A novel hemagglutinin protein produced in bacteria protects chickens against H5N1 highly pathogenic avian influenza viruses by inducing H5 subtype-specific neutralizing antibodies

Violetta Sączyńska , Agnieszka Romanik , Katarzyna Florys , Violetta Cecuda-Adamczewska , Małgorzata Kęsik-Brodacka , Krzysztof Śmietanka , Monika Olszewska , Katarzyna Domańska-Blicharz , Zenon Minta , Bogusław Szewczyk , Grażyna Płucienniczak , Andrzej Płucienniczak


The highly pathogenic (HP) H5N1 avian influenza viruses (AIVs) cause a mortality rate of up to 100% in infected chickens and pose a permanent pandemic threat. Attempts to obtain effective vaccines against H5N1 HPAIVs have focused on hemagglutinin (HA), an immunodominant viral antigen capable of eliciting neutralizing antibodies. The vast majority of vaccine projects have been performed using eukaryotic expression systems. In contrast, we used a bacterial expression system to produce vaccine HA protein (bacterial HA) according to our own design. The HA protein with the sequence of the H5N1 HPAIV strain was efficiently expressed in Escherichia coli, recovered in the form of inclusion bodies and refolded by dilution between two chromatographic purification steps. Antigenicity studies showed that the resulting antigen, referred to as rH5-E. coli, preserves conformational epitopes targeted by antibodies specific for H5-subtype HAs, inhibiting hemagglutination and/or neutralizing influenza viruses in vitro. The proper conformation of this protein and its ability to form functional oligomers were confirmed by a hemagglutination test. Consistent with the biochemical characteristics, prime-boost immunizations with adjuvanted rH5-E. coli protected 100% and 70% of specific pathogen-free, layer-type chickens against challenge with homologous and heterologous H5N1 HPAIVs, respectively. The observed protection was related to the positivity in the FluAC H5 test (IDVet) but not to hemagglutination-inhibiting antibody titers. Due to full protection, the effective contact transmission of the homologous challenge virus did not occur. Survivors from both challenges did not or only transiently shed the viruses, as established by viral RNA detection in oropharyngeal and cloacal swabs. Our results demonstrate that vaccination with rH5-E. coli could confer control of H5N1 HPAIV infection and transmission rates in chicken flocks, accompanied by reduced virus shedding. Moreover, the role of H5 subtype-specific neutralizing antibodies in anti-influenza immunity and a novel correlate of protection are indicated.
Author Violetta Sączyńska
Violetta Sączyńska,,
, Agnieszka Romanik
Agnieszka Romanik,,
, Katarzyna Florys
Katarzyna Florys,,
, Violetta Cecuda-Adamczewska
Violetta Cecuda-Adamczewska,,
, Małgorzata Kęsik-Brodacka
Małgorzata Kęsik-Brodacka,,
, Krzysztof Śmietanka
Krzysztof Śmietanka,,
, Monika Olszewska
Monika Olszewska,,
, Katarzyna Domańska-Blicharz
Katarzyna Domańska-Blicharz,,
, Zenon Minta
Zenon Minta,,
, Bogusław Szewczyk ZSzR
Bogusław Szewczyk,,
- Laboratory of Recombinant Vaccines
et al.
Other language title versions
Journal seriesPlos One, ISSN 1932-6203
Issue year2017
Publication size in sheets1
URL http://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0172008&type=printable
Languageen angielski
Score (nominal)40
ScoreMinisterial score = 35.0, 20-12-2017, ArticleFromJournal
Ministerial score (2013-2016) = 40.0, 20-12-2017, ArticleFromJournal
Publication indicators WoS Impact Factor: 2016 = 2.806 (2) - 2016=3.394 (5)
Citation count*0
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