The optimized #fusion protein HA1-2-FliC△D2D3 promotes mixed Th1/Th2 immune responses to #influenza #H7N9 with low induction of systemic proinflammatory #cytokines in mice (Antiviral Res., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Antiviral Res. 2018 Oct 30. pii: S0166-3542(18)30186-4. doi: 10.1016/j.antiviral.2018.10.027. [Epub ahead of print]

The optimized fusion protein HA1-2-FliC△D2D3 promotes mixed Th1/Th2 immune responses to influenza H7N9 with low induction of systemic proinflammatory cytokines in mice.

Song L1, Xiong D1, Kang X1, Jiao Y1, Zhou X2, Wu K1, Zhou Y1, Jiao X3, Pan Z4.

Author information: 1 Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu 225009, China; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu 225009, China; Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu 225009, China. 2 Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu 225009, China; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu 225009, China; Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu 225009, China; Pathobiology and Veterinary Science, College of Agriculture, Health and Natural Resources, University of Connecticut, Storrs, CT 06269, USA. 3 Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu 225009, China; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu 225009, China; Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu 225009, China. Electronic address: jiao@yzu.edu.cn. 4 Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu 225009, China; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu 225009, China; Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu 225009, China. Electronic address: zmpan@yzu.edu.cn.

 

Abstract

H7N9 influenza virus has an unusually high fatality rate of approximately 40%, and a safe and effective vaccine against this subtype is urgently needed. Flagellin, a Toll-like receptor (TLR) 5 agonist, has been deemed as a potent adjuvant candidate. However, its high antigenicity and potential for causing inflammatory injury might restrict its clinical application. Previously, we demonstrated that a fusion protein, HA1-2-FliC, comprising the hemagglutinin globular head protein (HA1-2) of H7N9 influenza virus and the full-length Salmonella typhimurium flagellin protein (FliC), had high efficiency against H7N9 in mouse and chicken models. Here, we constructed an improved fusion protein, HA1-2-FliC△D2D3, with HA1-2 fused to the FliC△D2D3 (lacking the hypervariable-region domains D2 and D3 of FliC). HA1-2-FliC△D2D3 exhibited efficient immunoreactivity and TLR5 agonist efficacy, and promoted innate immune-response activation in mouse macrophages, peripheral blood mononuclear cells, and splenocytes, based on cytokine- and chemokine-expression profiles. Mice immunized with HA1-2-FliCΔD2D3 showed significantly lower systemic inflammatory responses (compared with HA1-2-FliC) and highly reduced flagellin-specific antibody production, without affecting HA1-2-specific antibody production and cellular immune responses. Enhanced IFN-γ/IL-4 generation suggested that HA1-2-FliCΔD2D3 maintained balanced Th1/Th2 immune responses. Furthermore, virus challenge was performed in a chicken model. The results showed that chickens receiving FliCΔD2D3 adjuvant vaccine induced high levels of serum neutralizing antibodies, and exhibited a significant reduction of viral loads in throat and cloaca compared to chickens receiving only HA1-2. In conclusion, we constructed the H7N9 influenza subunit vaccine candidate HA1-2-FliCΔD2D3, with reduced immunogenicity against FliC and lower adverse events. The improved adjuvant FliCΔD2D3 can potentially help in developing safe and effective universal protein-based influenza vaccines for humans.

KEYWORDS: Adjuvanticity; Flagellin; H7N9 influenza virus; Hemagglutinin globular head; Hypervariable region; Immune response

PMID: 30389471 DOI: 10.1016/j.antiviral.2018.10.027

Keywords: Avian Influenza; Influenza A; H7N9; Vaccines.

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gimi69

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.

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