Immune profile and responses of a novel Dengue DNA vaccine encoding EDIII-NS1 consensus design based on Indo-African sequences

Following the recent clinical clearance of an Indian DNA COVID-19 vaccine, India and Africa are potential regions where DNA vaccines may become a major delivery system subject to a range of immunological and regulatory scrutiny. The ongoing COVID pandemic highlights the need to tackle viral variants and expand the number of antigens and assess diverse delivery systems. To address some of these key issues, we have created a Dengue DNA vaccine candidate with the EDIII region as the key antigen given the promise of this segment in not causing ADE, a challenge with this disease. In addition, we have added the NS1 region to broaden the immune response. Following a large Dengue viral sequencing exercise in India, complemented with data from east Africa, our approach was to generate a consensus of four serotypes ED3-NS1 vaccine to explore tackling the issue of diversity. Our In silico structural analysis of EDIII consensus vaccine sequence revealed that epitopes are structurally conserved and immunogenic across HLA diversity. Vaccination of mice with this construct induced pan-serotype neutralizing antibodies and antigen-specific T cell responses. Furthermore, the DNA vaccination confers protection against DENV challenge in AG129 mice. Finally, assaying of intracellular staining for IFN-γ, immunoglobulin IgG2(a/c) /IgG1 ratios as well as immune gene profiling suggested a strong Th1-dominant immune response. Our Dengue DNA platform with a focus on Indo-African sequences offers an approach for assessing cross reactive immunity in animal models and lays the foundation for human vaccine roll out either as a stand-alone or mix and match strategy.

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Optimized Adenovirus-Antibody Complexes Stimulate Strong Cellular and Humoral Immune Responses against an Encoded Antigen in Naïve Mice and Those with Preexisting Immunity

Clinical and Vaccine Immunology ◽

10.1128/cvi.05319-11 ◽

2011 ◽

Vol 19 (1) ◽

pp. 84-95 ◽

Cited By ~ 6

Author(s):

Jin Huk Choi ◽

Joe Dekker ◽

Stephen C. Schafer ◽

Jobby John ◽

Craig E. Whitfill ◽

...

Keyword(s):

Immune Response ◽

T Cell ◽

Immune Responses ◽

Neutralizing Antibodies ◽

T Cell Responses ◽

Transduction Efficiency ◽

Virus Antibody ◽

Cell Responses

ABSTRACTThe immune response to recombinant adenoviruses is the most significant impediment to their clinical use for immunization. We test the hypothesis that specific virus-antibody combinations dictate the type of immune response generated against the adenovirus and its transgene cassette under certain physiological conditions while minimizing vector-induced toxicity.In vitroandin vivoassays were used to characterize the transduction efficiency, the T and B cell responses to the encoded transgene, and the toxicity of 1 × 1011adenovirus particles mixed with different concentrations of neutralizing antibodies. Complexes formed at concentrations of 500 to 0.05 times the 50% neutralizing dose (ND50) elicited strong virus- and transgene-specific T cell responses. The 0.05-ND50formulation elicited measurable anti-transgene antibodies that were similar to those of virus alone (P= 0.07). This preparation also elicited very strong transgene-specific memory T cell responses (28.6 ± 5.2% proliferation versus 7.7 ± 1.4% for virus alone). Preexisting immunity significantly reduced all responses elicited by these formulations. Although lower concentrations (0.005 and 0.0005 ND50) of antibody did not improve cellular and humoral responses in naïve animals, they did promote strong cellular (0.005 ND50) and humoral (0.0005 ND50) responses in mice with preexisting immunity. Some virus-antibody complexes may improve the potency of adenovirus-based vaccines in naïve individuals, while others can sway the immune response in those with preexisting immunity. Additional studies with these and other virus-antibody ratios may be useful to predict and model the type of immune responses generated against a transgene in those with different levels of exposure to adenovirus.

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Immunization with DNA Plasmids Coding for Crimean-Congo Hemorrhagic Fever Virus Capsid and Envelope Proteins and/or Virus-Like Particles Induces Protection and Survival in Challenged Mice

Journal of Virology ◽

10.1128/jvi.02076-16 ◽

2017 ◽

Vol 91 (10) ◽

Cited By ~ 28

Author(s):

Jorma Hinkula ◽

Stéphanie Devignot ◽

Sara Åkerström ◽

Helen Karlberg ◽

Eva Wattrang ◽

...

Keyword(s):

Immune Response ◽

Immune Responses ◽

Dna Vaccine ◽

Neutralizing Antibodies ◽

Hemorrhagic Fever ◽

Fever Virus ◽

Vaccine Candidates ◽

Th1 Response ◽

Crimean Congo Hemorrhagic Fever ◽

Hemorrhagic Fever Virus

ABSTRACT Crimean-Congo hemorrhagic fever virus (CCHFV) is a bunyavirus causing severe hemorrhagic fever disease in humans, with high mortality rates. The requirement of a high-containment laboratory and the lack of an animal model hampered the study of the immune response and protection of vaccine candidates. Using the recently developed interferon alpha receptor knockout (IFNAR−/−) mouse model, which replicates human disease, we investigated the immunogenicity and protection of two novel CCHFV vaccine candidates: a DNA vaccine encoding a ubiquitin-linked version of CCHFV Gc, Gn, and N and one using transcriptionally competent virus-like particles (tc-VLPs). In contrast to most studies that focus on neutralizing antibodies, we measured both humoral and cellular immune responses. We demonstrated a clear and 100% efficient preventive immunity against lethal CCHFV challenge with the DNA vaccine. Interestingly, there was no correlation with the neutralizing antibody titers alone, which were higher in the tc-VLP-vaccinated mice. However, the animals with a lower neutralizing titer, but a dominant cell-mediated Th1 response and a balanced Th2 response, resisted the CCHFV challenge. Moreover, we found that in challenged mice with a Th1 response (immunized by DNA/DNA and boosted by tc-VLPs), the immune response changed to Th2 at day 9 postchallenge. In addition, we were able to identify new linear B-cell epitope regions that are highly conserved between CCHFV strains. Altogether, our results suggest that a predominantly Th1-type immune response provides the most efficient protective immunity against CCHFV challenge. However, we cannot exclude the importance of the neutralizing antibodies as the surviving immunized mice exhibited substantial amounts of them. IMPORTANCE Crimean-Congo hemorrhagic fever virus (CCHFV) is responsible for hemorrhagic diseases in humans, with a high mortality rate. There is no FDA-approved vaccine, and there are still gaps in our knowledge of the immune responses to infection. The recently developed mouse models mimic human CCHF disease and are useful to study the immunogenicity and the protection by vaccine candidates. Our study shows that mice vaccinated with a specific DNA vaccine were fully protected. Importantly, we show that neutralizing antibodies are not sufficient for protection against CCHFV challenge but that an extra Th1-specific cellular response is required. Moreover, we describe the identification of five conserved B-cell epitopes, of which only one was previously known, that could be of great importance for the development of diagnostics tools and the improvement of vaccine candidates.

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Cellular and Humoral Immunogenicity of a Candidate DNA Vaccine Expressing SARS-CoV-2 Spike Subunit 1

Vaccines ◽

10.3390/vaccines9080852 ◽

2021 ◽

Vol 9 (8) ◽

pp. 852

Author(s):

Khalid A. Alluhaybi ◽

Rahaf H. Alharbi ◽

Rowa Y. Alhabbab ◽

Najwa D. Aljehani ◽

Sawsan S. Alamri ◽

...

Keyword(s):

Immune Responses ◽

Dna Vaccine ◽

Neutralizing Antibodies ◽

Vaccine Development ◽

Cell Responses ◽

Cellular Immune Responses ◽

Specific Igg ◽

Cellular Immune ◽

Different Doses

The urgent need for effective, safe and equitably accessible vaccines to tackle the ongoing spread of COVID-19 led researchers to generate vaccine candidates targeting varieties of immunogens of SARS-CoV-2. Because of its crucial role in mediating binding and entry to host cell and its proven safety profile, the subunit 1 (S1) of the spike protein represents an attractive immunogen for vaccine development. Here, we developed and assessed the immunogenicity of a DNA vaccine encoding the SARS-CoV-2 S1. Following in vitro confirmation and characterization, the humoral and cellular immune responses of our vaccine candidate (pVAX-S1) was evaluated in BALB/c mice using two different doses, 25 µg and 50 µg. Our data showed high levels of SARS-CoV-2 specific IgG and neutralizing antibodies in mice immunized with three doses of pVAX-S1. Analysis of the induced IgG subclasses showed a Th1-polarized immune response, as demonstrated by the significant elevation of spike-specific IgG2a and IgG2b, compared to IgG1. Furthermore, we found that the immunization of mice with three doses of 50 µg of pVAX-S1 could elicit significant memory CD4+ and CD8+ T cell responses. Taken together, our data indicate that pVAX-S1 is immunogenic and safe in mice and is worthy of further preclinical and clinical evaluation.

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INO-4800 DNA Vaccine Induces Neutralizing Antibodies and T cell Activity Against Global SARS-CoV-2 Variants

10.1101/2021.04.14.439719 ◽

2021 ◽

Cited By ~ 1

Author(s):

Viviane M. Andrade ◽

Aaron Christensen-Quick ◽

Joseph Agnes ◽

Jared Tur ◽

Charles Reed ◽

...

Keyword(s):

T Cell ◽

Host Specificity ◽

Dna Vaccine ◽

Immune Evasion ◽

Neutralizing Antibodies ◽

Cell Activity ◽

T Cell Responses ◽

Cellular Responses ◽

Cell Responses ◽

Induced Immunity

AbstractGlobal surveillance has identified emerging SARS-CoV-2 variants of concern (VOC) associated with broadened host specificity, pathogenicity, and immune evasion to vaccine induced immunity. Here we compared humoral and cellular responses against SARS-CoV-2 VOC in subjects immunized with the DNA vaccine, INO-4800. INO-4800 vaccination induced neutralizing antibodies against all variants tested, with reduced levels detected against B.1.351. IFNγ T cell responses were fully maintained against all variants tested.

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Immunization with a Mixture of HIV Env DNA and VLP Vaccines Augments Induction of CD8 T Cell Responses

Journal of Biomedicine and Biotechnology ◽

10.1155/2010/497219 ◽

2010 ◽

Vol 2010 ◽

pp. 1-11 ◽

Cited By ~ 6

Author(s):

Ling Ye ◽

Zhiyuan Wen ◽

Ke Dong ◽

Lei Pan ◽

Zhigao Bu ◽

...

Keyword(s):

Immune Response ◽

T Cell ◽

Dna Vaccine ◽

Cell Response ◽

T Cell Responses ◽

Cd8 T Cell ◽

T Cell Response ◽

Antibody Responses ◽

Cell Responses ◽

Virus Like Particle

The immune response induced by immunization with HIV Env DNA and virus-like particle (VLP) vaccines was investigated. Immunization with the HIV Env DNA vaccine induced a strong CD8 T cell response but relatively weak antibody response against the HIV Env whereas immunization with VLPs induced higher levels of antibody responses but little CD8 T cell response. Interestingly, immunization with a mixture the HIV Env DNA and VLP vaccines induced enhanced CD8 T cell and antibody responses. Further, it was observed that the mixing of DNA and VLP vaccines during immunization is necessary for augmenting induction of CD8 T cell responses and such augmentation of CD8 T cell responses was also observed by mixing the HIV Env DNA vaccine with control VLPs. These results show that immunization with a mixture of DNA and VLP vaccines combines advantages of both vaccine platforms for eliciting high levels of both antibody and CD8 T cell responses.

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Design and immunogenicity of a Pan-SARS-CoV-2 synthetic DNA vaccine

10.1101/2021.05.11.443592 ◽

2021 ◽

Author(s):

Charles C Reed ◽

Katherine Schultheis ◽

Viviane M Andrade ◽

Richa Kalia ◽

Jared Tur ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

Dna Vaccine ◽

Murine Model ◽

Neutralizing Antibodies ◽

First Generation ◽

Synthetic Dna ◽

Cell Responses ◽

Escape Mutants ◽

Humoral Responses

First generation COVID-19 vaccines matched to the original Wuhan-Hu-1 (WT) strain are showing reduced efficacy against emerging SARS-CoV-2 variants of concern (VOC). In response, next generation vaccines either matched to a single variant or designed to provide broader coverage across the VOC group are being developed. The latter pan-SARS-CoV-2 approach may offer substantial advantages in terms of cross-strain protection, immune coverage, reduced susceptibility to escape mutants, and non-restricted geographical use. Here we have employed our SynCon® design technology to construct a DNA vaccine expressing a pan-Spike immunogen (INO-4802) to induce broad immunity across SARS-CoV-2 variants. Compared to WT and VOC-matched vaccines which showed limited cross-neutralizing activity, INO-4802 induced potent neutralizing antibodies and T cell responses against WT as well as B.1.1.7, P.1, and B.1.351 VOCs in a murine model. In addition, a hamster vaccination model showed enhanced humoral responses against VOCs in a heterologous pWT prime/INO-4802 boost setting. These results demonstrate the potential of the pan-SARS-CoV-2 vaccine, INO-4802 to induce cross-reactive immune responses against emerging VOCs as either a standalone vaccine, or as a potential boost for individuals previously immunized with WT-matched vaccines.

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INO-4800 DNA vaccine induces neutralizing antibodies and T cell activity against global SARS-CoV-2 variants

npj Vaccines ◽

10.1038/s41541-021-00384-7 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Viviane M. Andrade ◽

Aaron Christensen-Quick ◽

Joseph Agnes ◽

Jared Tur ◽

Charles Reed ◽

...

Keyword(s):

T Cell ◽

Host Specificity ◽

Dna Vaccine ◽

Immune Evasion ◽

Neutralizing Antibodies ◽

Cell Activity ◽

T Cell Responses ◽

Cellular Responses ◽

Cell Responses ◽

Induced Immunity

AbstractGlobal surveillance has identified emerging SARS-CoV-2 variants of concern (VOC) associated with broadened host specificity, pathogenicity, and immune evasion to vaccine-induced immunity. Here we compared humoral and cellular responses against SARS-CoV-2 VOC in subjects immunized with the DNA vaccine, INO-4800. INO-4800 vaccination induced neutralizing antibodies against all variants tested, with reduced levels detected against B.1.351. IFNγ T cell responses were fully maintained against all variants tested.

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HIV-1-Based Virus-like Particles that Morphologically Resemble Mature, Infectious HIV-1 Virions

Viruses ◽

10.3390/v11060507 ◽

2019 ◽

Vol 11 (6) ◽

pp. 507 ◽

Cited By ~ 4

Author(s):

Christopher A. Gonelli ◽

Georges Khoury ◽

Rob J. Center ◽

Damian F.J. Purcell

Keyword(s):

T Cell ◽

Dna Vaccine ◽

Neutralizing Antibodies ◽

T Cell Responses ◽

Expression Vectors ◽

Virus Like Particles ◽

Cell Responses ◽

Hiv 1

A prophylactic vaccine eliciting both broad neutralizing antibodies (bNAbs) to the HIV-1 envelope glycoprotein (Env) and strong T cell responses would be optimal for preventing HIV-1 transmissions. Replication incompetent HIV-1 virus-like particles (VLPs) offer the opportunity to present authentic-structured, virion-associated Env to elicit bNAbs, and also stimulate T cell responses. Here, we optimize our DNA vaccine plasmids as VLP expression vectors for efficient Env incorporation and budding. The original vector that was used in human trials inefficiently produced VLPs, but maximized safety by inactivating RNA genome packaging, enzyme functions that are required for integration into the host genome, and deleting accessory proteins Vif, Vpr, and Nef. These original DNA vaccine vectors generated VLPs with incomplete protease-mediated cleavage of Gag and were irregularly sized. Mutations to restore function within the defective genes revealed that several of the reverse transcriptase (RT) deletions mediated this immature phenotype. Here, we made efficient budding, protease-processed, and mature-form VLPs that resembled infectious virions by introducing alternative mutations that completely removed the RT domain, but preserved most other safety mutations. These VLPs, either expressed from DNA vectors in vivo or purified after expression in vitro, are potentially useful immunogens that can be used to elicit antibody responses that target Env on fully infectious HIV-1 virions.

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“Monozygotic twins discordant for severe clinical recurrence of COVID-19 show drastically distinct T cell responses to SARS-Cov-2”

10.1101/2021.03.26.21253645 ◽

2021 ◽

Author(s):

Mateus V. de Castro ◽

Keity S. Santos ◽

Juliana S. Apostolico ◽

Edgar R. Fernandes ◽

Rafael R. Almeida ◽

...

Keyword(s):

Immune Response ◽

T Cell ◽

Neutralizing Antibodies ◽

Twin Pair ◽

T Cell Responses ◽

Monozygotic Twin ◽

Type I ◽

T Cell Epitopes ◽

Clinical Recurrence ◽

Cell Responses

ABSTRACTBackgroundClinical recurrence of COVID-19 in convalescent patients has been reported, which immune mechanisms have not been thoroughly investigated. Presence of neutralizing antibodies suggests other types of immune response are involved.MethodsWe assessed the innate type I/III IFN response, T cell responses to SARS-CoV-2 with IFNγ ELISPOT, binding and neutralizing antibody assays, in two monozygotic twin pairs with one COVID-19 recurrence case.ResultsIn pair 1, four months after a first mild episode of infection for both siblings, one displayed severe clinical recurrence of COVID-19. Twin pair 2 of siblings underwent non-recurring asymptomatic infection. All fours individuals presented similar overall responses, except for remarkably difference found in specific cellular responses. Recurring sibling presented a reduced number of recognized T cell epitopes as compared to the other three including her non-recurring sibling.ConclusionsOur results suggest that an effective SARS-CoV-2-specific T cell immune response is key for complete viral control and avoidance of clinical recurrence of COVID-19. Besides, adaptive immunity can be distinct in MZ twins. Given the rising concern about SARS-CoV-2 variants that evade neutralizing antibodies elicited by vaccination or infection, our study stresses the importance of T cell responses in protection against recurrence/reinfection.Key pointsImmune parameters leading to COVID-19 recurrence/reinfection are incompletely understood. A COVID-19 recurrence case in a monozygotic twin pair is described with an intact antibody and innate type I/III Interferon response and drastically reduced number of recognized SARS-CoV-2 T cell epitopes.

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Antibodies elicited by SARS-CoV-2 infection and boosted by vaccination neutralize an emerging variant and SARS-CoV-1

10.1101/2021.02.05.21251182 ◽

2021 ◽

Cited By ~ 2

Author(s):

Leonidas Stamatatos ◽

Julie Czartoski ◽

Yu-Hsin Wan ◽

Leah J. Homad ◽

Vanessa Rubin ◽

...

Keyword(s):

South Africa ◽

Immune Response ◽

Monoclonal Antibodies ◽

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Fold Increase ◽

Cd4 T Cell ◽

Cell Responses ◽

Previous Infection ◽

Antibody Titers

AbstractThe emergence of SARS-CoV-2 variants raises concerns about their resistance to neutralizing antibodies elicited from previous infection, or from vaccination. Here we examined whether sera and monoclonal antibodies from convalescent donors, prior to and following a single immunization with the Pfizer or Moderna mRNA vaccines, neutralize the Wuhan-Hu-1 strain and a variant, B.1.351 from South Africa. Pre-vaccination sera weakly neutralized Wuhan-Hu-1 and sporadically neutralized B.1.351. Immunization with either vaccine generated anamnestic B and CD4+ T cell responses and a 1000-fold increase in neutralizing antibody titers against both strains and SARS-CoV-1. Neutralization was likely due to anti-RBD and anti-S2 antibodies. Our study highlights the importance of vaccination of both uninfected and of previously infected subjects, as the elicited immune response will neutralize distinct viral strains.

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