Glycan‐masking hemagglutinin antigens from stable CHO cell clones for H5N1 avian influenza vaccine development

ABSTRACTWe isolated two H5N1 viruses, A/duck/Hunan/S4020/2008 (DK/08) and A/chicken/Guangxi/S2039/2009 (CK/09), from live-bird markets during routine surveillance and found that these two viruses are genetically similar but differ in their replication and virulence in mice. The CK/09 virus is lethal for mice with a 50% mouse lethal dose (MLD50) of 1.6 log1050% egg infectious doses (EID50), whereas the DK/08 virus is nonpathogenic for mice with an MLD50value of 6.2 log10EID50. We explored the genetic basis of the virulence difference of these two viruses by generating a series of reassortant viruses and mutants in the lethal virus CK/09 background and evaluating their virulence in mice. We found that the PB1 gene of the DK/08 virus dramatically attenuated the virulence of the CK/09 virus and that the amino acid at position 622 in PB1 made an important contribution. We further demonstrated that the mutation of glycine (G) to aspartic acid (D) at position 622 in PB1 partially impaired the binding of PB1 to viral RNA, thereby dramatically decreasing the polymerase activity and attenuating H5N1 virus virulence in mice. Our results identify a novel virulence-related marker of H5N1 influenza viruses and provide a new target for live attenuated vaccine development.IMPORTANCEH5N1 avian influenza viruses have caused the deaths of nearly 60% of the humans that they have infected since 1997 and clearly represent a threat to public health. A thorough understanding of the genetic basis of virulence determinants will provide important insights for antiviral drug and live attenuated vaccine development. Several virulence-related markers in the PB2, PA, M1, and NS1 proteins of H5N1 viruses have been identified. In this study, we isolated two H5N1 avian influenza viruses that are genetically similar but differ in their virulence in mice, and we identified a new virulence-related marker in the PB1 gene. We found that the mutation of glycine (G) to aspartic acid (D) at position 622 in PB1 partially impairs the binding of PB1 to viral RNA, thereby attenuating H5N1 virus virulence in mice. This newly identified virulence-related marker could be applied to the development of live attenuated vaccines against H5N1 influenza.

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Nasal delivery of H5N1 avian influenza vaccine formulated with GenJet™ or in vivo-jetPEI® induces enhanced serological, cellular and protective immune responses

Drug Delivery ◽

10.1080/10717544.2018.1450909 ◽

2018 ◽

Vol 25 (1) ◽

pp. 773-779 ◽

Cited By ~ 3

Author(s):

Weiping Cao ◽

Margarita Mishina ◽

Samuel Amoah ◽

Wadzanai P. Mboko ◽

Caitlin Bohannon ◽

...

Keyword(s):

Avian Influenza ◽

Immune Responses ◽

Influenza Vaccine ◽

Nasal Delivery ◽

H5n1 Avian Influenza

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Coadministration of Recombinant Adenovirus Expressing GM-CSF with Inactivated H5N1 Avian Influenza Vaccine Increased the Immune Responses and Protective Efficacy Against a Wild Bird Source of H5N1 Challenge

Journal of Interferon & Cytokine Research ◽

10.1089/jir.2017.0043 ◽

2017 ◽

Vol 37 (10) ◽

pp. 467-473 ◽

Cited By ~ 3

Author(s):

Xiangwei Wang ◽

Xinglong Wang ◽

Yanqing Jia ◽

Chongyang Wang ◽

Qiuxia Tang ◽

...

Keyword(s):

Avian Influenza ◽

Immune Responses ◽

Influenza Vaccine ◽

Wild Bird ◽

Recombinant Adenovirus ◽

Protective Efficacy ◽

Gm Csf ◽

H5n1 Avian Influenza

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Individual and flock immunity responses of naïve ducks on smallholder farms after vaccination with H5N1 Avian Influenza vaccine: a study in a province of the Mekong Delta, Vietnam

PeerJ ◽

10.7717/peerj.6268 ◽

2019 ◽

Vol 7 ◽

pp. e6268

Author(s):

Hoa Thi Thanh Huynh ◽

Liem Tan Truong ◽

Tongkorn Meeyam ◽

Hien Thanh Le ◽

Veerasak Punyapornwithaya

Keyword(s):

Avian Influenza ◽

Influenza Vaccine ◽

Prevention And Control ◽

Booster Vaccination ◽

Primary Vaccination ◽

Vaccination Program ◽

Smallholder Farms ◽

H5n1 Avian Influenza ◽

Antibody Titers ◽

And Control

In Vietnam, vaccination has played a crucial role in the national strategy for the prevention and control of H5 highly pathogenic avian influenza (HPAI). This study aimed to evaluate antibody responses of immunologically naïve domestic ducks to H5N1 avian influenza vaccine currently used in the national mass vaccination program of Vietnam. Blood samples of 166 ducks reared on smallholder farms were individually collected at three sampling time points, namely, right before vaccination, 21 days after primary vaccination, and 21 days after booster vaccination. Vaccine-induced antibody titers of duck sera were measured by the hemagglutination inhibition assay. Temporal differences in mean antibody titers were analyzed using the generalized least-squares method. No sampled ducks showed anti-H5 seropositivity pre-vaccination. The geometric mean titer (GMT) of the vaccinated ducks was 5.30 after primary vaccination, with 80% of the vaccinated ducks showing seropositivity. This result indicates that the immunity of duck flocks met the targets of the national poultry H5N1 HPAI mass vaccination program. GMT and seropositive rates of the ducks were 6.48 and 96.3%, respectively, after booster vaccination, which were significantly higher than those after primary vaccination. Flock-level seroprotection rate significantly increased from 68% to 84.7%, whereas variability in GMT titers decreased from 34.87% to 26.3%. This study provided important information on humoral immune responses of ducks to the currently used H5N1 vaccine under field conditions. Our findings may help guide veterinary authorities in planning effective vaccine protocols for the prevention and control of H5N1 in the target poultry population.

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