A broadly neutralizing human monoclonal antibody against the hemagglutinin of avian influenza virus H7N9 / 中华医学杂志(英文版)

BACKGROUND@#The new emerging avian influenza A H7N9 virus, causing severe human infection with a mortality rate of around 41%. This study aims to provide a novel treatment option for the prevention and control of H7N9.@*METHODS@#H7 hemagglutinin (HA)-specific B cells were isolated from peripheral blood plasma cells of the patients previously infected by H7N9 in Jiangsu Province, China. The human monoclonal antibodies (mAbs) were generated by amplification and cloning of these HA-specific B cells. First, all human mAbs were screened for binding activity by enzyme-linked immunosorbent assay. Then, those mAbs, exhibiting potent affinity to recognize H7 HAs were further evaluated by hemagglutination-inhibiting (HAI) and microneutralization in vitro assays. Finally, the lead mAb candidate was selected and tested against the lethal challenge of the H7N9 virus using murine models.@*RESULTS@#The mAb 6-137 was able to recognize a panel of H7 HAs with high affinity but not HA of other subtypes, including H1N1 and H3N2. The mAb 6-137 can efficiently inhibit the HA activity in the inactivated H7N9 virus and neutralize 100 tissue culture infectious dose 50 (TCID50) of H7N9 virus (influenza A/Nanjing/1/2013) in vitro, with neutralizing activity as low as 78 ng/mL. In addition, the mAb 6-137 protected the mice against the lethal challenge of H7N9 prophylactically and therapeutically.@*CONCLUSION@#The mAb 6-137 could be an effective antibody as a prophylactic or therapeutic biological treatment for the H7N9 exposure or infection.

Repurposing carrimycin as an antiviral agent against human coronaviruses, including the currently pandemic SARS-CoV-2

COVID-19 pandemic caused by SARS-CoV-2 infection severely threatens global health and economic development. No effective antiviral drug is currently available to treat COVID-19 and any other human coronavirus infections. We report herein that a macrolide antibiotic, carrimycin, potently inhibited the cytopathic effects (CPE) and reduced the levels of viral protein and RNA in multiple cell types infected by human coronavirus 229E, OC43, and SARS-CoV-2. Time-of-addition and pseudotype virus infection studies indicated that carrimycin inhibited one or multiple post-entry replication events of human coronavirus infection. In support of this notion, metabolic labelling studies showed that carrimycin significantly inhibited the synthesis of viral RNA. Our studies thus strongly suggest that carrimycin is an antiviral agent against a broad-spectrum of human coronaviruses and its therapeutic efficacy to COVID-19 is currently under clinical investigation.

Preparation of Genistein Solid Dispersion and Its Properties Study / 中国药房

OBJECTIVE:To prepare Geinstein (GEN) solid dispersion,and improve the dissolution rate of GEN in vitro. METHODS:Using PVP K30,PEG6000,and PEG4000 as carriers,GEN solid dispersion was prepared by solvent melting meth-od,and its dissolution in vitro was investigated. The structure of the solid dispersion was characterized by FTIR and DSC. RE-SULTS:GEN solid dispersion prepared with PEG4000 as carrier was better than those with other carriers in dissolution,and drug-carrier ratio (1:5) was the best. The results of DSC and FTIR showed that GEN in solid dispersion took amorphous form. CONCLUSIONS:GEN solid dispersion is prepared successfully and significantly improve the dissolution of GEN in vitro.

Real-time PCR Detection Method for the Reston Subtype of the Ebola Virus / 病毒学报

We aimed to develop a real-time polymerase chain reaction (PCR) detection method for the Reston subtype of the Ebola virus. The NP gene of the Reston subtype of the Ebola virus was selected as the detection object. Sequences of different subtypes of Ebola viruses were aligned using Clustal W software. The most unique and conserved regions of the Reston subtype of the Ebola virus were recruited as candidate sequences for specific primers. Primer Express and Primer Premier 5. 0 software were used to filter the optimal pair of primers for detection. Real-time PCR was carried out using optimized parameters and positive DNA prepared by serial (tenfold) dilution of a recombinant plasmid and by plotting a standard curve. In addition, the reproducibility, accuracy, and specificity of the assay were tested. Results showed that the sensitivity of detection of the Reston subtype of the Ebola virus by real-time PCR could reached 10(2) copies/microL. The linear relationship (R2) reached 0.997, the slope of the standard curve was -0.3101, and amplification efficiency was 110.145%. A sharp and narrow melting peak appeared at 79.94 degrees C for all standards in different dilutions. In conclusion, a fast and sensitive real-time PCR detection system for the Reston subtype of the Ebola virus was developed. This system could be used as a supplementary diagnostic and monitoring approach for basic and clinical studies on the Reston subtype of the Ebola virus. The detection system does not require expensive technology or specialist operators.

Clinical and Biological Character in Mouse Models for Middle East Respiratory Syndrome Generated by Transduction with Different Doses of DPP4 Molecule / 病毒学报

In this study, we evaluated the difference ot biological characteristics in the MERS-CoV infected mice model in prior to transduction with different dosage of human DPP4. Firstly, we transduced different dosage of DPP4 (high or low) into mice, and then challenged them with MERS-CoV in order to establish the model. After establishment of mice model, we observed the clinical signs of disease, virus replication, immunopathogenesis and antibody response. The results indicated that the infected mice showed typical pneumonia, virus replication, histological lesions, and neutralizing antibody production. Moreover, the high dosage group was superior to the low dosage group. Fourteen days after infection, the specific antibody to virus structural protein and neutralizing antibody were analyzed, the high dosage group induced higher level antibody. In summary, the MERS-CoV infected mice model were established prior transduction with DPP4, and the level of DPP4 influenced the clinical signs of disease, virus replication and antibody response in this model.

Determination of Influenza Virus H5N1 and H7N9 Using MASA Technology / 病毒学报

To set up a new rapid method for the rapid determination of influenza virus H5N1 and H7N9 basing on the Multi-Analyte Suspension Array (MASA) technology. Sequence analysis and design of degenerate primers and specific probes were set in the comparison and analysis of H5, N1, H7 and N9 genes. In combination with MASA technology, these primers and probes were used for the determination of samples of H5N1 and H7N9 and other subtypes ( H1N1, PH1N1, H5N2, H3N2 and H9N2). We developed a rapid determination method. This method had high specificity and sensitivity that could detect H5N1 and H7N9 at one time, and could detect samples that containing 10 copies of H5N1 and H7N9. This determination method could be used for rapid determination of influenza virus H5N1 and H7N9 at one time.

Histopathological changes in EV71-infected mouse model:a transmission electron microscopic study / 中华病理学杂志

<p><b>OBJECTIVE</b>To document ultrastructural changes of brain, spinal cord, skeletal muscle, jejunum and lung of EV71 infection mouse model, and to explore the myotropism and pathogenesis of EV71 in nervous system.</p><p><b>METHODS</b>Ten-day-old suckling mice were infected with EV71 strain via the intraperitoneal route. Mice with paralysis were scarified on day 4 post infection and the brain, spinal cord, skeletal muscle, jejunum and lung were sampled for transmission electron microscopy and light microscopy.</p><p><b>RESULTS</b>Lesions in brain were generally mild with inner chamber swelling in some of mitochondria. Myelin sheaths of medullated fibers were split with vacuolated changes. The Nissl bodies in anterior motor neurons disappeared along with mitochondria swelling, rough endoplasmic reticulum swelling and degranulation. Cytoplasm of anterior motor neurons showed cribriform appearance accompanied by neuronophagia. The bands of skeletal muscle in the infected group disappeared with degeneration and karyopyknosis in myocytes, in addition to mitochondrial swelling. Microvilli of epithelium in jejunum became loosely arranged along with formation of spiral medullary sheath structure and mitochondria swelling. Interstitial pneumonia was observed in lungs with type II pneumocyte proliferation and evacuation of the multilamellar bodies.</p><p><b>CONCLUSIONS</b>EV71 infection causes severe myositis in the mouse model suggesting a strong myotropism of EV71 virus. The presence of lesions of various degrees in central nervous system and changes in anterior motor neurons may be associated with limb paralysis.</p>

Comparison of bio-medical parameters in SIV infected Chinese rhesus monkeys with diverse progression correlated to the pathogenesis of simian AIDS / 中华微生物学和免疫学杂志

Objective To compare the bio-medical parameters in SIV infected Chinese rhesus monkeys with diverse disease progression,by which the pathogenesis of simian AIDS were to be investigated.Methods Sixteen Chinese rhesus monkeys were inoculated intravenously with SIVmac239 and followed-up for 18 months.Based on their progression patterns and plasma viral loads,animals were divided into 3 groups,including 1 rapid progressor( RP),13 normal progressors(NP),and 2 elite controllor(EC).Their parameters of haematology,virology,immunology and pathology were examined and compared. Results Compared with other animals,RM449(RP) showed higher viral load,unresponsive humoral immunity,and higher level of auto-antibodies against lymph node,thymus,and spleen.Additionally,its effector memory CD4 count was lower,with the transformation progress being blocked-like from naive/central memory subsets to effector memory subset,as the flow-cytometry assay showed.Notable decrease in its peripheral B cell was also observed,especially to the sub-population of tissue-like memory B cells and activated memory B cells.Pathological examination showed the depletion of lymphoid tissue,atrophy of spleen and loss of thymus.Moreover,most of these parameters of RM450 and RM453 (EC) changed opposite to that of RP.Conclusion The hallmarks of RM449 were higher viraemia and lower SIV specific IgG level,which may due to the disturbance of T cells and B cells development and differentiation.Moreover,destructions of organs of the immune system may contribute to the disturbance.Our study suggest that the change of micro-environments of thymus induced by SIV infection,which is necessary in T cell and B cell development and differentiation,may contribute at least partially to the AIDS pathogenesis.