RESUMEN

BACKGROUND: Influenza viruses pose a persistent threat to global public health, necessitating the development of innovative and broadly effective vaccines. METHODS: This study focuses on a multiepitope vaccine (MEV) designed to provide broad-spectrum protection against different influenza viruses. The MEV, containing 19 B-cell linear epitopes, 7 CD4+ T cells, and 11 CD8+ T cells epitopes identified through enzyme-linked immunospot assay (ELISPOT) in influenza viruses infected mice, was administered through a regimen of two doses of DNA vaccine followed by one dose of a protein vaccine in C57BL/6 female mice. FINDINGS: Upon lethal challenge with both seasonal circulating strains (H1N1, H3N2, BV, and BY) and historical strains (H1N1-PR8 and H3N2-X31), MEV demonstrated substantial protection against different influenza seasonal strains, with partial efficacy against historical strains. Notably, the increased germinal centre B cells and antibody-secreting cells, along with robust T cell immune responses, highlighted the comprehensive immune defence elicited by MEV. Elevated hemagglutinin inhibition antibody was also observed against seasonal circulating and historical strains. Additionally, mice vaccinated with MEV exhibited significantly lower counts of inflammatory cells in the lungs compared to negative control groups. INTERPRETATION: Our results demonstrated the efficacy of a broad-spectrum MEV against influenza viruses in mice. Conducting long-term studies to evaluate the durability of MEV-induced immune responses and explore its potential application in diverse populations will offer valuable insights for the continued advancement of this promising vaccine. FUNDING: Funding bodies are described in the Acknowledgments section.

Asunto(s)

Epítopos de Linfocito B , Virus de la Influenza B , Vacunas contra la Influenza , Infecciones por Orthomyxoviridae , Animales , Vacunas contra la Influenza/inmunología , Vacunas contra la Influenza/administración & dosificación , Ratones , Virus de la Influenza B/inmunología , Infecciones por Orthomyxoviridae/prevención & control , Infecciones por Orthomyxoviridae/inmunología , Femenino , Epítopos de Linfocito B/inmunología , Virus de la Influenza A/inmunología , Anticuerpos Antivirales/inmunología , Epítopos de Linfocito T/inmunología , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Vacunas de ADN/inmunología , Vacunas de ADN/administración & dosificación , Estaciones del Año , Subtipo H3N2 del Virus de la Influenza A/inmunología , Humanos

RESUMEN

Severe acute respiratory syndrome (SARS)-coronavirus (CoV), Middle Eastern respiratory syndrome (MERS)-CoV, and SARS-CoV-2 have seriously threatened human life in the 21st century. Emerging and re-emerging ß-coronaviruses after the coronavirus disease 2019 (COVID-19) epidemic remain possible highly pathogenic agents that can endanger human health. Thus, pan-ß-coronavirus vaccine strategies to combat the upcoming dangers are urgently needed. In this study, four LNP-mRNA vaccines, named O, D, S, and M, targeting the spike protein of SARS-CoV-2 Omicron, Delta, SARS-CoV, and MERS-CoV, respectively, were synthesized and characterized for purity and integrity. All four LNP-mRNAs induced effective cellular and humoral immune responses against the corresponding spike protein antigens in mice. Furthermore, LNP-mRNA S and D induced neutralizing antibodies against SARS-CoV and SARS-CoV-2, which failed to cross-react with MERS-CoV. Subsequent evaluation of sequential and cocktail immunizations with LNP-mRNA O, D, S, and M effectively elicited broad immunity against SARS-CoV-2 variants, SARS-CoV, and MERS-CoV. A direct comparison of the sequential with cocktail regimens indicated that the cocktail vaccination strategy induced more potent neutralizing antibodies and T-cell responses against heterotypic viruses as well as broader antibody activity against pan-ß-coronaviruses. Overall, these results present a potential pan-ß-coronavirus vaccine strategy for improved preparedness prior to future coronavirus threats.

Asunto(s)

Liposomas , Nanopartículas , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo , Vacunas Virales , Animales , Ratones , Humanos , Vacunas de ARNm , SARS-CoV-2/genética , Vacunas contra la COVID-19 , Glicoproteína de la Espiga del Coronavirus/genética , Modelos Animales de Enfermedad , Vacunas Virales/genética , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/genética , Anticuerpos Neutralizantes , ARN Mensajero/genética , Inmunidad , Anticuerpos Antivirales

RESUMEN

Influenza remains a global health concern due to its potential to cause pandemics as a result of rapidly mutating influenza virus strains. Existing vaccines often struggle to keep up with these rapidly mutating flu viruses. Therefore, the development of a broad-spectrum peptide vaccine that can stimulate an optimal antibody response has emerged as an innovative approach to addressing the influenza threat. In this study, an immunoinformatic approach was employed to rapidly predict immunodominant epitopes from different antigens, aiming to develop an effective multiepitope influenza vaccine (MEV). The immunodominant B-cell linear epitopes of seasonal influenza strains hemagglutinin (HA) and neuraminidase (NA) were predicted using an antibody-peptide microarray, involving a human cohort including vaccinees and infected patients. On the other hand, bioinformatics tools were used to predict immunodominant cytotoxic T-cell (CTL) and helper T-cell (HTL) epitopes. Subsequently, these epitopes were evaluated by various immunoinformatic tools. Epitopes with high antigenicity, high immunogenicity, non-allergenicity, non-toxicity, as well as exemplary conservation were then connected in series with appropriate linkers and adjuvants to construct a broad-spectrum MEV. Moreover, the structural analysis revealed that the MEV candidates exhibited good stability, and the docking results demonstrated their strong affinity to Toll-like receptors 4 (TLR4). In addition, molecular dynamics simulation confirmed the stable interaction between TLR4 and MEVs. Three injections with MEVs showed a high level of B-cell and T-cell immune responses according to the immunological simulations in silico. Furthermore, in-silico cloning was performed, and the results indicated that the MEVs could be produced in considerable quantities in Escherichia coli (E. coli). Based on these findings, it is reasonable to create a broad-spectrum MEV against different subtypes of influenza A and B viruses in silico.

Asunto(s)

Vacunas contra la Influenza , Gripe Humana , Orthomyxoviridae , Humanos , Receptor Toll-Like 4 , Gripe Humana/prevención & control , Escherichia coli , Simulación del Acoplamiento Molecular , Epítopos de Linfocito T/química , Vacunas de Subunidad , Epítopos de Linfocito B , Biología Computacional/métodos

RESUMEN

IMPORTANCE: The development of broad-spectrum SARS-CoV-2 vaccines will reduce the global economic and public health stress from the COVID-19 pandemic. The use of conserved T-cell epitopes in combination with spike antigen that induce humoral and cellular immune responses simultaneously may be a promising strategy to further enhance the broad spectrum of COVID-19 vaccine candidates. Moreover, this research suggests that the combined vaccination strategies have the ability to induce both effective systemic and mucosal immunity, which may represent promising strategies for maximizing the protective efficacy of respiratory virus vaccines.

Asunto(s)

Vacunas contra la COVID-19 , COVID-19 , Vacunas Combinadas , Humanos , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19/prevención & control , Vacunas contra la COVID-19/inmunología , Inmunidad Celular , Inmunización , Pandemias/prevención & control , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Vacunación

RESUMEN

Although the development and clinical application of SARS-CoV-2 vaccines during the COVID-19 pandemic demonstrated unprecedented vaccine success in a short time frame, it also revealed a limitation of current vaccines in their inability to provide broad-spectrum or universal protection against emerging variants. Broad-spectrum vaccines, therefore, remain a dream and challenge for vaccinology. This review will focus on current and future efforts in developing universal vaccines targeting different viruses at the genus and/or family levels, with a special focus on henipaviruses, influenza viruses, and coronaviruses. It is evident that strategies for developing broad-spectrum vaccines will be virus-genus or family specific, and it is almost impossible to adopt a universal approach for different viruses. On the other hand, efforts in developing broad-spectrum neutralizing monoclonal antibodies have been more successful and it is worth considering broad-spectrum antibody-mediated immunization, or "universal antibody vaccine," as an alternative approach for early intervention for future disease X outbreaks.

Asunto(s)

COVID-19 , Vacunas contra la Influenza , Infecciones por Orthomyxoviridae , Humanos , Vacunas contra la COVID-19 , Pandemias/prevención & control , Anticuerpos Antivirales , COVID-19/prevención & control , SARS-CoV-2 , Anticuerpos Neutralizantes

RESUMEN

More than 80% of SARS-CoV-2 variants, including Alpha and Omicron, contain an N501Y mutation in the receptor-binding domain (RBD) of the spike protein. The N501Y change is an adaptive mutation enabling tighter interaction with the human ACE2 receptor. We have developed a broadly neutralizing antibody (nAb), D27LEY, whose binding affinity was intentionally optimized for Y501. This N501Y-centric antibody not only interacts with the Y501-containing RBDs of SARS-CoV-2 variants, including Omicron, with pico- or subnanomolar binding affinity, but also binds tightly to the RBDs with a different amino acid at residue 501. The crystal structure of the Fab fragment of D27LEY bound to the RBD of the Alpha variant reveals that the Y501-containing loop adopts a ribbon-like topology and serves as a small but major epitope in which Y501 is a part of extensive intermolecular interactions. A hydrophobic cleft on the most conserved surface of the RBD core serves as another major binding epitope. These data explain the broad and potent cross-reactivity of this N501Y-centric antibody, and suggest that a vaccine antigenic component composed of the RBD core and a part of receptor-binding motif (RBM) containing tyrosine at residue 501 might elicit broad and potent humoral responses across sarbecoviruses.

Asunto(s)

COVID-19 , SARS-CoV-2 , Humanos , Anticuerpos , Epítopos

RESUMEN

[This corrects the article DOI: 10.3389/fimmu.2022.1049867.].

RESUMEN

SARS-CoV-2 vaccine production has taken us by storm. We aim to fill in the history of concepts and the work of pioneers and provide a framework of strategies employing structural vaccinology. Cryo-electron microscopy became crucial in providing three-dimensional (3D) structures and creating candidates eliciting T and B cell-mediated immunity. It also determined structural changes in the emerging mutants in order to design new constructs that can be easily, quickly and safely added to the vaccines. The full-length spike (S) protein, the S1 subunit and its receptor binding domain (RBD) of the virus are the best candidates. The vaccine development to cease this COVID-19 pandemic sets a milestone for the pan-coronavirus vaccine's designing and manufacturing. By employing structural vaccinology, we propose that the mRNA and the protein sequences of the currently approved vaccines should be modified rapidly to keep up with the more infectious new variants.

RESUMEN

Coronavirus disease 2019, caused by SARS-CoV-2, remains an on-going pandemic, partly due to the emergence of variant viruses that can "break-through" the protection of the current vaccines and neutralizing antibodies (nAbs), highlighting the needs for broadly nAbs and next-generation vaccines. We report an antibody that exhibits breadth and potency in binding the receptor-binding domain (RBD) of the virus spike glycoprotein across SARS coronaviruses. Initially, a lead antibody was computationally discovered and crystallographically validated that binds to a highly conserved surface of the RBD of wild-type SARS-CoV-2. Subsequently, through experimental affinity enhancement and computational affinity maturation, it was further developed to bind the RBD of all concerning SARS-CoV-2 variants, SARS-CoV-1 and pangolin coronavirus with pico-molar binding affinities, consistently exhibited strong neutralization activity against wild-type SARS-CoV-2 and the Alpha and Delta variants. These results identify a vulnerable target site on coronaviruses for development of pan-sarbecovirus nAbs and vaccines.

Asunto(s)

Anticuerpos Antivirales/inmunología , Antígenos Virales/inmunología , Anticuerpos ampliamente neutralizantes/inmunología , COVID-19/inmunología , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Enzima Convertidora de Angiotensina 2/química , Enzima Convertidora de Angiotensina 2/metabolismo , Anticuerpos Antivirales/genética , Anticuerpos Antivirales/metabolismo , Afinidad de Anticuerpos , Especificidad de Anticuerpos , Reacciones Antígeno-Anticuerpo , Antígenos Virales/química , Antígenos Virales/genética , Anticuerpos ampliamente neutralizantes/genética , Anticuerpos ampliamente neutralizantes/metabolismo , Cristalografía por Rayos X , Epítopos/química , Epítopos/inmunología , Humanos , Fragmentos de Inmunoglobulinas/inmunología , Simulación del Acoplamiento Molecular , Método de Montecarlo , Pruebas de Neutralización , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Dominios Proteicos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/metabolismo , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética

RESUMEN

Colibacillosis is an economically important infectious disease in poultry, caused by avian pathogenic Escherichia coli (APEC). Salmonella enterica serovar Enteritidis (S. Enteritidis) is a major cause of food-borne diseases in human circulated through poultry-derived products, including meat and chicken eggs. Vaccine control is the mainstream approach for combating these infections, but it is difficult to create a vaccine for the broad-spectrum protection of poultry due to multiple serotypes of these pathogens. Our previous studies have shown that outer membrane vesicles (OMVs) derived from S. enterica serovar Typhimurium mutants with a remodeled outer membrane could induce cross-protection against heteroserotypic Salmonella infection. Therefore, in this study, we further evaluated the potential of broad-spectrum vaccines based on major outer membrane protein (OMP)-deficient OMVs, including ΔompA, ΔompC, and ΔompD, and determined the protection effectiveness of these candidate vaccines in murine and chicken infection models. The results showed that ΔompA led to an increase in the production of OMVs. Notably, ΔompAΔompCΔompD OMVs showed significantly better cross-protection against S. enterica serovar Choleraesuis, S. Enteritidis, APEC O78, and Shigella flexneri 2a than did other omp-deficient OMVs, with the exception of ΔompA OMVs. Subsequently, we verified the results in the chicken model, in which ΔompAΔompCΔompD OMVs elicited significant cross-protection against S. Enteritidis and APEC O78 infections. These findings further confirmed the feasibility of improving the immunogenicity of OMVs by remodeling the outer membrane and provide a new perspective for the development of broad-spectrum vaccines based on OMVs.

RESUMEN

Omptins represent a family of proteases commonly found in various Gram-negative pathogens. These proteins play an important role in host-pathogen interaction and have been recognized as key virulence factors, highlighting the possibility of developing an omptin-based broad-spectrum vaccine. The prototypical omptin, His-tagged recombinant Pla, was used as a model target antigen. In total, 46 linear and 24 conformational epitopes for the omptin family were predicted by the use of ElliPro service. Among these we selected highly conserved, antigenic, non-allergenic, and immunogenic B-cell epitopes. Five epitopes (2, 6, 8, 10, and 11 corresponding to Pla regions 52-60, 146-150, 231-234, 286-295, and 306-311, respectively) could be the first choice for the development of the new generation of target-peptide-based vaccine against plague. The partial residues of omptin epitopes 6, 8, and 10 (regions 136-145, 227-230, and 274-285) could be promising targets for the multi-pathogen vaccine against a group of enterobacterial infections. The comparative analysis and 3D modeling of amino acid sequences of several omptin family proteases, such as Pla (Yersinia pestis), PgtE (Salmonella enterica), SopA (Shigella flexneri), OmpT, and OmpP (Escherichia coli), confirmed their high cross-homology with respect to the identified epitope clusters and possible involvement of individual epitopes in host-pathogen interaction.

RESUMEN

Cocktail vaccines are proposed as an attractive way to increase protection efficacy against specific tick species. Furthermore, such vaccines made with different tick antigens have the potential of cross-protecting against a broad range of tick species. However, there are still limitations to the selection of immunogen candidates. Acknowledging that glutathione S-transferases (GSTs) have been exploited as vaccines against ticks and other parasites, this study aimed to analyze a GST-cocktail vaccine as a potential broad-spectrum tick vaccine. To constitute the GST-cocktail vaccine, five tick species of economic importance for livestock industry were studied (Rhipicephalus appendiculatus, Rhipicephalus decoloratus, Rhipicephalus microplus, Amblyomma variegatum, and Haemaphysalis longicornis). Tick GST ORF sequences were cloned, and the recombinant GSTs were produced in Escherichia coli. rGSTs were purified and inoculated into rabbits, and the immunological response was characterized. The humoral response against rGST-Rd and rGST-Av showed a stronger cross-reactivity against heterologous rGSTs compared to rGST-Hl, rGST-Ra, and rGST-Rm. Therefore, rGST-Rd and rGST-Av were selected for constituting an experimental rGST-cocktail vaccine. Vaccination experiment in rabbits showed that rGST-cocktail caused 35% reduction in female numbers in a Rhipicephalus sanguineus infestation. This study brings forward an approach to selecting immunogens for cocktail vaccines, and the results highlight rGST-Rd and rGST-Av as potentially useful tools for the development of a broad-spectrum tick vaccine.

Asunto(s)

Glutatión Transferasa/inmunología , Infestaciones por Garrapatas/prevención & control , Garrapatas/enzimología , Garrapatas/inmunología , Vacunas/inmunología , Animales , Reacciones Cruzadas/inmunología , Glutatión Transferasa/química , Glutatión Transferasa/genética , Sistemas de Lectura Abierta , Conejos , Rhipicephalus sanguineus/enzimología , Rhipicephalus sanguineus/inmunología , Vacunas/administración & dosificación

RESUMEN

Current available human papillomavirus (HPV) vaccines are based on the major capsid protein L1 virus-like particles (VLPs), which mainly induce type-specific neutralizing antibodies against vaccine types. Continuing to add more types of VLPs in a vaccine raises the complexity and cost of production which remains the principal impediment to achieve broad implementation of HPV vaccines, particularly in developing regions. In this study, we constructed 16L1-31L2 chimeric VLP (cVLP) by displaying HPV31 L2 aa.17-38 on the h4 coil surface region of HPV16 L1, and assessed its immunogenicity in mouse model. We found that the cVLP adjuvanted with alum plus monophosphoryl lipid A could induce cross-neutralizing antibody responses against 16 out of 17 tested HPV pseudoviruses, and the titer against HPV16 was as high as that was induced by HPV16 L1VLP (titer > 105), more importantly, titers over 103 were observed against two HR-HPVs including HPV31 (titer, 2,200) and -59 (titer, 1,013), among which HPV59 was not covered by Gardasil-9, and medium or low titers of cross-neutralizing antibodies against other 13 tested HPV pseudoviruses were also observed. Our data demonstrate that 16L1-31L2 cVLP is a promising candidate for the formulation of broader spectrum HPV vaccines.

Asunto(s)

Papillomavirus Humano 16/inmunología , Papillomavirus Humano 31/inmunología , Infecciones por Papillomavirus/prevención & control , Vacunas contra Papillomavirus/inmunología , Vacunas de Partículas Similares a Virus/inmunología , Animales , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Proteínas de la Cápside/genética , Proteínas de la Cápside/inmunología , Protección Cruzada/genética , Protección Cruzada/inmunología , Evaluación Preclínica de Medicamentos , Femenino , Papillomavirus Humano 16/genética , Papillomavirus Humano 31/genética , Ratones , Ratones Endogámicos BALB C , Modelos Animales , Proteínas Oncogénicas Virales/genética , Proteínas Oncogénicas Virales/inmunología , Infecciones por Papillomavirus/inmunología , Infecciones por Papillomavirus/virología , Vacunas contra Papillomavirus/genética , Péptidos , Ingeniería de Proteínas , Vacunas de Partículas Similares a Virus/genética

RESUMEN

Reverse vaccinology (RV) has become a popular method for developing vaccines. Although Edwardsiella tarda is deemed to be an important fish pathogen, so far, no reports have used a genome-based approach to screen vaccine candidates against E. tarda. In the current study, protective antigens of E. tarda were screened using RV. Large-scale cloning, expression and purification of potential candidates were carried out, and their immunoprotective potential was evaluated. A candidate fructose-bisphosphate aldolase (FBA) exhibited broad spectrum protection, as did another glycolysis-related protein glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which we reported previously, indicating the potential of other glycolysis-related proteins of E. tarda as broad spectrum protective antigens. In total, half (5 out 10) of these proteins showed prominent immunoprotective potential. Therefore, we suggest that glycolysis-related proteins are a class of potential broad spectrum protective antigens and that these proteins should be preferentially selected.

Asunto(s)

Vacunas Bacterianas/inmunología , Edwardsiella tarda/inmunología , Infecciones por Enterobacteriaceae/veterinaria , Enfermedades de los Peces/prevención & control , Fructosa-Bifosfato Aldolasa/inmunología , Gliceraldehído-3-Fosfato Deshidrogenasa (Fosforilante)/inmunología , Animales , Acuicultura , Vacunas Bacterianas/administración & dosificación , Infecciones por Enterobacteriaceae/prevención & control , Resultado del Tratamiento

RESUMEN

The development of aquaculture has been hampered by different aquatic pathogens that can cause edwardsiellosis, vibriosis, or other diseases. Therefore, developing a broad spectrum vaccine against different fish diseases is necessary. In this study, fructose 1,6-bisphosphate aldolase (FBA), a conserved enzyme in the glycolytic pathway, was demonstrated to be located in the non-cytoplasmic components of five aquatic pathogenic bacteria and exhibited remarkable protection and cross-protection against these pathogens in turbot and zebrafish. Further analysis revealed that sera sampled from vaccinated turbot had a high level of specific antibody and bactericidal activity against these pathogens. Meanwhile, the increased expressions of immune response-related genes associated with antigen recognition and presentation indicated that the adaptive immune response was effectively aroused. Taken together, our results suggest that FBA can be utilized as a broad-spectrum vaccine against various pathogenic bacteria of aquaculture in the future.

Asunto(s)

Bacterias/inmunología , Proteínas Bacterianas/inmunología , Vacunas Bacterianas/inmunología , Peces Planos/inmunología , Fructosa-Bifosfato Aldolasa/inmunología , Pez Cebra/inmunología , Inmunidad Adaptativa , Animales , Acuicultura , Proteínas Bacterianas/genética , Vacunas Bacterianas/genética , Fructosa-Bifosfato Aldolasa/genética , Inmunidad Innata , Análisis de Secuencia de ADN/veterinaria

RESUMEN

Frequent mutation of influenza viruses keep vaccinated and non-vaccinated populations vulnerable to new infections, causing serious burdens to public health and the economy. Vaccination with universal influenza vaccines would be the best way to effectively protect people from infection caused by mismatched or unforeseen influenza viruses. Presently, there is no FDA approved universal influenza vaccine. In this study, we expressed and purified a fusion protein comprising of influenza matrix 2 protein ectodomain peptides, a centralized influenza hemagglutinin stem region, and cholera toxin subunit B. Vaccination of BALB/c mice with this novel artificial antigen resulted in potent humoral immune responses, including induction of specific IgA and IgG, and broad protection against infection by multiple influenza viruses. Furthermore, our results demonstrated that when used as a mucosal antigen, cholera toxin subunit B improved antigen-stimulated T cell and memory B cell responses.

Asunto(s)

Antígenos Virales/administración & dosificación , Antígenos Virales/inmunología , Toxina del Cólera/administración & dosificación , Toxina del Cólera/inmunología , Inmunización/métodos , Orthomyxoviridae/inmunología , Administración Intranasal , Secuencia de Aminoácidos , Animales , Toxina del Cólera/genética , Femenino , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Datos de Secuencia Molecular , Orthomyxoviridae/efectos de los fármacos , Orthomyxoviridae/genética