DNA-based Vaccines Research Articles

Recent advances in HPV biotechnology: Understanding host-virus interactions and cancer progression-a review

Cervical cancer ranks as the fourth most common cancer among women globally, posing a significant mortality risk. Persistent infection with high-risk human papillomavirus (HPV) is the primary instigator of cervical cancer development, often alongside co-infection with other viruses, precipitating various malignancies. This study aimed to explore recent biotechnological advances in understanding HPV infection dynamics, host interactions, and its role in oncogenesis. The gathered data shed light on HPV biology, host-virus interplay, viral co-infections, and cellular transformations leading to HPV-associated cancers. Recent years have seen the introduction of diverse vaccination strategies, including live attenuated, subunit, and DNA-based vaccines, complemented by innovative nanotechnology and plant-based products. Despite rich data addressing research inquiries, urgent calls echo for the implementation of contemporary screening and therapeutic modalities at clinical levels. Moreover, extensive public awareness campaigns are imperative to alleviate the burden of HPV-related diseases, emphasizing the necessity for proactive intervention strategies in combating this global health challenge.

Comprehensive Details on Human Papillomavirus (HPV) Infections and Associated Malignancies: Awareness about Prophylaxis & Treatment Options Available for HPV Infections

Human Papilloma virus (HPV) role has now been widely accepted as a causative agent for cervical as well as head and neck squamous cell carcinomas. Screening and early detection of cervical cancer remains the key element to eradicate this deadly disease. Since it has a long natural history and disease progression, this gave an opportunity for early detection through screening of precancerous lesions which was adopted in high income countries (HIC) like UK which has led to the significant reduction of the cases. Unfortunately, Low- and middle-income countries are facing huge burden because of the lack of effective screening program. FDA approved Cervarix, Gardasil and Gardasil 9 are used as prophylaxis for cervical cancer & genital warts but screening is still essential after vaccination because these vaccines are not effective against all types of HPV types. HPV 16 & HPV 18 are highly oncogenic types and accounts for 70% of cervical cancers. The use of vaccine reduces the risk of getting HPV infection and decrease the rate of morbidity and mortality due to the cervical cancer. In addition to vaccines, many peptides or protein-based & cell or DNA-based vaccines are still in clinical trials; these prevention and management available in vaccines are likely to come up with significant benefits of health in future. Although it’s usually cured by immune system but presence of certain cofactors such as smoking, HIV etc. reduces the probability of an individual to eradicate the infection effectively. The aim of this study is to review literature regarding HPV related infections and malignancies. Moreover, it will make individuals aware about prophylaxis & treatment options available for HPV infection. This review article evaluates the HPV related diseases, there screening, evaluation and management currently available. Bangladesh Journal of Medical Science Vol. 23 No. 04 October’24 Page : 967-983

Codon optimized influenza H1 HA sequence but not CTLA-4 targeting of HA antigen to enhance the efficacy of DNA vaccines in an animal model

Infections caused by the influenza virus lead to both epidemic and pandemic outbreaks in humans and animals. Owing to their rapid production, safety, and stability, DNA vaccines represent a promising avenue for eliciting immunity and thwarting viral infections. While DNA vaccines have demonstrated substantial efficacy in murine models, their effectiveness in larger animals remains subdued. This limitation may be addressed by augmenting the immunogenicity of DNA-based vaccines. In the investigation here, protein expression was enhanced via codon optimization and then mouse cytotoxic T-lymphocyte antigen 4 (CTLA-4) was harnessed as a modulatory adjunct to bind directly to antigen-presenting cells. Further, the study evaluated the immunogenicity of two variants of the hemagglutinin (HA) antigen, i.e. the full-length and the C-terminal deletion versions. The study findings revealed that the codon-optimized HA gene (pcHA) led to increased protein synthesis, as evidenced by elevated mRNA levels. Codon optimization also significantly bolstered both cellular and humoral immune responses. In cytokine assays, all plasmid constructs, particularly pCTLA4-cHA, induced robust interferon (IFN)-γ production, while interleukin (IL)-4 levels remained uniformly non-significant. Mice immunized with pcHA displayed an augmented presence of IFNγ+ T-cells, underscoring the enhanced potency of the codon-optimized HA vaccine. Contrarily, CTLA-4-fused DNA vaccines did not significantly amplify the immune response.

Toward the Eradication of Herpes Simplex Virus: Vaccination and Beyond.

Herpes simplex virus (HSV) has coevolved with Homo sapiens for over 100,000 years, maintaining a tenacious presence by establishing lifelong, incurable infections in over half the human population. As of 2024, an effective prophylactic or therapeutic vaccine for HSV remains elusive. In this review, we independently screened PubMed, EMBASE, Medline, and Google Scholar for clinically relevant articles on HSV vaccines. We identified 12 vaccines from our literature review and found promising candidates across various classes, including subunit vaccines, live vaccines, DNA vaccines, and mRNA vaccines. Notably, several vaccines-SL-V20, HF10, VC2, and mRNA-1608-have shown promising preclinical results, suggesting that an effective HSV vaccine may be within reach. Additionally, several other vaccines such as GEN-003 (a subunit vaccine from Genocea), HerpV (a subunit vaccine from Agenus), 0ΔNLS/RVx201 (a live-attenuated replication-competent vaccine from Rational Vaccines), HSV 529 (a replication-defective vaccine from Sanofi Pasteur), and COR-1 (a DNA-based vaccine from Anteris Technologies) have demonstrated potential in clinical trials. However, GEN-003 and HerpV have not advanced further despite promising results. Continued progress with these candidates brings us closer to a significant breakthrough in preventing and treating HSV infections.

Immunogenicity and immunodominant linear B-cell epitopes of a new DNA-based tetravalent vaccine against four major enteroviruses causing hand, foot, and mouth disease

Hand, foot, and mouth disease (HFMD) poses a significant public health threat primarily caused by four major enteroviruses: enterovirus 71 (EV71), coxsackieviruses A16, A10, and A6. Broadly protective immune responses are essential for complete protection against these major enteroviruses. In this study, we designed a new tetravalent immunogen for HFMD, validated it in silico, in vivo evaluated the immunogenicity of the DNA-based tetravalent vaccine in mice, and identified immunogenic B-cell and T-cell epitopes. A new tetravalent immunogen, VP1me, was designed based on the chimeric protein and epitope-based vaccine principles. It contains a complete EV71 VP1 protein and six reported neutralizing B-cell epitopes derived from the four major enteroviruses causing HFMD. In silico validation using multiple immunoinformatic tools indicated good attributes of the VP1me immunogen suitable for vaccine development. The VP1me-based DNA vaccine efficiently induced both humoral and cellular immune responses in BALB/cAJcl mice. A combination of in silico prediction and immunoassays enabled the identification of immunogenic linear B-cell and CD8 T-cell epitopes within the VP1me immunogen. Immunodominant linear B-cell epitopes were identified in six regions of VP1me, with one epitope located at the N-terminus of the VP1 protein (aa 9–23) regarded as a novel epitope. Interestingly, some B-cell epitopes could also induce the CD8 T-cell response, suggesting their dual functions in immune stimulation. These results lay the groundwork for further development of VP1me as a new vaccine candidate.

Toward Greater DNA Stability by Leveraging the Proton-Donating Ability of Protic Ionic Liquids.

Deoxyribonucleic acid (DNA) stability is a prerequisite in many applications, ranging from DNA-based vaccines and data storage to gene therapy. However, the strategies to enhance DNA stability are limited, and the underlying mechanisms are poorly understood. Ionic liquids (ILs), molten salts of organic cations and organic/inorganic anions, are showing tremendous prospects in myriads of applications. With a judicious choice of constituent ions, the protic nature of ILs can be tuned. In this work, we investigate the relative stability of full-length genomic DNA in aqueous IL solutions of increasing protic nature. Our experimental measurements show that the protic ionic liquids (PILs) enhance the DNA melting temperature significantly while unaltering its native B-conformation. Molecular dynamics simulations and quantum mechanical calculation results suggest that the intramolecular Watson-Crick H-bonding in DNA remains unaffected and, in addition, the PILs induce stronger H-bonding networks in solution through their ability to make multiple intermolecular H-bonds with the nucleobases and among its constituent ions, thus aiding greater DNA stability. The detailed understanding obtained from this study could bring about the much-awaited breakthrough in improved DNA stability for its sustained use in the aforesaid applications!

Self-adjuvanting polymeric nanovaccines enhance IFN production and cytotoxic T cell response

Vaccines represent one of the most powerful and cost-effective innovations for controlling a wide range of infectious diseases caused by various viruses and bacteria. Unlike mRNA and DNA-based vaccines, subunit vaccines carry no risk of insertional mutagenesis and can be lyophilized for convenient transportation and long-term storage. However, existing adjuvants are often associated with toxic effect and reactogenicity, necessitating expanding the repertoire of adjuvants with better biocompatibility, for instance, designing self-adjuvating polymeric carriers. We herein report a novel subunit vaccine delivery platform constructed via in situ free radical polymerization of C7A (2-(Hexamethyleneimino) ethyl methacrylate) and acrylamide around the surface of individual protein antigens. Using ovalbumin (OVA) as a model antigen, we observed substantial increases in both diameter (∼70 nm) and surface potential (−1.18 mV) following encapsulation, referred to as n(OVA)C7A. C7A's ultra pH sensitivity with a transition pH around 6.9 allows for rapid protonation in acidic environments. This property facilitates crucial processes such as endosomal escape and major histocompatibility complex (MHC)-I-mediated antigen presentation, culminating in the substantial CD8+ T cell activation. Additionally, compared to OVA nanocapsules without the C7A components and native OVA without modifications, we observed heightened B cell activation within the germinal center, along with remarkable increases in serum antibody and cytokine production. It's important to note that mounting evidence suggests that adjuvant effects, particularly its targeted stimulation of type I interferons (IFNs), can contribute to advantageous adaptive immune responses. Beyond its exceptional potency, the nanovaccine also demonstrated robust formation of immune memory and exhibited a favorable biosafety profile. These findings collectively underscore the promising potential of our nanovaccine in the realm of immunotherapy and vaccine development.

Abstract 1174: Incorporation of multisector analysis into the design of personalized DNA vaccines for patients with newly diagnosed glioblastoma

Abstract Glioblastoma (GBM) is the most common malignant central nervous system (CNS) tumor in adults. Despite multimodality treatment including surgery, radiation, and chemotherapy, patients with GBM have a median survival of less than 2 years. Recent clinical trials have reported promising results using cancer vaccines to stimulate a tumor-directed immune response in several histologies. The majority of trials targeted tumor neoantigens derived from a single tumor sample, which limits the antigen pool in spatially heterogeneous cancers like GBM. Our group previously implemented multisector sequencing into the design of personalized peptide vaccines to increase the candidate pool of targetable neoantigens (NCT03422094). Although the peptide vaccine treatment was successful in stimulating an effector T cell response, it was limited by a long turnaround time from vaccine design to administration and a low peptide production rate. Therefore, we incorporated multisector sampling into the design of a personalized DNA-based GBM vaccine (NCT04015700). An average of 33% of the candidate targetable neoantigens were spatially restricted to a single sampled region, which would have been missed without multisector sequencing. DNA-based vaccines are potentially advantageous over peptide-based vaccines because they enable a higher neoantigen payload and faster manufacturing time with potent immunogenicity. Here, we report the results from 9 subjects enrolled onto the study. Spatially distinct tumor regions were subjected to whole exome sequencing (WES) and RNA-sequencing (RNA-seq), data from which were used to identify neoantigens through the pVACseq algorithm (http://pvactools.org). An average of 32 neoantigens were included in each DNA vaccine, compared to an average of only 9 for the peptide vaccine, and the turnaround time from date of surgery to administration of the DNA vaccine was about half the time. Three subjects had radiographic evidence of tumor progression prior to vaccination, highlighting the aggressive nature of GBM and the need for short manufacturing timeframes. PBMCs pre- and post-DNA vaccination were collected from 7/9 subjects. All subjects presented detectable responses and 6/7 tested revealed a sustained increment in T cell reactivity against tumor neoantigens post-treatment by IFN-γ ELISpot. Intracellular staining showed a neoantigen-specific antitumor CD8/CD4 T cell cytolytic (CD69+, CD107a+) and proliferative (Ki67+) profile. Post-vaccination tumor resections were performed for 2 subjects who also were treated with PD1 blockade upon progression, providing an opportunity to explore vaccine-induced changes in the tumor microenvironment. Herein, we demonstrate the advantages of incorporating multisector sequencing into the development of DNA-based GBM vaccines and provide insights into the resulting immune responses. Citation Format: Elizabeth A. Garfinkle, Katherine E. Miller, Alexandra J. Livingstone, Renzo Perales-Linares, Neil Cooch, Alfredo Perales-Puchalt, Sarah Rochestie, Joann Peters, Niranjan Y. Sardesai, William E. Gillanders, Elaine R. Mardis, Gavin P. Dunn, Tanner M. Johanns. Incorporation of multisector analysis into the design of personalized DNA vaccines for patients with newly diagnosed glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1174.

Abstract 6748: Intramuscular delivery of tumor associated antigen DNA vaccines elicits strong cellular immune response, delays tumor growth and prolongs survival

Abstract The development of effective cancer vaccines that can trigger strong and enduring memory T cell responses against specific tumor associated antigens (TAAs) is crucial for advancing immunotherapy. DNA-based cancer vaccines have shown promise in generating precise and long-lasting immune responses. In particular DNA vaccines are capable of inducing both humoral and cellular immune responses. In this study, we aimed to investigate the effectiveness of DNA vaccines targeting the mouse Tyrosine-related protein-2 (Trp2) and human New York esophageal squamous cell carcinoma 1 (NY-ESO-1) TAAs in mouse melanoma model. These DNA vaccines were formulated with a functionalized polymer designed to protect DNA from degradation and improve its bioavailability. DNA vaccines targeting both mouse Trp2 (pVACTR) and human NYESO-1 (pVACNY) were constructed. A mouse melanoma cell line (B16F10-NY) overexpressing human NYESO-1 was also generated and demonstrated to induce tumors in C57BL/6 mice. Female C57BL/6 mice received two doses of intramuscular (i.m.) injection of formulated pVACTR or pVACNY or a combination thereof, formulated with the synthetic functionalized polymer, with a 3-week interval. The DNA vaccination induced a potent T cell response, as evidenced by ELISPOT assays showing strong IFN-γ secreting T cells against NYESO-1 and Trp2. Flow cytometry analysis of spleenocytes showed strong IFN-γ and TNF-α secreting CD4 T cells against NYESO-1. We further evaluated the prophylactic and therapeutic efficacy of DNA vaccines targeting both Trp2 and NYESO-1 using a murine syngeneic model. Animals were challenged with a lethal dose of B16F10-NY two weeks after the second immunization exhibited a significant (p<0.0001) delay in tumor progression and a substantial increase in survival compared to the mock control group. In the therapeutic testing, animals challenged with B16F10-NY and subsequently vaccinated at 4, 11, and 25 days also demonstrated delayed tumor growth and prolonged survival. These findings indicate that formulated DNA vaccine delivered via i.m. triggers robust T cell responses and exhibit both prophylactic and therapeutic efficacy, leading to significantly prolonged survival and delayed tumor growth. A DNA-based vaccine independent of viral vector or device has potential to elicit potent anti-tumor responses with better safety and compliance. Citation Format: Kempaiah Rayavara, John Henderson, Meredyth Kinsella, Jessica Kim, Majed Matar, Subeena Sood, Olivia Signer, Chelsey Bellmon, Corinne Le Goff, Khursheed Anwer, Jean Boyer. Intramuscular delivery of tumor associated antigen DNA vaccines elicits strong cellular immune response, delays tumor growth and prolongs survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6748.

Humoral and Cellular Immune Responses Induced by Bivalent DNA Vaccines Expressing Fusion Capsid Proteins of Porcine Circovirus Genotypes 2a and 2b.

Porcine circovirus type 2 (PCV2) is the main causative agent of porcine circovirus-associated disease (PCVAD) that profoundly impacts the swine industry worldwide. While most of the commercial PCV vaccines are developed based on PCV genotype 2a (PCV2a), PCV genotype 2b (PCV2b) has become predominant since 2003. In this study, we developed and evaluated DNA-based bivalent vaccines covering both PCV2a and PCV2b. We generated a new immunogen, PCV2b-2a, by combining consensus sequences of the PCV2a and PCV2b capsid proteins (Cap2a and Cap2b) in a form of fusion protein. We also examined whether modifications of the PCV2b-2a fusion protein with a signal sequence (SS) and granulocyte macrophage-colony stimulating factor (GM-CSF) fusing with interleukine-4 (IL-4) (GI) could further improve the vaccine immunogenicity. An immunogenicity study of BALB/cAJcl mice revealed that the DNA vector pVAX1 co-expressing PCV2b-2a and GI (pVAX1.PCV2b-2a-GI) was most potent at inducing both antibody and cellular immune responses against Cap2a and Cap2b. Interestingly, the vaccines skewed the immune response towards Th1 phenotype (IgG2a > IgG1). By performing ELISA and ELISpot with predicted epitope peptides, the three most immunogenic B cell epitopes and five putative T cell epitopes were identified on Cap2a and Cap2b. Importantly, our DNA vaccines elicited broad immune responses recognizing both genotype-specific and PCV2-conserved epitopes. Sera from mice immunized with the DNAs expressing PCV2b-2a and PCV2b-2a-GI significantly inhibited PCV2a cell entry at serum dilution 1:8. All these results suggest a great potential of our PCV2b-2a-based vaccines, which can be further developed for use in other vaccine platforms to achieve both vaccine efficacy and economical production cost.

GSK and Elegen Team Up to Develop DNA-Based Medicines and Vaccines

GSK and Elegen Team Up to Develop DNA-Based Medicines and Vaccines

Transcriptional Targeting of Dendritic Cells Using an Optimized Human Fascin1 Gene Promoter

Deeper knowledge about the role of the tumor microenvironment (TME) in cancer development and progression has resulted in new strategies such as gene-based cancer immunotherapy. Whereas some approaches focus on the expression of tumoricidal genes within the TME, DNA-based vaccines are intended to be expressed in antigen-presenting cells (e.g., dendritic cells, DCs) in secondary lymphoid organs, which in turn induce anti-tumor T cell responses. Besides effective delivery systems and the requirement of appropriate adjuvants, DNA vaccines themselves need to be optimized regarding efficacy and selectivity. In this work, the concept of DC-focused transcriptional targeting was tested by applying a plasmid encoding for the luciferase reporter gene under the control of a derivative of the human fascin1 gene promoter (pFscnLuc), comprising the proximal core promoter fused to the normally more distantly located DC enhancer region. DC-focused activity of this reporter construct was confirmed in cell culture in comparison to a standard reporter vector encoding for luciferase under the control of the strong ubiquitously active cytomegalovirus promoter and enhancer (pCMVLuc). Both plasmids were also compared upon intravenous administration in mice. The organ- and cell type-specific expression profile of pFscnLuc versus pCMVLuc demonstrated favorable activity especially in the spleen as a central immune organ and within the spleen in DCs.

An Integrated in silico and in vivo study of nucleic acid vaccine against Nocardia seriolae infection in orange-spotted grouper Epinephelus coioides

Nocardiosis in aquatic animals caused by Nocardia seriolae is a frequently occurring serious infection that has recently spread to many countries. In this study, DNA vaccines containing potential bacterial antigens predicted using the reverse vaccinology approach were developed and evaluated in orange-spotted groupers. In silico analysis indicated that proteins including cholesterol oxidase, ld-transpeptidase, and glycosyl hydroxylase have high immunogenicity and are potential vaccine candidates. In vitro assays revealed the mature and biological configurations of these proteins. Importantly, when compared to a control PBS injection, N. seriolae DNA-based vaccines showed significantly higher expression of IL1β, IL17, and IFNγ at 1 or 2 days, in line with higher serum antibody production and expression of other cellular immune-related genes, such as MHCI, CD4, and CD8, at 7 days post-immunization. Remarkably, enhanced immune responses and strong protective efficacy against a highly virulent strain of N. seriolae were recorded in DNA vaccine-cholesterol oxidase (pcD::Cho) injected fish, with a relative survival rate of 73.3%. Our results demonstrate that the reverse vaccinology approach is a valid strategy for screening vaccine candidates and pcD::Cho is a promising candidate that can boost both innate and adaptive immune responses and confer considerable protection against N. seriolae infection.

Investigation of Immunostimulatory Effects of IFN-γ Cytokine and CD40 Ligand Costimulatory Molecule for Development of HIV-1 Therapeutic Vaccine Candidate.

The most crucial disadvantage of DNA-based vaccines is their low immunogenicity; therefore, finding an effectual adjuvant is essential for their development. Herein, immunostimulatory effects of IFNγ cytokine and a CD40 ligand (CD40L) costimulatory molecule are evaluated as combined with an antigen, and also linked to an antigen in mice. For this purpose, after preparation of the HIV-1 Nef, IFNγ, and CD40L DNA constructs, and also their recombinant protein in an Escherichia coli expression system, nine groups of female BALB/c mice are immunized with different regimens of DNA constructs. About 3 weeks and also 3 months after the last injection, humoral and cellular immune responses are assessed in mice sera and splenocytes. Additionally, mice splenocytes are exposed to single-cycle replicable (SCR) HIV-1 virions for evaluating their potency in the secretion of cytokines in vitro. The data indicate that the linkage of IFNγ and CD40L to Nef antigen can significantly induce the Th-1 pathway and activate cytotoxic T lymphocytes compared to other regimens. Moreover, groups receiving the IFNγ-Nef and CD40L-Nef fusion DNA constructs show higher secretion of IFNγ and TNF-α from virion-infected lymphocytes than other groups. Therefore, the IFNγ-Nef and CD40L-Nef fusion DNA constructs are suggested to be a potential option for development of an efficient HIV-1 vaccine.

Effects of single and multiple bouts of eccentric exercise on immune responses to HSV-gD1 DNA vaccination in mice

Abstract DNA vaccines comprise one modality of novel vaccination techniques. DNA vaccines employ intramuscular injection of DNA that codes for specific antigens from a pathogen. Prolonged eccentric endurance exercise can stimulate immune responses, possibly by increasing inflammatory mediators. This study aimed to determine the effects of one or three sessions of downhill running on the effectiveness of Herpes simplex virus type I glycoprotein D (HSV-gD1) DNA vaccination. Mice without or with one and three sessions of downhill running were vaccinated intramuscularly with the DNA vaccine or the empty vector. Cellular immune responses were assessed using an in vitro assay of lymphocyte proliferation in response to recall antigens. Also, a virus neutralisation test was used to determine the levels of neutralising antibodies in serum samples. In addition, Th1 and Th2 immune responses, and the ratio of the Th1/Th2 is considered an indicator of immune responses to infection in the current study. Multiple bouts of downhill running increased humoral immune responses after immunisation, also although Th2 immune responses decreased, lymphocyte proliferation and Th1/Th2 ratio immune responses increased following the viral challenge compared to the other groups. In addition, the timing of the 3-session exercise regimen plus DNA vaccination immediately following the last exercise session, as opposed to DNA vaccination 48 h before a single session of exercise, may account for the greater efficacy of DNA vaccination in the multiple bouts of the intensive exercise group. These findings indicate that short-term repeated bouts of eccentric endurance exercise have increased immune responses to intramuscular DNA-based vaccines.

Amyloidogenic propensity of self-assembling peptides and their adjuvant potential for use as DNA vaccines.

De novo designed peptides that self-assemble into cross-β rich fibrillar biomaterials have been pursued as an innovative platform for the development of adjuvant- and inflammation-free vaccines. However, they share structural and morphological properties similar to amyloid species implicated in neurodegenerative diseases, which has been a long-standing concern for their successful translation. Here, we comprehensively characterize the amyloidogenic character of the amphipathic self-assembling cross-β peptide KFE8, compared to pathological amyloid and amyloid-like proteins α-synuclein (α-syn) and TDP-43. Further, we developed plasmid-based DNA vaccines with the KFE8 backbone serving as a scaffold for delivery of a GFP model antigen. We find that expression of tandem repeats of KFE8 is non-toxic and efficiently cleared by autophagy. We also demonstrate that preformed KFE8 fibrils do not cross-seed amyloid formation of α-syn in mammalian cells compared to α-syn preformed fibrils. In mice, vaccination with plasmids encoding the KFE32-GFP fusion protein elicited robust immune responses, inducing production of significantly higher levels of anti-GFP antibodies compared to soluble GFP. Antigen-specific CD8+T cells were also detected in the spleens of vaccinated mice and cytokine profiles from antigen recall assays indicate a balanced Th1/Th2 response. These findings illustrate that cross-β-rich peptide nanofibers have distinct physicochemical properties from those of pathological amyloidogenic proteins, and are an attractive platform for the development of DNA vaccines with self-adjuvanting properties and improved safety profiles. STATEMENT OF SIGNIFICANCE: Biomaterials comprised of self-assembling peptides hold great promise for the development of new vaccines that do not require use of adjuvants. However, these materials have safety concerns, as they self-assemble into cross-β rich fibrils that are structurally similar to amyloid species implicated in disease. Here, we comprehensively study the properties of these biomaterials. We demonstrate that they have distinct properties from pathological proteins. They are non-toxic and do not trigger amyloidogenesis. Vaccination of these materials in mice elicited a robust immune response. Most excitingly, our work suggests that this platform could be used to develop DNA-based vaccines, which have few storage requirements. Further, due to their genetic encoding, longer sequences can be generated and the vaccines will be amenable to modification.

Successful Expression of DNA-Based Vaccine Construct Encoding Human Papillomavirus Type 16 E7 Fused to Heat Shock Protein B1 in Eukaryotic Cells

Successful Expression of DNA-Based Vaccine Construct Encoding Human Papillomavirus Type 16 E7 Fused to Heat Shock Protein B1 in Eukaryotic Cells

Induced protection from a CCHFV-M DNA vaccine requires CD8+ T cells

Crimean-Congo hemorrhagic fever (CCHF) is a World Health Organization prioritized disease because its broad distribution and severity of disease make it a global health threat. Despite advancements in preclinical vaccine development for CCHF virus (CCHFV), including multiple platforms targeting multiple antigens, a clear definition of the adaptive immune correlates of protection is lacking. Levels of neutralizing antibodies in vaccinated animal models do not necessarily correlate with protection, suggesting that cellular immunity, such as CD8+ T cells, might have an important role in protection in this model. Using a well-established IFN-I antibody blockade mouse model (IS) and a DNA-based vaccine encoding the CCHFV M-segment glycoprotein precursor, we investigated the role of humoral and T cell immunity in vaccine-mediated protection in mice genetically devoid of these immune compartments. We found that in the absence of the B-cell compartment (µMT knockout mice), protection provided by the vaccine was not reduced. In contrast, in the absence of CD8+ T cells (CD8+ knockout mice) the vaccine-mediated protection was significantly diminished. Importantly, humoral responses to the vaccine in CD8+ T-cell knockout mice were equivalent to wild-type mice. These findings indicated that CD8+ T-cell responses are necessary and sufficient to promote protection in mice vaccinated with the M-segment DNA vaccine. Identifying a crucial role of the cellular immunity to protect against CCHFV should help guide the development of CCHFV-targeting vaccines.

Real-world effectiveness of COVID-19 vaccines: A retrospective cohort study of vaccinated individuals in Jazan, Saudi Arabia

BackgroundCOVID-19 (Coronavirus Disease 2019) vaccinations are a critical control measure for the coronavirus pandemic that began in 2019. Several COVID-19 vaccines have been developed, and their effectiveness will almost certainly vary. ObjectiveThis study aimed to assess how effective two doses of the Pfizer and Oxford-AstraZeneca vaccines were in preventing SARS‐CoV‐2 infection six months after administration. MethodsThis is a retrospective cohort study of adult individuals from the Jazan Region of Saudi Arabia who received their second dose of the COVID-19 vaccine [Pfizer and Oxford-AstraZeneca (ASZ)] between April and June 2021. The monitoring and follow-up period continued until the end of January 2022. Data were retrieved from the Health Electronic Surveillance Network and National Vaccination Records. Logistic regression was performed to assess the risk of COVID-19 infection among the vaccinated subjects. ResultsThis study included randomly enrolled 4458 participants in Jazan who received two doses of the COVID-19 vaccine during the research period. The majority of them received the Pfizer vaccine (3136/4458; 70.3%), while the remaining received the ASZ vaccine (1322/4458; 29.7%). The study participants’ mean age was 59.7 years, with a male-to-female ratio of 1.9:1.0 (2920:1538). The results showed that the Pfizer and ASZ vaccines’ protection against infection decreased from 93.2% and 90.2%, respectively, during the first three months, to 68.5% and 68.1% after a six-month interval. In the current study population, being Saudi Arabian, younger as well as having longer intervals between vaccines or crossing a 6-month period after the second vaccine dose were factors linked to higher rates of breakthrough infections. ConclusionOur findings revealed variations in the efficacy of different COVID-19 vaccine types against COVID-19 breakthrough infections. The Pfizer (mRNA-based) vaccine was found to be relatively more effective than the ASZ (DNA-based) vaccine.

IgE-Mediated Shellfish Allergy in Children.

Shellfish, including various species of mollusks (e.g., mussels, clams, and oysters) and crustaceans (e.g., shrimp, prawn, lobster, and crab), have been a keystone of healthy dietary recommendations due to their valuable protein content. In parallel with their consumption, allergic reactions related to shellfish may be increasing. Adverse reactions to shellfish are classified into different groups: (1) Immunological reactions, including IgE and non-IgE allergic reactions; (2) non-immunological reactions, including toxic reactions and food intolerance. The IgE-mediated reactions occur within about two hours after ingestion of the shellfish and range from urticaria, angioedema, nausea, and vomiting to respiratory signs and symptoms such as bronchospasm, laryngeal oedema, and anaphylaxis. The most common allergenic proteins involved in IgE-mediated allergic reactions to shellfish include tropomyosin, arginine kinase, myosin light chain, sarcoplasmic calcium-binding protein, troponin c, and triosephosphate isomerase. Over the past decades, the knowledge gained on the identification of the molecular features of different shellfish allergens improved the diagnosis and the potential design of allergen immunotherapy for shellfish allergy. Unfortunately, immunotherapeutic studies and some diagnostic tools are still restricted in a research context and need to be validated before being implemented into clinical practice. However, they seem promising for improving management strategies for shellfish allergy. In this review, epidemiology, pathogenesis, clinical features, diagnosis, and management of shellfish allergies in children are presented. The cross-reactivity among different forms of shellfish and immunotherapeutic approaches, including unmodified allergens, hypoallergens, peptide-based, and DNA-based vaccines, are also addressed.