Preliminary identification of the cloning， expression， and function of Marmota himalayana type I interferon receptor β subunit / 临床肝胆病杂志

ObjectiveTo clone the gene of Marmota himalayana type ‍Ⅰ interferon receptor β subunit （mhIFNAR2）， and to perform antibody preparation and functional identification. MethodsRT-PCR was used for amplification in the spleen tissue of Marmota himalayana to obtain the sequence， which was cloned to the prokaryotic expression vector pRSET-B to express the recombinant protein. Electrophoresis and Western blot were used for identification. BALB/c mice were immunized with the recombinant protein to prepare the polyclonal antibody of its extracellular domain； immunohistochemistry， immunofluorescence assay， and Western Blot were used for identification， and the method of siRNA blockade was used to investigate its function. An analysis of variance was used for comparison of continuous data between multiple groups， and the least significant difference t-test was used for comparison between two groups. ResultsA fragment of mhIFNAR2 （149‍ ‍—‍ ‍1 ‍300 bp） was obtained from spleen tissue， which showed the highest homology of 98.05% in marmot. A prokaryotic expression plasmid was successfully constructed for expression of the extracellular domain of the mhIFNAR2（50-181aa） and was named pRSET-B.mhIFNAR2， and the recombinant protein expressed by this plasmid had a molecular weight of 27 kD， a purity of about 95% after purification， and a concentration of 160 μg/mL. After BALB/c mice were immunized with the purified recombinant protein， 1∶1 000 specific polyclonal antibodies were obtained， and immunohistochemistry and immunofluorescence assay showed the expression in cell membrane and cytoplasm. Among the three siRNAs synthesized， the siRNA starting from the 277 locus （siRNA277） could silence the expression of target genes and weaken the interferon signaling pathway compared with the blank control group and the negative control group （both P<0.05）. ConclusionThe fragment of mhIFNAR2 is obtained， and the polyclonal antibody for the extracellular domain of mhIFNAR2 is successfully prepared， with relatively high titer and specificity， and can be used for immunohistochemistry， immunofluorescence assay， and Western blot.

Research advances in the role of gut microbiota in chronic hepatitis B, chronic hepatitis C, and related liver diseases / 临床肝胆病杂志

Hepatitis B virus infection and hepatitis C virus infection often progress to end-stage liver diseases such as liver cirrhosis, liver failure, and hepatocellular carcinoma, which endanger the life of patients. Recent studies have shown that gut microbiota are closely associated with chronic viral liver diseases. This article reviews the association of gut microbiota with chronic hepatitis B (CHB), chronic hepatitis C (CHC), and their related liver diseases and the research advances in therapies targeting gut microbiota against CHB and its related liver diseases, in order to provide more ideas for the clinical treatment of CHB, CHC, and their related liver diseases.

SARS-CoV-2-specific T cell memory is long-lasting in the majority of convalsecent COVID-19 individuals

An unaddressed key question in the current coronavirus disease 2019 (COVID-19) pandemic is the duration of immunity for which specific T cell responses against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are an indispensable element. Being situated in Wuhan where the pandemic initiated enables us to conduct the longest analyses of memory T cell responses against SARS-CoV-2 in COVID-19 convalescent individuals (CIs). Magnitude and breadth of SARS-CoV-2 memory CD4 and CD8 T cell responses were heterogeneous between patients but robust responses could be detected up to 9 months post disease onset in most CIs. Loss of memory CD4 and CD8 T cell responses were observed in only 16.13% and 25.81% of CIs, respectively. Thus, the overall magnitude and breadth of memory CD4 and CD8 T cell responses were quite stable and not inversely correlated with the time from disease onset. Interestingly, the only significant decrease in the response was found for memory CD4 T cells in the first 6-month post COVID-19 disease onset. Longitudinal analyses revealed that the kinetics of SARS-CoV-2 memory CD4 and CD8 T cell responses were quite heterogenous between patients. Loss of memory CD4 T cell responses was observed more frequently in asymptomatic cases than after symptomatic COVID-19. Interestingly, the few CIs in which SARS-CoV-2-specific IgG responses disappeared showed more durable memory CD4 T cell responses than CIs who remained IgG-positive for month. Collectively, we provide the first comprehensive characterization of the long-term memory T cell response in CIs, suggesting that SARS-CoV-2-specific T cell immunity is long-lasting in the majority of individuals.

The analysis of the long-term impact of SARS-CoV-2 on the cellular immune system in individuals recovering from COVID-19 reveals a profound NKT cell impairment

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affects millions of people and killed hundred-thousands of individuals. While acute and intermediate interactions between SARS-CoV-2 and the immune system have been studied extensively, long-term impacts on the cellular immune system remained to be analyzed. Here, we comprehensively characterized immunological changes in peripheral blood mononuclear cells in 49 COVID-19 convalescent individuals (CI) in comparison to 27 matched SARS-CoV-2 unexposed individuals (UI). Despite recovery from the disease for more than 2 months, CI showed significant decreases in frequencies of invariant NKT and NKT-like cells compared to UI. Concomitant with the decrease in NKT-like cells, an increase in the percentage of Annexin V and 7-AAD double positive NKT-like cells was detected, suggesting that the reduction in NKT-like cells results from cell death months after recovery. Significant increases in regulatory T cell frequencies, TIM-3 expression on CD4 and CD8 T cells, as well as PD-L1 expression on B cells were also observed in CI, while the cytotoxic potential of T cells and NKT-like cells, defined by GzmB expression, was significantly diminished. However, both CD4 and CD8 T cells of CI showed increased Ki67 expression and were fully capable to proliferate and produce effector cytokines upon TCR stimulation. Collectively, we provide the first comprehensive characterization of immune signatures in patients recovering from SARS-CoV-2 infection, suggesting that the cellular immune system of COVID-19 patients is still under a sustained influence even months after the recovery from disease.

SARS-CoV-2 infection induces sustained humoral immune responses in convalescent patients following symptomatic COVID-19

Long-term antibody responses and neutralizing activities following SARS-CoV-2 infections have not yet been elucidated. We quantified immunoglobulin M (IgM) and G (IgG) antibodies recognizing the SARS-CoV-2 receptor-binding domain (RBD) of the spike (S) or the nucleocapsid (N) protein, and neutralizing antibodies during a period of six months following COVID-19 disease onset in 349 symptomatic COVID-19 patients, which were among the first world-wide being infected. The positivity rate and magnitude of IgM-S and IgG-N responses increased rapidly. High levels of IgM-S/N and IgG-S/N at 2-3 weeks after disease onset were associated with virus control and IgG-S titers correlated closely with the capacity to neutralize SARS-CoV-2. While specific IgM-S/N became undetectable 12 weeks after disease onset in most patients, IgG-S/N titers showed an intermediate contraction phase, but stabilized at relatively high levels over the six months observation period. At late time points the positivity rates for binding and neutralizing SARS-CoV-2-specific antibodies was still over 70%. Taken together, our data indicate sustained humoral immunity in recovered patients who suffer from symptomatic COVID-19, suggesting prolonged immunity.

The prevalence of antibodies to SARS-CoV-2 in asymptomatic healthcare workers with intensive exposure to COVID-19

The prevalence of asymptomatic SARS-CoV-2 infection in healthcare workers with intensive exposure to COVID-19 is unclear. In this study, we investigated the seroprevalence of SARS-CoV-2 in 797 asymptomatic healthcare workers with intensive exposure to COVID-19 patients in Wuhan, China. Positive IgG was detected from 35 asymptomatic healthcare workers, and the prevalence of antibodies to SARS-CoV-2 in asymptomatic healthcare workers was 4.39% (35/797). None of them developed COVID-19 until May 15. 33 of them have performed at least one chest CT scan showing no viral pneumonia features, and 16 have finished at least one-time SARS-CoV-2 RNA detection with negative results. When contacting with the patients, 15 of them dressed with full personal protective equipment (PPE), and 16 worn N95 mask and gown. To the best of our knowledge, this is the first investigation reported that the seroprevalence of SARS-CoV-2 was 4.39% in asymptomatic healthcare workers with applied PPE in a high epidemic area, which may provide useful information of estimating asymptomatic infection rate in general population.

Early, low-dose and short-term application of corticosteroid treatment in patients with severe COVID-19 pneumonia: single-center experience from Wuhan, China

BackgroundSevere patients with 2019 novel coronavirus (2019-nCoV) pneumonia progressed rapidly to acute respiratory failure. We aimed to evaluate the definite efficacy and safety of corticosteroid in the treatment of severe COVID-19 pneumonia. MethodsForty-six hospitalized patients with severe COVID-19 pneumonia hospitalized at Wuhan Union Hospital from January 20 to February 25, 2020, were retrospectively reviewed. The patients were divided into two groups based on whether they received corticosteroid treatment. The clinical symptoms and chest computed tomography(CT) results were compared. ResultsA total of 26 patients received intravenous administration of methylprednisolone with a dosage of 1-2mg/kg/d for 5-7 days, while the remaining patients not. There was no significant difference in age, sex, comorbidities, clinical or laboratory parameters between the two groups on admission. The average number of days for body temperature back to the normal range was significantly shorter in patients with administration of methylprednisolone when compared to those without administration of methylprednisolone (2.06{+/-}0.28 vs. 5.29{+/-}0.70, P=0.010). The patients with administration of methylprednisolone had a faster improvement of SpO2, while patients without administration of methylprednisolone had a significantly longer interval of using supplemental oxygen therapy (8.2days[IQR 7.0-10.3] vs. 13.5days(IQR 10.3-16); P<0.001). In terms of chest CT, the absorption degree of the focus was significantly better in patients with administration of methylprednisolone. ConclusionOur data indicate that in patients with severe COVID-19 pneumonia, early, low-dose and short-term application of corticosteroid was associated with a faster improvement of clinical symptoms and absorption of lung focus.

Longitudinal characteristics of lymphocyte responses and cytokine profiles in the peripheral blood of SARS-CoV-2 infected patients

BackgroundThe dynamic changes of lymphocyte subsets and cytokines profiles of patients with novel coronavirus disease (COVID-19) and their correlation with the disease severity remain unclear. MethodsPeripheral blood samples were longitudinally collected from 40 confirmed COVID-19 patients and examined for lymphocyte subsets by flow cytometry and cytokine profiles by specific immunoassays. ResultsOf the 40 COVID-19 patients enrolled, 13 severe cases showed significant and sustained decreases in lymphocyte counts but increases in neutrophil counts than 27 mild cases. Further analysis demonstrated significant decreases in the counts of T cells, especially CD8 + T cells, as well as increases in IL-6, IL-10, IL-2 and IFN-{gamma} levels in the peripheral blood in the severe cases compared to those in the mild cases. T cell counts and cytokine levels in severe COVID-19 patients who survived the disease gradually recovered at later time points to levels that were comparable to those of the mild cases. Moreover, the neutrophil-to-CD8+ T cell ratio (N8R) were identified as the most powerful prognostic factor affecting the prognosis for severe COVID-19. ConclusionsThe degree of lymphopenia and a proinflammatory cytokine storm is higher in severe COVID-19 patients than in mild cases, and is associated with the disease severity. N8R may serve as a useful prognostic factor for early identification of severe COVID-19 cases. SummaryLymphocyte subsets and cytokine profiles in the peripheral blood of COVID-19 patients were longitudinally characterized. The study revealed the kinetics features of immune parameters associated with the disease severity and identified N8R as a useful prognostic factor for predicting severe COVID-19 cases.

Genetic Diversity of Echinococcus granulosus Genotype G1 in Xinjiang, Northwest of China

Cystic echinococcosis (CE) caused by E. granulosus is a serious helminthic zoonosis in humans, livestock and wildlife. Xinjiang is one of high endemic province for CE in China. A total of 55 sheep and cattle livers containing echinococcal cysts were collected from slaughterhouses in Changji and Yining City, northern region of Xinjiang. PCR was employed for cloning 2 gene fragments, 12S rRNA and CO1 for analysis of phylogenetic diversity of E. granulosus. The results showed that all the samples collected were identified as G1 genotype of E. granulosus. Interestingly, YL5 and CJ75 strains were the older branches compared to those strains from France, Argentina, Australia. CO1 gene fragment showed 20 new genotype haploids and 5 new genotype haplogroups (H1-H5) by the analysis of Network 5.0 software, and the YLY17 strain was identified as the most ancestral haplotype. The major haplotypes, such as CJ75 and YL5 strains, showed identical to the isolates from Middle East. The international and domestic trade of livestock might contribute to the dispersal of different haplotypes for E. granulosus evolution.

Establishment of a functional cell line expressing both subunits of H1a and H2c of human hepatocyte surface molecule ASGPR / 华中科技大学学报（医学）（英德文版）

To better understand the effect of a new split variant of human asialoglycoprotein receptor (ASGPR H1b) on ASGPR ligands' binding ability, we established a functional cell line which expresses ASGPR. The full lengths of ASGPRH1a and H2c fragments from human liver were amplified by reverse transcript PCR (RT-PCR) and inserted into eukaryotic expression vector pIRES2EGFP, pCDNA3.1 (Zeo+) respectively. The recombinants were co-transfected into HeLa cells. After selection by using Neocin and Zeocin, a stably transfected cell line was established, which was designated 4-1-6. The transcription and expression of ASGPRH1a and H2c in 4-1-6 were confirmed by RT-PCR, Western blotting and immunofluorescence. The endocytosis function of the artificial "ASGPR" on the surface of 4-1-6 was tested by FACS. It was found that the cell line 4-1-6 could bind ASGPR natural ligand molecular asialo-orosomucoid (ASOR). After the eukaryotic plasmid H1b/pCDNA3.1 (neo) was transfected into cell line 4-1-6, H1b did not down-regulate the ligand binding ability of ASGPR. The eukaryotic expression plasmid H1b/pcDNA3.1 (neo) and H2c/pcDNA3.1 (neo) were co-transfected transiently into Hela cell. Neither single H1b nor H1b and H2c could bind ASOR. In conclusion, a functional cell line of human asialoglycoprotein receptor (ASGPR) which expresses both H1a and H2c stably was established. The new split variant H1b has no effect on ASGPR binding to ASOR. ASGPRH1b alone can't bind to ASOR, it yet can't form functional complex with ASGPRH2c.

Silencing of UBP43 by shRNA Enhances the Antiviral Activity of Interferon against Hepatitis B Virus / 中国病毒学·英文版

Previous studies have shown that expression of the interferon-sensitive gene (ISG)I5 protease UBP43 is increased in the liver biopsy specimens of patients who do not respond to interferon (IFN)-α therapy. We hypothesized that UBP43 might hinder the ability of IFN to inhibit HBV replication. In this study, we investigated whether vector-based siRNA promoted by Hi (psiUBP43) could enhance IFN inhibiting HBV replication in cell culture. UBP43 was specifically silenced using shRNA. In HepG2.2.15 cells, the HBeAg and HBV DNA levels were significantly reduced by IFN after transfection of shRNA, imphicated that vector-based siRNA promoted by HI (psiUBP43) could enhance IFN inhibiting HBV replication in cell culture. These data suggest that UBP43 modulates the anti-HBV type I IFN response, and is a possible therapeutic target for the treatment of HBV infection.

Cloning, Expression and Polyclonal Antibody Preparation of the Asialoglycoprotein Receptor of Marmota Himalayan / 华中科技大学学报（医学）（英德文版）

The objective of this study is to express the carbohydrate recognition domain (CRD) of the asialoglycoprotein receptor (ASGPR) H1 and H2 subunits of Marmota himalayan in vitro, and develop polyclonal antibodies against the recombinant proteins. RT-PCR was used to amplify ASGPR CRDH1 and CRDH2 from the liver tissue of Marmota himalayan. The products of amplification were subcloned into prokaryotic expression vector pRSET-B, and expressed in E. coli BL21(DE3)plysS. The recombinant proteins were purified using Ni-NTA spin column. The purified proteins were inoculated into BALB/c mice to develop polyclonal antibodies. The sensitivity and specificity of antibodies were evaluated by enzyme-linked immunosorbent assay (ELISA), Western blotting and immunohistochemical staining (IHC). The polyclonal antibodies showed high sensitivity and specificity against both denaturated and native ASGPR proteins. We successfully amplified and expressed the ASGPR CRDs of Marmota himalayan. The nucleic sequences of ASGPR CRDH1 and CRDH2 of Marmota himalayan have been submitted to Genbank and the sequence ID are DQ 845465 and DQ845466, respectively. The proteins and antibodies prepared can be used for targeting gene therapy in a new animal model-Marmota himalayan-for the research of infectious diseases of hepatitis viruses and liver cancer treatment.

Frequency of loss expression of the DPC4 protein in various locations of biliary tract carcinoma / 中华预防医学杂志

<p><b>OBJECTIVE</b>To clarify the relationship between the loss of expression of the deleted in pancreatic carcinoma locus 4 (DPC4) proteins and the pathogenesis of biliary tract carcinoma.</p><p><b>METHODS</b>71 primary biliary tract carcinoma (BTCa), including 38 common bile duct (CBD) carcinomas, 18 gallbladder carcinomas, 15 hilar bile ducts (HBD) carcinomas were examined by immunohistochemical staining. In addition, the CBD carcinomas were divided into two groups: tumors with metastasis (M(+) group, 27 cases) and tumors without metastasis (M(-) group, 11 cases).</p><p><b>RESULTS</b>The frequency of loss of the expression of DPC4 protein was 32.8% in BTCa, 47.3% in CBD carcinoma, 11% in gallbladder carcinoma, 13% in HBD carcinoma. Comparison of the frequency of loss expression of DPC4 was significant statistical difference in CBD carcinoma versus gallbladder carcinoma and HBD carcinoma (P < 0.01). The frequency of loss expression of DPC4 was 48.1% in the M(+) group and 45.4% in the M(-) group.</p><p><b>CONCLUSION</b>There are a close relationship between pathogenesis of BTCa and inactivation of DPC4 and different frequencies of DPC4 gene alternation in various locations of the biliary tract, which are not significantly increased with tumor metastasis in BTCa.</p>

Expression of heme oxygenase-1 mRNA in portal hypertension rats / 中国普通外科杂志

Objective To study the relationship between portal hypertension(PHT) and heme oxygenase-1(HO-1)mRNA expression in rats.Method An animal model of PHT induced by partial portal vein constriction was established to detect the expression of HO-1mRNA in the liver,spleen, and splenic vein of rats by situ hybridization method. Result HO-1mRNA was not detected in the liver, spleen, and splenic vein in the control group. In PHT rats, HO-1mRNA was not detected in the liver;but in the spleen,the expression of HO-1mRNA was 83.3%;in the splenic vein,the expression was 55.6%. Conclusions The PHT rat is in stress condition.The expression of HO-1mRNA in the spleen and splenic vein of PHT ratsare increased and the metabolic product of HO-1 may exacerbate the PHT.