Injection site vaccinology of a recombinant vaccinia-based vector reveals diverse innate immune signatures

Poxvirus systems have been extensively used as vaccine vectors. Herein a RNA-Seq analysis of intramuscular injection sites provided detailed insights into host innate immune responses, as well as expression of vector and recombinant immunogen genes, after vaccination with a new multiplication defective, vaccinia-based vector, Sementis Copenhagen Vector. Chikungunya and Zika virus immunogen mRNA and protein expression was associated with necrosing skeletal muscle cells surrounded by mixed cellular infiltrates. The multiple adjuvant signatures at 12 hours post-vaccination were dominated by TLR3, 4 and 9, STING, MAVS, PKR and the inflammasome. Th1 cytokine signatures were dominated by IFNγ, TNF and IL1β, and chemokine signatures by CCL5 and CXCL12. Multiple signatures associated with dendritic cell stimulation were evident. By day seven, vaccine transcripts were absent, and cell death, neutrophil, macrophage and inflammation annotations had abated. No compelling arthritis signatures were identified. Such injection site vaccinology approaches should inform refinements in poxvirus-based vector design.Jessamine E. Hazlewood, Troy Dumenil, Thuy T. Le, Andrii Slonchak, Stephen H. Kazakoff, Ann-Marie Patch ... et al

187: West Nile virus (WNV) infection alters the cytokines and TLRs transcriptome profiles in rabbit PBL

The peripheral innate immune response to WNV is crucial for control of virus spread to the brain. Therefore, transcriptomes involved in the innate immune response against WNV were investigated in a model organism of rabbit peripheral blood mononuclear leukocytes (PBLs). PBLs were challenged with WNVNSW2011 in vitro and mRNA expressions were quantified at 2 h, 6 h, 12 h and 24 h post challenge (pc) using qRT-PCR. Compared to mock infected PBL, WNV infected PBLs expressed high levels of IFNα at 6 h pc. IFNγ expression increased markedly, peaking at 12 h pc with a 4-fold increase. IL6, 12 & 22 expression peaked at 12 h pc; while CXCL10 and PTX3 expression were higher at 2 h pc and then declined. TLR1, 2, 3, 4, 6 & 10 were up-regulated at 2 h pc with highest expression seen for TLR3, 4 & 6. TLRs-associated downstream genes (MyD88, STAT1, TRAF3, IRF7 & IRF9) were up-regulated between 6 and 24 h pc. Higher expression of TRAF3, STAT1, IRF7 & IRF9 suggest the activation of TLR signaling pathways in order to detect and clear the virus. Higher expression of TNFα, HO1, iNOS, Caspase3 & Caspase9 transcripts suggest the involvement of oxidative stress and apoptosis pathway in WNV infected rabbit PBLs. The expression dynamics of selected genes were validated in PBLs from rabbits experimentally infected with WNV in vivo. Higher expression of IFNα, IFNβ, IFNγ, TNFα, IL6, IL22, PTX3, TLR3 & TLR4, IRF7 & IRF9, STST1, TRAF3, Caspase3 & Caspase9 were found in PBL from WNV infected rabbits compared to PBLs from un-infected control rabbits, and coincided with expression patterns of these genes in vitro. WNVNSW2011 gene expression increased over time in PBLs challenged in vitro but remained undetected in PBLs from in vivo infected and control rabbits. This study highlights the array of cytokines and TLRs involved in the host innate immune response to WNV

Tissue-specific transcription profile of cytokine and chemokine genes associated with flavivirus control and non-lethal neuropathogenesis in rabbits

We previously showed that New Zealand White (NZWRs) and cottontail rabbits (CTRs) are a suitable model for studying immune mechanisms behind virus control and non-lethal neuropathogenesis associated with West Nile virus (WNV) and Murray Valley encephalitis virus (MVEV) infections. In the current study, we observed that MVEV infection induced high IFNα, TNFα, IL6, and CXCL10 transcript levels in the brains of weanling NZWRs, unlike infection with the less virulent WNVNSW2011. These transcript levels also correlated with encephalitis severity. Widespread STAT1 protein expression in brain with moderate neuropathology suggests that IFN-I signaling is crucial for limiting neural infection and mediating non-lethal neuropathogenesis. Unlike NZWRs, CTRs limit neuroinvasion without upregulation of many cytokine/chemokine transcripts, suggesting a species-dependent virus control mechanism. However, the common IFNγ, TNFα and IL6 transcript upregulation in specific lymphoid organs suggest some conserved elements in the response against flaviviruses, unique to all rabbits

The vaccinia virus based Sementis Copenhagen Vector vaccine against Zika and chikungunya is immunogenic in non-human primates

The Sementis Copenhagen Vector (SCV) is a new vaccinia virus-derived, multiplication-defective, vaccine technology assessed herein in non-human primates. Indian rhesus macaques (Macaca mulatta) were vaccinated with a multi-pathogen recombinant SCV vaccine encoding the structural polyproteins of both Zika virus (ZIKV) and chikungunya virus (CHIKV). After one vaccination, neutralising antibody responses to ZIKV and four strains of CHIKV, representative of distinct viral genotypes, were generated. A second vaccination resulted in significant boosting of neutralising antibody responses to ZIKV and CHIKV. Following challenge with ZIKV, SCV-ZIKA/CHIK-vaccinated animals showed significant reductions in viremias compared with animals that had received a control SCV vaccine. Two SCV vaccinations also generated neutralising and IgG ELISA antibody responses to vaccinia virus. These results demonstrate effective induction of immunity in non-human primates by a recombinant SCV vaccine and illustrates the utility of SCV as a multi-disease vaccine platform capable of delivering multiple large immunogens.Natalie A. Prow, Liang Liu, Mary K. McCarthy, Kevin Walters, Raj Kalkeri, Jillian Geiger, Fusataka Koide, Tamara H. Cooper, Preethi Eldi, Eri Nakayama, Kerrilyn R. Diener, Paul M. Howley, John D. Hayball, Thomas E. Morrison, and Andreas Suhrbi

Arthritogenic alphavirus vaccines: serogrouping versus cross-protection in mouse models

Chikungunya virus (CHIKV), Ross River virus (RRV), o’nyong nyong virus (ONNV), Mayaro virus (MAYV) and Getah virus (GETV) represent arthritogenic alphaviruses belonging to the Semliki Forest virus antigenic complex. Antibodies raised against one of these viruses can cross-react with other serogroup members, suggesting that, for instance, a CHIKV vaccine (deemed commercially viable) might provide cross-protection against antigenically related alphaviruses. Herein we use human alphavirus isolates (including a new human RRV isolate) and wild-type mice to explore whether infection with one virus leads to cross-protection against viremia after challenge with other members of the antigenic complex. Persistently infected Rag1(-/-) mice were also used to assess the cross-protective capacity of convalescent CHIKV serum. We also assessed the ability of a recombinant poxvirus-based CHIKV vaccine and a commercially available formalin-fixed, whole-virus GETV vaccine to induce cross-protective responses. Although cross-protection and/or cross-reactivity were clearly evident, they were not universal and were often suboptimal. Even for the more closely related viruses (e.g., CHIKV and ONNV, or RRV and GETV), vaccine-mediated neutralization and/or protection against the intended homologous target was significantly more effective than cross-neutralization and/or cross-protection against the heterologous virus. Effective vaccine-mediated cross-protection would thus likely require a higher dose and/or more vaccinations, which is likely to be unattractive to regulators and vaccine manufacturers.Wilson Nguyen, Eri Nakayama, Kexin Yan, Bing Tang, Thuy T. Le, Liang Liu, Tamara H. Cooper, John D. Hayball, Helen M. Faddy, David Warrilow, Richard J. N. Allcock, Jody Hobson-Peters, Roy A. Hall, Daniel J. Rawle, Viviana P. Lutzky, Paul Young, Nidia M. Oliveira, Gunter Hartel, Paul M. Howley, Natalie A. Prow, and Andreas Suhrbie