Quick and improved immune responses to inactivated H9N2 avian influenza vaccine by purified active fraction of Albizia julibrissin saponins

Abstract Background H9N2 Low pathogenic avian influenza virus (LPAIV) raises public health concerns and its eradication in poultry becomes even more important in preventing influenza. AJSAF is a purified active saponin fraction from the stem bark of Albizzia julibrissin. In this study, AJSAF was evaluated for the adjuvant potentials on immune responses to inactivated H9N2 avian influenza virus vaccine (IH9V) in mice and chicken in comparison with commercially oil-adjuvant. Results AJSAF significantly induced faster and higher H9 subtype avian influenza virus antigen (H9–Ag)-specific IgG, IgG1, IgG2a and IgG2b antibody titers in mice and haemagglutination inhibition (HI) and IgY antibody levels in chicken immunized with IH9V. AJSAF also markedly promoted Con A-, LPS- and H9–Ag-stimulated splenocyte proliferation and natural killer cell activity. Furthermore, AJSAF significantly induced the production of both Th1 (IL-2 and IFN-γ) and Th2 (IL-10) cytokines, and up-regulated the mRNA expression levels of Th1 and Th2 cytokines and transcription factors in splenocytes from the IH9V-immunized mice. Although oil-formulated inactivated H9N2 avian influenza vaccine (CH9V) also elicited higher H9–Ag-specific IgG and IgG1 in mice and HI antibody titer in chicken, this robust humoral response was later produced. Moreover, serum IgG2a and IgG2b antibody titers in CH9V-immunized mice were significantly lower than those of IH9V alone group. Conclusions AJSAF could improve antigen-specific humoral and cellular immune responses, and simultaneously trigger a Th1/Th2 response to IH9V. AJSAF might be a safe and efficacious adjuvant candidate for H9N2 avian influenza vaccine.

Download Full-text

Comparison of chicken immune responses after inoculation with H5 avian influenza virus-like particles produced by insect cells or pupae

Journal of Veterinary Research ◽

10.2478/jvetres-2021-0026 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Dean Huang ◽

Yu-Chan Chao ◽

Zhengbing Lv ◽

Jia-Tsrong Jan ◽

Yu-Chih Yang ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Immune Responses ◽

Avian Influenza Virus ◽

Matrix Protein ◽

Haemagglutination Inhibition ◽

Virus Like Particles ◽

Silkworm Pupae ◽

Ifn Γ ◽

Silkworm Pupa

Abstract Introduction Novel clade 2.3.4.4 H5 highly pathogenic avian influenza virus (HPAIV) outbreaks have occurred since early 2015 in Taiwan and impacted the island economically, like they have many countries. This research investigates the immunogenicity of two HPAIV-like particles to assess their promise as vaccine candidates. Material and Methods The haemagglutinin (HA) gene derived from clade 2.3.4.4 H5 HPAIV and matrix protein 1 (M1) gene were cloned into the pFastBac Dual baculovirus vector. The resulting recombinant viruses were expressed in Spodoptera frugiperda moth (Sf)21 cells and silkworm pupae to generate Sf21 virus-like particles (VLP) and silkworm pupa VLP. Two-week-old specific pathogen–free chickens were immunised and their humoral and cellular immune responses were analysed. Results The silkworm pupa VLP had higher haemagglutination competence. Both VLP types elicited haemagglutination inhibition antibodies, anti-HA antibodies, splenic interferon gamma (IFN-γ) and interleukin 4 (IL-4) mRNA expression, and CD4+/CD8+ ratio elevation. However, chickens receiving silkworm pupa VLP exhibited a significantly higher anti-HA antibody titre in ELISA after vaccination. Although Sf21 VLP recipients expressed more IFN-γ and IL-4, the increase in IFN-γ did not significantly raise the CD4+/CD8+ ratio and the increase in IL-4 did not promote anti-HA antibodies. Conclusion Both VLP systems possess desirable immunogenicity in vivo. However, in respect of immunogenic efficacy and the production cost, pupa VLP may be the superior vaccine candidate against clade 2.3.4.4 H5 HPAIV infection.

Download Full-text

Assessment of Human Immune Responses to H7 Avian Influenza Virus of Pandemic Potential: Results from a Placebo–Controlled, Randomized Double–Blind Phase I Study of Live Attenuated H7N3 Influenza Vaccine

PLoS ONE ◽

10.1371/journal.pone.0087962 ◽

2014 ◽

Vol 9 (2) ◽

pp. e87962 ◽

Cited By ~ 45

Author(s):

Larisa Rudenko ◽

Irina Kiseleva ◽

Anatoly N. Naykhin ◽

Marianna Erofeeva ◽

Marina Stukova ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Immune Responses ◽

Influenza Vaccine ◽

Phase I ◽

Avian Influenza Virus ◽

Phase I Study ◽

Double Blind ◽

Human Immune

Download Full-text

Characterization of Host Responses against a Recombinant Fowlpox Virus-Vectored Vaccine Expressing the Hemagglutinin Antigen of an Avian Influenza Virus

Clinical and Vaccine Immunology ◽

10.1128/cvi.00487-09 ◽

2010 ◽

Vol 17 (3) ◽

pp. 454-463 ◽

Cited By ~ 21

Author(s):

Hamid R. Hghihghi ◽

Leah R. Read ◽

Hakimeh Mohammadi ◽

Yanlong Pei ◽

Claudia Ursprung ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Immune Responses ◽

Avian Influenza Virus ◽

Cultured Cells ◽

Type I Interferons ◽

Host Responses ◽

Type I ◽

Fowlpox Virus ◽

Time Points

ABSTRACT There currently are commercial fowlpox virus (FPV)-vectored vaccines for use in chickens, including TROVAC-AIV H5, which expresses the hemagglutinin (HA) antigen of an avian influenza virus and can confer immunity against avian influenza in chickens. Despite the use of recombinant FPV (rFPV) for vaccine delivery, very little is known about the immune responses generated by these viruses in chickens. The present study was designed to investigate host responses to rFPV in vivo and in vitro. In cultured cells infected with TROVAC-AIV H5, there was an early increase in the expression of type I interferons (IFN), Toll-like receptors 3 and 7 (TLR3 and TLR7, respectively), TRIF, and MyD88, which was followed by a decrease in the expression of these genes at later time points. There also was an increase in the expression of interleukin-1β (IL-1β), IL-8, and beta-defensin genes at early time points postinfection. In chickens immunized with TROVAC-AIV H5, there was higher expression of IFN-γ and IL-10 at day 5 postvaccination in spleen of vaccinated birds than in that of control birds. We further investigated the ability of the vaccine to induce immune responses against the HA antigen and discovered that there was a cell-mediated response elicited in vaccinated chickens against this antigen. The findings of this study demonstrate that FPV-vectored vaccines can elicit a repertoire of responses marked by the early expression of TLRs, type I interferons, and proinflammatory cytokines, as well as cytokines associated with adaptive immune responses. This study provides a platform for designing future generations of rFPV-vectored vaccines.

Download Full-text