Cytochrome P450 Enzyme-Mediated Bioactivation as an Underlying Mechanism of Columbin-Induced Hepatotoxicity.

Columbin, a furanoid compound, is the major bioactive ingredient of Tinospora sagittata (Oliv.) Gagnep, a traditional Chinese medicine that has been reported to cause liver injury in the clinic. The aim of this study was to investigate the hepatotoxicity caused by columbin and its underlying mechanism. Our results indicated that columbin could result in a dose-dependent increase of mice serum alanine aminotransferase and aspartate aminotransferase after oral treatment with columbin, as well as local spotty necrosis in the liver of mice treated with columbin. No hepatotoxicity was observed in mouse treated with the same dose of tetrahydrocolumbin. Pretreatment with ketoconazole preserved the mice from columbin-induced hepatotoxicity. Further studies suggested that bioactivation of the furan ring played an indispensable role in columbin-caused hepatotoxicity. In vitro and in vivo metabolism studies demonstrated that columbin could be metabolized into the cis-butene-1,4-dial intermediate, which readily reacted with glutathione and N-acetyllysine to form stable adducts. Ketoconazole displayed strong inhibitory effect on the generation of M4 and M5 both in vitro and in vivo. Further recombinant human CYP450 screening demonstrated that CYP3A4 was the major enzyme responsible for columbin bioactivation. The present study demonstrated that columbin was hepatotoxic and CYP3A4-mediated bioactivation of the furan ring would serve as an underlying mechanism for columbin-induced hepatotoxicity.

Siglec1 enhances inflammation through miR-1260-dependent degradation of IκBα in COPD.

It has been documented that sialic acid-binding Ig-like lectin 1 (Siglec1) is a cell surface protein with a variety of functions in the immune system. In the present study, we evaluated whether Siglec1 plays a role in chronic obstructive pulmonary disease (COPD). Results show that the expression of Siglec1 was increased in the lung of COPD rats, and that Siglec1 overexpression greatly enhanced the expression of inflammatory cytokines including tumor necrosis factor α (TNF-α), interleukin 1ß (IL-1ß) and IL-6 in cigarette smoke extract (CSE)-treated NR8383 cells, a rat lung-derived macrophage cell line. Notably, the proinflammatory effect of Siglec1 was totally inhibited by overexpression of nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor α (IκBα). Importantly, Siglec1 overexpression increased miR-1260, which then degraded IκBα through its 3' untranslated region (3'UTR). Further study demonstrated that miR-1260 inhibitor attenuated inflammation in CSE-induced rat COPD lung and in CSE-treated NR8383 cells. Finally, the inhibitory effect of miR-1260 on inflammation was totally lost when IκBα was inhibited. In summary, the present study demonstrated that Siglec1 exerts its proinflammatory effects through increasing miR-1260, leading to decreased expression of IκBα.

A novel small RNA contributes to restrain cellular chain length and anti-phagocytic ability in Streptococcus suis 2.

Streptococcus suis serotype 2 (SS2) is an important porcine and human pathogen. Regulatory small non-coding RNAs (sRNAs) play an essential role in diverse physiological processes, although they remain poorly understood in SS2. In this study, we identified eight novel sRNAs through a combination of computational strategies and experimental identification. To explore roles of these novel sRNAs, sRNA34 was preferentially selected to assess phenotypes of the deletion strain in vitro and in vivo. The inactivation of sRNA34 significantly elongated the cellular chain, remarkably increased sensitivity to phagocytosis by RAW264.7, and attenuated virulence in a mouse infection model. Transcriptomic analysis revealed that inactivation of sRNA34 altered expression of multiple genes contributing to cellular chain formation and elongation, indicating a potential mechanism of sRNA34 in maintaining proper bacterial chain length to resist phagocytosis by the host cell. In summary, sRNA34 is a novel sRNA that contributes to cellular chain regulation and the anti-phagocytosis ability of SS2.

Efficacy and safety of Sofosbuvir-containing regimens in patients co-infected with chronic hepatitis C virus and human immunodeficiency virus: a meta-analysis.

BACKGROUND: The treatment of hepatitis C virus (HCV) in HCV/human immunodeficiency virus (HIV) co-infected patients remains complex. This present meta-analysis evaluated the efficacy and safety of Sofosbuvir (SOF) for treatment in HCV/HIV co-infected patients using the most recent and available data. METHODS: A systematic search of the published data was conducted in PubMed Medline, EMBASE and Cochrane databases. Eligible studies were clinical trials, case-control studies or prospective cohort studies aiming at assessing the efficacy and safety of the SOF-containing regimens in patients co-infected with HCV and HIV. Heterogeneity of results was assessed and a pooled analysis was performed using random effects model with maximum likelihood estimate and 95% confidence intervals (95%CI). Subgroup analysis and assessment of publication bias through Egger's test were also performed. STATA 13.0 software was used to analyze the data. RESULTS: Seven studies (n = 1167 co-infected patients) were included in this analysis. The pooled estimate of sustained virological response at 12 weeks (SVR12) was 94.0% (95%CI: 92.0%-95.0%). Subgroup analysis showed that the treatment-naïve patients had higher SVR12 compared with patients that were treated before (χ2 = 21.39, P < 0.01). The pooled incidence of any adverse events (AEs) was 79.6% (95%CI: 77.1%-82.1%). Publication bias did not exist. CONCLUSION: The results of this study showed that the treatment response of SOF-containing regimens in patients co-infected with HIV and HCV was satisfied. Attention should be paid to the high rates of AEs.

Genetic variants in human leukocyte antigen-DP influence both hepatitis C virus persistence and hepatitis C virus F protein generation in the Chinese Han population.

Chronic hepatitis C is a serious liver disease that often results in cirrhosis or hepatocellular carcinoma. The aim of this study was to assess the association of human leukocyte antigen-DP (HLA-DP) variants with risk of chronic hepatitis C virus (HCV) or anti-F antibody generation. We selected two single nucleotide polymorphisms (SNPs) in a region including HLA-DPA1 (rs3077) and HLA-DPB1 (rs9277534) and genotyped SNPs in 702 cases and 342 healthy controls from the Chinese population using TaqMan SNP genotyping assay. Moreover, the exon 2 of the HLA-DPA1 and HLA-DPB1 genes were amplified and determined by sequencing-based typing (SBT). The results showed that rs3077 significantly increased the risk of chronic HCV infection in additive models and dominant models (odds ratio (OR) = 1.32 and 1.53). The rs3077 also contributed to decrease the risk of anti-F antibody generation in additive models and dominant models (OR = 0.46 and 0.56). Subsequent analyses revealed the risk haplotypes (DPA1*0103-DPB1*0501 and DPA1*0103-DPB1*0201) and protective haplotypes (DPA1*0202-DPB1*0501 and DPA1*0202-DPB1*0202) to chronic HCV infection. Moreover, we also found that the haplotype of DPA1*0103-DPB1*0201 and DPA1*0202-DPB1*0202 were associated with the anti-F antibody generation. Our findings show that genetic variants in HLA-DP gene are associated with chronic HCV infection and anti-F antibody generation.

Pathogenicity of a natural reassortant hantavirus CGRn9415 in newborn rats and newborn mice.

To better understand the pathogenicity and infectivity of a natural reassortant CGRn9415 generated from Hantaan virus (HTNV) and Seoul virus (SEOV), CGRn9415, HTNV 76-118 and SEOV L99 were used to infect newborn Kunming (KM) mice and newborn Wistar rats. In KM mice, there was no statistical difference between the death rate with CGRn9415 and that of L99, while 76-118 killed all mice even at low dosage; CGRn9415 killed all infected rats similar to L99 at the dosage of 10(5) f.f.u., while no death occurred in rats infected with 76-118 even as high as 2 × 10(5) f.f.u., suggesting that the reassortant CGRn9415 possesses similar pathogenicity as L99. Furthermore, the reassortant CGRn9415 could establish a persistent infection in both KM mice and Wistar rats more easily than 76-118 or L99. These data suggest that the reassorted hantavirus behaves more like SEOV as far as the pathogenicity is concerned.

[A novel bacterial cell-surface display system based on NCgl1221 from Corynebacterium glutamicum].

OBJECTIVE: To develop a novel Escherichia coli cell surface display system by using C-terminally truncated NCgl1221 as the anchoring protein, which greatly enriched or optimized the bacterial displayed systems. METHODS: We amplified the sequence of C-terminally truncated NCgl1221 and beta-amylase, and constructed the fusion expression vector. Then we transformed the recombinant plasmids PET-NA and PET-28a into Rosetta (DE3) pLysS. The fusion protein expression was induced by IPTG and identified by SDS-PAGE and Western blot analysis. The IPTG induced strains were immunostained and investigated by fluorescence microscope and flow cytometry to detect the displayed beta-amylase. Finally, we analyzed the activity of beta-amylase and starch hydrolization in order to determine whether the displayed beta-amylase has the activity or not. RESULTS: The fusion protein was successfully expressed in E. coli, and the active beta-amylase was displayed on the cell surface by fusing it to the C terminus of the anchor. The recombinant strain displaying beta-amylase can utilize soluble starch in the medium. CONCLUSION: A novel E. coli surface display system by using C-terminally truncated NCgl1221 as the anchor motif was successfully developed. The active enzyme with a molecular size of 56 kDa was displayed on E. coli by this system, which provided the basis for the application of the system in whole-cell biocatalyst or biosorbent.

CircFAM53B promotes the proliferation and metastasis of glioma through activating the c-MET/PI3K/AKT pathway via sponging miR-532-3p.

Increasing evidence reveals that circular RNAs (circRNAs) regulate multiple biological functions in glioma. Previously, several reports have illustrated that circFAM53B contributes to cancer development. However, the functions and mechanisms of circFAM53B in glioma remain elusive. Here, we gauged the circFAM53B profile in glioma tissues and cell lines and conducted gain-of-function assays of circFAM53B to verify circFAM53B's influence on the proliferation and metastasis of glioma cells (including A172 and LN18). As a result, circFAM53B was up-regulated in glioma tissues (vs. the matched non-tumor tissues). Higher levels of circFAM53B predicted poorer survival of glioma patients. Functionally, circFAM53B up-regulation accelerated cell proliferation, colony formation, invasion and epithelial-mesenchymal transition (EMT), and heightened Bax/Bcl2 ratio. By contrast, circFAM53B down-regulation repressed glioma development in vitro. Mechanistically, bioinformatics analysis suggested that circFAM53B served as a competitive endogenous RNA (ceRNA) by sponging miR-532-3p, which targeted proto-oncogene (MET) and receptor tyrosine kinase (c-MET). miR-532-3p up-regulation delayed glioma development and inactivated the PI3K/AKT axis. Moreover, the treatment of the c-MET inhibitor SGX523, the PI3K inhibitor LY294002, and the Akt inhibitor MK-2206 reduced circFAM53B-mediated oncogenic effects. Conclusively, circFAM53B aggravated glioma progression by up-regulating the c-MET/PI3K/AKT pathway and down-regulating miR-532-3p. Thus, the circFAM53B/miR-532-3p/c-MET/PI3K/AKT axis is a potential treatment target for glioma.

[Study on the transmission of Hantaan virus and Orientia tsutsugamushi by naturally dual infected Leptotrombidium scutellare through stinging].

OBJECTIVE: To investigate whether Leptotrombidium scutellare could be naturally infected by both Hantaan virus (HV) and Orientia tsutsugamushi (OT) and transmission status by stinging. METHODS: 3459 Leptotrombidium scutellares from mice bodies and 3265 which were free were collected in the epidemic area of hemorrhagic fever with renal syndrome (HFRS) and tsutsugamushi disease.15 days later, the suspensions of lung and spleen of mice with 6 in a group stung by 1, 5 or 10 infected mites were injected intra-cerebrally into other mice for the detection of HV and OT in the next 6 generations of the mice, with immunofluorescent antibody technique (IFAT) and Giemsa staining technique. The passages of Vero-E6 cells inoculated on the aseptic filtrations from different number of infected mites were used to detect HV and OT pathogens. HV-RNA and OT-DNA were detected by PCR. RESULTS: After passage, HV positive mouse body mite group out of both 5 and 10 mites in the sixth generation, OT positive mouse body mite group out of the 10 mites in the sixth generation, both HV and OT positive mouse body mite group out of 1 mite in the fifth and sixth generation, both HV and OT positive mouse body mite group out of 5 and 10 mites in the sixth generation, and free mites group out of 1, 5 and 10 mites in the sixth generation, were found one mouse infected by both HV and OT, respectively. Out of the fourth generation of Vero-E6 cells, one sample was found both HV and OT positive out of 5 and 10 HV and OT mouse body mite group, respectively. In the sixth generation, both HV and OT positive cells were detected in one mouse mite group and the 1, 5, 10 free mite groups, respectively. HV-RNA and OT-DNA were all detected by PCR. CONCLUSION: Both HV and OT could be coexisted in wild Leptotrombidium scutellare and transmitted by stinging.

Display of alpha-amylase on the surface of Corynebacterium glutamicum cells by using NCgl1221 as the anchoring protein, and production of glutamate from starch.

We developed a new cell surface display system in Corynebacterium glutamicum based on the C-terminally truncated NCgl1221 anchor protein to increase L-glutamate production from starch directly. The C-terminally truncated NCgl1221 protein is a mutant NCgl1221 and leads to the constitutive export of L-glutamate. The N terminus of alpha-amylase (AmyA) was fused to truncated NCgl1221, and the resulting fusion protein was expressed on the cell surface by IPTG induction. Localization of the fusion protein was confirmed by immunofluorescence microscopy and flow cytometric analysis. The results of L-glutamate fermentation showed that the soluble starch was utilized to grow and produce L-glutamate by the recombinant strain displaying AmyA. The amount of soluble starch was reduced from 30.0 +/- 2.8 to 4.5 +/- 0.7 g/l under non-inducing condition and from 50.0 +/- 2.4 to 12.5 +/- 1.1 g/l under biotin limitation in 36 h. The glutamate concentration in the medium was transiently increased in 14 h under no induction, while under biotin-limiting condition, glutamate production was continuously elevated during fermentation. The amount of glutamate reached 19.3 +/- 2.1 g/l after 26 h of fermentation with biotin limitation, which was greater than that produced by the strain using PgsA, one of the poly-gamma-glutamate synthetase complexes, as the anchor protein under the same condition. Therefore, the truncated NCgl1221 anchor protein has more advantages than the PgsA anchor protein in glutamate fermentation because truncated NCgl1221 leads to the constitutive export of L-glutamate without any treatments.

Double deletion of dtsR1 and pyc induce efficient L: -glutamate overproduction in Corynebacterium glutamicum.

Corynebacterium glutamicum strains are used for the fermentative production of L-glutamate. Five C. glutamicum deletion mutants were isolated by two rounds of selection for homologous recombination and identified by Southern blot analysis. The growth, glucose consumption and glutamate production of the mutants were analyzed and compared with the wild-type ATCC 13032 strain. Double disruption of dtsR1 (encoding a subunit of acetyl-CoA carboxylase complex) and pyc (encoding pyruvate carboxylase) caused efficient overproduction of L-glutamate in C. glutamicum; production was much higher than that of the wild-type strain and DeltadtsR1 strain under glutamate-inducing conditions. In the absence of any inducing conditions, the amount of glutamate produced by the double-deletion strain DeltadtsR1Deltapyc was more than that of the mutant DeltadtsR1. The activity of phosphoenolpyruvate carboxylase (PEPC) was found to be higher in the DeltadtsR1Deltapyc strain than in the DeltadtsR1 strain and the wild-type strain. Therefore, PEPC appears to be an important anaplerotic enzyme for glutamate synthesis in DeltadtsR1 derivatives. Moreover, this conclusion was confirmed by overexpression of ppc and pyc in the two double-deletion strains (DeltadtsR1Deltappc and DeltadtsR1Deltapyc), respectively. Based on the data generated in this investigation, we suggest a new method that will improve glutamate production strains and provide a better understanding of the interaction(s) between the anaplerotic pathway and fatty acid synthesis.

WITHDRAWN: LncRNA DSCAM-AS1 Promotes Proliferation, Migration and Invasion of Colorectal Cancer Cells via Modulating miR-144-5p/CDKL1.

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[Molecular epidemiological study on the host and role of the Hantavirus and Orientia tsutsugamushi in the same epidemic area].

OBJECTIVE: To investigate whether Hantavirus (HV) and Orientia tsutsugamushi ( OT) can naturally infect and coexist in their host and role. METHODS: By field epidemiological study, Leptotrombidium scutellare (3829) was collected and separated from mice(166) in epidemic areas. The cells of mites separated from their host and role were cultured. PCR was used to detect HV-RNA and OT-DNA in the cell culture. RESULTS: In 105 Apodemus agrarius, 3 HV-RNA positive, 2 OT-DNA positive and 2 coinfection with HV and OT were detected;in 41 Brown rattus, 2 HV-RNA positive, 1 OT-DNA positive and 1 co-infection with HV and OT were detected. From 15 mites co-infected with HV and OT, 2 strains of HV pathogen, 2 strains of OT pathogen were separated and 1 HV and OT pathogen in the same mite were separate. CONCLUSION: The study demonstrates that co-infection of HV and OT did simultaneously exist in wild Leptotrombidium scutellare. This theory has some significance to the epidemic and precaution of HV and OT.

Anti-tumor effects of immunotherapeutic peptide on the treatment of hepatocellular carcinoma with HBc carrier.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death. Tumor specific cellular and humoral immunotherapy may be a viable approach for the treatment of HCC. This study investigated specific inhibitory and cytotoxic effects on hepatocellular carcinoma (HCC) induced by the peptide, designated HBc Delta-5L, using HBc carrier with multiple T cell and B cell sequence insertions. We developed the HBc Delta carrier containing insertions of multiple CTL and T helper (Th) epitopes, which were selected from HCC tumor associated antigens (TAAs) including alpha fetoprotein (AFP), melanoma antigen gene (MAGE) and telomerase reverse transcriptase (TERT) antigen, and ligands for EGFR and IGFR, designated HBc Delta-5L. LDH release assay and IFN-gamma ELISPOT assay were carried to determine whether HBc Delta-5L could induce specific cytotoxicity in peripheral blood mononuclear cells (PBMC) of HCC donors. The levels of antibodies and inhibitory effects of sera of immunized mice against HBc Delta-5L were also identified. LDH release assay revealed that PBMC from HCC donor group (n=8) stimulated with HBc Delta-5L could specifically kill target tumor cells and specific lysis was 62.7% (E:T=60:1). ELISPOT assay showed a significant increase in secretion of IFN-gamma from PBMC of HCC donor group in response to HBc Delta-5L. Further, high specific antibody titers were elicited in immunized mice and revealed 42% inhibition of cell growth. These results indicated that inhibitory and cytotoxic effects could be efficiently induced by HBc Delta-5L recombinant particles using HBc Delta as carrier and suggested that it could be important in design of immunotherapeutic approaches.

Blockade of Notch signaling promotes acetaminophen-induced liver injury.

Liver injury after experimental acetaminophen treatment is mediated both by direct hepatocyte injury through a P450-generated toxic metabolite and indirectly by activated liver Kupffer cells and neutrophils. This study was designed to investigate the role of Notch signaling in the regulation of innate immune responses in acetaminophen (APAP)-induced liver injury. Using a mouse model of APAP-induced liver injury, wild-type (WT) and toll-like receptor 4 knockout (TLR4 KO) mice were injected intraperitoneally with APAP or PBS. Some animals were injected with γ-secretase inhibitor DAPT or DMSO vehicle. For the in vitro study, bone marrow-derived macrophages (BMMs) were transfected with Notch1 siRNA, TLR4 siRNA, and non-specific (NS) siRNA and stimulated with LPS. Indeed, paracetamol/acetaminophen-induced liver damage was worse after Notch blockade with DAPT in wild-type mice, which was accompanied by significantly increased ALT levels, diminished hairy and enhancer of split-1 (Hes1), and phosphorylated Stat3 and Akt but enhanced high mobility group box 1 (HMGB1), TLR4, NF-κB, and NLRP3 activation after APAP challenge. Mice receiving DAPT increased macrophage and neutrophil accumulation and hepatocellular apoptosis. However, TLR4 KO mice that received DAPT reduced APAP-induced liver damage and NF-κB, NLRP3, and cleaved caspase-1 activation. BMMs transfected with Notch1 siRNA reduced Hes1 and phosphorylated Stat3 and Akt but augmented HMGB1, TLR4, NF-κB, and NLRP3. Furthermore, TLR4 siRNA knockdown resulted in decreased NF-κB and NLRP3 and cleaved caspase-1 and IL-1ß levels following LPS stimulation. These results demonstrate that Notch signaling regulates innate NLRP3 inflammasome activation through regulation of HMGB1/TLR4/NF-κB activation in APAP-induced liver injury. Our novel findings underscore the critical role of the Notch1-Hes1 signaling cascade in the regulation of innate immunity in APAP-triggered liver inflammation. This might imply a novel therapeutic potential for the drug-induced damage-associated lethal hepatitis.

DNA vaccine against Taenia solium cysticercosis expressed as a modified hepatitis B virus core particle containing three epitopes shared by Taenia crassiceps and Taenia solium.

Many studies have provided evidence that the hepatitis B core antigen particle is useful as a vaccine carrier for foreign epitopes. Epitopes KETc1, KETc12, and GK-1 are three promising candidates for designing a vaccine against Taenia solium cysticercosis. In the present study, epitopes KETc1 and KETc12 were inserted into the immunodominant loop of the truncated HBc149, and epitope GK-1 was fused to its C-terminus. The fused protein deltaC-3n was expressed and purified successfully. The polymeric character was tested by SDS-PAGE. After inoculation of BALB/c mice with deltaC-3n, antibody titers were assayed by ELISA, and the antibody specification was analyzed by Western blot. Dot ELISA was performed to verify the protection of the three epitopes. Results showed that the purified polymeric protein was formed, high antibody titers were induced in immunized mice and three antibodies different in molecular weight were induced, serum specific antibody recognized the native peptide localized mainly in cyst wall cells, and there was no specific antibody toward the three epitopes in sera of infected pig and humans. All these revealed that the protein deltaC-3n was a potential candidate for vaccine against cysticercosis. So the deltaC-3n sequence and the signal peptide sequence of IL-2 were cloned to a vector pVAX3.0 to construct pVAX-S-deltaC-3n. Pigs were immunized with pVAX-S-deltaC-3n. Two weeks after the immunization booster, pigs were introduced to infectious T. solium eggs. The relative protective rate induced in pigs immunized with the DNA vaccine pVAX-S-deltaC-3n was 83%.

[Distribution of hemorrhagic fever with renal syndrome virus in gamasid mites and chigger mites].

OBJECTIVE: To study the distribution of hemorrhagic fever with renal syndrome virus (HFRSV) in mites. METHODS: In situ reverse transcription-polymerase chain reaction (IS RT-PCR) was used for detecting the distribution of HFRSV in mites. RESULTS: HFRSV RNA was mainly located in ovary and mid-gut tissues of gamasid mites and chigger mites. The positive signal intensity in the third and fourth generations of gamasid mite was stronger than that in the first and second generations, and that in nymph of chigger mite more than larva. CONCLUSION: Both chigger mite and gamasid mite could play an important role in the transmission of HFRSV.

Sex-specific association between X-linked Toll-like receptor 7 with the outcomes of hepatitis C virus infection.

Toll-like receptor 7 (TLR7) senses hepatitis C virus (HCV) infection and drives the host specific innate and adaptive immune response. The aim of this study was to estimate the distributions of TLR7 single nucleotide polymorphisms (SNPs), including rs179019 and rs3853839, as well as the effect of TLR7 gene variants on TLR7 mRNA expression and cytokine production in response to TLR7 agonist in vitro. TLR7 SNP genotyping was performed among a Chinese sample population of 418 patients with persistent HCV infection, 317 patients with HCV spontaneous clearance, and 989 healthy controls. TLR7 mRNA expression and TLR7-specific IFN-α and IL-6 secretion in peripheral blood mononuclear cells, derived from 60 healthy individuals in vitro, were then quantified. We identified the association of TLR7 rs3853839C allele, haplotype CC and haplotype AC (rs179019/rs3853839) with protection against HCV persistence in Chinese females (OR=0.49, 95% CI=0.29-0.81, P=0.01 for rs3853839 GC; OR=0.29, 95% CI=0.11-0.75, P=0.01 for rs3853839 CC; OR=0.51, 95% CI=0.38-0.77, P<0.01 for haplotype CC; OR=0.29, 95% CI=0.10-0.88, P=0.03 for haplotype AC). In addition, the rs3853839 CC genotype among female carriers had significantly low TLR7 mRNA expression (P=0.006 for GG vs. CC, P=0.021 for GC vs. CC), along with decreased IFN-α (P=0.002 for GG vs. CC, P=0.021 for GC vs. CC) and increased antiviral IL-6 production (P=0.002 for GG vs. CC, P=0.030 for GC vs. CC), after treatment with Imiquimod in vitro. The cytokine profile among rs3853839 CC genotype female carriers may indicate a pronounced protective effect against persistent HCV infection. The functional polymorphism of TLR7 rs3853839C allele was found to be sex-specific and associated with protection against HCV persistence among Chinese females, which may be due to specific IFN-α and IL-6 secretion profiles.

Sex-specific association of estrogen receptor 2 polymorphisms with hepatitis C virus infection outcomes in a high-risk Chinese Han population.

Hepatitis C virus (HCV) has different clinical and biological characteristics in women versus men, which suggests the potential involvement of estrogen. Estrogen signaling is mediated by the estrogen receptor, and genetic variations in the estrogen receptor gene might affect the pathology of HCV infection. We performed logistic regression analysis to explore the associations between rs1256049, rs4986938 and rs944459 polymorphisms of the estrogen receptor 2 gene (ESR2) and HCV infection outcomes. The variant A allele of rs4986938 was associated with an increased HCV infection susceptibility in the males (additive model: adjusted OR=1.493, P=0.010) and a significantly reduced risk of HCV infection in the female subgroup (GA vs. GG: adjusted OR=0.710, P=0.012; dominant model: adjusted OR=0.686, P=0.004; additive model: adjusted OR=0.703, P=0.002). In addition, females carrying the rs4986938 AA genotype appeared to clear HCV spontaneously more readily (adjusted OR=0.237, P=0.011), and additive model analyses showed that each additional allele contributed a decreased risk of approximately 34% for HCV chronicity (adjusted OR=0.659, P=0.006). Furthermore, a significant multiplicative interaction between the combined rs1256049 and rs4986938 genotypes was found to decrease HCV infection risk (adjusted OR=0.583, P=3.000×10(-4)). The area under the curve, based on the model and including age, gender, HCV genotypes and the three SNPs, was significantly related to the clearance of HCV (P=0.003). We provide here the first report that rs4986938 in the ESR2 gene played a potential sex-specific role in the etiology of HCV infection in a high-risk Chinese Han population, suggesting that ESR2 is a candidate susceptibility gene for HCV infection and viral clearance.

Hepatitis C virus alternate reading frame protein decreases interferon-α secretion in peripheral blood mononuclear cells.

The hepatitis C virus (HCV) alternate reading frame protein (ARFP or F protein) of the HCV 1b genotype is a double-frameshift product of the HCV core protein (Core). The discovery of HCV F protein challenges various biological functions attributed to Core. However, the specific characteristics of the host cellular immune response to F protein during HCV infection have yet to be fully elucidated. Therefore, the present study investigated the cytokine response to HCV Core or F protein in peripheral blood mononuclear cells (PBMCs) and plasmacytoid dendritic cells (PDCs) from patients with chronic HCV and healthy donors in vitro. The results demonstrated that the levels of interferon (IFN)-α, analyzed by an enzyme-linked immunosorbent assay, secreted by PBMCs in patients positive for the anti-F protein antibody, were lower than those of patients negative for the anti-F protein antibody. Moreover, the frequency of PDCs in patients negative for the anti-F protein antibody, were higher than in the group positive for the anti-F protein antibody. Furthermore, HCV F protein and Core not only inhibited specific unmethylated CpG oligonucleotide sequences of type A (CpG­A)-induced IFN-α production by PBMCs and PDCs, but also upregulated the production of interleukin (IL)-10 by PBMCs in patients with chronic HCV and healthy controls. Notably, following neutralization of IL-10 in the media and in vitro Core or F protein stimulation, levels of IFN-α were increased. Moreover, the results revealed that the roles of F protein and Core were similar with regard to the induction of apoptosis of PDCs in patients with chronic HCV. These findings suggest that F protein may inhibit PBMC IFN-α secretion by regulating the production of IL-10, and may contribute to an increase in the rates of apoptosis in PDCs. In conclusion, the results have revealed a potential involvement of F protein in the mechanisms of chronic hepatitis C.