DNA Vaccine Research Articles

1023P Long-term follow up of patients treated with a DNA vaccine (pTVG-HP) for PSA-recurrent prostate cancer

1023P Long-term follow up of patients treated with a DNA vaccine (pTVG-HP) for PSA-recurrent prostate cancer

Antigenic analysis of the influenza B virus hemagglutinin protein

Influenza B viruses (IBVs) primarily infect humans and are a common cause of respiratory infections in humans. Here, to systematically analyze the antigenicity of the IBVs Hemagglutinin (HA) protein, 31 ​B/Victoria and 19 ​B/Yamagata representative circulating strains were selected from Global Initiative of Sharing All Influenza Data (GISAID), and pseudotyped viruses were constructed with the vesicular stomatitis virus system. Guinea pigs were immunized with three doses of vaccines (one dose of DNA vaccines following two doses of pseudotyped virus vaccines) of the seven IBV vaccine strains, and neutralizing antibodies against the pseudotyped viruses were tested. By comparing differences between various vaccine strains, we constructed several pseudotyped viruses that contained various mutations based on vaccine strain BV-21. The vaccine strains showed good neutralization levels against the epidemic virus strains of the same year, with neutralization titers ranging from 370 to 840, while the level of neutralization against viruses prevalent in previous years decreased 1–10-fold. Each of the high-frequency epidemic strains of B/Victoria and B/Yamagata not only induced high neutralizing titers, but also had broadly neutralizing effects against virus strains of different years, with neutralizing titers ranging from 1000 to 7200. R141G, D197 ​N, and R203K were identified as affecting the antigenicity of IBV. These mutation sites provide valuable references for the selection and design of a universal IBV vaccine strain in the future.

Maternal Immunity and Immune Improvement of Koi Cyprinus rubrofuscus Larvae after DNA Vaccine against Hoi Herpesvirus

Vaccination is an efficient step in preventing disease caused by koi herpesvirus in koi fish (Cyprinus rubrofuscus). This study aimed to investigates the impact of maternal broodstock vaccination with ORF81 DNA vaccine on the transmission of maternal immunity to offspring against KHV. The ORF81 DNA vaccine has been shown to increase RPS, but its effect on maternal immunity in koi offspring after vaccination has not been evaluated. The study examined koi broodstocks vaccinated with the ORF81 DNA vaccine 45 and 60 days before spawning (45V and 60V) at a dose of 12.5 μg/100 g. Immunological parameters were assessed in broodstock, eggs, and larvae. Immune gene expression was also analyzed using the qPCR method. The results showed that lysozyme activity and antibody levels in eggs from vaccinated mothers were higher, though not significantly different. Meanwhile, lysozyme activity and antibody levels in mothers were significantly higher (p<0.05) compared to controls. Immunoglobulin-M gene (IgM) and recombination-activating gene 1 (RAG1), were significantly induced. The relative survival percentage increased significantly in larvae produced from broodstocks with 60V. These findings indicate that broodstocks treated with the ORF81 DNA vaccine can enhance the immune response of their offspring.

Lipid nanoparticle-encapsulated DNA vaccine confers protection against swine and human-origin H1N1 influenza viruses.

Swine influenza A virus (IAV) is widespread and causes significant economic losses to the swine industry. Moreover, bidirectional transmission of IAV between swine and humans commonly occurs. Once introduced into the swine population, human-origin IAV often reassorts with endemic swine IAV, resulting in reassortant viruses. Thus, it is imperative to develop a vaccine that is not only effective against IAV strains endemic in swine but also capable of preventing the spillover of human-origin IAV. In this study, we developed a lipid nanoparticle-encapsulated DNA plasmid vaccine (LNP-DNA) that demonstrates efficacy against both swine- and human-origin H1N1 viruses. The LNP-DNA vaccines are non-infectious and non-viable, meeting the criteria to serve as a vaccine platform for rapidly updating vaccines. Collectively, this LNP-DNA vaccine approach holds great potential for alleviating the impact of IAV on the swine industry and preventing the emergence of reassortant IAV strains.

Production and evaluation of three kinds of vaccines against largemouth bass virus, and DNA vaccines show great application prospects

Largemouth bass virus (LMBV) infections has resulted in high mortality and economic losses to the global largemouth bass industry and has seriously restricted the healthy development of the bass aquaculture industry. There are currently no antiviral therapies available for the control of this disease. In this study, we developed three types of vaccine against LMBV; whole virus inactivated vaccine (I), a subunit vaccine composed of the major viral capsid protein MCP (S) as well as an MCP DNA vaccine(D), These were employed using differing immunization and booster strategies spaced 2 weeks apart as follows: II, SS, DD and DS. We found that all vaccine groups induced humoral and cellular immune responses and protected largemouth bass from a lethal LMBV challenge to varying degrees and DD produced the best overall effect. Specifically, the levels of specific IgM in serum in all immunized groups were elevated and significantly higher than those in the control group. Moreover, the expression of humoral immunity (CD4 and IgM) and cellular immunity (MHCI-α) as well as cytokines (IL-1β) was increased, and the activity of immunity-related enzymes ACP, AKP, LZM, and T-SOD in the serum was significantly enhanced. In addition, the relative percent survival of fish following an LMBV lethal challenge 4 weeks after the initial immunizations were high for each group: DD(89.5 %),DS(63.2 %),SS(50 %) and II (44.7 %). These results indicated that the MCP DNA vaccine is the most suitable and promising vaccine candidate for the effective control of LMBV disease.

Evaluation of protective immune response of immersion inactivated vaccine against Singapore grouper iridovirus

Singapore grouper iridovirus (SGIV) always causes high transmission efficiency and mortality in the larval and juvenile stages of grouper in aquaculture industry. Although inactivated virus and recombinant DNA vaccines administered via intraperitoneal injection have shown efficacy in protection against SGIV, their potential applications in field testing were limited due to the vaccine delivery methods. Here, we developed an immersion vaccine containing inactivated virus and Montanide IMS 1312 adjuvant (IMS 1312) and evaluated its protective efficacy against SGIV infection. Compared to the PBS group, fish vaccinated with immersion inactivated vaccine with or without IMS 1312 were significantly protected against SGIV, with a relative percent survival (RPS) of 57.69 % and 38.47 %, respectively. Furthermore, the transcripts of viral core genes were reduced, and the histopathological severity caused by SGIV were relatively mild in multiple tissues of the IMS + V group. The immersion vaccine activated the AKP and ACP activities and increased the mRNA levels of IFN and inflammation-associated genes. The transcriptome analysis showed that a total of 731 and 492 genes were significantly regulated in the spleen and kidney from the IMS + V group compared to the PBS group, respectively. Among them, 129 DEGs were co-regulated, and enriched in the KEGG pathways related to immune and cell proliferation, including MAPK signaling, JAK-STAT signaling and PI3K-Akt signaling pathways. Similarly, the DEGs specially regulated in the kidney and spleen upon vaccine immunization were significantly enriched in the KEGG pathways related to interferon and inflammation response. Together, our results elucidated that the immersion vaccine of inactivated SGIV with IMS 1312 induced a protective immune response of grouper against SGIV.

PLA-PEG as an alternative to PEGylated lipids for nanoparticle-based DNA vaccination against SARS-CoV-2

PLA-PEG as an alternative to PEGylated lipids for nanoparticle-based DNA vaccination against SARS-CoV-2

Flt3 ligand augments immune responses to soluble PD1-based DNA vaccine via expansion of type 1 conventional DCs

DNA vaccines are prospective for their efficient manufacturing process, but their immunogenicity is limited as they cannot efficiently induce CD8+ T cell responses. A promising approach is to induce cross-presentation by targeting antigens to DCs. Flt3L can expand the number of type 1 conventional DCs and thereby improve cross-presentation. In this study, we first constructed a DNA vaccine expressing soluble PD1 and found that the therapeutic effect of targeting DCs with only the sPD1 vaccine was limited. When combined the vaccine with Flt3L, the anti-tumor effect was significantly enhanced. Considering the complexity of tumors and that a single method may not be able to activate a large number of effective CD8+ T cells, we combined different drugs and the vaccine with Flt3L based on the characteristics of different tumors. In 4T1 model, we reduced Tregs through cyclophosphamide. In Panc02 model, we increased activated DCs by using aCD40. Both strategies triggered strong CD8+ T cell responses and significantly improved the therapeutic effect. Our study provides important support for the clinical exploration of DC-targeted DNA vaccines in combination with Flt3L.

Combination of a MIP3α-antigen fusion therapeutic DNA vaccine with treatments of IFNα and 5-Aza-2'Deoxycytidine enhances activated effector CD8+ T cells expressing CD11c in the B16F10 melanoma model.

Previous studies in the B16F10 mouse melanoma model have demonstrated that combining a DNA vaccine comprised of regions of gp100 and tyrosinase-related protein 2 fused to Macrophage-inflammatory protein 3-alpha (MIP3α) with recombinant Interferon alpha (IFN) and 5-Aza-2'-Deoxycytidine (5Aza) treatments resulted in significantly greater anti-tumor activity and immunogenicity in the tumor microenvironment (TME). This brief report details that the combination of vaccine with treatments IFN and 5Aza results in both the upregulation of genes expressing CD11c-interacting proteins and an increase in the TME of a distinct CD11c+ CD8+ T cell population. This cell population correlates with tumor size, is primarily comprised of effector or effector memory T cells, and has a more robust response to ex vivo stimulation as compared to CD11c- CD8+ T cells as measured by surface activation markers 4-1BB (CD137) and KLRG1 (Killer cell lectin-like receptor G1) and intracellular IFNγ production. In conclusion, this combination therapy results in greater presence of highly active effector CD8+ T-cells expressing CD11c in the TME that correlate with and are likely primary contributors to treatment efficacy.

Combination of a MIP3α-antigen fusion therapeutic DNA vaccine with treatments of IFNα and 5-Aza-2'Deoxycytidine enhances activated effector CD8+ T cells expressing CD11c in the B16F10 melanoma model.

Previous studies in the B16F10 mouse melanoma model have demonstrated that combining a DNA vaccine comprised of regions of gp100 and tyrosinase-related protein 2 fused to Macrophage-inflammatory protein 3-alpha (MIP3α) with recombinant Interferon alpha (IFN) and 5-Aza-2'-Deoxycytidine (5Aza) treatments resulted in significantly greater anti-tumor activity and immunogenicity in the tumor microenvironment (TME). This brief report details that the combination of vaccine with treatments IFN and 5Aza results in both the upregulation of genes expressing CD11c-interacting proteins and an increase in the TME of a distinct CD11c+ CD8+ T cell population. This cell population correlates with tumor size, is primarily comprised of effector or effector memory T cells, and has a more robust response to ex vivo stimulation as compared to CD11c- CD8+ T cells as measured by surface activation markers 4-1BB (CD137) and KLRG1 (Killer cell lectin-like receptor G1) and intracellular IFNγ production. In conclusion, this combination therapy results in greater presence of highly active effector CD8+ T-cells expressing CD11c in the TME that correlate with and are likely primary contributors to treatment efficacy.

Lipid nanoparticle encapsulation of a Delta spike-CD40L DNA vaccine improves effectiveness against Omicron challenge in Syrian hamsters

The effectiveness of mRNA vaccines largely depends on their lipid nanoparticle (LNP) component. Herein, we investigate the effectiveness of DLin-KC2-DMA (KC2) and SM-102-based LNPs for the intramuscular delivery of a plasmid encoding B.1.617.2 (Delta) spike fused with CD40 ligand. LNP encapsulation of this CD40L-adjuvanted DNA vaccine with either LNP formulation drastically enhanced antibody responses, enabling neutralization of heterologous Omicron variants. The DNA-LNP formulations provided excellent protection from homologous challenge, reducing viral replication, and preventing histopathological changes in the pulmonary tissues. Moreover, theDNA-LNP vaccines maintained a high level of protection against heterologous Omicron BA.5 challenge despite a reduced neutralizing response. In addition, we observed that DNA-LNP vaccination led to the pulmonary downregulation of interferon signaling, interleukin-12 signaling, and macrophage response pathways following SARS-CoV-2 challenge, shedding some light on the mechanisms underlying the prevention of pulmonary injury. These results highlight the potential combination of molecular adjuvants with LNP-based vaccine delivery to induce greater and broader immune responses capable of preventing inflammatory damage and protecting against emerging variants. These findings could be informative for the future design of both DNA and mRNA vaccines.

DNA Vaccines Encoding HTNV GP-Derived Th Epitopes Benefited from a LAMP-Targeting Strategy and Established Cellular Immunoprotection.

Vaccines has long been the focus of antiviral immunotherapy research. Viral epitopes are thought to be useful biomarkers for immunotherapy (both antibody-based and cellular). In this study, we designed a novel vaccine molecule, the Hantaan virus (HTNV) glycoprotein (GP) tandem Th epitope molecule (named the Gnc molecule), in silico. Subsequently, computer analysis was used to conduct a comprehensive and in-depth study of the various properties of the molecule and its effects as a vaccine molecule in the body. The Gnc molecule was designed for DNA vaccines and optimized with a lysosomal-targeting membrane protein (LAMP) strategy. The effects of GP-derived Th epitopes and multiepitope vaccines were initially verified in animals. Our research has resulted in the design of two vaccines based on effective antiviral immune targets. The effectiveness of molecular therapies has also been preliminarily demonstrated in silico and in laboratory animals, which lays a foundation for the application of a vaccines strategy in the field of antivirals.

The Impact of COVID-19 Vaccination Side-Effects on Work Attendance among Saudi Healthcare Workers.

This cross-sectional-survey-based study aimed to investigate the severity of side-effects from Coronavirus disease (COVID-19) mRNA (Pfizer, Moderna), viral vector DNA (Oxford-AstraZeneca, J&J/Janssen), inactivated virus (Sinopharm, Sinovac), and other vaccines among healthcare workers (HCWs) in Saudi Arabia, focusing on their impact on work attendance. A total of 894 HCWs residing in Saudi Arabia participated in this study from March 2023 to May 2023. Participants completed an online questionnaire assessing demographic information, vaccination status, comorbidities, vaccine side-effects, and missed work information after vaccination. Descriptive statistics and chi-square tests were used for data analysis. The majority of participants were female (83.7%) and aged 25-34 years (42.8%). Most participants were predominantly vaccinated with mRNA vaccines. Common side-effects included pain at the injection site, fatigue, fever, and chills. However, no significant association was found between vaccine type, side-effects, and work absenteeism. While demographic factors such as age and healthcare profession did not influence work absenteeism, variations were observed among different racial groups. COVID-19 vaccination among HCWs in Saudi Arabia is associated with common side-effects, but their impact on work attendance is not significant. Understanding these implications can inform strategies to support the healthcare workforce and mitigate the impact on patient care and staffing during the ongoing COVID-19 pandemic.

Improved cellular immune response induced by intranasal boost immunization with chitosan coated DNA vaccine against H9N2 influenza virus challenge

The H9N2 avian influenza virus (AIV) is spreading worldwide. Presence of H9N2 virus tends to increase the chances of infection with other pathogens which can lead to more serious economic losses. In a previous study, a regulated delayed lysis Salmonella vector was used to deliver a DNA vaccine named pYL233 encoding M1 protein, mosaic HA protein and chicken GM-CSF adjuvant. To further increase its efficiency, chitosan as a natural adjuvant was applied in this study. The purified plasmid pYL233 was coated with chitosan to form a DNA containing nanoparticles (named CS233) by ionic gel method and immunized by intranasal boost immunization in birds primed by oral administration with Salmonella strain. The CS233 DNA nanoparticle has a particle size of about 150 nm, with an encapsulation efficiency of 93.2 ± 0.12 % which protected the DNA plasmid from DNase I digestion and could be stable for a period of time at 37°. After intranasal boost immunization, the CS233 immunized chickens elicited higher antibody response, elevated CD4+ T cells and CD8+ T cells activation and increased T-lymphocyte proliferation, as well as increased productions of IL-4 and IFN-γ. After challenge, chickens immunized with CS233 resulted in the lowest levels of pulmonary virus titer and viral shedding as compared to the other challenge groups. The results showed that the combination of intranasal immunization with chitosan-coated DNA vaccine and oral immunization with regulatory delayed lytic Salmonella strain could enhance the immune response and able to provide protection against H9N2 challenge.

Crimean Congo hemorrhagic fever virus nucleoprotein and GP38 subunit vaccine combination prevents morbidity in mice

Immunizing mice with Crimean-Congo hemorrhagic fever virus (CCHFV) nucleoprotein (NP), glycoprotein precursor (GPC), or with the GP38 domain of GPC, can be protective when the proteins are delivered with viral vectors or as a DNA or RNA vaccine. Subunit vaccines are a safe and cost-effective alternative to some vaccine platforms, but Gc and Gn glycoprotein subunit vaccines for CCHFV fail to protect despite eliciting high levels of neutralizing antibodies. Here, we investigated humoral and cellular immune responses and the protective efficacy of recombinant NP, GP38, and GP38 forms (GP85 and GP160) associated with the highly glycosylated mucin-like (MLD) domain, as well as the NP + GP38 combination. Vaccination with GP160, GP85, or GP38 did not confer protection, and vaccination with the MLD-associated GP38 forms blunted the humoral immune responses to GP38, worsened clinical chemistry, and increased viral RNA in the blood compared to the GP38 vaccination. In contrast, NP vaccination conferred 100% protection from lethal outcome and was associated with mild clinical disease, while the NP + GP38 combination conferred even more robust protection by reducing morbidity compared to mice receiving NP alone. Thus, recombinant CCHFV NP alone is a promising vaccine candidate conferring 100% survival against heterologous challenge. Moreover, incorporation of GP38 should be considered as it further enhances subunit vaccine efficacy by reducing morbidity in surviving animals.

Immunogenicity of trivalent DNA vaccine candidate encapsulated in Chitosan-TPP nanoparticles against EV-A71 and CV-A16.

Aim: To develop a trivalent DNA vaccine candidate encapsulated in Chitosan-TPP nanoparticles against hand foot and mouth disease (HFMD) and assess its immunogenicity in mice.Materials & methods: Trivalent plasmid carrying the VP1 and VP2 genes of EV-A71, VP1 gene of CV-A16 was encapsulated in Chitosan-TPP nanoparticles through ionic gelation. In vitro characterization and in vivo immunization studies of the CS-TPP-NPs (pIRES-VP121) were performed.Results: Mice administered with CS-TPP NPs (pIRES-VP121) intramuscularly were observed to have the highest IFN-γ response. Sera from mice immunized with the naked pDNA and CS-TPP-NPs (pIRES-VP121) demonstrated good viral clearance against wild-type EV-A71 and CV-A16 in RD cells.Conclusion: CS-TPP-NPs (pIRES-VP121) could serve as a prototype for future development of multivalent HFMD DNA vaccine candidates.

Personalized neoantigen vaccines as early intervention in untreated patients with lymphoplasmacytic lymphoma: a non-randomized phase 1 trial

Lymphoplasmacytic lymphoma (LPL) is an incurable low-grade lymphoma with no standard therapy. Nine asymptomatic patients treated with a first-in-human, neoantigen DNA vaccine experienced no dose limiting toxicities (primary endpoint, NCT01209871). All patients achieve stable disease or better, with one minor response, and median time to progression of 72+ months. Post-vaccine single-cell transcriptomics reveal dichotomous antitumor responses, with reduced tumor B-cells (tracked by unique B cell receptor) and their survival pathways, but no change in clonal plasma cells. Downregulation of human leukocyte antigen (HLA) class II molecules and paradoxical upregulation of insulin-like growth factor (IGF) by the latter suggest resistance mechanisms. Vaccine therapy activates and expands bone marrow T-cell clonotypes, and functional neoantigen-specific responses (secondary endpoint), but not co-inhibitory pathways or Treg, and reduces protumoral signaling by myeloid cells, suggesting favorable perturbation of the tumor immune microenvironment. Future strategies may require combinations of vaccines with agents targeting plasma cell subpopulations, or blockade of IGF-1 signaling or myeloid cell checkpoints.

COVID-19 vaccine adverse events: Evaluating the pathophysiology with an emphasis on sulfur metabolism and endotheliopathy.

In this narrative review, we assess the pathophysiology of severe adverse events that presented after vaccination with DNA and mRNA vaccines against COVID-19. The focus is on the perspective of an undersulfated and degraded glycocalyx, considering its impact on immunomodulation, inflammatory responses, coagulation and oxidative stress. The paper explores various factors that lead to glutathione and inorganic sulfate depletion and their subsequent effect on glycocalyx sulfation and other metabolites, including hormones. Components of COVID-19 vaccines, such as DNA and mRNA material, spike protein antigen and lipid nanoparticles, are involved in possible cytotoxic effects. The common thread connecting these adverse events is endotheliopathy or glycocalyx degradation, caused by depleted glutathione and inorganic sulfate levels, shear stress from circulating nanoparticles, aggregation and formation of protein coronas; leading to imbalanced immune responses and chronic release of pro-inflammatory cytokines, ultimately resulting in oxidative stress and systemic inflammatory response syndrome. By understanding the underlying pathophysiology of severe adverse events, better treatment options can be explored.

Safety pharmacology of human endogenous retrovirus-enveloped baculoviral DNA vaccines against SARS-CoV-2 in Sprague-Dawley rats and beagle dogs

The coronavirus disease 2019 (COVID-19) emerged as a major global health crisis, posing significant health, economic, and social challenges. Vaccine development has been a crucial response to the severe-acute-respiratory-syndrome-related coronavirus-2 pandemic owing to the critical role of immunization in controlling infectious diseases, leading to the expedited development of several effective vaccines. Although mRNA platform-based COVID-19 vaccines authorized under emergency-use authorization have been administered globally, concerns regarding the vaccines have increased owing to the occurrence of various side effects. The present study aimed to evaluate the safety of a non-replicating recombinant baculovirus expressing the human endogenous retrovirus envelope gene (AcHERV) vaccine encoding SARS-CoV-2 antigens. Owing to the limited number of existing safety pharmacology studies on AcHERV as a viral vector vaccine, we conducted neurobehavior (Modified Irwin’s Test), body temperature, and respiratory function studies in rats and cardiovascular system studies in male beagle dogs, which were administered the AcHERV-COVID-19 vaccine using telemetry. The safety assessment revealed no significant toxicological alterations. However, in rats, both sexes administered with the AcHERV-COVID-19 vaccine exhibited a temporary increase in body temperature, which normalized or showed signs of recovery. In conclusion, AcHERV-COVID-19 demonstrates a sufficient safety profile that supports its potential evaluation in future clinical trials.

Application of nervous necrosis virus capsid protein-based antigen-presenting particles for vaccine development

Nervous necrosis virus (NNV) capsid protein plays an important role in producing viral particles without any genetic elements. Thus, NNV is a promising candidate for vaccine development and is widely used for constructing vaccines, including DNA, recombinant proteins, and virus-like particles (VLPs). Our study aimed to investigate the potential of NNV capsid protein (NNV) and NNV capsid protein fused to enhanced green fluorescent protein (NNV-EGFP) through VLP formation and whether their application can induce specific antibody responses against certain antigens. We focused on producing DNA and recombinant protein vaccines consisting of the genes for NNV, EGFP, and NNV-EGFP. The approach using NNV-EGFP allowed NNV to act as a carrier or inducer while EGFP was incorporated as part of the capsid protein, thereby enhancing the immune response. In vitro studies demonstrated that all DNA vaccines expressed in HINAE cells resulted in varying protein expression levels, with particularly low levels observed for pNNV and pNNV-EGFP. Consequently, structural proteins derived from HINAE cells could not be observed using transmission electron microscopy (TEM). In contrast, recombinant proteins of NNV and NNV-EGFP were expressed through the Escherichia coli expression system. TEM revealed that rNNV was assembled into VLPs with an approximate size of 30 nm, whereas rNNV-EGFP presented particles ranging from 10 nm to 50 nm in size. For the vaccination test, DNA vaccination marginally induced specific antibody responses in Japanese flounder compared to unvaccinated fish. Meanwhile, NNV and NNV-EGFP recombinant vaccines enhanced a greater anti-NNV antibody response than the others, whereas antibody responses against EGFP were also marginal. These results indicate that NNV capsid protein-based antigens, presenting as particles, play an important role in eliciting a specific anti-NNV antibody response and have the potential to improve fish immune responses.