RESUMO
Immunological memory is the basis of protective immunity provided by vaccines and previous infections. Immunological memory can develop from multiple branches of the adaptive immune system, including CD4 T cells, CD8 T cells, B cells, and long-lasting antibody responses. Extraordinary progress has been made in understanding memory to SARS-CoV-2 infection and COVID-19 vaccines, addressing development; quantitative and qualitative features of different cellular and anatomical compartments; and durability of each cellular component and antibodies. Given the sophistication of the measurements; the size of the human studies; the use of longitudinal samples and cross-sectional studies; and head-to-head comparisons between infection and vaccines or between multiple vaccines, the understanding of immune memory for 1 year to SARS-CoV-2 infection and vaccines already supersedes that of any other acute infectious disease. This knowledge may help inform public policies regarding COVID-19 and COVID-19 vaccines, as well as the scientific development of future vaccines against SARS-CoV-2 and other diseases.
Assuntos
Vacinas contra COVID-19 , COVID-19 , Anticorpos Antivirais , COVID-19/prevenção & controle , Estudos Transversais , Humanos , Memória Imunológica , SARS-CoV-2RESUMO
BACKGROUND: The adjuvanted RSV prefusion F protein-based vaccine (RSVPreF3 OA) was efficacious against RSV-related lower respiratory tract disease (RSV-LRTD) in ≥60-years-olds over 1 RSV season. We evaluated efficacy and safety of 1 RSVPreF3 OA dose and of 2 RSVPreF3 OA doses given 1 year apart against RSV-LRTD over 2 RSV seasons post-dose 1. METHODS: In this phase 3, blinded trial, ≥60-year-olds were randomized (1:1) to receive RSVPreF3 OA or placebo pre-season 1. RSVPreF3 OA recipients were re-randomized (1:1) to receive a second RSVPreF3 OA dose (RSV_revaccination group) or placebo (RSV_1dose group) pre-season 2; participants who received placebo pre-season 1 received placebo pre-season 2 (placebo group). Efficacy of both vaccine regimens against RSV-LRTD was evaluated over 2 seasons combined (confirmatory secondary objective, success criterion: lower limits of 2-sided CIs around efficacy estimates >20%). RESULTS: The efficacy analysis comprised 24 967 participants (RSV_1dose: 6227; RSV_revaccination: 6242; placebo: 12 498). Median efficacy follow-up was 17.8 months. Efficacy over 2 seasons of 1 RSVPreF3 OA dose was 67.2% (97.5% CI: 48.2-80.0%) against RSV-LRTD and 78.8% (95% CI: 52.6-92.0%) against severe RSV-LRTD. Efficacy over 2 seasons of a first dose followed by revaccination was 67.1% (97.5% CI: 48.1-80.0%) against RSV-LRTD and 78.8% (95% CI: 52.5-92.0%) against severe RSV-LRTD. Reactogenicity/safety of the revaccination dose were similar to dose 1. CONCLUSIONS: One RSVPreF3 OA dose was efficacious against RSV-LRTD over 2 RSV seasons in ≥60-year-olds. Revaccination 1 year post-dose 1 was well tolerated but did not seem to provide additional efficacy benefit in the overall study population. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov: NCT04886596.
Assuntos
Infecções por Vírus Respiratório Sincicial , Vacinas contra Vírus Sincicial Respiratório , Vírus Sincicial Respiratório Humano , Proteínas Virais de Fusão , Humanos , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vacinas contra Vírus Sincicial Respiratório/administração & dosagem , Vacinas contra Vírus Sincicial Respiratório/efeitos adversos , Masculino , Feminino , Vírus Sincicial Respiratório Humano/imunologia , Idoso , Pessoa de Meia-Idade , Proteínas Virais de Fusão/imunologia , Anticorpos Antivirais/sangue , Idoso de 80 Anos ou mais , Estações do Ano , Eficácia de Vacinas , Método Duplo-Cego , Imunização SecundáriaRESUMO
In the landscape of infectious diseases, human coronaviruses such as SARS-CoV, MERS-CoV, and SARS-CoV-2 pose significant threats, characterized by severe respiratory illnesses and notable resistance to conventional treatments due to their rapid evolution and the emergence of diverse variants, particularly within SARS-CoV-2. This study investigated the development of broad-spectrum coronavirus vaccines using heterodimeric RBD-Fc proteins engineered through the "Knob-into-Hole" technique. We constructed various recombinant proteins incorporating the receptor-binding domains (RBDs) of different coronaviruses. Heterodimers combining RBDs from SARS-CoV-2 with those of SARS-CoV or MERS-CoV elicited superior neutralizing responses compared to homodimeric proteins in murine models. Additionally, heterotetrameric proteins, specifically D614G_Delta/BA.1_XBB.1.5-RBD and MERS_D614G/BA.1_XBB.1.5-RBD, elicited remarkable breadth and potency in neutralizing all known SARS-CoV-2 variants, SARS-CoV, related sarbecoviruses like GD-Pangolin and WIV1, and even MERS-CoV pseudoviruses. Furthermore, these heterotetrameric proteins also demonstrated enhanced cellular immune responses. These findings underscore the potential of recombinant hetero proteins as a universal vaccine strategy against current and future coronavirus threats.
Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinas contra COVID-19 , Coronavírus da Síndrome Respiratória do Oriente Médio , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Camundongos , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/química , Vacinas contra COVID-19/imunologia , Humanos , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Fragmentos Fc das Imunoglobulinas/imunologia , Fragmentos Fc das Imunoglobulinas/genética , Fragmentos Fc das Imunoglobulinas/química , COVID-19/prevenção & controle , COVID-19/imunologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/imunologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Camundongos Endogâmicos BALB C , Feminino , Domínios Proteicos , Testes de Neutralização , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/genéticaRESUMO
Vaccines have demonstrated remarkable effectiveness in protecting against COVID-19; however, concerns regarding vaccine-associated enhanced respiratory diseases (VAERD) following breakthrough infections have emerged. Spike protein subunit vaccines for SARS-CoV-2 induce VAERD in hamsters, where aluminum adjuvants promote a Th2-biased immune response, leading to increased type 2 pulmonary inflammation in animals with breakthrough infections. To gain a deeper understanding of the potential risks and the underlying mechanisms of VAERD, we immunized ACE2-humanized mice with SARS-CoV-2 Spike protein adjuvanted with aluminum and CpG-ODN. Subsequently, we exposed them to increasing doses of SARS-CoV-2 to establish a breakthrough infection. The vaccine elicited robust neutralizing antibody responses, reduced viral titers, and enhanced host survival. However, following a breakthrough infection, vaccinated animals exhibited severe pulmonary immunopathology, characterized by a significant perivascular infiltration of eosinophils and CD4+ T cells, along with increased expression of Th2/Th17 cytokines. Intracellular flow cytometric analysis revealed a systemic Th17 inflammatory response, particularly pronounced in the lungs. Our data demonstrate that aluminum/CpG adjuvants induce strong antibody and Th1-associated immunity against COVID-19 but also prime a robust Th2/Th17 inflammatory response, which may contribute to the rapid onset of T cell-mediated pulmonary immunopathology following a breakthrough infection. These findings underscore the necessity for further research to unravel the complexities of VAERD in COVID-19 and to enhance vaccine formulations for broad protection and maximum safety.
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Vacinas contra COVID-19 , COVID-19 , Glicoproteína da Espícula de Coronavírus , Animais , Humanos , Camundongos , Adjuvantes Imunológicos , Adjuvantes Farmacêuticos , Alumínio , Enzima de Conversão de Angiotensina 2 , Infecções Irruptivas , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , SARS-CoV-2RESUMO
This study evaluated the possible effects of blood types on coronavirus disease (COVID-19) vaccine immunogenicity and antibody (Ab) persistency. Five different vaccinated groups against COVID-19 were investigated at Pasteur Institute of Iran from April 2021 to December 2022. Anti-Spike IgG and neutralizing Ab rise were tracked on Day 21 as well as the humoral immune persistency assessment 180 after booster shots. Late adverse events up to 6 months after the booster dose were collected. The results showed that blood type A, led to a significantly higher anti-Spike Ab rise in AstraZeneca primed recipients in comparison with Sinopharm primed ones in heterologous regimens (p: 0.019). Furthermore, blood type O was a great co-effector in homologous AstraZeneca recipients regarding neutralizing Ab rise (0.013). In addition, blood type O led to a better anti-Spike Ab persistency in the Sinopharm homologous group whereas type A had the best effect on neutralizing Ab durability in the same vaccine group. What is more, Rh-positive individuals in AstraZeneca + PastoCovac Plus group had a higher rate of anti-Spike Ab rise (p = 0.001). Neutralizing Ab rise was also induced in AstraZeneca homologous and heterologous regimens of Rh-positive individuals significantly higher than Sinopharm primed cases. The present study showed the potential impact of blood types A/O and Rh-positive on a better humoral immune responses and Ab persistency. It is proposed that blood type A and Rh-positive could increase the Ab rise in AstraZeneca vaccinated individuals. Moreover, blood type O might be a better co-effector of anti-Spike Ab persistency in Sinopharm recipients.
Assuntos
COVID-19 , Imunidade Humoral , Humanos , Vacinas contra COVID-19 , COVID-19/prevenção & controle , Anticorpos Neutralizantes , Vacinação , Anticorpos AntiviraisRESUMO
Persistent nocardiosis has prompted exploration of the effectiveness of heterologous approaches to prevent severe infections. We have previously reported the efficacy of a nucleic acid vaccine in protecting groupers from highly virulent Nocardia seriolae infections. Ongoing research has involved the supplementation of recombinant cholesterol oxidase (rCho) proteins through immunization with a DNA vaccine to enhance the protective capacity of orange-spotted groupers. Recombinant rCho protein exhibited a maturity and biological structure comparable to that expressed in N. seriolae, as confirmed by Western blot immunodetection assays. The immune responses observed in vaccinated groupers were significantly higher than those observed in single-type homologous vaccinations, DNA or recombinant proteins alone (pcD:Cho and rCho/rCho), especially cell-mediated immune and mucosal immune responses. Moreover, the reduction in N. seriolae occurrence in internal organs, such as the head, kidney, and spleen, was consistent with the vaccine's efficacy, which increased from approximately 71.4 % to an undetermined higher percentage through heterologous vaccination strategies of 85.7 %. This study underscores the potential of Cho as a novel vaccine candidate and a heterologous approach for combating chronic infections such as nocardiosis.
Assuntos
Vacinas Bacterianas , Doenças dos Peixes , Nocardiose , Nocardia , Animais , Nocardiose/veterinária , Nocardiose/prevenção & controle , Nocardiose/imunologia , Nocardia/imunologia , Doenças dos Peixes/prevenção & controle , Doenças dos Peixes/imunologia , Vacinas Bacterianas/imunologia , Vacinas Bacterianas/administração & dosagem , Vacinas de DNA/imunologia , Vacinas de DNA/administração & dosagem , Bass/imunologia , Colesterol Oxidase/imunologia , Colesterol Oxidase/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/administração & dosagemRESUMO
Brucellosis is a global zoonotic infection caused by Brucella bacteria, which poses a significant burden on society. While transmission prevention is currently the most effective method, the absence of a licenced vaccine for humans necessitates the urgent development of a safe and effective vaccine. Recombinant protein-based subunit vaccines are considered promising options, and in this study, the Brucella BP26 protein is expressed using prokaryotic expression systems. The immune responses are evaluated using the well-established adjuvant CpG-ODN. The results demonstrate that rBP26 supplemented with a CpG adjuvant induces M1 macrophage polarization and stimulates cellular immune responses mediated by Th1 cells and CD8 + T cells. Additionally, it generates high levels of rBP26-specific antibodies in immunized mice. Furthermore, rBP26 immunization activates, proliferates, and produces cytokines in T lymphocytes while also maintaining immune memory for an extended period of time. These findings shed light on the potential biological function of rBP26, which is crucial for understanding brucellosis pathogenesis. Moreover, rBP26 holds promise as an effective subunit vaccine candidate for use in endemic areas.
Assuntos
Ativação de Macrófagos , Camundongos Endogâmicos BALB C , Células Th1 , Vacinas de Subunidades Antigênicas , Animais , Células Th1/imunologia , Vacinas de Subunidades Antigênicas/imunologia , Camundongos , Ativação de Macrófagos/imunologia , Ativação de Macrófagos/efeitos dos fármacos , Feminino , Brucelose/prevenção & controle , Brucelose/imunologia , Vacina contra Brucelose/imunologia , Brucella/imunologia , Macrófagos/imunologia , Linfócitos T CD8-Positivos/imunologia , Adjuvantes Imunológicos/farmacologia , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/genética , Oligodesoxirribonucleotídeos/imunologia , Citocinas/metabolismo , Citocinas/imunologia , Proteínas de MembranaRESUMO
Global containment of COVID-19 still requires accessible and affordable vaccines for low- and middle-income countries (LMICs). Recently approved vaccines provide needed interventions, albeit at prices that may limit their global access. Subunit vaccines based on recombinant proteins are suited for large-volume microbial manufacturing to yield billions of doses annually, minimizing their manufacturing cost. These types of vaccines are well-established, proven interventions with multiple safe and efficacious commercial examples. Many vaccine candidates of this type for SARS-CoV-2 rely on sequences containing the receptor-binding domain (RBD), which mediates viral entry to cells via ACE2. Here we report an engineered sequence variant of RBD that exhibits high-yield manufacturability, high-affinity binding to ACE2, and enhanced immunogenicity after a single dose in mice compared to the Wuhan-Hu-1 variant used in current vaccines. Antibodies raised against the engineered protein exhibited heterotypic binding to the RBD from two recently reported SARS-CoV-2 variants of concern (501Y.V1/V2). Presentation of the engineered RBD on a designed virus-like particle (VLP) also reduced weight loss in hamsters upon viral challenge.
Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Engenharia de Proteínas/métodos , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/genética , Animais , Anticorpos Antivirais/imunologia , Antígenos Virais , Sítios de Ligação , COVID-19/virologia , Vacinas contra COVID-19/economia , Humanos , Imunogenicidade da Vacina , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Saccharomycetales/metabolismo , Vacinas de Subunidades AntigênicasRESUMO
Vibrio parahaemolyticus (V. parahaemolyticus) is a major pathogen that causes substantial losses in the marine fishery. With the emergence of antibiotic resistance, vaccines have become the most effective approach against V. parahaemolyticus infection. Adhesion factors on the cell surface are pivotal in the colonization and pathogenesis of V. parahaemolyticus within the host, highlighting their potential as vaccine candidates. This study aims to assess the immunogenicity and potential of recombinant V. parahaemolyticus MAM7 (rMAM7) as a vaccine candidate. Initially, we cloned and purified the MAM7 protein of V. parahaemolyticus. Moreover, after 4 weeks of vaccination, the fish were challenged with V. parahaemolyticus. rMAM7 demonstrated a certain protective effect. Immunological analysis revealed that rMAM7 immunization-induced antibody production and significantly increased acid phosphatase (ACP) and alkaline phosphatase (AKP) activity in hybrid tilapia. Furthermore, serum bactericidal tests demonstrated a lower bacterial survival rate in the rMAM7 group compared to PBS and rTrxa. qRT-PCR results indicated that rMAM7 significantly upregulated CD4, CD8 and IgM gene expression, suggesting the induction of Th1 and Th2 responses in hybrid tilapia. Overall, these findings highlight the potential application of MAM7 from V. parahaemolyticus in the development of protein vaccines.
Assuntos
Ciclídeos , Doenças dos Peixes , Tilápia , Vacinas , Vibrioses , Vibrio parahaemolyticus , Animais , Tilápia/microbiologia , Vibrio parahaemolyticus/fisiologia , Doenças dos Peixes/microbiologia , Vibrioses/prevenção & controle , Vibrioses/veterinária , ImunidadeRESUMO
The development of cross-reactive vaccines is one of the central aims of modern vaccinology. Continuous mutation and the emergence of new SARS-CoV-2 variants and subvariants create the problem of universal coronavirus vaccine design. Previously, the authors devised three recombinant coronavirus antigens, which were based on the sequence collected in 2019 (the Wuhan variant) and produced in an E. coli bacterial expression system. The present work has shown, for the first time, that these recombinant antigens induce the production of antibodies that clearly interact with produced in CHO full-length S-protein of the Omicron variant. The immunogenicity of these recombinant antigens was studied in formulations with different adjuvants: Freund's adjuvant, Al(OH)3 and an adjuvant based on spherical particles (SPs), which are structurally modified plant virus. All adjuvanted formulations effectively stimulated Omicron-specific IgG production in mice. These universal coronavirus antigens could be considered the main component for the further development of broad-spectrum coronavirus vaccines for the prevention of SARS-CoV-2 infection. The present work also provides evidence that the synthetic biology approach is a promising strategy for the development of highly cross-reactive vaccines. Moreover, it is important to note that the bacterial expression system might be appropriate for the production of antigenically active universal antigens.
Assuntos
Anticorpos Antivirais , COVID-19 , Escherichia coli , Proteínas Recombinantes , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Animais , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Camundongos , Anticorpos Antivirais/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/genética , COVID-19/prevenção & controle , COVID-19/imunologia , Vacinas contra COVID-19/imunologia , Camundongos Endogâmicos BALB C , Feminino , Antígenos Virais/imunologia , Antígenos Virais/genética , Humanos , Adjuvantes Imunológicos , Imunoglobulina G/imunologia , CricetulusRESUMO
Bacterial flagella are involved in infection through their roles in host cell adhesion, cell invasion, auto-agglutination, colonization, the formation of biofilms, and the regulation and secretion of nonflagellar bacterial proteins that are involved in the virulence process. In this study, we constructed a fusion protein vaccine (FliCD) containing the Clostridioides difficile flagellar proteins FliC and FliD. The immunization of mice with FliCD induced potent IgG and IgA antibody responses against FliCD, protected mice against C. difficile infection (CDI), and decreased the C. difficile spore and toxin levels in the feces after infection. Additionally, the anti-FliCD serum inhibited the binding of C. difficile vegetative cells to HCT8 cells. These results suggest that FliCD may represent an effective vaccine candidate against CDI.
Assuntos
Clostridioides difficile , Infecções por Clostridium , Animais , Camundongos , Proteínas Recombinantes de Fusão/genética , Clostridioides/metabolismo , Infecções por Clostridium/microbiologia , Proteínas de Bactérias/metabolismo , Vacinas Bacterianas/genéticaRESUMO
OBJECTIVES: To investigate the potential relationship between age and Streptococcus pneumoniae vaccination coverage in kindergarten children, and to provide a basis for guiding vaccination and developing new protein vaccines. METHODS: The stratified cluster random sampling method was used to select 1 830 healthy children from six kindergartens in Shunde District, Foshan City, China, and nasopharyngeal swabs were collected for the isolation and identification of Streptococcus pneumoniae. The logistic regression model based on restricted cubic spline was used to analyze the dose-response relationship between age and Streptococcus pneumoniae vaccination coverage. RESULTS: The rate of nasal Streptococcus pneumoniae carriage was 22.46% (411/1 830) among the kindergarten children, with the predominant serotypes of 6B, 19F, 15A, 23A, 34, and 23F. The coverage rates of 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13) were 53.0% and 57.9%, respectively, and there was a significant non-linear dose-response relationship between age and the coverage rates of PCV10 and PCV13 (P<0.05), with a higher coverage rate of PCV10 (88.0%) and PCV13 (91.1%) in the children aged 2 years. There was a significant non-linear dose-response relationship between age and the coverage rates of pilus islet 1 (PI-1) and pilus islet 2 (PI-2) (P<0.05), with a lower vaccination coverage rate for PI-1 (37.7%) and PI-2 (16.1%). The coverage rates of PI-1 (13.0%-58.5%) and PI-2 (6.0%-29.4%) were lower in all age groups. The virulence genes lytA (99.5%) and ply (99.0%) associated with candidate protein vaccines showed higher vaccination coverage rates. CONCLUSIONS: There is a significant non-linear dose-response relationship between the age of kindergarten children and the coverage rates of PCV10 and PCV13 serotypes, and kindergarten children aged 2 years have a relatively high coverage rate of PCV. The high prevalence of the virulence genes lytA and ply shows that they are expected to become candidate virulence factors for the development of a new generation of recombinant protein vaccines.
Assuntos
Infecções Pneumocócicas , Streptococcus pneumoniae , Humanos , Criança , Lactente , Streptococcus pneumoniae/genética , Infecções Pneumocócicas/prevenção & controle , Infecções Pneumocócicas/epidemiologia , Cobertura Vacinal , Vacinas Pneumocócicas , Sorogrupo , Vacinação , Nasofaringe , Portador Sadio/epidemiologiaRESUMO
Pneumococcal SP0148 and pneumolysin (Ply) derivatives are important vaccine candidates. SP0148 is a conserved lipoprotein with high immunogenicity produced by Streptococcus pneumoniae. We have previously demonstrated that SP0148 can confer protection against fatal infections caused by S. pneumoniae. ΔA146Ply is a noncytotoxic mutant of Ply that retains the TLR4 agonistic effect and has mucosal and subcutaneous adjuvant activities suggested to induce protective immunity against S. pneumoniae infection. In this study, we constructed the fusion protein ΔA146Ply-SP0148, composed of ΔA146Ply and SP0148, and evaluated the immunoprotective effect of the fusion protein. When mice were subcutaneously immunized with the fusion protein ΔA146Ply-SP0148, high levels of anti-ΔA146Ply and anti-SP0148 IgG antibodies were induced in the serum. Specific antibodies can bind to a variety of different serotypes of S. pneumoniae. Compared with mice immunized with ΔA146Ply and SP0148 alone, mice immunized subcutaneously with the fusion protein ΔA146Ply-SP0148 with Al(OH)3 had a higher survival rate when challenged by a lethal dose of S. pneumoniae, and they also had significantly lower lung bacterial loads and milder lung inflammation. In addition, mice immunized subcutaneously with the fusion protein ΔA146Ply-SP0148 stimulated strong Th1, Th2, and Th17 cell responses. In summary, these results suggest that subcutaneous immunization with the ΔA146Ply-SP0148 fusion protein can protect mice against fatal pneumococcal infection and lung infection. The fusion protein ΔA146ply-SP0148 can be a new pneumococcal vaccine target.
Assuntos
Anticorpos Antibacterianos , Infecções Pneumocócicas , Animais , Proteínas de Bactérias/genética , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas , Streptococcus pneumoniae/genéticaRESUMO
Toxoplasma gondii is an intracellular apicomplexan parasite, which can cause a serious infectious disease in pregnant women and immunocompromised individuals. Therefore, the development of a polyvalent vaccine consisting of all stages of the parasite life cycle using the epitopes from tachyzoites, bradyzoites, and sporozoites is likely to be required for complete protective immunity. In this study, we designed protein vaccine candidate based on the prediction of specific epitopes (i.e., B cell and T cell) from three Toxoplasma gondii antigens. The MRS protein (MIC3: 30-180, ROP8: 85-185, and SAG1: 85-235) was expressed in Escherichia coli, and purification was performed using a HisTrap HP column and then we evaluated immunogenicity and protective property in BALB/c mice. Seventy-two mice were randomly divided into six groups, including three vaccinations (i.e., MRS, MRS-Freund, and MRS-Calcium Phosphate Nanoparticles (MRS-CaPNs)) and three control (i.e., Phosphate-buffered saline, Freund, and CaPNs) groups. All groups were immunized three times via subcutaneous injection within three-week intervals. In the vaccination groups, the BALB/c mice were injected with 20 µg of MRS protein for the first time and 10 µg of MRS for the next two times. Antibodies, cytokines, and splenocytes proliferation in the immunized mice were assayed using the enzyme-linked immunosorbent assay. Protective efficacy was analyzed by challenging the immunized mice with T. gondii of RH strain. Antibody, cytokine, and lymphocyte proliferation assays showed that the mice immunized with MRS induced stronger humoral and T helper type 1 cell-mediated immune responses, compared to the control mice. However, co-immunization with adjuvants (i.e., Freund and CaNPs) resulted in impaired immune responses. Effective protection against the parasite achieved an increase in survival time in the immunized mice, especially in the MRS-CaNPs group. The obtained results of the present study demonstrated that multi-epitope protein vaccination, MRS, is a potential strategy against toxoplasmosis infection. In addition, the vaccine co-delivered with CaPNs could provide an important key for vaccine candidate to control T. gondii infection.
Assuntos
Vacinas Protozoárias , Toxoplasma , Toxoplasmose , Vacinas de DNA , Animais , Anticorpos Antiprotozoários , Antígenos de Protozoários , Citocinas , Epitopos , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Gravidez , Proteínas de Protozoários/genética , Toxoplasmose/prevenção & controleRESUMO
Nocardia seriolae is an important pathogenic bacterium that causes nocardiosis in various fish species and leads to economic losses in the fish industry. To develop an effective subunit vaccine against nocardial infection, the truncated resuscitation-promoting factor (tRPF) of N. seriolae was selected and recombinantly produced using the Escherichia coli expression system. Western blotting results indicated that the recombinant protein could be strongly recognised by largemouth bass anti-N. seriolae antibodies. The protective efficacy of tRPF recombinant protein was assessed in combination with the commercial adjuvant Montanide™ ISA 763 A VG. The results showed that emulsified tRPF + ISA significantly induced high serum antibody response and serum lysozyme activity in the vaccinated fish. Quantitative reverse transcription polymerase chain reaction analysis indicated that tRPF + ISA could notably enhance the expression of immune-related genes in both the head kidney and spleen of the vaccinated fish. Finally, vaccinated largemouth bass displayed higher immuno-protection with a relative percent survival of 69.23% compared to the control groups. Taken together, the combination of tRPF + ISA is an ideal vaccine candidate against N. seriolae infection.
Assuntos
Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Bass , Doenças dos Peixes/prevenção & controle , Imunogenicidade da Vacina , Nocardiose/veterinária , Nocardia/imunologia , Animais , Doenças dos Peixes/imunologia , Imunidade , Nocardiose/imunologia , Nocardiose/prevenção & controle , Proteínas Recombinantes/imunologia , Vacinas de Subunidades Antigênicas/imunologiaRESUMO
BACKGROUND: Toxoplasma gondii is an obligate intracellular parasite that can infect almost all warm-blooded animals, avian species and humans. Toxoplasmosis is asymptomatic in healthy individuals, whereas it may lead to death in immune suppressed or deficient patients. A vaccine against T. gondii is required to prevent consequences of the infection. The aim of this study is to generate a multivalent recombinant protein vaccine against T. gondii. METHODS: 49 previously discovered antigenic proteins of T gondii were evaluated by their expression level in E. coli and by comprehensive bioinformatics analyses to determine antigenic epitopes. Based on these analyses, six vaccine candidate proteins were selected to generate a hexavalent recombinant protein vaccine adjuvanted with Montanide ISA 50 V. Humoral and cellular immune responses were determined by flow cytometry and ELISA. Vaccinated mice were challenged with T. gondii Ankara strain tachyzoites. RESULTS: In mice vaccinated with hexavalent vaccine, strong total IgG (P < 0.0001) and IgG2a (P < 0.001) responses were induced compared to controls, the ratio of CD4+ and CD8+ T lymphocytes secreting IFN-γ increased, and significantly higher extracellular IFN-γ secretion was achieved compared to the controls (P < 0.001). The survival time of the vaccinated mice increased to 8.38 ± 2.13 days which was significantly higher than controls (P < 0.01). CONCLUSIONS: Altogether, these results show that the hexavalent vaccine which is developed for the first time against T. gondii induced strong and balanced Th1 and Th2 immune responses as well as conferred significant protection against challenge with lethal toxoplasmosis in murine model.
Assuntos
Adjuvantes Imunológicos/farmacologia , Manitol/análogos & derivados , Vacinas Protozoárias/farmacologia , Toxoplasmose/prevenção & controle , Vacinas de DNA/farmacologia , Animais , Ensaio de Imunoadsorção Enzimática , Epitopos/genética , Epitopos/imunologia , Escherichia coli/genética , Feminino , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Imunoglobulina G/sangue , Manitol/farmacologia , Camundongos , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Vacinas Protozoárias/genética , Vacinas Protozoárias/imunologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Toxoplasma/patogenicidade , Toxoplasmose/imunologia , Vacinas de DNA/imunologiaRESUMO
As the COVID-19 pandemic is intensifying globally, more and more people are pinning their hopes on the development of vaccines. At present, there are many research teams who have adopted different vaccine technology routes to develop 2019-nCoV vaccines. This article reviews and analyzes the current development and research status of 2019-nCoV vaccines in different routes, and explores their possible development in the future.
Assuntos
Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinas Virais/uso terapêutico , Betacoronavirus , COVID-19 , Vacinas contra COVID-19 , Humanos , SARS-CoV-2RESUMO
BACKGROUND: Active immunotherapy targeting amyloid-ß (Aß) is a promising treatment for Alzheimer's disease (AD). Numerous preclinical studies and clinical trials demonstrated that a safe and effective AD vaccine should induce high titers of anti-Aß antibodies while avoiding the activation of T cells specific to Aß. RESULTS: An untagged Aß1-6 chimeric protein vaccine against AD based on norovirus (NoV) P particle was expressed in Escherichia coli and obtained by sequential chromatography. Analysis of protein characteristics showed that the untagged Aß1-6 chimeric protein expressed in soluble form exhibited the highest particle homogeneity, with highest purity and minimal host cell protein (HCP) and residual DNA content. Importantly, the untagged Aß1-6 chimeric soluble protein could induce the strongest Aß-specific humoral immune responses without activation of harmful Aß-specific T cells in mice. CONCLUSIONS: The untagged Aß1-6 chimeric protein vaccine is safe and highly immunogenic. Further research will determine the efficacy in cognitive improvement and disease progression delay.
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Vacinas contra Alzheimer/imunologia , Peptídeos beta-Amiloides/imunologia , Anticorpos/imunologia , Vetores Genéticos , Norovirus , Proteínas Recombinantes de Fusão , Doença de Alzheimer/terapia , Vacinas contra Alzheimer/administração & dosagem , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/isolamento & purificação , Animais , Especificidade de Anticorpos/imunologia , Modelos Animais de Doenças , Imunização , Camundongos , Norovirus/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismoRESUMO
Toxoplasma gondii, the etiological agent of toxoplasmosis, can cause severe or lethal damages in both animals and man. So, tends to develop a more effective vaccine to prevent this disease is extremely needed and would be so prominent. The novel dense granule antigen 14 (GRA14) has been identified as a potential vaccine candidate against T. gondii infection. The aim of this study was evaluation of protective immunity induced by prime/boost vaccination strategy of GRA14 antigen with calcium phosphate (CaPNs) or Aluminum hydroxide (Alum) nano-adjuvants in BALB/c mice. The finding showed that immunization with the prime-boost strategy using plasmid DNA (pcGRA14) and recombinant protein (rGRA14) with nano-adjuvants significantly elicited levels of specific IgG antibodies and cytokines against T. gondii infection. Given that, there were the high levels of total IgG, IgG2a, IFN-γ in mice of rGRA14-CaPNs and pcGRA14 + rGRA14-CaPNs groups, which indicating a Th-1 type response. While immunization of mice with Alum based rGRA14 and pcGRA14 + rGRA14 elicited specific IgG1 and IL-4 levels, which was confirmed a Th-2 type response. Mice immunized with DNA prime-protein boost vaccine with nano-adjuvants produce more vigorous specific lymphoproliferative responses than mice immunized with other antigen formulations. In addition, the CaPNs-based prime-boost vaccine of pcGRA14 + rGRA14 showed the longest survival time in mice and the lowest parasitic load in their brain tissue compared to the other groups. The results obtained in this study show that the use of GRA14 based DNA prime-protein boost vaccination regime with CaPNs can dramatically enhanced both humoral and cellular immune responses. Therefore, this strategy can provide a promising approach to the development of an effective vaccine against T. gondii infection in the future.
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Antígenos de Protozoários/imunologia , Imunização Secundária/métodos , Proteínas de Protozoários/imunologia , Vacinas Protozoárias/imunologia , Proteínas Recombinantes/imunologia , Toxoplasma/imunologia , Toxoplasmose Animal/prevenção & controle , Vacinação , Adjuvantes Imunológicos , Hidróxido de Alumínio , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/genética , Fosfatos de Cálcio , Citocinas/sangue , Modelos Animais de Doenças , Feminino , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Imunoglobulina G/sangue , Interferon gama/sangue , Interleucina-4/sangue , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Carga Parasitária , Proteínas de Protozoários/genética , Vacinas Protozoárias/genética , Toxoplasma/genética , Toxoplasmose Animal/imunologia , Vacinas de DNA/imunologiaRESUMO
BACKGROUND: Oral vaccine is highly desired for infectious disease which is caused by pathogens infection through the mucosal surface. The design of suitable vaccine delivery system is ongoing for the antigen protection from the harsh gastric environment and target to the Peyer's patches to induce sufficient mucosal immune responses. Among various potential delivery systems, bacterial inclusion bodies have been widely used as delivery systems in the field of nanobiomedicine. However, a large number of heterologous complex proteins could be difficult to propagate in E. coli and fusion partners are often used to enhance target protein expression. As a safety concern the fusion protein need to be removed from the target protein to get tag-free protein, especially for the production of protein antigen in vaccinology. Until now, there is no report on how to remove fusion tag from inclusion body particles in vitro and in vivo. Coxsackievirus B3 (CVB3) is a leading causative agent of viral myocarditis and orally protein vaccine is high desired for CVB3-induced myocarditis. In this context, we explored a tag-free VP1 inclusion body nanoparticles production protocol though a truncated Ssp DnaX mini-intein spontaneous C-cleavage in vivo and also exploited the VP1 inclusion bodies as an oral protein nanoparticle vaccine to protect mice against CVB3-induced myocarditis. RESULTS: We successfully produced the tag-free VP1 inclusion body nanoparticle antigen of CVB3 and orally administrated to mice. The results showed that the tag-free VP1 inclusion body nanoparticles as an effective antigen delivery system targeting to the Peyer's patches had the capacity to induce mucosal immunity as well as to efficiently protect mice from CVB3 induce myocarditis without any adjuvant. Then, we proposed the use of VP1 inclusion body nanoparticles as good candidate for oral vaccine to against CVB3-induced myocarditis. CONCLUSIONS: Our tag-free inclusion body nanoparticles production procedure is easy and low cost and may have universal applicability to produce a variety of tag-free inclusion body nanoparticles for oral vaccine.