Self-Amplifying Pestivirus Replicon RNA Encoding Influenza Virus Nucleoprotein and Hemagglutinin Promote Humoral and Cellular Immune Responses in Pigs

Self-amplifying replicon RNA (RepRNA) promotes expansion of mRNA templates encoding genes of interest through their replicative nature, thus providing increased antigen payloads. RepRNA derived from the non-cytopathogenic classical swine fever virus (CSFV) targets monocytes and dendritic cells (DCs), potentially promoting prolonged antigen expression in the DCs, contrasting with cytopathogenic RepRNA. We engineered pestivirus RepRNA constructs encoding influenza virus H5N1 (A/chicken/Yamaguchi/7/2004) nucleoprotein (Rep-NP) or hemagglutinin (Rep-HA). The inherent RNase-sensitivity of RepRNA had to be circumvented to ensure efficient delivery to DCs for intracellular release and RepRNA translation; we have reported how only particular synthetic delivery vehicle formulations are appropriate. The question remained concerning RepRNA packaged in virus replicon particles (VRPs); we have now compared an efficient polyethylenimine (PEI)-based formulation (polyplex) with VRP-delivery as well as naked RepRNA co-administered with the potent bis-(3’,5’)-cyclic dimeric adenosine monophosphate (c-di-AMP) adjuvant. All formulations contained a Rep-HA/Rep-NP mix, to assess the breadth of both humoral and cell-mediated defences against the influenza virus antigens. Assessment employed pigs for their close immunological relationship to humans, and as natural hosts for influenza virus. Animals receiving the VRPs, as well as PEI-delivered RepRNA, displayed strong humoral and cellular responses against both HA and NP, but with VRPs proving to be more efficacious. In contrast, naked RepRNA plus c-di-AMP could induce only low-level immune responses, in one out of five pigs. In conclusion, RepRNA encoding different influenza virus antigens are efficacious for inducing both humoral and cellular immune defences in pigs. Comparisons showed that packaging within VRP remains the most efficacious for delivery leading to induction of immune defences; however, this technology necessitates employment of expensive complementing cell cultures, and VRPs do not target human cells. Therefore, choosing the appropriate synthetic delivery vehicle still offers potential for rapid vaccine design, particularly in the context of the current coronavirus pandemic.

Download Full-text

Immunogenicity in Swine of Orally Administered Recombinant Lactobacillus plantarum Expressing Classical Swine Fever Virus E2 Protein in Conjunction with Thymosin α-1 as an Adjuvant

Applied and Environmental Microbiology ◽

10.1128/aem.00127-15 ◽

2015 ◽

Vol 81 (11) ◽

pp. 3745-3752 ◽

Cited By ~ 27

Author(s):

Yi-Gang Xu ◽

Xue-Ting Guan ◽

Zhong-Mei Liu ◽

Chang-Yong Tian ◽

Li-Chun Cui

Keyword(s):

Immune Responses ◽

Lactobacillus Plantarum ◽

Classical Swine Fever Virus ◽

Oral Vaccine ◽

Classical Swine Fever ◽

Fever Virus ◽

Economic Losses ◽

E2 Protein ◽

Content Type ◽

Cellular Immune

ABSTRACTClassical swine fever, caused by classical swine fever virus (CSFV), is a highly contagious disease that results in enormous economic losses in pig industries. The E2 protein is one of the main structural proteins of CSFV and is capable of inducing CSFV-neutralizing antibodies and cytotoxic T lymphocyte (CTL) activitiesin vivo. Thymosin α-1 (Tα1), an immune-modifier peptide, plays a very important role in the cellular immune response. In this study, genetically engineeredLactobacillus plantarumbacteria expressing CSFV E2 protein alone (L. plantarum/pYG-E2) and in combination with Tα1 (L. plantarum/pYG-E2-Tα1) were developed, and the immunogenicity of each as an oral vaccine to induce protective immunity against CSFV in pigs was evaluated. The results showed that recombinantL. plantarum/pYG-E2 andL. plantarum/pYG-E2-Tα1 were both able to effectively induce protective immune responses in pigs against CSFV infection by eliciting immunoglobulin A (IgA)-based mucosal, immunoglobulin G (IgG)-based humoral, and CTL-based cellular immune responses via oral vaccination. Significant differences (P< 0.05) in the levels of immune responses were observed betweenL. plantarum/pYG-E2-Tα1 andL. plantarum/pYG-E2, suggesting a better immunogenicity ofL. plantarum/pYG-E2-Tα1 as a result of the Tα1 molecular adjuvant that can enhance immune responsiveness and augment specific lymphocyte functions. Our data suggest that the recombinantLactobacillusmicroecological agent expressing CSFV E2 protein combined with Tα1 as an adjuvant provides a promising strategy for vaccine development against CSFV.

Download Full-text

Differential cellular immune responses between chickens and ducks to H9N2 avian influenza virus infection

Veterinary Immunology and Immunopathology ◽

10.1016/j.vetimm.2012.09.010 ◽

2012 ◽

Vol 150 (3-4) ◽

pp. 169-180 ◽

Cited By ~ 14

Author(s):

Zhenyu Huang ◽

Dong Fang ◽

Peng Lv ◽

Xuebing Bian ◽

Xizhen Ruan ◽

...

Keyword(s):

Influenza Virus ◽

Virus Infection ◽

Avian Influenza ◽

Immune Responses ◽

Avian Influenza Virus ◽

Influenza Virus Infection ◽

H9n2 Avian Influenza Virus ◽

Cellular Immune Responses ◽

Cellular Immune

Download Full-text

Cellular immune responses to hepatitis B virus antigens in man

Liver International ◽

10.1111/j.1600-0676.1991.tb00485.x ◽

2008 ◽

Vol 11 (1) ◽

pp. 1-23 ◽

Cited By ~ 6

Author(s):

Staffan P. E. Sylvan

Keyword(s):

Hepatitis B Virus ◽

Hepatitis B ◽

Immune Responses ◽

Cellular Immune Responses ◽

B Virus ◽

Hepatitis B Virus Antigens ◽

Virus Antigens ◽

Cellular Immune

Download Full-text

A Comparison of the Humoral and Cellular Immune Responses at Different Immunological Sites after Split Influenza Virus Vaccination of Mice

Scandinavian Journal of Immunology ◽

10.1111/j.1365-3083.2006.01862.x ◽

2007 ◽

Vol 65 (1) ◽

pp. 14-21 ◽

Cited By ~ 15

Author(s):

S. Hauge ◽

A. S. Madhun ◽

R. J. Cox ◽

K. A. Brokstad ◽

L. R. Haaheim

Keyword(s):

Influenza Virus ◽

Immune Responses ◽

Virus Vaccination ◽

Cellular Immune Responses ◽

Cellular Immune

Download Full-text

Induction of Broad-Based Immunity and Protective Efficacy by Self-amplifying mRNA Vaccines Encoding Influenza Virus Hemagglutinin

Journal of Virology ◽

10.1128/jvi.01786-15 ◽

2015 ◽

Vol 90 (1) ◽

pp. 332-344 ◽

Cited By ~ 54

Author(s):

Michela Brazzoli ◽

Diletta Magini ◽

Alessandra Bonci ◽

Scilla Buccato ◽

Cinzia Giovani ◽

...

Keyword(s):

T Cells ◽

Influenza Virus ◽

Immune Responses ◽

Upper Respiratory Tract ◽

Vaccine Platform ◽

Major Health Problem ◽

Cellular Immune Responses ◽

Influenza Virus Hemagglutinin ◽

Cellular Immune ◽

The Impact

ABSTRACTSeasonal influenza is a vaccine-preventable disease that remains a major health problem worldwide, especially in immunocompromised populations. The impact of influenza disease is even greater when strains drift, and influenza pandemics can result when animal-derived influenza virus strains combine with seasonal strains. In this study, we used the SAM technology and characterized the immunogenicity and efficacy of a self-amplifying mRNA expressing influenza virus hemagglutinin (HA) antigen [SAM(HA)] formulated with a novel oil-in-water cationic nanoemulsion. We demonstrated that SAM(HA) was immunogenic in ferrets and facilitated containment of viral replication in the upper respiratory tract of influenza virus-infected animals. In mice, SAM(HA) induced potent functional neutralizing antibody and cellular immune responses, characterized by HA-specific CD4 T helper 1 and CD8 cytotoxic T cells. Furthermore, mice immunized with SAM(HA) derived from the influenza A virus A/California/7/2009 (H1N1) strain (Cal) were protected from a lethal challenge with the heterologous mouse-adapted A/PR/8/1934 (H1N1) virus strain (PR8). Sera derived from SAM(H1-Cal)-immunized animals were not cross-reactive with the PR8 virus, whereas cross-reactivity was observed for HA-specific CD4 and CD8 T cells. Finally, depletion of T cells demonstrated that T-cell responses were essential in mediating heterologous protection. If the SAM vaccine platform proves safe, well tolerated, and effective in humans, the fully synthetic SAM vaccine technology could provide a rapid response platform to control pandemic influenza.IMPORTANCEIn this study, we describe protective immune responses in mice and ferrets after vaccination with a novel HA-based influenza vaccine. This novel type of vaccine elicits both humoral and cellular immune responses. Although vaccine-specific antibodies are the key players in mediating protection from homologous influenza virus infections, vaccine-specific T cells contribute to the control of heterologous infections. The rapid production capacity and the synthetic origin of the vaccine antigen make the SAM platform particularly exploitable in case of influenza pandemic.

Download Full-text

PCEP enhances IgA mucosal immune responses in mice following different immunization routes with influenza virus antigens

Journal of Immune Based Therapies and Vaccines ◽

10.1186/1476-8518-8-4 ◽

2010 ◽

Vol 8 (1) ◽

pp. 4 ◽

Cited By ~ 17

Author(s):

Nelson F Eng ◽

Srinivas Garlapati ◽

Volker Gerdts ◽

Lorne A Babiuk ◽

George K Mutwiri

Keyword(s):

Influenza Virus ◽

Immune Responses ◽

Virus Antigens ◽

Mucosal Immune Responses

Download Full-text

H5N1 influenza virus-like particles produced by transient expression in mammalian cells induce humoral and cellular immune responses in mice

Canadian Journal of Microbiology ◽

10.1139/w2012-006 ◽

2012 ◽

Vol 58 (4) ◽

pp. 391-401 ◽

Cited By ~ 4

Author(s):

Ling Tao ◽

Jianjun Chen ◽

Zhenhua Zheng ◽

Jin Meng ◽

Zhenfeng Zhang ◽

...

Keyword(s):

Influenza Virus ◽

Immune Responses ◽

Cleavage Site ◽

Mammalian Cells ◽

Influenza Virus Infection ◽

Influenza Viruses ◽

Virus Like Particles ◽

Cellular Immune Responses ◽

H5n1 Influenza ◽

Cellular Immune

Vaccination is an effective way to protect from influenza virus infection. Among the new candidates of influenza vaccines, influenza virus-like particles (VLPs) seem to be promising. Here, we generated 2 types of H5N1 influenza VLPs by co-expressing influenza virus Env (envelope protein) and murine leukemia virus (MLV) Gag–Pol. VLPs generated by co-transfection of pHCMV-wtH5 or pHCMV-mtH5 with pSV-Mo-MLVgagpol and pHCMV-N1 were named as wtH5N1 VLPs or mtH5N1 VLPs. The plasmid of pHCMV-wtH5 encoded the wild-type hemagglutinin (HA) (wtH5) from A/swine/Anhui/ca/2004 (H5N1) with a multibasic cleavage site, while pHCMV-mtH5 encoded the modified mutant-type (mtH5) with a monobasic cleavage site. Influenza virus HA VLPs were characterized and equal amounts of them were used to immunize mice subcutaneously, intraperitoneally, or intramuscularly. The levels of HA-specific IgG1, IFN-γ, and neutralization antibodies were significantly induced in mice immunized with wtH5N1 VLPs or mtH5N1 VLPs via all 3 routes, while HA-specific IgG2a was barely detectable. IL-4 secretion was detected in mice subcutaneously immunized with wtH5N1 VLPs or mtH5N1 VLPs, or intramuscularly immunized with mtH5N1 VLPs. Our results indicated that both H5N1 influenza VLPs could induce specific humoral and cellular immune responses in immunized mice. In conclusion, our study provides helpful information for designing new candidate vaccines against H5N1 influenza viruses.

Download Full-text