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1.
Immunol Res ; 67(4-5): 398-407, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31773490

RESUMO

Limited protective effects of commercially available vaccines necessitate the development of novel pneumococcal vaccines. We recently reported a pneumococcal systemic vaccine containing two proteins, Pneumococcal surface protein A (PspA of family 1 and 2) and a bacterium-like particle-based pneumococcal mucosal vaccine containing PspA2 and PspA4 fragments, both eliciting broad protective immune responses. We had previously reported that subcutaneous (s.c.+s.c.+s.c.) immunization with the systemic vaccine induced more pronounced humoral serum IgG responses, while intranasal (i.n.+i.n.+i.n.) immunization with the mucosal vaccine elicited a more pronounced mucosal secretory IgA (sIgA) response. We hypothesized that a combinatorial administration of the two vaccines might elicit more pronounced and broader protective immune responses. Therefore, this study aimed to determine the efficacy of combinatorial prime-boost immunization using both systemic and mucosal vaccines for a pneumococcal infection. Combinatorial prime-boost immunization (s.c.+i.n. and i.n.+s.c.) induced not only IgG, but also mucosal sIgA production at high levels. Systemic priming and mucosal boosting immunization (s.c.+i.n.) provided markedly better protection than homologous prime-boost immunization (s.c.+s.c.+s.c. and i.n.+i.n.+i.n.). Moreover, it induced more robust Th1 and Th17 cell-mediated immune responses than mucosal priming and systemic boosting immunization (i.n.+s.c.). These results indicate that combinatorial prime-boost immunization potentially induces a robust systemic and mucosal immune response, making it an optimal alternative for maximum protection against lethal pneumococcal infections.

2.
Med Microbiol Immunol ; 208(2): 215-226, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30707297

RESUMO

Streptococcuspneumoniae, or pneumococcus, is a major respiratory-tract pathogen that causes high levels of mortality and morbidity in infants and elderly individuals. Despite the development of various capsular polysaccharide vaccines to prevent pneumococcal disease, it remains epidemic. Pneumococcal surface protein A (PspA) is a highly immunogenic surface protein existing in all strains of S. pneumoniae, and it can elicit immunizing protection against pneumococcal infection. In our previous studies, a fusion protein (PsaA-PspA23), consisting of PspA and pneumococcal surface antigen A (PsaA), displayed greater immunogenicity and provided better protection in mice against S. pneumoniae strains than either PsaA or PspA. In this study, the fusion protein PsaA-PspA23, together with PspA4, was formulated with four adjuvants Al(OH)3, MF59, AS03, and AS02, and subsequently subjected to dose optimization and immunological evaluation for determination of the antibody titers, bacterial burden, survival rates, and levels of cytokines in mice. All vaccines with high adjuvant doses displayed higher antigen-specific immunoglobulin G (IgG) titers. Bacterial burdens were notably decreased to different extents in the lungs and blood of mice immunized with the antigen and various adjuvants. Among these adjuvants, AS02 provided outstanding protection against challenge with pathogenic bacteria from different families and clades; it also induced high titers of IgG1 and IgG2a. Moreover, only AS02 elicited high levels of cytokines, such as TNF-α, IFN-γ, IL-2, and IL-4. These results suggest that PsaA-PspA23 and PspA4 formulated with AS02 may potentially be used as a subunit vaccine against deadly pneumococcal infection.


Assuntos
Adesinas Bacterianas/imunologia , Adjuvantes Imunológicos/administração & dosagem , Proteínas de Bactérias/imunologia , Lipoproteínas/imunologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/imunologia , Adesinas Bacterianas/genética , Animais , Anticorpos Antibacterianos/sangue , Carga Bacteriana , Proteínas de Bactérias/genética , Citocinas/análise , Modelos Animais de Doenças , Feminino , Lipoproteínas/genética , Camundongos Endogâmicos BALB C , Vacinas Pneumocócicas/administração & dosagem , Vacinas Pneumocócicas/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Análise de Sobrevida , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
3.
Hum Vaccin Immunother ; 15(2): 371-380, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30235046

RESUMO

Streptococcus pneumoniae is an infectious pathogen mainly infecting host bodies through the respiratory system. An effective pneumococcal vaccine would be targeted to the mucosa and provide not only protection against invasive infection but also against colonization in the respiratory system. In the present work, we applied bacterium-like particles (BLPs) as an adjuvant for the development of a PspA mucosal vaccine, in which the PspA protein was displayed on the surface of BLPs. Intranasal immunization with the PspA-BLP pneumococcal vaccine, comprised of PspA2 from pneumococcal family 1 and PspA4 from pneumococcal family 2, not only induced a high level of serum IgG antibodies but also a high level of mucosal SIgA antibodies. Analysis of binding of serum antibodies to intact bacteria showed a broad coverage of binding to pneumococcal strains expressing PspA from clade 1 to 5. Immunization with the PspA-BLP vaccine conferred protection against fatal intranasal challenge with both PspA family 1 and family 2 pneumococcal strains regardless of serotype. Therefore, the PspA-BLP pneumococcal vaccine was demonstrated to be a promising strategy for mucosal immunization to enhance both systemic and mucosal immune responses.

4.
Immunol Res ; 66(4): 528-536, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30128745

RESUMO

Streptococcus pneumoniae is an important pathogen accounting for a large number of deaths worldwide. Despite the multitude of capsular polysaccharide vaccines used to guard against pneumococcal disease, fatal pneumococcal disease remains epidemic due to the narrow range of protection afforded by the capsular polysaccharide vaccines and rate of change in serotypes. The most promising solution is to develop an improved protein-based vaccine with broad protection. In this study, we tested a bivalent vaccine containing antigens mixed with the fusion protein PsaA-pneumococcal surface protein A (PspA)23 and single protein PspA4, including conserved PsaA and PspA from clades 2, 3, and 4 with coverage for families 1 and 2. The vaccine induced a significant increase of anti-PspA IgG, which demonstrated cross-reactivity with the 22 different S. pneumoniae strains from serotypes contained in PPV23 by Western blot. The wide ranging protection was determined by challenging mice with S. pneumoniae from PspA clades 1 to 5. Bacterial loads in the blood and lung and survival rate after challenge were measured. After immunization, the number of bacteria in mice was significantly reduced. The clearance rates with all strains were greater than 90% in the lung, and bacterial loads in the blood were decreased to lower than 10 CFU/ml. The survival rates in immunized animals also were greatly increased (all over 50%) compared with controls. Therefore, this bivalent PspA vaccine may be a good substitute for capsular polysaccharide vaccines.


Assuntos
Adesinas Bacterianas/imunologia , Proteínas de Bactérias/imunologia , Lipoproteínas/imunologia , Pulmão/imunologia , Infecções Pneumocócicas/imunologia , Vacinas Pneumocócicas/imunologia , Streptococcus pneumoniae/fisiologia , Animais , Anticorpos Antibacterianos/sangue , Carga Bacteriana , Reações Cruzadas , Feminino , Humanos , Imunoglobulina G/sangue , Pulmão/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Sorogrupo , Vacinação
5.
Microb Pathog ; 123: 115-119, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29959043

RESUMO

Streptococcus pneumoniae is a major respiratory tract pathogen causing high levels of mortality and morbidity in infants and the elderly. In spite of the multitude of capsular polysaccharide vaccines used to guard against pneumococcal disease, fatal pneumococcal disease remains epidemic. Immunization with pneumococcal surface protein A (PspA), a highly immunogenic surface protein present in all strains of S. pneumoniae, can elicit protection against deadly pneumococcal infection. We have previously evaluated PspA in systemic vaccination. However, the mucosal immune system, as a first line of defense against respiratory infection, plays the most important role against the invasion of S. pneumoniae. In this study, we employed bacterium-like particles (BLPs) as an adjuvant for a PspA mucosal vaccine. The BLPs served as a carrier for PspA proteins bound to their surface. Mice were immunized intranasally with the PspA-BLP pneumococcal vaccine consisting of PspA3 from pneumococcal family 2. Not only did the immunized mice show a high level of serum IgG antibodies but also a high level of SIgA antibodies in the respiratory tract. After immunization with the PspA3-BLP vaccine, the mice were broadly protected against fatal intranasal challenge with homologous and heterogenous pneumococcal strains of different PspA families regardless of serotype, and the colony count was notably decreased in the lungs. Therefore, the PspA3-BLP pneumococcal vaccine has the potential to serve as a novel mucosal vaccine to enhance both systemic and mucosal immune responses to this disease.


Assuntos
Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/imunologia , Vacinas Pneumocócicas/imunologia , Pneumonia Pneumocócica/imunologia , Pneumonia Pneumocócica/prevenção & controle , Streptococcus pneumoniae/imunologia , Adjuvantes Imunológicos/administração & dosagem , Administração Intranasal , Animais , Carga Bacteriana/imunologia , Proteínas de Bactérias/administração & dosagem , Proteção Cruzada/imunologia , Imunização/métodos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Camundongos , Camundongos Endogâmicos BALB C , Vacinas Pneumocócicas/administração & dosagem , Pneumonia Pneumocócica/microbiologia , Sistema Respiratório/imunologia
6.
Protein Expr Purif ; 151: 56-61, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29908315

RESUMO

Streptococcus pneumoniae is a major pathogen that causes life-threatening diseases, such as pneumonia, otitis media, bacteremia, and meningitis, worldwide and especially in young children and the elderly. Pneumococcal surface protein A (PspA) is a widely studied candidate protein vaccine that represents a promising replacement for current polysaccharide and polysaccharide-conjugate vaccines. In this study, we describe a simple method to produce PspA of clade 4 from an Escherichia coli expression system using hydroxylapatite and ion-exchange chromatography. Using this method, we successfully expressed soluble PspA4 in 10 L of autoinducing culture medium, with a wet-cell yield of 19 g/L and a final PspA4 concentration of 22.8 mg/L. Additionally, we improved PspA4 purity from 17% to 70% in a single step through the use of hydroxylapatite, resulting in acquisition of recombinant PspA4 (>95% purity) at a final yield of 43% from the starting cell-lysis solution. We subsequently verified the secondary structure molecular weight of recombinant PspA4 by circular dichroism and mass spectrometry, respectively. These results demonstrated a highly efficient method for mass producing PspA4 protein and that can also be applied for purification of PspA proteins from other clades.


Assuntos
Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/isolamento & purificação , Durapatita/química , Escherichia coli/metabolismo , Cromatografia por Troca Iônica , Escherichia coli/genética , Fermentação , Expressão Gênica , Estrutura Secundária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação
7.
Infect Immun ; 86(6)2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29610257

RESUMO

Streptococcus pneumoniae is a major cause of invasive pneumococcal disease, septicemia, and meningitis that can result in high morbidity rates in children under 5 years old. The current polysaccharide-based vaccines can provide type-specific immunity, but a broad-spectrum vaccine would provide greater coverage. Therefore, developing pneumococcal-protein-based vaccines that can extend to more serum types is highly important. In this study, we vaccinated mice via the subcutaneous (s.c.) route with a systemic vaccine that is a mixture of fusion protein PsaA-PspA23 and a single protein, PspA4, with aluminum hydroxide as an adjuvant. As a comparison, mice were immunized intranasally with a mucosal vaccine that is a mixture of PspA2-PA-BLP (where PA is protein anchor and BLP is bacterium-like particle) and PspA4-PA-BLP, via the intranasal (i.n.) route. The two immunization processes were followed by challenge with Streptococcus pneumoniae bacteria from two different PspA families. Specific IgG titers in the serum and specific IgA titers in the mucosa were determined following immunizations. Bacterial loads and survival rates after challenge were compared. Both the systemic vaccine and the mucosal vaccine induced a significant increase of IgG against PspAs. Only the mucosal vaccine also induced specific IgA in the mucosa. The two vaccines provided protection, but each vaccine showed an advantage. The systemic vaccine induced higher levels of serum antibodies, whereas the mucosal vaccine limited the bacterial load in the lung and blood. Therefore, coimmunizations with the two types of vaccines may be implemented in the future.


Assuntos
Proteínas de Bactérias/imunologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/imunologia , Streptococcus pneumoniae/imunologia , Streptococcus pneumoniae/metabolismo , Animais , Anticorpos Antibacterianos/sangue , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Vacinas Pneumocócicas/administração & dosagem , Proteínas Recombinantes
8.
Immunol Invest ; 47(4): 403-415, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29498560

RESUMO

BACKGROUND: Streptococcus pneumoniae is a major pathogen accounting for a large number of pneumococcal disease in worldwide. Due to the mucosal immune pathway induces both systemic and mucosal immune responses, the potential strategy to prevent pneumococcal disease may be to develop a mucosal vaccine. METHOD: In this study, we developed an intranasal pneumococcal protein vaccine based on a bacterium-like particle (BLP) delivery system. PspA is expressed and exposed on the surface of all pneumococcal strains, which confers the potential to induce immune responses to protect against pneumococcal infection. We fused one of the pneumococcal surface proteins (PspA, family2 clade4) with the protein anchor (PA) protein in order to display PspA on the surface of BLPs. RESULT: The current results showed that intranasal immunization with BLPs/PspA-PA efficiently induced both PspA-specific IgG in the serum and PspA-specific IgA in mucosal washes. And intranasal immunization of BLPs/PspA-PA could provide complete protection in a mouse challenge model with pneumococci of different two clades of both homologous and heterologous PspA families. DISCUSSION AND CONCLUSION: Thus, targeted delivery of multiple bacterial antigens via BLPs may prevent pneumococcal disease by inducing both systemic and mucosal immune responses.


Assuntos
Proteínas de Bactérias/imunologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/imunologia , Pneumonia Pneumocócica/imunologia , Administração Intranasal , Animais , Anticorpos Antibacterianos/imunologia , Especificidade de Anticorpos , Proteínas de Bactérias/genética , Modelos Animais de Doenças , Imunidade nas Mucosas , Imunização , Camundongos , Vacinas Pneumocócicas/administração & dosagem , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
9.
Vaccine ; 34(48): 5953-5958, 2016 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-27997342

RESUMO

We evaluated the safety and efficacy of a live attenuated influenza vaccine (LAIV) product in ferrets. The BCHT LAIV product was significantly less virulent than wild-type H1N1 virus, when evaluated by comparing virus shedding and histopathologic lesions. The data indicated strong evidence for an attenuated phenotype of LAIV. Furthermore, the vaccine induced robust humoral immune responses in seronegative ferrets, and protected ferrets against development of fever, weight loss and turbinate inflammatory lesions after challenging with H3N2 wide-type influenza virus. Thus, the BCHT LAIV product was safe in healthy seronegative ferrets and protected ferrets against infection of H3N2 influenza virus.


Assuntos
Vírus da Influenza A Subtipo H3N2/imunologia , Vacinas contra Influenza/efeitos adversos , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Animais , Anticorpos Antivirais/sangue , China , Furões , Humanos , Imunidade Humoral , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/patogenicidade , Vírus da Influenza A Subtipo H3N2/fisiologia , Vírus da Influenza B/imunologia , Vírus da Influenza B/isolamento & purificação , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Masculino , Infecções por Orthomyxoviridae/imunologia , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/imunologia , Eliminação de Partículas Virais
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