Vaccine Components Research Articles

Sex Differences in Exercise-Induced Modulation of the Humoral Immune Response to Influenza Vaccination

Physical activity is known to modulate immune cell function and understanding its role in vaccine-induced immunity is critical for both optimizing vaccine strategies and implementing lifestyle factors that contribute to better immune health. This study aimed to elucidate the impact of physical activity on antibody responses following influenza vaccination, with a specific focus on biological sex differences among male and female cross-country athletes. Based on previous studies, we hypothesized that physical activity would increase immune responses, regardless of biological sex. Two cohorts of male and female Division III college cross-country runners and two cohorts of non-athletes (no physical activity) participated in this longitudinal investigation. Studies were conducted in two separate influenza seasons where participants received a quadrivalent seasonal influenza vaccine (2020-21 and 2022-23). An estimated non-adjusted VO2 max was calculated, and a survey was administered to identify overall health status prior to the start of the study. Blood samples were collected at predefined intervals to assess pre- and post-vaccination antibody responses specific for the H1N1 component of each seasonal influenza vaccine. VO2 max, a measure of overall fitness, was higher in the athletes as compared to those participants who were not physically active, and these results were consistent among both males and females. All participants mounted an immune response to the seasonal influenza vaccine as indicated by a rise in vaccine-specific antibody titers from pre-vaccination to post-vaccination. However, the differences in titers were sex specific, with greater neutralizing antibody titers in females as compared to males — regardless of their level of physical activity. When data were further partitioned by physical activity level, it was identified that although males have lower antibody responses than females, males that were cross country runners had significantly greater antibody responses than males that were not physically active. This study contributes valuable insights into the complex interplay between exercise, sex, and immune responses. Understanding these dynamics could inform recommendations for individuals to be engaged in regular physical activity to optimize overall immune health. This research was funded by a College of Saint Benedict and Saint John's University Faculty Development and Research Committee Award. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Precision Vaccine Development: Unraveling the Immunoinformatics Code Against Epstein-Barr Virus's T41 Glycoprotein 350/220

Epstein-Barr Virus (EBV) poses a substantial global health threat, with a 90% morbidity rate in adults worldwide. Linked to infectious mononucleosis, autoimmune diseases, and cancers, there is an imperative for effective preventive measures, given the absence of current vaccines or medications. This study employs a bioinformatics strategy to design an epitope vaccine targeting EBV. The primary target for immunity is the EBV glycoprotein 350/220 (gp350), which mediates attachment to B cells through complement receptor 2 (CR2/CD21). The selected protein, EBV glycoprotein 350/220 was chosen based on its role in pathogenicity. In the post-therapeutic approach, three-dimensional structure prediction, validation, and verification processes were conducted, followed by molecular docking studies to identify potential drug-binding sites and suitable therapeutic inhibitors for the target protein. The protein's ability to stimulate humoral and cell-mediated immunity was assessed, leading to the identification of a peptide segment ATNLFLLEL from positions 342 to 356 as the predominant T cell epitope. This epitope demonstrated compatibility with various HLA profiles, enhanced by its interaction with eight HLA-A and HLA-B alleles. Population coverage analysis revealed broad responsiveness across geographies, suggesting its potential as a widely applicable vaccine component. Its non-allergic classification further supports its potential efficacy for diverse individuals. Docking studies with HLA-B*3501 confirmed its significant affinity for MHC-I molecules, establishing it as a promising vaccination candidate. Additionally, a region from amino acid positions 253 to 310 was identified as containing potential B-cell epitopes, with the sequence "LGAGELALTMRSKKLP" showing promise due to its antigenic potential. This computational approach to epitope-based peptide vaccine design and target site prediction against EBV represents a pioneering advancement in EBV virus research, emphasizing the need for validation through <i>in vitro</i> and <i>in vivo</i> trials.

Spectroscopic analysis of the bacterially expressed head domain of rotavirus VP6.

The rotavirus capsid protein VP6 forms the middle of three protein layers and is responsible for many critical steps in the viral life cycle. VP6 as a structural protein can be used in various applications including as a subunit vaccine component. The head domain of VP6 (VP6H) contains key sequences that allow the protein to trimerize and that represent epitopes that are recognized by human antibodies in the viral particle. The domain is rich in β-sheet secondary structures. Here, VP6H was solubilised from bacterial inclusion bodies and purified using a single affinity chromatography step. Spectral (far-UV circular dichroism and intrinsic tryptophan fluorescence) analysis revealed that the purified domain had native-like secondary and tertiary structures. The domain could maintain structure up to 44°C during thermal denaturation following which structural changes result in an intermediate forming and finally irreversible aggregation and denaturation. The chemical denaturation with urea and guanidinium hydrochloride produces intermediates that represent a loss in the cooperativity. The VP6H domain is stable and can fold to produce its native structure in the absence of the VP6 base domain but cannot be defined as an independent folding unit.

Naturally Occurring Anti-D in a Male Blood Donor, Unresolved Mystery.

In accordance with numerous national and international criteria, screening donated blood for abnormal antibodies against red cell antigens is crucial for patient safety. Antibodies can be formed by three mechanisms: by immune responses, naturally occurring, or passively acquired. In accordance with departmental policy, ICT was performed on a 30-yearold male blood donor's sample in addition to ABO Rh grouping. He tested A Rh Dnegative and had a positive ICT (+ 2). Anti-D was identified by using the antibody screening and identification panel. Retesting revealed similar results, so we called the donor. We were unable to find a source for the Rh isoimmunization during the course of his history. On further work-up, we found that antibodies reacted only in the antiglobulin phase with no reaction in the saline phase, suggesting an IgG type of antibody. Also, the anti-D titers (IgG) of the donor were up to 1:32. All potential sources of Rh isoimmunization have been ruled out for a male donor. Therefore, we assume that this donor has naturally occurring anti-D, perhaps created by certain environmental factors, bacteria, or components of the COVID vaccine that have cross-reactivity with the D antigen. This instance emphasizes how crucial the ICT test on the donor blood is. In our case, all potential causes of alloimmunization were ruled out, leaving only exposure to antigens with antigenic similarity to D antigens as a viable explanation.

How Real Are Allergic Reactions to Vaccine Components in Children? − Experiences of Clinicians

Objective − Vaccine components have the potential to induce allergic reactions, although such reactions are infrequent, especially anaphylactic reactions, which are very rare (occurring at a rate of 1 per million vaccine doses). The objective of this study was to assess objectively the frequency of allergic reactions to vaccine components in children with suspected allergic reactions to vaccine components. Materials andMethods − We retrospectively analyzed the medical records of 209 patients aged 1 to 18 years with suspected allergic reactions to vaccine components, who underwent the standardized diagnostic procedures and tests to common allergens and vaccine components at Srebrnjak Children`s Hospital, Zagreb, Croatia. Results − Of the 209 children vaccinated in the hospital setting, only two (0.95%) developed side effects during their hospital stay, and 2.63% with a positive history of IgE mediated vaccine allergy were positive for one of the components of the vaccine. Local reactions to the vaccine were the most frequent adverse events in our patients. 62.6% of them were referred due to a positive history of egg protein allergy. Conclusion − Allergic reactions to vaccine components are rare and mild in most cases. In patients with a suggestive history, it is important to choose appropriate diagnostic tests to determine if vaccination can be performed safely. Only patients at risk of egg protein anaphylaxis generally require medically supervised vaccination in a hospital facility. Patients with a history or a documented and immediate allergic reaction (<4 h) require an allergy workup to avoid the risk of repeated anaphylaxis after further administration.

MRNA Vaccines and Therapeutics: Current Science and Implications for Future Development

The recent success of messenger RNA (mRNA) vaccines against SARS-CoV-2 has highlighted the value of mRNA technology to combat infectious diseases. Several decades of investigation on mRNA-based approaches hold promise for further application of mRNA in developing vaccines and therapeutics. The core components of mRNA-based vaccines are one or more mRNA sequences, which are synthesized by in vitro transcription and surrounded by a vehicle designed to stably deliver the mRNA across cell membranes. Currently, all approved SARS-CoV-2 mRNA vaccines use a lipid nanoparticle (LNP) as a delivery vehicle. Modifications in both the mRNA and LNP components can optimize mRNA stability, protein expression, and immunogenicity. The technology of mRNA-based vaccines enables a platform-based approach to development, as the same core components are used for each agent. This review discusses the key components of current mRNA-based vaccines and the advantages of the platform approach for vaccine development, mechanisms of mRNA vaccine-associated immune responses, and safety. Current challenges and future directions for mRNA technology are also described, including the expansion of the mRNA platform to develop novel therapeutics.

Vaccination and screening strategies to accelerate cervical cancer elimination in Norway: a model-based analysis.

Experts have proposed an 'EVEN FASTER' concept targeting age-groups maintaining circulation of human papillomavirus (HPV). We explored effects of the vaccination component of these proposals compared with cervical cancer (CC) screening-based interventions on age-standardized incidence rate (ASR) and CC elimination (<4 cases/100,000) timing in Norway. We used a model-based approach to evaluate HPV vaccination and CC screening scenarios compared with a status-quo scenario reflecting previous vaccination and screening. For cohorts ages 25-30 years, we examined 6 vaccination scenarios that incrementally increased vaccination coverage from current cohort-specific rates. Each vaccination scenario was coupled with three screening strategies that varied screening frequency. Additionally, we included 4 scenarios that alternatively increased screening adherence. Population- and cohort-level outcomes included ASR, lifetime risk of CC, and colposcopy referrals. Several vaccination strategies coupled with de-intensified screening frequencies lowered ASR, but did not accelerate CC elimination. Alternative strategies that increased screening adherence could both accelerate elimination and improve ASR. The vaccination component of an 'EVEN FASTER' campaign is unlikely to accelerate CC elimination in Norway but may reduce population-level ASR. Alternatively, targeting under- and never-screeners may both eliminate CC faster and lead to greater health benefits compared with vaccination-based interventions we considered.

High purity and recovery of native filamentous hemagglutinin (FHA) from Bordetella pertussis using affinity chromatography

Filamentous hemagglutinin (FHA) is a critical adhesion molecule produced by Bordetella pertussis (BP), the causative agent of highly contagious respiratory infection known as whooping cough. FHA plays a pivotal role in the pathogenesis of whooping cough and is a key component of acellular pertussis vaccines (aPV). However, conventional purification methods for FHA often involve labor-intensive processes and result in low purity and recovery rates. Therefore, this study explores the use of monoclonal and polyclonal antibodies as specific tools to achieve highly pure and efficient FHA purification. To generate FHA-specific antibodies, polyclonal antibodies were produced by immunizing sheep and monoclonal antibodies (MAbs) were generated by immunizing mice with recombinant and native FHA. The MAbs were selected based on affinity, isotypes, and specificity, which were assessed through ELISA and Western blot assays. Two immunoaffinity columns, one monoclonal and one polyclonal, were prepared for FHA antigen purification. The purity and recovery rates of these purifications were determined using ELISA, SDS-PAGE, and immunoblotting. Furthermore, the MAbs were employed to develop an ELISA assay for FHA antigen concentration determination. The study's findings revealed that immunoaffinity column-based purification of FHA resulted in a highly pure antigen with recovery rates of approximately 57% ± 6.5% and 59% ± 7.9% for monoclonal and polyclonal columns, respectively. Additionally, the developed ELISA exhibited appropriate reactivity for determining FHA antigen concentration. This research demonstrates that affinity chromatography is a viable and advantageous method for purifying FHA, offering superior purity and recovery rates compared to traditional techniques. This approach provides a practical alternative for FHA purification in the context of aPV development.

CoPoP liposomes displaying stabilized clade C HIV-1 Env elicit tier 2 multiclade neutralization in rabbits

One of the strategies towards an effective HIV-1 vaccine is to elicit broadly neutralizing antibody responses that target the high HIV-1 Env diversity. Here, we present an HIV-1 vaccine candidate that consists of cobalt porphyrin-phospholipid (CoPoP) liposomes decorated with repaired and stabilized clade C HIV-1 Env trimers in a prefusion conformation. These particles exhibit high HIV-1 Env trimer decoration, serum stability and bind broadly neutralizing antibodies. Three sequential immunizations of female rabbits with CoPoP liposomes displaying a different clade C HIV-1 gp140 trimer at each dosing generate high HIV-1 Env-specific antibody responses. Additionally, serum neutralization is detectable against 18 of 20 multiclade tier 2 HIV-1 strains. Furthermore, the peak antibody titers induced by CoPoP liposomes can be recalled by subsequent heterologous immunization with Ad26-encoded membrane-bound stabilized Env antigens. Hence, a CoPoP liposome-based HIV-1 vaccine that can generate cross-clade neutralizing antibody immunity could potentially be a component of an efficacious HIV-1 vaccine.

Abstract CT107: Durable immunogenicity of ELI-002 2P in AMPLIFY-201: Lymph node targeted mKRAS-specific amphiphile vaccine in pancreatic and colorectal cancer

Abstract Background: Colorectal cancer (CRC) and pancreatic ductal adenocarcinoma (PDAC) are the second and third leading causes of cancer death in the United States. Kirsten rat sarcoma driver mutations (mKRAS) are prevalent in CRC (52%) and PDAC (93%), making them attractive targets for immunotherapy where therapeutic options are otherwise limited. ELI-002 2P immunotherapy enhances lymph node delivery and immune responses using Amphiphile (Amph) modification of vaccine components. 84% of patients (21/25) induced mKRAS-specific T-cells post-vaccination as assessed by direct ex vivo Fluorospot and/or ICS assays with an average 58-fold increase from baseline. A balanced CD4+ and CD8+ T cell response was observed in 59% of patients. Reductions in ctDNA or serum tumor biomarker antigen from baseline were observed in 84% of patients (21/25) and 24% (6/25) had complete biomarker clearance. The induction of strong mKRAS T cell responses correlated with reductions in tumor biomarker response/clearance and relapse-free survival (RFS) in patients. Methods: ELI-002-001 is a first-in-human Phase 1 trial (NCT04853017) of ELI-002 2P cancer vaccine as adjuvant treatment for patients with high relapse-risk mKRAS+ PDAC and CRC. ELI-002 2P consists of 2 Amph-modified mKRAS peptide antigens, Amph-G12D and Amph-G12R (Amph-Peptides 2P), and an Amph-modified immune-stimulatory oligonucleotide adjuvant (Amph-CpG-7909). 25 patients received ELI-002 2P at 1.4 mg of Amph-Peptides 2P and Amph-CpG-7909 at 5 dose levels; 0.1, 0.5, 2.5, 5, and 10 mg. Peripheral blood and circulating tumor DNA (ctDNA) or serum tumor antigen were collected longitudinally to assess T cell immunogenicity and reductions in clinical biomarkers. Results: A majority of patients who received the booster immunizations maintained or increased mKRAS-specific T cell responses relative to baseline. A high frequency of polyfunctional cells secreting IFNγ, TNFα, IL-2, and/or Granzyme B was observed. CD4+ T regulatory cells were not induced after ELI-002 2P immunization. Assessment of the breadth of responses to 7 different KRAS mutations revealed broad cross-reactivity to KRAS mutants, including non-immunizing epitopes, and no responses to WT. Additional phenotypic and functional qualities were assessed. Conclusions: ELI-002 is an off-the-shelf vaccine targeting common KRAS tumor mutations demonstrating several key advantages: lymph node-targeted vaccine design, high immunogenicity, with balanced CD4+ and CD8+ T cell responses, HLA-agnostic activity, and targeting of vaccine antigens critical for tumor survival. A randomized Phase 2 clinical trial (NCT05726864) investigating a 7-peptide formulation (G12D, R, V, A, C, S, G13D) is underway. Citation Format: James R. Perry, Haley VanWyk, Amy M. Tavares, Thian Kheoh, Esther Welkowsky, Christopher M. Haqq, Peter C. DeMuth, Lisa K. McNeil. Durable immunogenicity of ELI-002 2P in AMPLIFY-201: Lymph node targeted mKRAS-specific amphiphile vaccine in pancreatic and colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT107.

Abstract 4099: AMP-peptide vaccination against multiple p53 mutant epitopes promotes lymph node delivery to generate potent, functional T cell immunity

Abstract Background p53 is the most commonly mutated gene in human cancer, prevalent in nearly all tumor types. Despite its significant medical relevance and the knowledge that human T cells recognize these mutations[1,2], immunotherapies designed to promote responses against mutated p53 (mp53) have not had the hoped-for clinical impact[3]. The Amphiphile (AMP) platform improves the potency of vaccine immunotherapy by programming the delivery of vaccine components to the lymph nodes where efficient uptake by immune cells initiates tumor-targeted immune responses. AMP-modification of vaccine components (peptide antigens, molecular adjuvants) results in covalent conjugation to albumin-binding lipids. Upon injection, AMP-vaccines associate with tissue-resident albumin which efficiently distributes to draining lymph nodes. This approach was shown to promote activation of polyfunctional, cytotoxic T cells with promising safety and improved clinical outcomes in a Phase 1 trial of ELI-002, an mKRAS AMP therapeutic vaccine (AMPLIFY-201 NCT05726864). Application of this strategy to p53 mutations with ELI-008 offers the potential for improved immunotherapeutic activity in a setting of significant unmet need. Methods Following immunization of C57BL/6J mice with AMP-modified or soluble comparator vaccines consisting of mp53 peptides and CpG adjuvant, analyses were performed 7 days after the third bi-weekly dose. To assess antigen-specific T cell responses, ELISpot (IFNγ, GzmB), multiplexed proteomic, and flowcytometric analysis of effector cytokines (IFNγ, TNFα, IL-2) were performed following antigenic stimulation. Responses were determined in secondary lymphoid tissues and lung. Cytolytic capabilities of antigen-specific T cells were evaluated by monitoring specific killing of IV-transferred antigen-pulsed target cells. Results AMP-immunization generated robust immune responses yielding strong T cell activation against common p53 hot spot mutations (R248W, R248Q, R175H, G245S, R273H, Y220C, C135Y, R158H, H214R). Responses to AMP-vaccination were characterized by the generation of increased frequency of polyfunctional T cells (IFNγ, TNFα, IL2) specific to mp53 epitopes. Induced T cells demonstrated significant levels of cytolytic activity including GzmB production and elimination of target cells in vivo. Non-lymph targeted vaccines using soluble comparators were inactive. Conclusions AMP-conjugation permits efficient delivery directly to the lymph nodes and thus improves the immunogenicity of peptide vaccination. These substantially improved immune responses induced by ELI-008 represent a promising therapeutic opportunity for targeting cancer in a large fraction of human tumors. The AMP-platform technology is simple, rapid and scalable, promising broad clinical, off-the-shelf application for treating p53 mutated tumors. Citation Format: Martin P. Steinbuck, Xavier Cabana-Puig, Erica Palmer, Mimi M. Jung, Thomas Williams, Kristen Osaer, Jeff Zhang, Christopher M. Haqq, Peter C. DeMuth. AMP-peptide vaccination against multiple p53 mutant epitopes promotes lymph node delivery to generate potent, functional T cell immunity [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 4099.

Abstract 4100: AMP-peptide vaccination against mutant BRAF epitopes promotes lymph node delivery to generate potent, functional T cell immunity

Abstract Background Mutations in BRAF cause ~8% of human cancers[1]. Nonetheless, therapies designed to promote immune responses against mutated BRAF (mBRAF) have led to limited clinical success[2], despite evidence confirming T cell recognition of these mutations[3,4]. The Amphiphile (AMP) platform improves the potency of vaccine immunotherapy by programming the delivery of vaccine components to the lymph nodes where efficient uptake by resident immune cells initiates tumor-targeted immune responses. AMP-modification of vaccine components including peptide antigens and molecular adjuvants results in covalent conjugation to albumin-binding lipids. Upon injection, AMP-vaccines associate with tissue resident albumin which efficiently distributes to draining lymph nodes. This approach was shown to promote activation of polyfunctional, cytotoxic T cells with promising safety, and improved clinical outcomes in a Phase 1 trial of ELI-002, an mKRAS AMP therapeutic vaccine (AMPLIFY-201 NCT04853017). Application of this strategy to prevalent BRAF mutations with ELI-007 offers the potential for improved therapeutic activity in a setting of significant unmet need, as BRAF inhibitors benefit only a fraction of patients, with near universal progression. Methods Following multi-dose immunization of C57BL/6J mice with AMP-modified or soluble comparator vaccines consisting of mBRAF V600E/K peptides and CpG adjuvant, immunological readouts were performed 7 days after dosing. Antigen-specific T cell responses were assessed after ex vivo re-stimulation of cells with mBRAF overlapping peptides. Assays included analysis of antigen-specific T cell frequencies, multiplexed proteomics determining polyfunctionality, and effector function and cytotoxic potential evaluation. Responses were determined in secondary lymphoid tissues (spleen), as well as lung, to which many BRAF driven cancers metastasize. Results AMP-immunization generated robust in vivo immune responses yielding strong T cell activation against mBRAF epitopes. Non-lymph node targeted vaccination using soluble comparators were inactive with no response above mock treated mice. Responses to AMP-vaccination were characterized by the generation of significantly increased frequency of Th1-skewed, polyfunctional T cells (IFNγ, TNFα, IL2) specific to mBRAF V600E and V600K. Induced T cells further exhibited mBRAF-specific cytotoxic function. Conclusions AMP-conjugation enhances efficient delivery directly to the lymph nodes and thus improves the immunogenicity of peptide vaccination. These enhanced immune responses provide an encouraging therapeutic opportunity to treat &amp;gt;90% of BRAF-mutated cancers[5] with the AMP-mBRAF vaccine, ELI-007. Moreover, the AMP-platform technology is simple, rapidly executable, and scalable, promising broad clinical off-the-shelf application for BRAF. Citation Format: Martin P. Steinbuck, Xavier Cabana-Puig, Erica Palmer, Mimi M. Jung, Thomas Williams, Kristen Osaer, Jeff Zhang, Christopher M. Haqq, Peter C. DeMuth. AMP-peptide vaccination against mutant BRAF epitopes promotes lymph node delivery to generate potent, functional T cell immunity [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 4100.

Abstract 481: Proteomimetic polymers limit tumor growth in multiple models via potent antigen-specific T cell activation

Abstract Background: Patient-specific cancer vaccines derived from tumor antigen have been explored as a promising therapeutic strategy, however, challenges delivering vaccine components in a coordinated fashion to elicit antitumor responses remain. To overcome these, we utilize a novel nanoplatform called the Protein-Like Polymer (PLP), which allows for sustained and targeted delivery of tumor antigens in conjunction with adjuvants. Methods: PLPs containing peptide antigens were synthesized via ring-opening metathesis polymerization (ROMP) and characterized. A library of compounds with different sidechain linkage chemistries, degrees of polymerization (DP), and inclusion/exclusion of Oligo-ethylene glycol (OEG) were made to determine design rules for immune activation. Cell uptake and functional assays using payload-specific T Cells were conducted. Immunization in three independent tumor models was done to show generalizability. Ability of PLPs to co-deliver adjuvants was tested by electrostatically coupling small molecule STING agonist, 2’3’ cGAMP. Results: Conjugating peptide antigens to the polymer via a cleavable disulfide linkage, which reduces intracellularly in APCs, resulted in increased endosomal localization, higher levels of induced T cell proliferation, cytokine production, and expression of activation markers in CTLs and APCs. Incorporating a diluent amount of OEG side chains reduced enzymatic degradation while increasing immunogenicity and uptake. Additionally, increasing the DP, and therefore the density of antigen side chains, further improved vaccine efficacy and resistance to proteolysis. Antigen-PLP conjugates enhanced dendritic cell activation and T-cell response only when paired with cells from their cognate system, with no activity in immune cells not expressing receptors for the payload demonstrating antigen-specificity. Mice bearing established B16F10, MC38, or TC-1 tumors treated with PLPs containing gp100, adpgk, or E7 respectively all showed increased survival times, reduced tumor burden with corresponding changes in immune cell profiles, and immunological memory upon rechallenge. Impressively, mice treated with STING-PLP complexes had significantly smaller tumors vs control at day 14 (0.038g vs 0.76g; p &amp;lt;0.0001) and allowed for subcutaneous administration of 2’3’ cGAMP, which traditionally requires intratumoral injection. Studies on the effects of vaccinating with pools of neoantigens multiplexed onto one PLP are ongoing. Conclusion: This work validates the ability of PLPs to overcome major limitations in cancer vaccine development. The modularity of the platform allows for complex nano-architectures including systems capable of delivering challenging compounds, ie small molecule STING agonists, subcutaneously through electrostatic coupling, highlighting its potential to revolutionize cancer vaccinology. Citation Format: Max Wang, Miran Choi, Bin Zhang, Nathan Gianneschi. Proteomimetic polymers limit tumor growth in multiple models via potent antigen-specific T cell activation [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 481.

Construction of prokaryotic system for expression of porcine circovirus type 2 ORF-2 gene fragment

Porcine circovirus-associated diseases (PCVDs) are among the most significant challenges for pig farming in developed countries. Porcine circovirus type 2 (PCV-2) is considered the main etiological agent of postweaning multisystemic wasting syndrome in piglets. Mass PCVD occurrence has been reported in most regions of the world, that results in serious economic consequences. Optimal PCVD prevention is known to be achieved through a set of veterinary and sanitary measures in combination with vaccination. High evolutionary virus variability facilitating new genotype and strain emergence requires development of new candidate recombinant vaccines against PCV-2 infection. The study was aimed at construction of prokaryotic system for PCV-2 ORF-2 gene fragment expression and its functionality assessment. A genetic insert constructed from the most immunogenic type-specific PCV-2 epitopes based on genotype 2a, 2b, 2d strain and isolate consensus sequence was cloned into the expression vector pET-22b(+) that was incorporated into the Escherichia coli strain Rosetta 2(DE3). The transformants were selected based on the marker gene of ampicillin resistance on a selective medium. Target gene expression was induced by adding of isopropyl-β-D-1-thiogalactopyranoside at different concentrations. As a result, Escherichia coli Rosetta 2(DE3)/pET-22b-ORF-2 strain, a producer of capsid protein fragment (92–233 amino acid residues), was constructed. It was found that in the presence of 1 mM isopropyl-β-D-1-thiogalactopyranoside, the expression level of soluble truncated rCap was 35–40 mg/L 6 hours after induction. The expression product was tested for its specificity with indirect ELISA using whole-virion PCV-2-hyperimmunized porcine serum. It was shown that the positivity coefficient of producer strain cell lysates averaged to 4.34 (p &lt; 0.005). The recombinant rCap protein is suitable for serological diagnosis and is also of interest as a vaccine component, which is the goal of our further studies.

Primary Cutaneous CD4 Small/Medium T-Cell Lymphoproliferative Disorder Following COVID-19 Vaccination-What Do We Know about Lymphoproliferative Disorders and Cutaneous Lymphomas after COVID-19 Vaccination? A Report of an Atypical Case and a Review of the Literature.

The association between Primary cutaneous CD4 small/medium T-cell lymphoproliferative disorder (PCSM-TCLPD) and COVID-19 immunization has been sparsely documented in the medical literature. Reviewing the literature, albeit infrequently, we can find cases of the recurrence and new onset of lymphoproliferative processes and cutaneous lymphomas following the COVID-19 vaccine. Many of the entities we encounter are classified as cutaneous lymphoproliferative disorders. The prevailing hypothesis suggests that the predominant cutaneous reactions to SARS-CoV-2 vaccines may stem from T-cell-mediated immune activation responses to vaccine components, notably messenger RNA (mRNA). Specifically, it is posited that the presence of cutaneous lymphoid infiltrates may be linked to immune system stimulation, supported by the absence, to date, of instances of primary cutaneous B-cell lymphoma following mRNA vaccination. Within this context, it is imperative to underscore that the etiological association between PCSM-TCLPD and COVID-19 vaccination should not discourage vaccination efforts. Instead, it underscores the necessity for continuous surveillance, in-depth investigation, and comprehensive follow-up studies to delineate the specific attributes and underlying mechanisms of such cutaneous manifestations post vaccination.

Design and Preclinical Evaluation of a Nanoparticle Vaccine against Respiratory Syncytial Virus Based on the Attachment Protein G.

Human respiratory syncytial virus (RSV) poses a significant human health threat, particularly to infants and the elderly. While efficacious vaccines based on the F protein have recently received market authorization, uncertainties remain regarding the future need for vaccine updates to counteract potential viral drift. The attachment protein G has long been ignored as a vaccine target due to perceived non-essentiality and ineffective neutralization on immortalized cells. Here, we show strong G-based neutralization in fully differentiated human airway epithelial cell (hAEC) cultures that is comparable to F-based neutralization. Next, we designed an RSV vaccine component based on the central conserved domain (CCD) of G fused to self-assembling lumazine synthase (LS) nanoparticles from the thermophile Aquifex aeolicus as a multivalent antigen presentation scaffold. These nanoparticles, characterized by high particle expression and assembly through the introduction of N-linked glycans, showed exceptional thermal and storage stability and elicited potent RSV neutralizing antibodies in a mouse model. In conclusion, our results emphasize the pivotal role of RSV G in the viral lifecycle and culminate in a promising next-generation RSV vaccine candidate characterized by excellent manufacturability and immunogenic properties. This candidate could function independently or synergistically with current F-based vaccines.

Impact of SARS-CoV-2 spike stability and RBD exposure on antigenicity and immunogenicity

The spike protein (S) of SARS-CoV-2 induces neutralizing antibodies and is the key component of current COVID-19 vaccines. The most efficacious COVID-19 vaccines are genetically-encoded spikes with a double proline substitution in the hinge region to stabilize S in the prefusion conformation (S-2P). A subunit vaccine can be a valuable addition to mRNA and viral vector-based vaccines but requires high stability of spike. In addition, further stabilization of the prefusion conformation of spike might improve immunogenicity. To test this, five spike proteins were designed and characterized, ranging from low to high stability. The immunogenicity of these proteins was assessed in mice, demonstrating that a spike (S-closed-2) with a high melting temperature, which still allowed ACE2 binding, induced the highest neutralization titers against homologous and heterologous strains (up to 16-fold higher than the least stabilized spike). In contrast, the most stable spike variant (S-locked), in which the receptor binding domains (RBDs) were locked in a closed conformation and thus not able to breathe, induced relatively low neutralizing antibody titers against heterologous strains. These data demonstrate that S protein stabilization with RBDs exposing highly conserved epitopes may be needed to increase the immunogenicity of spike proteins for future COVID-19 vaccines.

Evaluation of different types of adjuvants in a malaria transmission-blocking vaccine

Adjuvants are critical components for vaccines, which enhance the strength and longevity of the antibody response and influence the types of immune response. Limited research has been conducted on the immunogenicity and protective efficacy of various adjuvants in malaria transmission-blocking vaccines (TBVs). In this study, we formulated a promising TBV candidate antigen, the P. berghei ookinete surface antigen PSOP25, with different types of adjuvants, including the TLR4 agonist monophosphoryl lipid A (MPLA), the TLR9 agonist cytosine phosphoguanosine oligodeoxynucleotides (CpG ODN 1826) (CpG), a saponin adjuvant QS-21, aluminum hydroxide (Alum), and two combination adjuvants MPLA + QS-21 and QS-21 + CpG. We demonstrated that adjuvanted vaccines results in elevated elicited antibody levels, increased proliferation of plasma cells, and efficient formation of germinal centers (GCs), leading to enhanced long-term protective immune responses. Furthermore, CpG group exhibited the most potent inhibition of ookinete formation and transmission-blocking activity. We found that the rPSOP25 with CpG adjuvant was more effective than MPLA, QS-21, MPLA + QS-21, QS-21 + CpG adjuvants in dendritic cells (DCs) activation and differentiation. Additionally, the CpG adjuvant elicited more rubust immune memory response than Alum adjuvant. CpG and QS-21 adjuvants could activate the Th1 response and promote the secretion of IFN-γ and TNF-α. PSOP25 induced a higher number of Tfh cells in splenocytes when combined with MPLA, CpG, and QS-21 + CpG; and there was no increase in these cell populations when PSOP25 was administered with Alum. In conclusion, CpG may confer enhanced efficacy for the rPSOP25 vaccine, as evidenced by the ability of the elicited antisera to induce protective immune responses and improved transmission-blocking activity.

Strategies to enhance stress tolerance in lactic acid bacteria across diverse stress conditions.

Lactic acid bacteria (LAB) hold significant importance in diverse fields, including food technology, industrial biotechnology, and medicine. As basic components of starter cultures, probiotics, immunomodulators, and live vaccines, LAB cells resist a variety of stressors, including temperature fluctuations, osmotic and pH shocks, exposure to oxidants and ultraviolet radiation, substrate deprivation, mechanical damage, and more. To stay alive in these adversities, LAB employ a wide range of stress response strategies supported by various mechanisms, for example rearrangement of metabolism, expression of specialized biomolecules (e.g., chaperones and antioxidants), exopolysaccharide synthesis, and complex repair and regulatory systems. LAB can coordinate responses to various stressors using global regulators. In this review, we summarize current knowledge about stress response strategies used by LAB and consider mechanisms of response to specific stressful factors, supported by illustrative examples. In addition, we discuss technical approaches to increase the stress resistance of LAB, including pre-adaptation, genetic modification of strains, and adjustment of cultivation conditions. A critical analysis of the recent findings in this field augments comprehension of stress tolerance mechanisms in LAB, paving the way for prospective research directions with implications in fundamental and practical areas.

Back to Basics: Determining Units of Immunization Administration

Physicians and other qualified health care professionals (QHPs) must select the appropriate administration codes and units of service for each code when reporting immunization administration (IA). This article reviews the following: Codes for reporting IA Determining components of vaccine and toxoid products Reporting multiple IA services