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1.
Nanomedicine ; 13(8): 2463-2474, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28887213

RESUMO

Despite the broad knowledge about the pathogenicity of Streptococcus pyogenes there is still a controversy about the correlate of protection in GAS infections. We aimed in further improving the immune responses stimulated against GAS comparing different vaccine formulations including bis-(3',5')-cyclic dimeric adenosine monophosphate (c-di-AMP) and BPPCysMPEG, a derivative of the macrophage-activating lipopeptide (MALP-2), as adjuvants, respectively, to be administered with and without the universal T helper cell epitope P25 along with the optimized B cell epitope J14 of the M protein and B and T cell epitopes of SfbI. Lipopeptide based nano carrier systems (LCP) were used for efficient antigen delivery across the mucosal barrier. The stimulated immune responses were efficient in protecting mice against a respiratory challenge with a lethal dose of a heterologous S. pyogenes strain. Moreover, combination of the LCP based peptide vaccine with c-di-AMP allowed reduction of antigen dose at the same time maintaining vaccine efficacy.


Assuntos
Adjuvantes Imunológicos/uso terapêutico , Infecções Estreptocócicas/prevenção & controle , Vacinas Estreptocócicas/uso terapêutico , Streptococcus pyogenes/imunologia , Vacinas de Subunidades Antigênicas/uso terapêutico , Adjuvantes Imunológicos/administração & dosagem , Administração Intranasal , Animais , Formação de Anticorpos , Fosfatos de Dinucleosídeos/administração & dosagem , Fosfatos de Dinucleosídeos/uso terapêutico , Epitopos/administração & dosagem , Epitopos/uso terapêutico , Feminino , Lipopeptídeos/administração & dosagem , Lipopeptídeos/uso terapêutico , Camundongos Endogâmicos BALB C , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/uso terapêutico , Infecções Estreptocócicas/imunologia , Vacinas Estreptocócicas/administração & dosagem , Vacinas de Subunidades Antigênicas/administração & dosagem
2.
Hum Vaccin ; 7 Suppl: 85-93, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21245658

RESUMO

Considerable success has been made with many peptide antigen formulations and it appears that peptide-based vaccines are emerging as the next generation of prophylactic and remedial immunotherapy. However, peptides are typically poorly immunogenic and rely on delivery with potent immunostimulatory adjuvants that activate the innate and adaptive arms of the immune system. Our research aims to develop novel peptide antigen delivery systems that incorporate multiple pattern-recognition receptor (PRR) agonists and is focused on those designed to stimulate Toll-like receptors (TLRs) on dendritic cells (DCs). The cytokine (IL-4, IL-6, IL-10, IL-12 and IL-23) profiles of DCs induced by individual TLR agonists have been evaluated. From this data we predicted which TLR agonists may influence a particular T helper cell (Th) response. Using purified DCs that were derived from precursor cells in murine bone marrow and then stimulated simultaneously with multiple TLR agonists, we have shown synergy between various TLR agonist pairs leading to enhanced cytokine production. Using various mitogen-activated protein kinase (MAPK) inhibitors (c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38 MAPK) we have demonstrated the importance of p38 MAPK and ERK signaling pathways in IL-12p70 and IL-12p40 production in DCs induced by TLR stimulation, whereas the JNK pathway appeared to have a negative regulatory role on cytokine production in DCs stimulated with certain TLR agonists. An important role for nuclear factor-kappa B and phosphoinositol-3-kinase as positive regulators of TLR signaling in DCs leading to cytokine production was also demonstrated. The significance of this research lies not only in improving potency, but by understanding the immunological mechanisms of adjuvanticity, in being able to tailor peptide vaccines to generate specific types of Th responses required for immunity against various types of pathogens.


Assuntos
Adjuvantes Imunológicos/metabolismo , Células Dendríticas/imunologia , Imunomodulação , Receptores Toll-Like/agonistas , Receptores Toll-Like/metabolismo , Vacinas de Subunidades Antigênicas/imunologia , Animais , Citocinas/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Transdução de Sinais
3.
J Infect Dis ; 202(2): 318-29, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20524851

RESUMO

BACKGROUND: Triggering Toll-like receptors (TLRs) on dendritic cells (DCs) induces inflammatory cytokine production necessary for T helper type 1 immunity. The present study investigated whether simultaneous stimulation of two TLRs that signal through the same or different pathway(s) enhances cytokine production in DCs. METHODS: Fms-like tyrosine kinase-3 ligand-generated murine DCs were used in stimulation assays with TLR agonists with or without pharmacological inhibitors of cell signaling pathways. Cytokine levels were evaluated by enzyme-linked immunosorbent assay or cytometric bead array. RESULTS: There was synergistic enhancement of interleukin (IL)-6 and IL-12, which were significantly inhibited by inhibitors of nuclear factor-kappaB and phosphatidylinositol 3-kinase. IL-12p40 was significantly inhibited by both p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase inhibitors, whereas IL-12p70 was inhibited by p38 MAPK inhibitor alone. IL-6 was significantly inhibited by extracellular signal-regulated kinase and, variably, by p38 MAPK and c-Jun N-terminal kinase inhibitors. CONCLUSIONS: Production of cytokines in DCs after simultaneous stimulation of TLRs that signal through the same or different pathway(s) showed differential use of MAPK signaling pathways, yet both nuclear factor-kappaB and the phosphatidylinositol 3-kinase pathway as a positive regulator of TLR signaling were important. Our data suggest an important role for MyD88-dependent signaling pathways in TLR-mediated synergistic enhancement of inflammatory cytokine production in DCs.


Assuntos
Células da Medula Óssea/citologia , Células da Medula Óssea/fisiologia , Citocinas/genética , Células Dendríticas/fisiologia , Fator 88 de Diferenciação Mieloide/fisiologia , Receptores Toll-Like/fisiologia , Animais , Células da Medula Óssea/efeitos dos fármacos , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Ativação Enzimática , Ensaio de Imunoadsorção Enzimática , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Citometria de Fluxo , Interleucina-12/genética , Interleucina-6/genética , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Recombinantes/farmacologia , Receptor 3 Toll-Like/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
4.
Infect Immun ; 77(5): 2177-83, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19273562

RESUMO

The etiology of rheumatic fever and rheumatic heart disease (RF/RHD) is believed to be autoimmune, involving immune responses initiated between streptococcal and host tissue proteins through a molecular mimicry mechanism(s). We sought to investigate the humoral and cellular responses elicited in a Lewis rat model of group A streptococcus M-protein- or peptide-induced experimental valvulitis/carditis, a recently developed animal model which may, in part, represent human rheumatic carditis. Recombinant streptococcal M5 protein elicited opsonic antibodies in Lewis rats, and anti-M5 antisera recognized epitopes within the B- and C-repeat regions of M5. One peptide from the streptococcal M5 protein B-repeat region (M5-B.6, amino acids 161 to 180) induced lymphocytes that responded to both recombinant M5 and cardiac myosin. Rats immunized with streptococcal M5 protein developed valvular lesions, distinguished by infiltration of CD3(+), CD4(+), and CD68(+) cells into valve tissue, consistent with human studies that suggest that RF/RHD are mediated by inflammatory CD4(+) T cells and CD68(+) macrophages. The current study provides additional information that supports the use of the rat autoimmune valvulitis model for investigating RF/RHD.


Assuntos
Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Linfócitos B/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Transporte/imunologia , Endocardite/induzido quimicamente , Endocardite/imunologia , Streptococcus pyogenes/química , Linfócitos T/imunologia , Animais , Antígenos de Bactérias/isolamento & purificação , Proteínas da Membrana Bacteriana Externa/isolamento & purificação , Proteínas de Transporte/isolamento & purificação , Feminino , Valvas Cardíacas/patologia , Humanos , Macrófagos/imunologia , Miocárdio/patologia , Miosinas/imunologia , Ratos , Subpopulações de Linfócitos T/química , Subpopulações de Linfócitos T/imunologia , Linfócitos T/química
5.
J Med Chem ; 51(5): 1447-52, 2008 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-18278857

RESUMO

Group A streptococcus (GAS) is associated with many human diseases, ranging in severity from benign to life-threatening. A promising strategy for developing vaccines against GAS involves the use of carbohydrates as carriers for peptide antigens. This study describes the optimized synthesis of d-glucose and d-galactose derived carriers, bearing an adipate linker and four tert-butoxycarbonyl protected aminopropyl groups. Prophylactic GAS vaccine candidates were synthesized by conjugating multiple copies of a single GAS M protein derived peptide antigen (either J8 or J14) onto the carbohydrate carriers. These antigens contain peptide sequences, which are highly conserved and offer the potential to prevent infections caused by up to 70% of GAS strains. Lipophilic amino acids were also conjugated to the d-glucose anomeric carbon to produce a self-adjuvanting liposaccharide vaccine. High serum IgG antibody titers against each of the incorporated peptide epitopes were detected following subcutaneous immunization of B10.BR (H-2 (k)) mice with the liposaccharide vaccine candidates.


Assuntos
Antígenos de Bactérias/química , Proteínas da Membrana Bacteriana Externa/química , Proteínas de Transporte/química , Galactose/química , Glucose/química , Ácidos Láuricos/química , Vacinas Estreptocócicas/síntese química , Streptococcus pyogenes/imunologia , Animais , Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Bactérias/química , Proteínas de Bactérias/imunologia , Proteínas de Transporte/imunologia , Portadores de Fármacos , Ensaio de Imunoadsorção Enzimática , Epitopos , Feminino , Glicopeptídeos/química , Glicopeptídeos/imunologia , Imunoglobulina G/biossíntese , Camundongos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Vacinas Estreptocócicas/administração & dosagem , Vacinas Estreptocócicas/química , Vacinas Estreptocócicas/imunologia , Vacinas de Subunidades Antigênicas
6.
J Med Chem ; 50(19): 4721-7, 2007 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-17705361

RESUMO

Four lipid-core peptide systems were synthesized using stepwise solid-phase peptide synthesis, incorporating a sequence from the human papillomavirus type-16 (HPV-16) E7 protein (E744-62), for the purpose of developing vaccines against HPV-16 associated cervical cancer. d-Mannose was conjugated to the vaccine in order to investigate whether the targeting of dendritic cell mannose receptors would improve vaccine efficacy. The ability of the vaccines to clear or reduce the size of HPV-16 associated tumors was assessed in C57BL/6 (H-2b) mice using the TC-1 HPV-16 tumor model. Overall, significant reductions in the size of TC-1 tumors were observed in the mouse model, with the conjugation of mannose to these vaccines demonstrated to clear or reduce the size of TC-1 tumors to a greater extent than non-mannose-containing vaccines (37 out of 40 versus 21 out of 30 tumors cleared, respectively).


Assuntos
Vacinas Anticâncer/síntese química , Papillomavirus Humano 16/imunologia , Lipoproteínas/síntese química , Vacinas contra Papillomavirus/síntese química , Peptídeos/síntese química , Animais , Vacinas Anticâncer/imunologia , Vacinas Anticâncer/uso terapêutico , Células Dendríticas/metabolismo , Epitopos , Feminino , Glucose/química , Lectinas Tipo C/metabolismo , Lipoproteínas/imunologia , Lipoproteínas/uso terapêutico , Manose/química , Receptor de Manose , Lectinas de Ligação a Manose/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Proteínas Oncogênicas Virais/química , Proteínas E7 de Papillomavirus , Infecções por Papillomavirus/tratamento farmacológico , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/imunologia , Vacinas contra Papillomavirus/uso terapêutico , Fragmentos de Peptídeos/química , Peptídeos/imunologia , Peptídeos/uso terapêutico , Receptores de Superfície Celular/metabolismo , Transplante Heterólogo , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/imunologia , Neoplasias do Colo do Útero/prevenção & controle , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/uso terapêutico
7.
Curr Opin Mol Ther ; 9(1): 25-34, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17330399

RESUMO

Infection with the human bacterial pathogen group A Streptococcus (GAS) is estimated to cause over 500,000 deaths per year, the majority of which are related to rheumatic fever (RF) and rheumatic heart disease (RHD). While GAS is an important cause of morbidity and mortality globally, the burden of GAS-associated diseases is greater in less developed countries and in indigenous populations of developed countries. The antiphagocytic bacterial surface M protein is a major candidate antigen in the development of a vaccine to prevent GAS infection and RF/RHD. A major obstacle, however, in the development of an M-protein-based vaccine is the widespread diversity of circulating GAS strains and M protein types. Added to this is the possibility of inducing autoimmunity following vaccination as a result of molecular mimicry between the M protein and host tissue proteins. Research has been aimed at the development of a safe GAS vaccine that is able to induce broad-coverage protective immunity. The development of subunit vaccine approaches targeting the M protein using various vaccine delivery technologies is the focus of this review.


Assuntos
Proteínas de Bactérias/imunologia , Febre Reumática/imunologia , Febre Reumática/prevenção & controle , Cardiopatia Reumática/imunologia , Cardiopatia Reumática/prevenção & controle , Vacinas de Subunidades Antigênicas/imunologia , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/química , Técnicas de Tipagem Bacteriana , Humanos , Dados de Sequência Molecular , Febre Reumática/microbiologia , Cardiopatia Reumática/microbiologia , Streptococcus pyogenes/imunologia , Streptococcus pyogenes/patogenicidade , Vacinas de Subunidades Antigênicas/química
8.
J Infect Dis ; 194(3): 316-24, 2006 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-16826479

RESUMO

BACKGROUND: We investigated the lipid core peptide (LCP) system for mucosal vaccine delivery against infection with group A streptococcus (GAS)--the causative pathogen of rheumatic fever and rheumatic heart disease. METHODS: An LCP vaccine formulation containing 2 different peptide epitopes of the antiphagocytic M protein of GAS--a conformational epitope from the carboxyterminal conserved C-repeat region and an aminoterminal serotypic epitope--was intranasally administered to mice with cholera toxin B subunit or without additional adjuvant. RESULTS: Our data demonstrate that the LCP vaccine formulation induced the elicitation of antigen-specific systemic immunoglobulin G responses when administered with or without cholera toxin B subunit, whereas cholera toxin B subunit was required for the induction of antigen-specific mucosal immunoglobulin A responses. Immune serum samples from vaccinated mice were capable of opsonization of a homologous GAS strain, as well as opsonization of a heterologous GAS strain. Furthermore, mice were protected from GAS challenge following immunization with the LCP vaccine formulation, even in the absence of additional adjuvant. CONCLUSIONS: These data support the potential of the LCP system in the development of a self-adjuvanting, synthetic, peptide-based mucosal GAS vaccine for the prevention of diseases caused by GAS.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Transporte/imunologia , Imunoterapia Ativa/métodos , Lipídeos/administração & dosagem , Fragmentos de Peptídeos/imunologia , Vacinas Estreptocócicas/administração & dosagem , Vacinas de Subunidades Antigênicas/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Administração Intranasal , Administração Oral , Sequência de Aminoácidos , Animais , Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/sangue , Toxoide Diftérico/administração & dosagem , Toxoide Diftérico/imunologia , Sistemas de Liberação de Medicamentos/métodos , Epitopos/imunologia , Imunidade nas Mucosas/imunologia , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Lipídeos/química , Lipídeos/imunologia , Camundongos , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/prevenção & controle , Vacinas Estreptocócicas/imunologia , Streptococcus pyogenes/imunologia , Vacinas de Subunidades Antigênicas/imunologia
9.
Immunol Res ; 35(3): 233-48, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17172649

RESUMO

Rheumatic fever (RF) and rheumatic heart disease (RHD) are postinfectious complications of an infection (or repeated infection) with the Gram-positive bacterium, Streptococcus pyogenes (also known as group A streptococcus, GAS). RF and RHD are global problems and affect many indigenous populations of developed countries and many developing countries. However, RF and RHD are only part of a larger spectrum of diseases caused by this organism. The development of a vaccine against GAS has primarily targeted the abundant cell-surface protein called the M-protein. This review focuses on different M-protein-based-subunit vaccine approaches and the different delivery technologies used to administer these vaccine candidates in preclinical studies.


Assuntos
Proteínas da Membrana Bacteriana Externa/imunologia , Febre Reumática/prevenção & controle , Cardiopatia Reumática/prevenção & controle , Vacinas Estreptocócicas , Sequência de Aminoácidos , Animais , Proteínas da Membrana Bacteriana Externa/genética , Humanos , Dados de Sequência Molecular , Febre Reumática/etiologia , Cardiopatia Reumática/etiologia , Vacinas Estreptocócicas/imunologia , Streptococcus pyogenes , Vacinas de Subunidades Antigênicas
10.
J Med Chem ; 49(21): 6364-70, 2006 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-17034142

RESUMO

We have developed a highly pure, self-adjuvanting, triepitopic Group A Streptococcal vaccine based on the lipid core peptide system, a vaccine delivery system incorporating lipidic adjuvant, carrier, and peptide epitopes into a single molecular entity. Vaccine synthesis was performed using native chemical ligation. Due to the attachment of a highly lipophilic adjuvant, addition of 1% (w/v) sodium dodecyl sulfate was necessary to enhance peptide solubility in order to enable ligation. The vaccine was synthesized in three steps to yield a highly pure product (97.7% purity) with an excellent overall yield. Subcutaneous immunization of B10.BR (H-2(k)) mice with the synthesized vaccine, with or without the addition of complete Freund's adjuvant, elicited high serum IgG antibody titers against each of the incorporated peptide epitopes.


Assuntos
Antígenos de Bactérias/química , Proteínas da Membrana Bacteriana Externa/química , Proteínas de Transporte/química , Lipídeos/química , Peptídeos/síntese química , Vacinas Estreptocócicas/síntese química , Streptococcus pyogenes/imunologia , Animais , Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Transporte/imunologia , Epitopos , Feminino , Imunoglobulina G/sangue , Camundongos , Peptídeos/química , Peptídeos/imunologia , Vacinas Estreptocócicas/imunologia , Vacinação , Vacinas de Subunidades Antigênicas/síntese química , Vacinas de Subunidades Antigênicas/imunologia
11.
BMC Microbiol ; 6: 71, 2006 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-16895610

RESUMO

BACKGROUND: Most group A streptococcal (GAS) vaccine strategies have focused on the surface M protein, a major virulence factor of GAS. The amino-terminus of the M protein elicits antibodies, that are both opsonic and protective, but which are type specific. J14, a chimeric peptide that contains 14 amino acids from the M protein conserved C-region at the carboxy-terminus, offers the possibility of a vaccine which will elicit protective opsonic antibodies against multiple different GAS strains. In this study, we searched for J14 and J14-like sequences and the number of their repeats in the C-region of the M protein from GAS strains isolated from the Northern Thai population. Then, we examined the bactericidal activity of J14, J14.1, J14-R1 and J14-R2 antisera against multiple Thai GAS strains. RESULTS: The emm genes of GAS isolates were sequenced and grouped as 14 different J14-types. The most diversity of J14-types was found in the C1-repeat. The J14.1 type was the major sequence in the C2 and C3-repeats. We have shown that antisera raised against the M protein conserved C-repeat region peptides, J14, J14.1, J14-R1 and J14-R2, commonly found in GAS isolates from the Northern Thai population, are able to kill GAS of multiple different emm types derived from an endemic area. The mean percent of bactericidal activities for all J14 and J14-like peptide antisera against GAS isolates were more than 70%. The mean percent of bactericidal activity was highest for J14 antisera followed by J14-R2, J14.1 and J14-R1 antisera. CONCLUSION: Our study demonstrated that antisera raised against the M protein conserved C-repeat region are able to kill multiple different strains of GAS isolated from the Northern Thai population. Therefore, the four conserved "J14" peptides have the potential to be used as GAS vaccine candidates to prevent streptococcal infections in an endemic area.


Assuntos
Anticorpos/imunologia , Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Transporte/imunologia , Fragmentos de Peptídeos/imunologia , Streptococcus pyogenes/imunologia , Sequência de Aminoácidos , Anticorpos/administração & dosagem , Anticorpos/sangue , Antígenos de Bactérias/química , Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Transporte/química , Proteínas de Transporte/genética , Sequência Conservada/genética , Ensaio de Imunoadsorção Enzimática , Humanos , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Reação em Cadeia da Polimerase , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/prevenção & controle , Vacinas Estreptocócicas/administração & dosagem , Vacinas Estreptocócicas/química , Vacinas Estreptocócicas/imunologia , Streptococcus pyogenes/isolamento & purificação , Streptococcus pyogenes/metabolismo , Sequências Repetidas Terminais/genética , Tailândia
12.
BMC Microbiol ; 5: 63, 2005 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-16225702

RESUMO

BACKGROUND: Group A streptococcal (GAS) infections can lead to the development of severe post-infectious sequelae, such as rheumatic fever (RF) and rheumatic heart disease (RHD). RF and RHD are a major health concern in developing countries, and in indigenous populations of developed nations. The majority of GAS isolates are M protein-nontypeable (MNT) by standard serotyping. However, GAS typing is a necessary tool in the epidemiologically analysis of GAS and provides useful information for vaccine development. Although DNA sequencing is the most conclusive method for M protein typing, this is not a feasible approach especially in developing countries. To overcome this problem, we have developed a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based assay for molecular typing the M protein gene (emm) of GAS. RESULTS: Using one pair of primers, 13 known GAS M types showed one to four bands of PCR products and after digestion with Alu I, they gave different RFLP patterns. Of 106 GAS isolates examined from the normal Thai population and from patients with GAS-associated complications including RHD, 95 isolates gave RFLP patterns that corresponded to the 13 known M types. Only 11 isolates gave RFLP patterns that differed from the 13 known M types. These were then analyzed by DNA sequencing and six additional M types were identified. In addition, we found that M93 GAS was the most common M type in the population studied, and is consistent with a previous study of Thai GAS isolates. CONCLUSION: PCR-RFLP analysis has the potential for the rapid screening of different GAS M types and is therefore considerably advantageous as an alternative M typing approach in developing countries in which GAS is endemic.


Assuntos
Antígenos de Bactérias/isolamento & purificação , Proteínas da Membrana Bacteriana Externa/isolamento & purificação , Proteínas de Transporte/isolamento & purificação , Polimorfismo de Fragmento de Restrição , Streptococcus pyogenes/genética , Streptococcus pyogenes/isolamento & purificação , Sequência de Bases , Primers do DNA , Humanos , Reação em Cadeia da Polimerase/métodos , Streptococcus pyogenes/classificação , Tailândia
13.
J Med Chem ; 45(6): 1387-90, 2002 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-11882009

RESUMO

Lipoamino acid-based synthetic peptides (lipid core peptides, LCP) derived from the type-specific and conserved region determinants of group A streptococci (GAS) were evaluated as potential candidate sequences in a vaccine to prevent GAS-associated diseases, including rheumatic heart disease and poststreptococcal acute glomerulonephritis. The LCP peptides had significantly enhanced immunogenicity as compared with the monomeric peptide epitopes. Furthermore, the peptides incorporated into the LCP system generated epitope-specific antibodies without the use of any conventional adjuvant.


Assuntos
Adjuvantes Imunológicos/síntese química , Vacinas Bacterianas/imunologia , Epitopos/imunologia , Peptídeos/imunologia , Infecções Estreptocócicas/imunologia , Streptococcus pyogenes/imunologia , Adjuvantes Imunológicos/farmacologia , Sequência de Aminoácidos , Animais , Anticorpos Antibacterianos/sangue , Vacinas Bacterianas/normas , Feminino , Humanos , Camundongos , Dados de Sequência Molecular , Peptídeos/síntese química , Infecções Estreptocócicas/prevenção & controle
14.
J Med Chem ; 47(16): 4100-4, 2004 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-15267249

RESUMO

Using native chemical ligation, we synthesized a group A streptococcal (GAS) vaccine that contained three different GAS M protein peptide epitopes in a chemically well-characterized construct in high purity. Two of the peptide epitopes represented variable amino terminal serotype determinants, and the third represented a carboxyl terminal conserved region determinant of the GAS M protein. We also synthesized a lipid core peptide (LCP) construct containing the same three peptides. Upon immunization of mice, the non-LCP construct only elicited antibody responses to all three epitopes with the use of adjuvant. The LCP construct, however, elicited excellent antibody responses to all three epitopes without the need for any additional adjuvant or carrier. We have synthesized the LCP synthetic vaccine system with good reproducibility.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Transporte/imunologia , Vacinas Estreptocócicas/síntese química , Streptococcus pyogenes/imunologia , Sequência de Aminoácidos , Animais , Antígenos de Bactérias/química , Proteínas da Membrana Bacteriana Externa/química , Proteínas de Transporte/química , Sequência Conservada , Epitopos , Feminino , Camundongos , Dados de Sequência Molecular , Vacinas Estreptocócicas/imunologia , Streptococcus pyogenes/química , Streptococcus pyogenes/isolamento & purificação
15.
Expert Rev Vaccines ; 3(1): 43-58, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14761243

RESUMO

The antiphagocytic surface M protein of group A streptococcus has been widely studied as the major candidate antigen for a vaccine to prevent group A streptococcus infection. Approaches that have proven to be effective in animal models include the use of multi-epitope vaccines incorporating highly variable amino terminal serotypic determinants, those based on the carboxy terminal conserved region and combination vaccines incorporating both serotypic and conserved region determinants of the M protein. The use of lipid core peptide technology is at the forefront of this research in the quest to develop a broad-strain protective vaccine that can be delivered via the mucosal route, stimulating mucosal and systemic immunity. This review aims to cover the various strategies and technologies that have been investigated with regard to group A streptococcus vaccine design and development.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Transporte/imunologia , Sistemas de Liberação de Medicamentos/métodos , Lipídeos/imunologia , Vacinas Estreptocócicas/administração & dosagem , Streptococcus pyogenes/imunologia , Animais , Antígenos de Bactérias/química , Doenças Autoimunes/imunologia , Doenças Autoimunes/prevenção & controle , Proteínas da Membrana Bacteriana Externa/química , Proteínas de Transporte/química , Humanos , Imunidade nas Mucosas , Lipídeos/química , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/prevenção & controle , Vacinas Estreptocócicas/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
16.
Indian J Med Res ; 119 Suppl: 88-94, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15232170

RESUMO

BACKGROUND & OBJECTIVES: To develop a broad strain coverage GAS vaccine, several strategies have been investigated which included multi-epitope approaches as well as targeting the M protein conserved Cregion. These approaches, however, have relied on the use of adjuvants that are toxic for human application. The development of safe and effective adjuvants for human use is a key issue in the development of effective vaccines. In this study, we investigated the lipid polylysine core peptide (LCP) system as a self-adjuvanting GAS vaccine delivery approach. METHODS: An LCP-GAS construct was synthesised incorporating multiple copies of a protective peptide epitope (J8) from the conserved carboxy terminal C-repeat region of the M protein. B10.BR mice were immunized parenterally with the LCP-J8 construct, with or without conventional adjuvant, prior to the assessment of immunogenicity and the induction of serum opsonic antibodies. RESULTS: Our data demonstrated immunogenicity of LCP-J8 when coadministered in complete Freund's adjuvant (CFA), or administered in the absence of conventional adjuvant. In both cases, immunization led to the induction of high-titre J8 peptide-specific serum IgG antibody responses, and the induction of heterologous opsonic antibodies that did not cross-react with human heart tissue proteins. INTERPRETATION & CONCLUSION: These data indicated the potential of a novel self-adjuvanting LCP vaccine delivery system incorporating a synthetic GAS M protein C-region peptide immunogen in the induction of broadly protective immune responses, and pointed to the potential application of this system in human vaccine development against infectious diseases.


Assuntos
Proteínas de Bactérias/química , Vacinas Bacterianas/administração & dosagem , Lipídeos/química , Peptídeos/química , Streptococcus/imunologia , Sequência de Aminoácidos , Anticorpos Antibacterianos/biossíntese , Vacinas Bacterianas/química , Vacinas Bacterianas/imunologia , Western Blotting , Ensaio de Imunoadsorção Enzimática , Dados de Sequência Molecular
19.
Expert Rev Vaccines ; 11(2): 237-56, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22309671

RESUMO

The innate immune system plays an essential role in the host's first line of defense against microbial invasion, and involves the recognition of distinct pathogen-associated molecular patterns by pattern recognition receptors (PRRs). Activation of PRRs triggers cell signaling leading to the production of proinflammatory cytokines, chemokines and Type 1 interferons, and the induction of antimicrobial and inflammatory responses. These innate responses are also responsible for instructing the development of an appropriate pathogen-specific adaptive immune response. In this review, the focus is on different classes of PRRs that have been identified, including Toll-like receptors, nucleotide-binding oligomerization domain-like receptors, and the retinoic acid-inducible gene-I-like receptors, and their importance in host defense against infection. The role of PRR cooperation in generating optimal immune responses required for protective immunity and the potential of targeting PRRs in the development of a new generation of vaccine adjuvants is also discussed.


Assuntos
Imunidade Adaptativa/imunologia , Imunidade Inata/imunologia , Infecções/imunologia , Receptores de Reconhecimento de Padrão/metabolismo , Adjuvantes Imunológicos , Humanos , Inflamassomos/imunologia , Inflamassomos/metabolismo , Receptores de Reconhecimento de Padrão/classificação , Receptores de Reconhecimento de Padrão/imunologia , Vacinas
20.
Clin Vaccine Immunol ; 19(2): 268-76, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22205658

RESUMO

Virus-like particles (VLPs) based on the small envelope protein of hepatitis B virus (HBsAg-S) are immunogenic at the B- and T-cell level. In this study, we inserted overlapping sequences encoding the carboxy terminus of the Helicobacter pylori katA gene product into HBsAg-S. The HBsAg-S-KatA fusion proteins were able to assemble into secretion-competent VLPs (VLP-KatA). The VLP-KatA proteins were able to induce KatA-specific antibodies in immunized mice. The mean total IgG antibody titers 41 days post-primary immunization with VLP-KatA (2.3 × 10(3)) were significantly greater (P < 0.05) than those observed for vaccination with VLP alone (5.2 × 10(2)). Measurement of IgG isotypes revealed responses to both IgG1 and IgG2a (mean titers, 9.0 × 10(4) and 2.6 × 10(4), respectively), with the IgG2a response to vaccination with VLP-KatA being significantly higher than that for mice immunized with KatA alone (P < 0.05). Following challenge of mice with H. pylori, a significantly reduced bacterial load in the gastric mucosa was observed (P < 0.05). This is the first report describing the use of VLPs as a delivery vehicle for H. pylori antigens.


Assuntos
Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Catalase/imunologia , Infecções por Helicobacter/prevenção & controle , Antígenos de Superfície da Hepatite B/imunologia , Animais , Anticorpos Antibacterianos/sangue , Carga Bacteriana , Proteínas de Bactérias/genética , Vacinas Bacterianas/administração & dosagem , Catalase/genética , Epitopos/imunologia , Feminino , Infecções por Helicobacter/imunologia , Helicobacter pylori/genética , Helicobacter pylori/imunologia , Antígenos de Superfície da Hepatite B/genética , Vírus da Hepatite B/genética , Vírus da Hepatite B/imunologia , Imunoglobulina G/sangue , Camundongos , Camundongos Endogâmicos C57BL , Vacinação , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/imunologia , Proteínas Virais de Fusão/imunologia
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