Cross-neutralizing Anti-hemagglutinin Antibodies Isolated from Patients Infected with Avian Influenza A (H5N1) Virus / 生物医学与环境科学（英文）

Objective@#To recover broad-neutralizing monoclonal antibodies (BnAbs) from avian influenza A (H5N1) virus infection cases and investigate their genetic and functional features.@*Methods@#We screened the Abs repertoires of expanded B cells circulating in the peripheral blood of H5N1 patients. The genetic basis, biological functions, and epitopes of the obtained BnAbs were assessed and modeled.@*Results@#Two BnAbs, 2-12D5, and 3-37G7.1, were respectively obtained from two human H5N1 cases on days 12 and 21 after disease onset. Both Abs demonstrated cross-neutralizing and Ab-dependent cellular cytotoxicity (ADCC) activity. Albeit derived from distinct Ab lineages, , V 1-69-D2-15-J 4 (2-12D5) and V 1-2-D3-9-J 5 (3-32G7.1), the BnAbs were directed toward CR6261-like epitopes in the HA stem, and HA I45 in the hydrophobic pocket was the critical residue for their binding. Signature motifs for binding with the HA stem, namely, IFY in V 1-69-encoded Abs and LXYFXW in D3-9-encoded Abs, were also observed in 2-12D5 and 3-32G7.1, respectively.@*Conclusions@#Cross-reactive B cells of different germline origins could be activated and re-circulated by avian influenza virus. The HA stem epitopes targeted by the BnAbs, and the two Ab-encoding genes usage implied the VH1-69 and D3-9 are the ideal candidates triggered by influenza virus for vaccine development.

Experimental infection and pathology of clade 2.2 H5N1 virus in gulls

During 2006, H5N1 HPAI caused an epizootic in wild birds, resulting in a die-off of Laridae in the Novosibirsk region at Chany Lake. In the present study, we infected common gulls (Larus canus) with a high dose of the H5N1 HPAI virus isolated from a common gull to determine if severe disease could be induced over the 28 day experimental period. Moderate clinical signs including diarrhea, conjunctivitis, respiratory distress and neurological signs were observed in virus-inoculated birds, and 50% died. The most common microscopic lesions observed were necrosis of the pancreas, mild encephalitis, mild myocarditis, liver parenchymal hemorrhages, lymphocytic hepatitis, parabronchi lumen hemorrhages and interstitial pneumonia. High viral titers were shed from the oropharyngeal route and virus was still detected in one bird at 25 days after infection. In the cloaca, the virus was detected sporadically in lower titers. The virus was transmitted to direct contact gulls. Thus, infected gulls can pose a significant risk of H5N1 HPAIV transmission to other wild migratory waterfowl and pose a risk to more susceptible poultry species. These findings have important implications regarding the mode of transmission and potential risks of H5N1 HPAI spread by gulls.

Effect and Mechanism of Extracts of Nidus Collocaliae on Resisting Avian Influenza A H5N1 Virus / 广州中医药大学学报

Objective To observe the inhibitory effect of the extracts of Nidus Collocaliae on avian influenza A H5N1 virus in vitro. Methods Nidus Collocaliae water extract, artificial gastric juice digestion products of Nidus Collocaliae water extract, and artifitial intestinal juice digestion products of Nidus Collocaliae water extract were prepared for the experimental study. 293T cells transfection in vitro was carried out. The effects of 3 kinds of Nidus Collocaliae extracts on H5N1 pseudovirus and VSV-G pseudovirus were determined by luciferase detection kit. Blood clotting response to erythrocyte hemagglutinin subtypes H5, H7, H9 antigens and the inhibitory effects of 3 kinds of Nidus Collocaliae extracts were observed. The effects of 3 kinds of Nidus Collocaliae extracts on neuraminidase activity were determined by neuraminidase inhibitor screen kit. Results The 3 kinds of Nidus Collocaliae extracts had inhibitory effects on H5N1 avian influenza pseudovirus, the effects being enhanced with the increase of the concentrations of Nidus Collocaliae extracts. Of the 3 extracts, artificial intestinal digestion products had the strongest inhibitory effect, while Nidus Collocaliae water extract had the weakest effect. However, Nidus Collocaliae extracts had no obvious effect on VSV-G pseudovirus. The concentration of H5, H7 antigen for positive blood clotting response was 1 ∶ 128, and that of H9 antigen was 1 ∶ 256. The 3 kinds of Nidus Collocaliae extracts at certain concentrations could inhibit blood clotting response to H5, H7, H9 antigen, but had no obvious effect on neuraminidase. Conclusion The anti-H5N1 virus effect of Nidus Collocaliae extracts has been achieved probably through resisting hemagglutinin.

Statistical screening of the B-cell epitopes for the nucleoprotein of human H5N1 virus predicted by computerization / 中华微生物学和免疫学杂志

Objective To predict and screen the B-cell epitopes on nucleoprotein(NP)of human avian H5N1 virus strain.Methods As NP nucleotide sequences of strain A/GD/01/06(H5N1)were sequenced,B-cell epitopes were predicted by the analysis of the flexible regions of secondary structure for NPprotein and by screening on B-cell epitopes for NP protein with methods of Hydrophilicity Plot by KyteDoolittle,Surface Probability Plot by Emini,and Antigenic Index by Jameson-Wolf.Then a screening method was established by Hierarchical cluster,Bivariate correlate and Quartiles in SPSS13.0.and the variation of amino acids in NP protein was appraised in epitope prediction.Resuits The computer-predicted most possible epitopes for NP protein were located within or nearby its N-terminal 317-326,452-457,467-473,367-370,491-498,375-378,171-177,48-53,245-250.76-104 and so on.NP protein in A/GD/01/06(H5N1)increased a glycoprotein domain(NES368-370)by the substitution of N370S and changed the bio-features.Conclusion Stepwise prediction of the B-cell epitopes for the NP protein based on multiple parameters is helpful for the molecular-immunology and drug-screening,and the substitution of N370 S in NP of A/GD/01/06(H5N1)varied its antigenicity but didn't change the epitope size(SNEN367-370).

Control of Avian Influenza: Calls for International Collaboration / 한국역학회지

The 1918 "Spanish Flu", cause of the largest causality rate ever recorded in human history with 50 million deaths, is genetically related to the current H5N1 virus, suggesting the potential emergence of H5N1 influenza as the next pandemic wave. In the process of co-infection and genetic reassortment of human and H5N1 avian influenza, the H5N1 strain could acquire human viral gene(s) to ignite the human to human spread, as occurred in 1957 and 1976 pandemics. All countries are vulnerable to infection as no effective vaccine has yet been developed for avian influenza. Once developed into a pandemic, the socio-economic impact of avian influenza would be enormous. In response to this danger, Korea recently proposed to establish an international consortium, the Pandemic Influenza Consortium, Korea (PICK), to emphasize close collaboration, especially among Pacific Rim countries. PICK proposes to support the following three areas: 1) international efforts in the implementation of national and regional preparedness plans through the development of epidemiological, microbiological and clinical tools and mechanisms for early detection of pandemic influenza epidemics, 2) the development and clinical evaluation of pandemic influenza candidate vaccine, and 3) the establishment of appropriate mechanisms to ensure the capacity to produce, the availability of supply, and the rational distribution of pandemic influenza vaccines to countries suffering from or at high risk of experiencing outbreaks. Finally, the effort is expected to serve as a basis for initiating, establishing and strengthening the international infrastructure for investigation of the infection mechanism and devising prophylactic and therapeutic responses to various infectious diseases.

The pathohistology change of the people died from H_5N_1 avian influenza virus / 中国法医学杂志

The people died from H5N1 avian influenza virus,which was diagnosed by serological test.The remarkable pathohistology change is as follows:thick and homogeneous things dyed red can be seen on the face of pulmonary alveoli;the alveolar septum become wider and there are a lot of inflammatory cells in the pulmonary alveoli.Above all,we think that the histology changes can provide evidence to help coroners identify people died from H5N1 avian influenza virus or not.