, p = 0.0077). There were no significant differences in the genotypic and allelic distributions of rs217727 between cases and controls. Interestingly, the average level of H19 rs2839698 was statistically significantly higher for patients with CT and TT genotypes than from those with the CC genotype (p < 0.0001). Our results indicate that H19 SNP rs2839698, but not rs217727, may serve as a novel susceptibility marker for childhood leukemia.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Erika Calvano Küchler ◽  
Agnes Schröder ◽  
Vinicius Broska Teodoro ◽  
Ute Nazet ◽  
Rafaela Scariot ◽  
...  

Abstract Background This study aimed to investigate, if different physiological concentrations of vitamin D (25(OH)D3) and single nucleotide polymorphisms in vitamin D receptor (VDR) gene have an impact on gene expression in human periodontal ligament (hPDL) fibroblasts induced by simulated orthodontic compressive strain. Methods A pool of hPDL fibroblasts was treated in absence or presence of 25(OH)D3 in 3 different concentrations (10, 40 and 60 ng/ml). In order to evaluate the role of single nucleotide polymorphisms in the VDR gene, hPDL fibroblasts from 9 patients were used and treated in absence or presence of 40 ng/ml 25(OH)D3. Each experiment was performed with and without simulated orthodontic compressive strain. Real-time PCR was used for gene expression and allelic discrimination analysis. Relative expression of dehydrocholesterol reductase (DHCR7), Sec23 homolog A, amidohydrolase domain containing 1 (AMDHD1), vitamin D 25-hydroxylase (CYP2R1), Hydroxyvitamin D-1-α hydroxylase, receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), cyclooxygenase-2 (COX-2) and interleukin-6 (IL6) was assessed. Three single nucleotide polymorphisms in VDR were genotyped. Parametric or non-parametric tests were used with an alpha of 5%. Results RANKL, RANKL:OPG ratio, COX-2, IL-6, DHCR7, CYP2R1 and AMDHD1 were differentially expressed during simulated orthodontic compressive strain (p < 0.05). The RANKL:OPG ratio was downregulated by all concentrations (10 ng/ml, 40 ng/ml and 60 ng/ml) of 25(OH)D3 (mean = 0.96 ± 0.68, mean = 1.61 ± 0.66 and mean = 1.86 ± 0.78, respectively) in comparison to the control (mean 2.58 ± 1.16) (p < 0.05). CYP2R1 gene expression was statistically modulated by the different 25(OH)D3 concentrations applied (p = 0.008). Samples from individuals carrying the GG genotype in rs739837 presented lower VDR mRNA expression and samples from individuals carrying the CC genotype in rs7975232 presented higher VDR mRNA expression (p < 0.05). Conclusions Simulated orthodontic compressive strain and physiological concentrations of 25(OH)D3 seem to regulate the expression of orthodontic tooth movement and vitamin-D-related genes in periodontal ligament fibroblasts in the context of orthodontic compressive strain. Our study also suggests that single nucleotide polymorphisms in the VDR gene regulate VDR expression in periodontal ligament fibroblasts in the context of orthodontic compressive strain.


2010 ◽  
Vol 70 (4) ◽  
pp. 668-674 ◽  
Author(s):  
P Dieudé ◽  
M Guedj ◽  
J Wipff ◽  
B Ruiz ◽  
G Riemekasten ◽  
...  

BackgroundRecent evidence has highlighted a potential role of interleukin 1β (IL-1β) in systemic sclerosis (SSc). NLRP1 provides a scaffold for the assembly of the inflammasome that promotes the processing and maturation of pro-IL-1β. In addition, NLRP1 variants were found to confer susceptibility to autoimmune disorders.ObjectiveTo study a possible association of the NLRP1 rs6502867, rs2670660 and rs8182352, rs12150220 and rs4790797 with SSc in the European Caucasian population.MethodsNLRP1 single nucleotide polymorphisms were genotyped in 3227 individuals comprising a discovery set (870 SSc patients and 962 controls) and a replication set including individuals from Germany (532 SSc patients and 324 controls) and Italy (527 SSc patients and 301 controls), all individuals being of European Caucasian origin.ResultsConditional analyses revealed a significant association for the NLRP1 rs8182352 variant with both anti-topoisomerase-positive and SSc-related fibrosing alveolitis (FA) subsets under an additive model: p=0.0042, OR 1.23 (95% CI 1.07 to 1.41) and p=0.0065 OR 1.19 (95% CI 1.05 to 1.36), respectively. Logistic regression analysis showed an additive effect of IRF5 rs2004640, STAT4 rs7574865 and NLRP1 rs8182352 risk alleles on SSc-related FA.ConclusionsOur results establish NLRP1 as a new genetic susceptibility factor for SSc-related pulmonary fibrosis and anti-topoisomerase-positive SSc phenotypes. This provides new insights into the pathogenesis of SSc, underlining the potential role of innate immunity in particular in the FA-positive SSc subphenotype, which represents a severe subset of the disease.


2008 ◽  
Vol 200 (1) ◽  
pp. 23-33 ◽  
Author(s):  
S Schmidt ◽  
A Hommel ◽  
V Gawlik ◽  
R Augustin ◽  
N Junicke ◽  
...  

Deletion of glucose transporter geneSlc2a3(GLUT3) has previously been reported to result in embryonic lethality. Here, we define the exact time point of growth arrest and subsequent death of the embryo.Slc2a3−/−morulae and blastocysts developed normally, implantedin vivo, and formed egg-cylinder-stage embryos that appeared normal until day 6.0. At day 6.5, apoptosis was detected in the ectodermal cells ofSlc2a3−/−embryos resulting in severe disorganization and growth retardation at day 7.5 and complete loss of embryos at day 12.5. GLUT3 was detected in placental cone, in the visceral ectoderm and in the mesoderm of 7.5-day-old wild-type embryos. Our data indicate that GLUT3 is essential for the development of early post-implanted embryos.


1995 ◽  
Vol 182 (5) ◽  
pp. 1415-1421 ◽  
Author(s):  
T C Wu ◽  
A Y Huang ◽  
E M Jaffee ◽  
H I Levitsky ◽  
D M Pardoll

Introduction of the B7-1 gene into murine tumor cells can result in rejection of the B7-1 transductants and, in some cases, systemic immunity to subsequent challenge with the nontransduced tumor cells. These effects have been largely attributed to the function of B7-1 as a costimulator in directly activating tumor specific, major histocompatibility class I-restricted CD8+ T cells. We examined the role of B7-1 expression in the direct rejection as well as in the induction of systemic immunity to a nonimmunogenic murine tumor. B-16 melanoma cells with high levels of B7-1 expression did not grow in C57BL/6 recipient mice, while wild-type B-16 cells and cells with low B7-1 expression grew progressively within 21 d. In mixing experiments with B7-1hi and wild-type B-16 cells, tumors grew out in vivo even when a minority of cells were B7-1-. Furthermore, the occasional tumors that grew out after injection of 100% B-16 B7-1hi cells showed markedly decreased B7-1 expression. In vivo antibody depletions showed that NK1.1 and CD8+ T cells, but not CD4+ T cells, were essential for the in vivo rejection of tumors. Animals that rejected B-16 B7-1hi tumors did not develop enhanced systemic immunity against challenge with wild-type B-16 cells. These results suggest that a major role of B7-1 expression by tumors is to mediate direct recognition and killing by natural killer cells. With an intrinsically nonimmunogenic tumor, this direct killing does not lead to enhanced systemic immunity.


2018 ◽  
Vol 315 (4) ◽  
pp. G433-G442 ◽  
Author(s):  
Kayte A. Jenkin ◽  
Peijian He ◽  
C. Chris Yun

Lysophosphatidic acid (LPA) is a bioactive lipid molecule, which regulates a broad range of pathophysiological processes. Recent studies have demonstrated that LPA modulates electrolyte flux in the intestine, and its potential as an antidiarrheal agent has been suggested. Of six LPA receptors, LPA5 is highly expressed in the intestine. Recent studies by our group have demonstrated activation of Na+/H+ exchanger 3 (NHE3) by LPA5. However, much of what has been elucidated was achieved using colonic cell lines that were transfected to express LPA5. In the current study, we engineered a mouse that lacks LPA5 in intestinal epithelial cells, Lpar5ΔIEC, and investigated the role of LPA5 in NHE3 regulation and fluid absorption in vivo. The intestine of Lpar5ΔIEC mice appeared morphologically normal, and the stool frequency and fecal water content were unchanged compared with wild-type mice. Basal rates of NHE3 activity and fluid absorption and total NHE3 expression were not changed in Lpar5ΔIEC mice. However, LPA did not activate NHE3 activity or fluid absorption in Lpar5ΔIEC mice, providing direct evidence for the regulatory role of LPA5. NHE3 activation involves trafficking of NHE3 from the terminal web to microvilli, and this mobilization of NHE3 by LPA was abolished in Lpar5ΔIEC mice. Dysregulation of NHE3 was specific to LPA, and insulin and cholera toxin were able to stimulate and inhibit NHE3, respectively, in both wild-type and Lpar5ΔIEC mice. The current study for the first time demonstrates the necessity of LPA5 in LPA-mediated stimulation of NHE3 in vivo. NEW & NOTEWORTHY This study is the first to assess the role of LPA5 in NHE3 regulation and fluid absorption in vivo using a mouse that lacks LPA5 in intestinal epithelial cells, Lpar5ΔIEC. Basal rates of NHE3 activity and fluid absorption, and total NHE3 expression were not changed in Lpar5ΔIEC mice. However, LPA did not activate NHE3 activity or fluid absorption in Lpar5ΔIEC mice, providing direct evidence for the regulatory role of LPA5.


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