Novel H1N1 influenza A virus infection in a patient with acute rejection after liver transplantation

BACKGROUND:The 2009 H1N1 influenza A virus was first identified in April 2009 and rapidly evolved into a pandemic. Recipients of solid-organ transplants have a higher risk for severe infection because of immunosuppression.There are limited reports of 2009 H1N1 influenza in liver transplant recipients,especially in China. METHODS:We present a case of a 48-year-old male liver transplant recipient with 2009 H1N1 influenza A virus.He received therapy for acute rejection after transplantation and was confirmed with H1N1 virus infection. RESULTS:The patient was started on oseltamivir(75 mg, orally twice daily)and had a benign hospital course,with defervescence and resolution of symptoms within 72 hours. The follow-up chest radiograph after discharge was normal. CONCLUSIONS:The 2009 H1N1 influenza in this hospitalized transplant recipient was relatively mild,and prolonged viral shedding was not noted.Oseltamivir can be a valid measure in immunocompromised individuals.

In silico modification of oseltamivir as neuraminidase inhibitor of influenza A virus subtype H1N1

This research focused on the modification of the functional groups of oseltamivir as neuraminidase inhibitor against influenza A virus subtype H1N1.Interactions of three of the best ligands were evaluated in the hydrated state using molecular dynamics simulation at two different temperatures.The docking result showed that AD3BF2 D ligand（N-[（1S,6R）-5-amino-5-{[（2R,3S,4S）-3,4-dihydroxy-4-（hydroxymethyl） tetrahydrofuran-2-yl]oxy}-4-formylcyclohex-3-en-1-yl]acetamide-3-（1-ethylpropoxy）-1-cyclohexene-1-carboxylate） had better binding energy values than standard oseltamivir.AD3BF2 D had several interactions,including hydrogen bonds,with the residues in the catalytic site of neuraminidase as identified by molecular dynamics simulation.The results showed that AD3BF2 D ligand can be used as a good candidate for neuraminidase inhibitor to cope with influenza A virus subtype H1N1.

Characterization of Highly Pathogenic Avian Influenza H5N1 Viruses Isolated from Domestic Poultry in China

The highly pathogenic avian influenza （HPAI） H5N1 virus has caused several outbreaks in domestic poultry. Despite great efforts to control the spread of this virus, it continues to evolve and poses a substantial threat to public health because of a high mortality rate. In this study, we sequenced whole genomes of eight H5N1 avian influenza viruses isolated from domestic poultry in eastern China and compared them with those of typical influenza virus strains. Phylogenetic analyses showed that all eight genomes belonged to clade 2.3.2.1 and clade 7.2, the two main circulating clades in China. Viruses that clustered in clade 2.3.2.1 shared a high degree of homology with H5N1 isolates located in eastern Asian. Isolates that clustered in clade 7.2 were found to circulate throughout China, with an east-to-west density gradient. Pathogenicity studies in mice showed that these isolates replicate in the lungs, and clade 2.3.2.1 viruses exhibit a notably higher degree of virulence compared to clade 7.2 viruses. Our results contribute to the elucidation of the biological characterization and pathogenicity of HPAI H5N1 viruses.

Morphofunctional Characteristics of Pulmonary Surfactant System and Its Effect on Immune Cells in Influenza A (H1N1) Pathogenesis

There is an annual increase of influenza-related SARI cases in winter months. Despite the high relevance of this problem, influenza pathogenesis and the role of surfactant system and its SP-A (surfactant protein A) enzyme in antiviral defense remain poorly understood. SP-A activates macrophage M1 polarization and triggers an antiviral response due to the activation of T-cells and dendritic cells. Therefore, surfactant system is an important element of infection protection and a promising therapeutic target.

Antiviral activity of five Asian medicinal pant crude extracts against highly pathogenic H5N1 avian influenza virus

Objective: To study the antiviral properties of the five Asian medicinal plants against in vitro infection by the highly pathogenic avian influenza virus(H5N1).Methods: Crude extracts of Andrographis paniculata, Curcuma longa(C. longa),Gynostemma pentaphyllum, Kaempferia parviflora(K. parviflora), and Psidium guajava obtained by both water and ethanol extractions were investigated for their cytotoxicity in the Madin–Darby canine kidney cells. Thereafter, they were investigated in vitro for antiviral activity and cytokine response upon H5N1 virus infection.Results: The results revealed that both water and ethanol extracts of all the five studied plants showed significant antiviral activity against H5N1 virus. Among these plants,C. longa and K. parviflora showed strong anti-H5N1 activity. Thus, they were selected for further studies on their cytokine response upon virus infection. It was found that ethanol and water crude extracts of C. longa and K. parviflora induced significant upregulation of TNF-a and IFN-b m RNA expressions, suggesting their roles in the inhibition of H5N1 virus replication.Conclusions: To the best of the authors' knowledge, this study is among the earliest reports to illustrate the antiviral property of these Asian medicinal plants against the highly pathogenic avian H5N1 influenza virus. The results of this study shed light on alternative therapeutic sources for treatment of H5N1 influenza virus infection in the future.

Cloning of M and NP Gene of H5N1 Avian Influenza Virus and Immune Efficacy of their DNA Vaccines

H5N1 鸟的流行性感冒病毒(A/chicken/Hubei/489/2004 ) 的 M 和 NP 基因被 RT-PCR 从病毒的 RNA 放大，并且分别地克隆向量进 pMD18-T。包含 M 基因(pHM6-m ) 或 NP 基因(pHM6-np ) 的表示 plasmid 然后被把 M 或 NP 基因插入到 pHM6 优核质表示向量构造；构造 plasmid 然后被定序。32 只 BALB/c 老鼠(6-week-old ) 在随机被划分成四个组。三组 BALB/c 老鼠被接种一次有 plasmid pHM6-m， plasmid pHM6-np 的 30 渭 g 或 plasmid pHM6-m (15 渭 g ) 和 pHM6-np (15 渭 g ) 的混合的任何一个 30 渭 g 的肌内的线路分别地。老鼠的一个另外的组作为控制与 100 渭 l PBS 被注射。二个星期以后，所有老鼠与相应 H5N1 鸟的流行性感冒病毒被质问，并且在下列 12 天内观察了。在 pHM6-m 组， pHM6-np 组和混合 plasmids 组的老鼠的幸存率分别地是 62.5% ， 25.0% 和 50.0% 。结果证明有效保护能被 pHM6-m 或 pHM6-np 提供，但是 pHM6-m 比 pHM6-np 提供了更好保护的效果。关键词 H5N1 流行性感冒病毒 - M 基因 - NP 基因 - 克隆 - DNA 疫苗的 CLC 数字 S852.65 基础条款：国家基本科学才能训练资助(NSFC J0630648 )

Close Relationship between the 2009 H1N1 Virus and South Dakota AIV Strains

Although previous publications suggest the 2009 pandemic influenza A (H1N1) virus was reassorted from swine viruses of North America and Eurasia,the immediate ancestry still remains elusive due to the big evolutionary distance between the 2009 H1N1 virus and the previously isolated strains. Since the unveiling of the 2009 H1N1 influenza,great deal of interest has been drawn to influenza,consequently a large number of influenza virus sequences have been deposited into the public sequence databases. Blast analysis demonstrated that the recently submitted 2007 South Dakota avian influenza virus strains and other North American avian strains contained genetic segments very closely related to the 2009 H1N1 virus,which suggests these avian influenza viruses are very close relatives of the 2009 H1N1 virus. Phylogenetic analyses also indicate that the 2009 H1N1 viruses are associated with both avian and swine influenza viruses circulating in North America. Since the migrating wild birds are preferable to pigs as the carrier to spread the influenza viruses across vast distances,it is very likely that birds played an important role in the inter-continental evolution of the 2009 H1N1 virus. It is essential to understand the evolutionary route of the emerging influenza virus in order to find a way to prevent further emerging cases. This study suggests the close relationship between 2009 pandemic virus and the North America avian viruses and underscores enhanced surveillance of influenza in birds for understanding the evolution of the 2009 pandemic influenza.

Phosphorylation of PB2 at serine 181 restricts viral replication and virulence of the highly pathogenic H5N1 avian influenza virus in mice

Influenza A virus(IAV)continues to pose a pandemic threat to public health,resulting a high mortality rate annually and during pandemic years.Posttranslational modification of viral protein plays a substantial role in regulating IAV infection.Here,based on immunoprecipitation(IP)-based mass spectrometry(MS)and purified virus-coupled MS,a total of 89 phosphorylation sites distributed among 10 encoded viral proteins of IAV were identified,including 60 novel phosphorylation sites.Additionally,for the first time,we provide evidence that PB2 can also be acetylated at site K187.Notably,the PB2 S181 phosphorylation site was consistently identified in both IP-based MS and purified virus-based MS.Both S181 and K187 are exposed on the surface of the PB2 protein and are highly conserved in various IAV strains,suggesting their fundamental importance in the IAV life cycle.Bioinformatic analysis results demonstrated that S181E/A and K187Q/R mimic mutations do not significantly alter the PB2 protein structure.While continuous phosphorylation mimicked by the PB2 S181E mutation substantially decreases viral fitness in mice,PB2 K187Q mimetic acetylation slightly enhances viral virulence in mice.Mechanistically,PB2 S181E substantially impairs viral polymerase activity and viral replication,remarkably dampens protein stability and nuclear accumulation of PB2,and significantly weakens IAV-induced inflammatory responses.Therefore,our study further enriches the database of phosphorylation and acetylation sites of influenza viral proteins,laying a foundation for subsequent mechanistic studies.Meanwhile,the unraveled antiviral effect of PB2 S181E mimetic phosphorylation may provide a new target for the subsequent study of antiviral drugs.

Epidemiology and Genotypic Diversity of Eurasian Avian-Like H1N1 Swine Influenza Viruses in China

Eurasian avian-like H1 N1(EA H1 N1)swine influenza virus(SIV)outside European countries was first detected in Hong Kong Special Administrative Region(Hong Kong,SAR)of China in 2001.Afterwards,EA H1 N1 SIVs have become predominant in pig population in this country.However,the epidemiology and genotypic diversity of EA H1 N1 SIVs in China are still unknown.Here,we collected the EA H1 N1 SIVs sequences from China between 2001 and 2018 and analyzed the epidemic and phylogenic features,and key molecular markers of these EA H1 N1 SIVs.Our results showed that EA H1 N1 SIVs distributed in nineteen provinces/municipalities of China.After a long-time evolution and transmission,EA H1 N1 SIVs were continuously reassorted with other co-circulated influenza viruses,including 2009 pandemic H1 N1(A(H1 N1)pdm09),and triple reassortment H1 N2(TR H1 N2)influenza viruses,generated 11 genotypes.Genotype 3 and 5,both of which were the reassortments among EA H1 N1,A(H1 N1)pdm09 and TR H1 N2 viruses with different origins of M genes,have become predominant in pig population.Furthermore,key molecular signatures were identified in EA H1 N1 SIVs.Our study has drawn a genotypic diversity image of EA H1 N1 viruses,and could help to evaluate the potential risk of EA H1 N1 for pandemic preparedness and response.

Detection and pathogenesis of a novel swine H3N2 influenza virus containing three genes from the 2009 pandemic H1N1 influenza viruses in Korea in 2015

Dear Editor,Influenza A viruses cause pandemics at an interval of approximately 10-40 years,and pigs are regarded as a＂mixing vessel＂because they are easily infected with avian and human influenza viruses（Ito et al.,1998）.According to previous studies,H3N2,H1N2,and H1N1 subtypes o（swine influenza viruses have been detected in Korean pigs （Pascua et al., 2013; Kim et al., 2014; Song et al., 2007）. Moreover, a novel H3N2 influenza virus containing the matrix （34） gene from a 2009 pandemic influenza virus was detected in Korean pigs in 2013 （Pascua et al., 2013）, an H1N2 influenza virus con- taining the internal genes from a 2009 pandemic influ- enza virus was found in Korean pigs in 2014 （Kim et al., 2014）, and an H1N1 influenza virus containing all genes from the classical swine influenza viruses was isolated from Korean pigs in 2007 （Song et al., 2007）.

尾静脉注射和鼻腔接种禽流感H5N1亚型病毒对血细胞的影响

[目的]Balb/c小鼠通过尾静脉注射和鼻腔接种禽流感H5N1亚型病毒造疾病模型,观察其血细胞变化。[方法]以禽流感H5N1亚型病毒通过静脉和鼻腔接种Balb/c小鼠,分别在0~7天和0~11天取血进行血细胞计数和分类,同时对于静脉接种方法进行了0~8小时的短时间监控。[结果]静脉接种途径在接种病毒后2小时就能显著的降低小鼠的白细胞总数、粒细胞及淋巴细胞数,白细胞总数及淋巴细胞数在第3天、粒细胞数在第2天就恢复正常而后均显著升高;而鼻腔接种仅在1~3天淋巴细胞有所降低,而后恢复正常;1~6天白细胞总数及粒细胞数显著升高,而后恢复正常。[结论]从血细胞变化而言,静脉接种相比鼻腔接种方法要好。

Reference Gene Selection for Normalization of PCR Analysis in Chicken Embryo Fibroblast Infected with H5N1 AIV

Chicken embryo fibroblasts (CEFs) are among the most commonly used cells for the study of interactions between chicken hosts and H5N1 avian influenza virus (AIV).In this study,the expression of eleven housekeeping genes typically used for the normalization of quantitative real-time PCR (QPCR) analysis in mammals were compared in CEFs infected with H5N1 AIV to determine the most reliable reference genes in this system.CEFs cultured from 10-day-old SPF chicken embryos were infected with 100 TCID50 of H5N1 AIV and harvested at 3,12,24 and 30 hours post-infection.The expression levels of the eleven reference genes in infected and uninfected CEFs were determined by real-time PCR.Based on expression stability and expression levels,our data suggest that the ribosomal protein L4 (RPL4) and tyrosine 3-monooxygenase tryptophan 5-monooxygenase activation protein zeta polypeptide (YWHAZ) are the best reference genes to use in the study of host cell response to H5N1 AIV infection.However,for the study of replication levels of H5N1 AIV in CEFs,the β-actin gene (ACTB) and the ribosomal protein L4 (RPL4) gene are the best references.

Hospitalized patients with novel influenza A （H1N1） virus infection： Shanghai, June-July 2009

Background From late May 2009, sporadic imported cases of novel influenza A （HIN1） were continuously confirmed in Shanghai, but there were few reports on its clinical presentation in China. The aim of the study was to investigate the demographic and clinical features of the laboratory-confirmed cases and the treatment with oseltamivir. Method We performed a retrospective study in the Shanghai Public Health Clinical Center （SHAPHC）, reviewing the medical records of the laboratory-confirmed patients derived from June 10 to July 20, 2009. Results A total of 156 cases were enrolled, of whom 152 had a history of recent travel. The mean age was 22.6 years and 89 cases （57.1%） were males. The most common symptoms were fever, cough, and sore throat, with children more likely to run a temperature above 38.5℃ than adults. The mean leucocyte count was 5.4×10^9/L, the mean neutrophil count 3.2×10^9/L and the mean lymphocyte count 1.4×10^9/L. Other findings included a normal range or elevated level of C-reactive protein （CRP） and glutamic-pyruvic transaminase and a normal or decreased level of prealbumin; the levels of prealbumin and CRP were significantly lower in the children than in the adults. Fifty-two patients had abnormal chest CT results, with small unilateral or bilateral pulmonary infiltrates, axillary and mediastinal lymphadenopathy and local pleural thickening, while no cases showed symptoms of hypoxia. All the patients received oseltamivir and recovered without complications, but the duration of fever and virus shedding were significantly longer in the children than in the adults. Conclusions Travel-related circulation may be an important reason for the H1N1 epidemic in the non-epidemic areas, and the virus caused mild respiratory symptoms. The infection in children was more severe in terms of prealbumin levels, temperature, the duration of fever and virus shedding. Oseltamivir was effective for H1N1, but more effective in the adults than in the children.

Efficacy of seasonal pandemic influenza hemagglutinin DNA vaccines delivered by electroporation against aseasonal H1N1 virus challenge in mice

Prophylactic DNA vaccines against the influenza virus are promising alternatives to conventional vaccines. In this study, we generated two candidate gene-based influenza vaccines encoding either the seasonal or pandemic hemagglutinin antigen （HA） from the strains A/New Caledonia/20/99 （HIN1） （pV1AS） and A/Califorrtia/04/2009 （H1N1） （pVEH1）, respectively. After verifying antigen expression, the immunogenicity of the vaccines delivered intramuscularly with electroporation was tested in a mouse model. Sera of immunized animals were tested in hemagglutination inhibition assays and by ELISA for the presence of HA-specific antibodies. HA-specific T-cells were also measured in IFN-γ ELISpot assays. The protective efficacy of the candidate influenza vaccines was evaluated by measuring mortality rates and body weight after a challenge with 100 LD50 of mouse-adapted A/New Caledonia/20/99 （H1N1）. Mice immunized with either one of the two vaccines showed significantly higher T cell and humoral immune responses （P〈0.05） than the pVAX1 control group. Additionally, the pV1A5 vaccine effec- tively protected the mice against a lethal homologous mouse-adapted virus challenge with a survival rate of 100% compared with a 40% survival rate in the pVEH1 vaccinated group （P〈0.05）. Our study indicates that the seasonal influenza DNA vac- cine completely protects against the homologous A/New Caledonia/20/99 virus （H1N1）, while the pandemic influenza DNA vaccine only partially protects against this virus.

Reduning plus ribavirin display synergistic activity against severe pneumonia induced by H1N1 influenza A virus in mice

OBJECTIVE:To investigate synergistic effect of Reduning(RDN)injection plus ribavirin against severe pneumonia induced by H1 N1 influenza A virus in mice.METHODS:We established a mouse model of severe pneumonia induced by influenza A virus by infecting Balb/c mice with CA07 virus.We randomly assigned the infected mice into four groups,and treated them with normal saline(NS group),RDN(injection,86.6 mg/kg),ribavirin(injection,66.6 mg/kg)or double Ribavirin plus RDN group,the same dosage as used in the single treatments)for 5 d.Lung index and lung pathology were recorded or calculated in terms of the curative effective.Cytokines,NOD-like receptor family pyrin domain containing 3(NLRP3)inflammasome related protein including caspase-associated recruitment domain(CARD)domain Apoptosis-associated speck-like protein containing a caspase recruitment domain(ASC),caspase-1 and NOD-like receptor family,pyrin domain containing 3(NLRP3),and reactive oxygen species were simultaneously investigated.RESULTS:RDN plus ribavirin treatment,not RDN or ribavirin alone,provided a significant survival benefit to the influenza A virus-infected mice.The combination treatment protected the mice against severe influenza infection by attenuating the severe lung injury.The combined treatment also reduced the viral titers in mouse lungs and lung index,downregulated their immunocytokine levels,including IL-1βand IL-18,and down regulated the NLRP3,especially the transcription and translation of caspase-1.Meanwhile NS group had significantly higher reactive oxygen species(ROS)expression which could was dramatically reduced by the treatment of RDN plus ribavirin.CONCLUSION:Our study showed that RDN combined with ribavirin could protect the mice,and reduce the lung immunopathologic damage caused by severe influenza pneumonia.The mechanism could be that it reduced ROS produce and inhibited NLRP3 inflammasome activation so that mainly lower the downstream inflammatory cytokines IL-1βand IL-18.

Influenza A pandemic （H1N1） 2009 virus infection

The clinical spectrum of the 2009 pandemic influenza A （H1N1） infection ranged from self-limited mild illness to progressive pneumonia, or even a fatal outcome. We summarize the clinical manifestations, risk factors for severe and fatal cases, pathologic findings and treatment of this disease in this paper based on current reports from different regions of the world.

Clinical features of initial cases of 2009 pandemic influenza A （H1N1） in Macao, China

Background The first case of pandemic influenza A （H1N1） virus infection in Macao Special Administrative Region （SAR） of the People＇s Republic of China was documented on June 18, 2009. Subsequently, persons with suspected infection or of contact with suspected cases received screening. All the confirmed cases were hospitalized and treated with oseltamivir. Their clinical features were observed. This may help for better management for later patients and be of benefit to the government of Macao SAR to adjust its strategy to combat the pandemic influenza A （H1N1） virus infection more efficiently. Methods From June to July 2009, the initial 72 cases of influenza A （H1N1） in Macao were hospitalized in Common Hospital Centre S. Januario （CHCSJ）. The infection was confirmed by real-time reverse-transcriptase polymerase chain reaction （RT-PCR）. The clinical features of the disease were closely observed and documented. Oseltamivir was given to all patients within 48 hours after the onset of disease and maintained for 5 days. Results The mean age of the 72 patients was 21 years old. Forty of them were men and 32 were women. The median incubation of the virus was 2 days （1 to 7 days）. The most common symptoms were fever （97.2%） and cough （77.8%）. The rate of gastrointestinal symptoms including nausea, vomiting, and diarrhea was 2.8%. Fever typically lasted for 3 days （1 to 9 days）. The median time from the onset to positive results of real-time RT-PCR was 6 days （3 to 13 days）. After treatment with oseltamivir, most patients became afebrile within 48 hours. Only one aged patient with a history of glaucoma and hypothyroidism was found to have lung infiltration on chest X-ray. Conclusions The initial cases of pandemic influenza A （H1N1） virus infection in Macao SAR showed that most of the infected persons had a mild course. The virus could be detected by real-time RT-PCR within a median of 6 days from the onset. Oseltamivir was effective.

A Mechanism-based 3D-QSAR and DFT Approach for the Prediction of H5N1 Entry Inhibitory Potency of 3-O-β-chacotriosyl Ursolic Acid Derivatives

In this work, 25 3-O-β-chacotriosyl ursolic acid derivatives were employed to achieve the highly reliable and predictive 3 D-QSAR models by Co MFA and Co MSIA methods, respectively. The predictive capabilities of two constructed CoMFA and CoMSIA models were verified by the leave-one-out cross-validation method. The results showed that the cross-validated coefficient（q2） and non-cross-validated coefficient（R2） were 0.559, 0.981 in the CoMFA model and 0.696, 0.978 in the CoM SIA model, respectively, which suggests that these two models are robust and have good exterior predictive capabilities. Furthermore, based on the contour maps information of two models, ten novel inhibitors with higher inhibitory potency were designed, and the quantum chemical calculation of density functional theory（DFT） was performed to investigate the mechanism why the designed molecules have stronger inhibitory activity than the lead compound. The calculations show that the C-50 position of lead compound is a key active site for the enhancement of inhibitory activity, and it should be introduced into the large electron withdrawing group, which would result in generating potent and selective H5 N1 entry inhibitors. We expect that the results in this paper could provide important information to develop new potent H5 N1 entry inhibitors.

Sixty-two severe and critical patients with 2009 influenza A （H1N1） in Shanghai, China

Background Pandemic influenza A （H1N1） emerged rapidly in China in May 2009. Preliminary comparisons with seasonal influenza suggest that pandemic 2009 influenza A （HIN1） disproportionately affects younger ages and causes generally mild disease. To characterize disease progress, comorbidities, and treatment outcomes among consecutive severe and critically ill patients in a hospital served as a reference center for the care of patients with HIN1 in Shanghai, China.Methods A retrospective study on 62 severe and critically ill patients with 2009 influenza A （H1N1） was conducted in Shanghai Public Health Clinical Center. Demographic data, symptoms, comorbidities, disease progression, treatments, and clinical outcomes were collected for analysis.