Laboratory

Today, the liboratory will has a meeting. I am so nervous, For do my best and do it perfectly, I prepare my paper and report overnight.


This is my report! I type every word by myself>< It's really tired me..

The topic:
Evaluation of Replication and Pathogenicity of Avian Influenza A H7 Subtype Viruses in a Mouse Model

Abstract:

•Avian influenza A H7 subtype viruses pose a significant threat to human health because of their ability to transmit directly from domestic poultry to humans and to cause disease and, sometimes, death.

•The virulence of the 10 viruses for mice and the immunogenicity of the viruses in mice and ferrets were evaluated to study the extent of antigenic relatedness and the level of cross-reactivity of antibodies.

•H7 subtype viruses were able to infect mice without adaptation and manifested different levels of lethality and kinetics of replication.

•A subset of the viruses was also evaluated for the ability to replicate and cause disease in BALB/c mice following intranasal administration.

Introduction:


•Avian influenza A H7 subtype viruses pose a significant threat to human health because of their ability to transmit directly from domestic poultry to humans and to cause disease and, sometimes, death.

•The virulence of the 10 viruses for mice and the immunogenicity of the viruses in mice and ferrets were evaluated to study the extent of antigenic relatedness and the level of cross-reactivity of antibodies.

•H7 subtype viruses were able to infect mice without adaptation and manifested different levels of lethality and kinetics of replication.

•A subset of the viruses was also evaluated for the ability to replicate and cause disease in BALB/c mice following intranasal administration.

Disccusion:


•The percentage of amino acid sequence identity among the viruses ranged from 88.6 to 98%, and the VA/02 virus showed the lowest percentage of identity due to a deletion of eight amino acid residues in the HA1 domain of the HA protein.

•The HP H7 viruses also were characterized by their spread to extrapulmonary tissues, as evidenced by their presence in the brain and the spleen, However, the H7 viruses were detected in the brain as early as 1 dpi, while H5N1 viruses were detected at 4 to 6 dpi.

•Very low doses of the HP viruses were lethal to mice,whereas LP viruses did not kill mice even at high doses. Interestingly, in contrast to the UT/95 virus, the VA/02 virus that replicated to a high titer in the upper and lower respiratory tracts of mice did not cause significant weight loss during the course of infection.

•In this study, viruses from the Eurasian lineage elicited broadly cross-reactive antibodies that neutralized viruses from both Eurasian and North American lineages, but the converse was not true.


•The cross-neutralization titers suggest that NL/03 is a suitable candidate virus for vaccine development, because it elicited broadly cross-reactive antibodies that neutralized viruses from both lineages.

•Although the UT/95 and BC/04 viruses elicited a broader range of cross-reactive antibodies among the viruses from the North American lineage, the BC/04 virus was selected for vaccine development, because it is a recently identified isolate that has caused human infections.

•On the basis of phylogenetic data and the induction of broadly cross-neutralizing antibodies in postinfection mouse and ferret sera, we have selected NL/03 (H7N7) and BC/04 (H7N3) viruses for the development of vaccines against H7 pandemic influenza.