Project description:Avian influenza in the North Atlantic and characterization of newly introduced highly pathogenic avian influenza viruses from North America
Project description:Over the last decade, more than half of humans infected with highly pathogenic avian influenza (HPAI) H5N1 viruses have died, and yet virus-induced host signaling has yet to be clearly elucidated. Airway epithelia are known to produce inflammatory mediators that contribute to HPAI H5N1-mediated pathogenicity, but a comprehensive analysis of the host response in this cell type is lacking. Here, we leveraged a systems biology method called weighted gene correlation network analysis (WGCNA) to identify and statistically validate signaling sub-networks that define the dynamic transcriptional response of human bronchial epithelial cells after infection with influenza A/Vietnam/1203/2004 (H5N1, VN1203). A detailed examination of two sub-networks involved in the immune response and keratin filament formation revealed potential novel mediators of HPAI H5N1 pathogenesis, and additional experiments validated upregulation of these transcripts in response to VN1203 infection in C57BL/6 mice. Using emergent network properties, we provide fresh insight into the host response to HPAI H5N1 virus infection, and identify novel avenues for perturbation studies and potential therapeutic intervention of fatal HPAI H5N1 disease.
Project description:Over the last decade, more than half of humans infected with highly pathogenic avian influenza (HPAI) H5N1 viruses have died, and yet virus-induced host signaling has yet to be clearly elucidated. Airway epithelia are known to produce inflammatory mediators that contribute to HPAI H5N1-mediated pathogenicity, but a comprehensive analysis of the host response in this cell type is lacking. Here, we leveraged a systems biology method called weighted gene correlation network analysis (WGCNA) to identify and statistically validate signaling sub-networks that define the dynamic transcriptional response of human bronchial epithelial cells after infection with influenza A/Vietnam/1203/2004 (H5N1, VN1203). A detailed examination of two sub-networks involved in the immune response and keratin filament formation revealed potential novel mediators of HPAI H5N1 pathogenesis, and additional experiments validated upregulation of these transcripts in response to VN1203 infection in C57BL/6 mice. Using emergent network properties, we provide fresh insight into the host response to HPAI H5N1 virus infection, and identify novel avenues for perturbation studies and potential therapeutic intervention of fatal HPAI H5N1 disease. Calu-3 cells were infected with VN1203 influenza virus and profiled at 0, 3, 7, 12, 18, and 24 hours post infection. There are 3 mock and infected replicates for each time point.
Project description:Viral pneumonia has been frequently reported during early stages of influenza virus pandemics and in many human cases of highly pathogenic avian influenza (HPAI) H5N1 virus infection. To better understand the pathogenesis of this disease, we produced non-lethal viral pneumonia in rhesus macaques by using an HPAI H5N1 virus (A/Anhui/2/2005; referred to as Anhui/2). Infected macaques were monitored for 14 days, and tissue samples were collected at 6 time points for virologic, histopathologic and transcriptomic analyses.
Project description:Adjuvants play a central role in enhancing the immunogenicity of otherwise poorly immunogenic vaccine antigens. Combining adjuvants has the potential to enhance vaccine immunogenicity compared with single adjuvants, although the cellular and molecular mechanisms of combination adjuvants are not well understood. Using the influenza virus hemagglutinin H5 antigen, we define the immunological landscape of combining CpG and MPLA (TLR-9 and TLR-4 agonists, respectively) with a squalene nanoemulsion (AddaVax) using immunologic and transcriptomic profiling. Mice immunized and boosted with recombinant H5 in AddaVax, CpG+MPLA, or AddaVax plus CpG+MPLA (IVAX-1) produced comparable levels of neutralizing antibodies and were equally well protected against the H5N1 challenge. However, after challenge with H5N1 virus, H5/IVAX-1–immunized mice had 100- to 300-fold lower virus lung titers than mice receiving H5 in AddaVax or CpG+MPLA separately. Consistent with enhanced viral clearance, unsupervised expression analysis of draining lymph node cells revealed the combination adjuvant IVAX-1 significantly downregulated immune homeostasis genes, and induced higher numbers of antibody-producing plasmablasts than either AddaVax or CpG+MPLA. IVAX-1 was also more effective after single-dose administration than either AddaVax or CpG+MPLA. These data reveal a novel molecular framework for understanding the mechanisms of combination adjuvants, such as IVAX-1, and highlight their potential for the development of more effective vaccines against respiratory viruses.