RESUMO
Parkinson's disease (PD) is the second most common age-related neurodegenerative disorder. Multiple genetic and environmental factors leading to progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SN) and consequent depletion of dopamine were described. Current clinical approaches, such as dopamine replacement or deep brain stimulation using surgically implanted probes, provide symptomatic relief but cannot modify disease progression. Therefore, disease-modifying therapeutic tools are urgently needed. Immunotherapy approaches, including passive transfer of protective antibodies and their fragments, have shown therapeutic efficacy in several animal models of neurodegenerative diseases, including PD. Recombinant antibody fragments are promising alternatives to conventional full-length antibodies. Modern computational approaches and molecular biology tools, directed evolution methodology, and the design of tissue-penetrating fusion peptides allowed for the development of recombinant antibody fragments with superior specificity and affinity, reduced immunogenicity, the capacity to target hidden epitopes and cross the blood-brain barrier (BBB), higher solubility and stability, the ability to refold after heat denaturation, and inexpensive large-scale production. In addition, antibody fragments do not induce microglia Fcγ receptor (FcγR)-mediated proinflammatory response and tissue damage in the central nervous system (CNS), because they lack the Fc portion of the immunoglobulin molecule. In the present review, we summarized data on recombinant antibody fragments evaluated as immunotherapeutics in preclinical models of PD and discussed their potential for developing therapeutic and preventive protocols for patients with PD.
Assuntos
Doença de Parkinson , Animais , Humanos , Doença de Parkinson/terapia , Dopamina , Substância Negra , Anticorpos , Fragmentos de Imunoglobulinas , ImunoterapiaRESUMO
Recombinant antibody fragments are promising alternatives to full-length immunoglobulins, creating big opportunities for the pharmaceutical industry. Nowadays, antibody fragments such as antigen-binding fragments (Fab), single-chain fragment variable (scFv), single-domain antibodies (sdAbs), and bispecific antibodies (bsAbs) are being evaluated as diagnostics or therapeutics in pre-clinical models and in clinical trials. Immunotherapy approaches, including passive transfer of protective antibodies, have shown therapeutic efficacy in several animal models of Alzheimer Ìs disease(AD), Parkinson Ìs disease (PD), frontotemporal dementia (FTD), Huntington Ìs disease (HD), transmissible spongiform encephalopathies (TSEs) and multiple sclerosis (MS). There are various antibodies approved by the Food and Drug Administration (FDA) for treating multiple sclerosis and two amyloid beta-specific humanized antibodies, Aducanumab and Lecanemab, for AD. Our previous review summarized data on recombinant antibodies evaluated in pre-clinical models for immunotherapy of neurodegenerative diseases. Here, we explore recent studies in this fascinating research field, give an update on new preventive and therapeutic applications of recombinant antibody fragments for neurological disorders and discuss the potential of antibody fragments for developing novel approaches for crossing the blood-brain barrier (BBB) and targeting cells and molecules of interest in the brain.
RESUMO
The development of recombinant antibody fragments as promising alternatives to full-length immunoglobulins offers vast opportunities for biomedicine. Antibody fragments have important advantages compared with conventional monoclonal antibodies that make them attractive for the biotech industry: superior stability and solubility, reduced immunogenicity, higher specificity and affinity, capacity to target the hidden epitope and cross the blood-brain barrier, the ability to refold after heat denaturation and inexpensive and easy large-scale production. Different antibody formats such as antigen-binding fragments (Fab), single-chain fragment variable (scFv) consisting of the antigen-binding domains of Ig heavy (VH) and light (VL) chain regions connected by a flexible peptide linker, single-domain antibody fragments (sdAbs) like camelid heavy-chain variable domains (VHHs) and shark variable new antigen receptor (VNARs), and bispecific antibodies (bsAbs) are currently being evaluated as diagnostics or therapeutics in preclinical studies and clinical trials. In the present review, we summarize and discuss studies on VNARs, the smallest recombinant antibody fragment, obtained after the screening of different types of phage display antibody libraries. Results published until March 2023 are discussed.
Assuntos
Bacteriófagos , Tubarões , Animais , Fragmentos de Imunoglobulinas , Tubarões/genética , Proteínas Recombinantes/genética , Anticorpos Monoclonais , Biblioteca de PeptídeosRESUMO
Breast cancer is one of the leading causes of death that affects the female population worldwide. Despite advances in treatments and a greater understanding of the disease, there are still difficulties in successfully treating patients. Currently, the main challenge in the field of cancer vaccines is antigenic variability which can reduce antigen-specific T- cell response efficacy. The search for and validation of immunogenic antigen targets increased dramatically over the past few decades and, with the advent of modern sequencing techniques, permitting the fast and accurate identification of the neoantigen landscape of tumor cells, will undoubtedly continue to grow exponentially for years to come. We have previously implemented Variable Epitope Libraries (VEL) as an unconventional vaccine strategy in preclinical models and for identifying and selecting mutant epitope variants. Here, we used an alanine-based sequence to generate a 9-mer VEL-like combinatorial mimotope library G3d as a new class of vaccine immunogen. An in silico analysis of the 16,000 G3d-derived sequences revealed potential MHC-I binders and immunogenic mimotopes. We demonstrated the antitumor effect of treatment with G3d in the 4T1 murine model of breast cancer. Moreover, two different T cell proliferation screening assays against a panel of randomly selected G3d-derived mimotopes allowed the isolation of both stimulatory and inhibitory mimotopes showing differential therapeutic vaccine efficacy. Thus, the mimotope library is a promising vaccine immunogen and a reliable source for isolating molecular cancer vaccine components.
Assuntos
Neoplasias , Biblioteca de Peptídeos , Feminino , Animais , Camundongos , Epitopos , Modelos Animais de Doenças , Antígenos de NeoplasiasRESUMO
After decades of cancer vaccine efforts, there is an imperious necessity for novel ideas that may result in better tumor control in patients. We have proposed the use of a novel Variable Epitope Library (VEL) vaccine strategy, which incorporates an unprecedented number of mutated epitopes to target antigenic variability and break tolerance against tumor-associated antigens. Here, we used an oncofetal antigen/immature laminin receptor protein-derived sequence to generate 9-mer and 43-mer VEL immunogens. 4T1 tumor-bearing mice developed epitope-specific CD8+IFN-γ+ and CD4+IFN-γ+ T cell responses after treatment. Tumor and lung analysis demonstrated that VELs could increase the number of tumor-infiltrating lymphocytes with diverse effector functions while reducing the number of immunosuppressive myeloid-derived suppressor and regulatory T cells. Most importantly, VEL immunogens inhibited tumor growth and metastasis after a single dose. The results presented here are consistent with our previous studies and provide evidence for VEL immunogens' feasibility as promising cancer immunotherapy.
Assuntos
Antígenos de Neoplasias/imunologia , Neoplasias da Mama , Vacinas Anticâncer/imunologia , Epitopos de Linfócito T/imunologia , Receptores de Laminina/imunologia , Animais , Vacinas Anticâncer/farmacologia , Modelos Animais de Doenças , Mapeamento de Epitopos/métodos , Feminino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
In this communication, we will analyze some important factors and immunological phenomena related to neoantigen cancer vaccines, with particular emphasis on recently published Phase I clinical trials. Several obstacles and issues are addressed that challenge the current paradigm and inquire if neoantigens, which are essentially single-use vaccine candidates, are legitimate targets to induce protective immune responses with regard to the evolving mutational landscape. We also share insights into the striking similarities between cancer and antigenically variable pathogens and suggest that any successful vaccine against either should demonstrate a similar property: efficient induction of a diverse pool of immune cells equipped to prevent immune escape. Hence, to confront antigenic variability directly, we have employed our innovative vaccine concept, Variable Epitope Libraries, composed of large combinatorial libraries of heavily mutated epitopes, as a "universal" vaccine platform. Collectively, we offer critical analyses on key issues, which ultimately reflect on the prospective clinical relevance of personalized neoantigen vaccines which is still undefined.
Assuntos
Antígenos de Neoplasias/uso terapêutico , Vacinas Anticâncer/uso terapêutico , Neoplasias/terapia , Desenvolvimento de Vacinas/métodos , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Ensaios Clínicos Fase I como Assunto , Epitopos/genética , Epitopos/imunologia , Humanos , Imunogenicidade da Vacina , Mutação , Neoplasias/genética , Neoplasias/imunologia , Resultado do Tratamento , Evasão Tumoral/genética , Desenvolvimento de Vacinas/tendênciasRESUMO
Antibodies, T cell receptors and major histocompatibility complex molecules are members of the immunoglobulin superfamily and have pivotal roles in the immune system. The fine interrelation between them regulates several immune functions. Here, we describe lesser-known functions ascribed to these molecules in generating and maintaining immune response. Particularly, we outline the contribution of antibody- and T cell receptor-derived complementarity-determining region neoantigens, antigenized antibodies, as well as major histocompatibility complex class I molecules-derived epitopes to the induction of protective/therapeutic immune responses against pathogens and cancer. We discuss findings of our own and other studies describing protective mechanisms, based on immunogenic properties of immunoglobulin superfamily members, and evaluate the perspectives of application of this class of immunogens in molecular vaccines design.
Assuntos
Anticorpos/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Sequência de Aminoácidos/genética , Animais , Formação de Anticorpos , Epitopos/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Imunidade/imunologia , Cadeias Pesadas de Imunoglobulinas , Região Variável de Imunoglobulina , Imunoglobulinas/imunologia , Imunoglobulinas/metabolismoRESUMO
Although various immune checkpoint inhibitors (ICIs), used for the treatment of advanced cancer, showed remarkably durable tumor regression in a subset of patients, there are important limitations in a large group of non-responders, and the generation of novel immunogens capable of inducing protective cellular immune responses is a priority in cancer immunotherapy field. During the last decades, several types of vaccine immunogens have been used in numerous preclinical studies and clinical trials. However, although immunity to tumor Ags can be elicited by most vaccines tested, their clinical efficacy remains modest. Recently, we have developed an innovative vaccine concept, called Variable Epitope Libraries (VELs), with the purpose to exploit the high antigenic variability of many important pathogens and tumor cells as starting points for the construction of a new class of vaccine immunogens capable of inducing the largest possible repertoire of both B and T cells. In the present study, we decided to generate VEL immunogens derived from both classical and non-classical major histocompatibility complex (MHC) class I molecules. The MHC molecules, responsible for antigen presentation and subsequent activation of T lymphocytes, undergo multiple modifications that directly affect their proper function, resulting in immune escape of tumor cells. Two large VELs derived from multi-epitope region of H2-Kd and Qa-2 sequences (46 and 34 amino acids long, respectively), along with their wild type counterparts have been generated as synthetic peptides and tested in an aggressive 4T1 mouse model of breast cancer. Significant inhibition of tumor growth and the reduction of metastatic lesions in the lungs of immunized mice were observed. This study demonstrated for the first time the successful application of VELs carrying combinatorial libraries of epitope variants derived from MHC class I molecules as novel vaccine immunogens.
Assuntos
Vacinas Anticâncer/imunologia , Epitopos/imunologia , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Animais , Vacinas Anticâncer/genética , Proliferação de Células , Modelos Animais de Doenças , Epitopos/genética , Feminino , Biblioteca Gênica , Humanos , Imunidade , Camundongos , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/metabolismo , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , VacinaçãoRESUMO
PURPOSE: Glioblastoma multiforme is the most frequent primary brain tumor, it has poor prognosis, and it remains refractory to current treatment. The success of temozolomide (TMZ) appears to be limited by the occurrence of chemoresistance. Recently, we report the use of pertussis toxin as adjuvant immunotherapy in a C6 glioma model; showing a decrease in tumoral size, it induced selective cell death in Treg cells, and it elicited less infiltration of tumoral macrophages. Here, we evaluated the cytotoxic effect of pertussis toxin in combination with TMZ for glioma treatment, both in vitro and in vivo RG2 glioma model. METHODS: We determined cell viability, cell cycle, apoptosis, and autophagy on treated RG2 cells through flow cytometry, immunofluorescence, and Western blot assays. Twenty-eight rats were divided in four groups (n = 7) for each treatment. After intracranial implantation of RG2 cells, animals were treated with TMZ (10 mg/Kg/200 µl of apple juice), PTx (2 µg/200 µl of saline solution), and TMZ + PTx. Animals without treatment were considered as control. RESULTS: We found an induction of apoptosis in around 20 % of RG2 cells, in both single treatments and in their combination. Also, we determined the presence of autophagy vesicles, without any modifications in the cell cycle in the TMZ - PTx-treated groups. The survival analyses showed an increase due to individual treatments; while in the group treated with the combination TMZ - PTx, this effect was enhanced. CONCLUSION: We show that the concomitant use of pertussis toxin plus TMZ could represent an advantage to improve the glioma treatment.
Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Dacarbazina/análogos & derivados , Modelos Animais de Doenças , Glioma/tratamento farmacológico , Glioma/mortalidade , Toxina Pertussis/uso terapêutico , Animais , Protocolos de Quimioterapia Combinada Antineoplásica , Apoptose/efeitos dos fármacos , Autofagia , Western Blotting , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Dacarbazina/uso terapêutico , Glioma/patologia , Masculino , Ratos , Ratos Wistar , Taxa de Sobrevida , TemozolomidaRESUMO
Extracellular and intraneuronal accumulation of amyloid-beta aggregates has been demonstrated to be involved in the pathogenesis of Alzheimer's disease (AD). However, the precise mechanism of amyloid-beta neurotoxicity is not completely understood. Previous studies suggest that binding of amyloid-beta to a number of macromolecules has deleterious effects on cellular functions. Mitochondria were found to be the target for amyloid-beta, and mitochondrial dysfunction is well documented in AD. In the present study we have shown for the first time that Aß 1-42 bound to a peptide comprising the amino-terminal region of cytochrome c oxidase subunit 1. Phage clone, selected after screening of a human brain cDNA library expressed on M13 phage and bearing a 61 amino acid fragment of cytochrome c oxidase subunit 1, bound to Aß 1-42 in ELISA as well as to Aß aggregates present in AD brain. Aß 1-42 and cytochrome c oxidase subunit 1 co-immunoprecipitated from mitochondrial fraction of differentiated human neuroblastoma cells. Likewise, molecular dynamics simulation of the cytochrome c oxidase subunit 1 and the Aß 1-42 peptide complex resulted in a reliable helix-helix interaction, supporting the experimental results. The interaction between Aß 1-42 and cytochrome c oxidase subunit 1 may explain, in part, the diminished enzymatic activity of respiratory chain complex IV and subsequent neuronal metabolic dysfunction observed in AD.
Assuntos
Peptídeos beta-Amiloides/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Fragmentos de Peptídeos/metabolismo , Sequência de Aminoácidos , Peptídeos beta-Amiloides/química , Animais , Bovinos , Complexo IV da Cadeia de Transporte de Elétrons/química , Humanos , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Ligação Proteica , Multimerização Proteica , Estrutura Secundária de ProteínaRESUMO
The extreme antigenic variability of human immunodeficiency virus (HIV) leads to immune escape of the virus, representing a major challenge in the design of effective vaccine. We have developed a novel concept for immunogen construction based on introduction of massive mutations within the epitopes targeting antigenically variable pathogens and diseases. Previously, we showed that these immunogens carrying large combinatorial libraries of mutated epitope variants, termed as variable epitope libraries (VELs), induce potent, broad and long lasting CD8+IFN-γ+ T-cell response. Moreover, we demonstrated that these T cells recognize more than 50% of heavily mutated variants (5 out of 10 amino acid positions were mutated in each epitope variant) of HIV-1 gp120 V3 loop-derived cytotoxic T lymphocyte epitope (RGPGRAFVTI) in mice. The constructed VELs had complexities of 10000 and 12500 individual members, generated as plasmid DNA or as M13 phage display combinatorial libraries, respectively, and with structural composition RGPGXAXXXX or XGXGXAXVXI, where X is any of 20 natural amino acids. Here, we demonstrated that sera from mice immunized with these VELs are capable of neutralizing 5 out of 10 viral isolates from Tier 2 reference panel of subtype B envelope clones, including HIV-1 isolates which are known to be resistant to neutralization by several potent monoclonal antibodies, described previously. These data indicate the feasibility of the application of immunogens based on VEL concept as an alternative approach for the development of molecular vaccines against antigenically variable pathogens.
Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , Formação de Anticorpos , Epitopos/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Animais , Bases de Dados de Proteínas , Feminino , Biblioteca Gênica , Proteína gp120 do Envelope de HIV/imunologia , Evasão da Resposta Imune , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Fragmentos de Peptídeos/imunologia , Linfócitos T Citotóxicos/imunologiaRESUMO
This paper provides macroscopic and histological evidence on the statistically significant protective effects of S3Pvac-phage vaccination against porcine cysticercosis and hydatidosis. The study included 391 rustically bred pigs (187 vaccinated and 204 controls). Vaccination significantly reduced the prevalence of cysticercosis by 61.7%. Vaccination also significantly reduced by 56.1% the prevalence of hydatidosis caused by Echinococcus granulosus in pigs. The presence of the vaccine epitopes in both cestodes is probably involved in the cross-protection observed. Increased inflammation was found in 5% of cysticerci recovered from controls, versus 24% from vaccinated pigs (P<0.01). Hydatid cysts were non-inflammatory in either group. Vaccination was effective to prevent one single disease, but it failed to prevent the simultaneous infections with both parasites in a same pig. The widening of the S3Pvac-phage vaccine protective repertoire to include hydatidosis is a convenient feature that should reduce the prevalence of two frequent zoonoses that affect rustic porcine breading with a single action. Thus, the costs of two different vaccination programs would be reduced to a single one with significant reduction in both zoonoses.
Assuntos
Cisticercose/veterinária , Equinococose/veterinária , Proteínas de Helminto/imunologia , Doenças dos Suínos/prevenção & controle , Vacinas/imunologia , Animais , Cisticercose/prevenção & controle , Equinococose/prevenção & controle , Proteínas de Helminto/genética , Proteínas Recombinantes , Suínos , Doenças dos Suínos/parasitologiaRESUMO
N-truncated/modified forms of amyloid beta (Aß) peptide are found in diffused and dense core plaques in Alzheimer's disease (AD) and Down's syndrome patients as well as animal models of AD, and represent highly desirable therapeutic targets. In the present study we have focused on N-truncated/modified Aß peptide bearing amino-terminal pyroglutamate at position 11 (AßN11(pE)). We identified two B-cell epitopes recognized by rabbit anti-AßN11(pE) polyclonal antibodies. Interestingly, rabbit anti-AßN11(pE) polyclonal antibodies bound also to full-length Aß1-42 and N-truncated/modified AßN3(pE), suggesting that the three peptides may share a common B-cell epitope. Importantly, rabbit anti-AßN11(pE) antibodies bound to naturally occurring Aß aggregates present in brain samples from AD patients. These results are potentially important for developing novel immunogens for targeting N-truncated/modified Aß aggregates as well, since the most commonly used immunogens in the majority of vaccine studies have been shown to induce antibodies that recognize the N-terminal immunodominant epitope (EFRH) of the full length Aß, which is absent in N-amino truncated peptides.
Assuntos
Peptídeos beta-Amiloides/metabolismo , Anticorpos/farmacologia , Linfócitos B/imunologia , Epitopos de Linfócito B/efeitos dos fármacos , Ácido Pirrolidonocarboxílico/imunologia , Doença de Alzheimer/patologia , Análise de Variância , Animais , Anticorpos Anti-Idiotípicos/imunologia , Anticorpos Anti-Idiotípicos/metabolismo , Linfócitos B/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular Tumoral , Ensaio de Imunoadsorção Enzimática/métodos , Epitopos de Linfócito B/imunologia , Humanos , Neuroblastoma/patologia , Ligação Proteica/efeitos dos fármacos , CoelhosRESUMO
While the antigenic variability is the major obstacle for developing vaccines against antigenically variable pathogens (AVPs) and cancer, this issue is not addressed adequately in current vaccine efforts. We developed a novel variable epitope library (VEL)-based vaccine strategy using immunogens carrying a mixture of thousands of variants of a single epitope. In this proof-of-concept study, we used an immunodominant HIV-1-derived CD8+ cytotoxic T-lymphocyte (CTL) epitope as a model antigen to construct immunogens in the form of plasmid DNA and recombinant M13 bacteriophages. We generated combinatorial libraries expressing epitope variants with random amino acid substitutions at 2-5 amino acid positions within the epitope. Mice immunized with these immunogens developed epitope-specific CD8+ IFN-gamma+ T-cell responses that recognized more than 50% of heavily mutated variants of wild-type epitope, as demonstrated in T-cell proliferation assays and FACS analysis. Strikingly, these potent and broad epitope-specific immune responses were long lasting: after 12 months of priming, epitope variants were recognized by CD8+ cells and effector memory T cells were induced. In addition, we showed, for the first time, the inhibition of T-cell responses at the molecular level by immune interference: the mice primed with wild-type epitope and 8 or 12 months later immunized with VELs, were not able to recognize variant epitopes efficiently. These data may give a mechanistic explanation for the failure of recent HIV vaccine trials as well as highlight specific hurdles in current molecular vaccine efforts targeting other important antigenically variable pathogens and diseases. These findings suggest that the VEL-based strategy for immunogen construction can be used as a reliable technological platform for the generation of vaccines against AVPs and cancer, and contribute to better understanding complex host-pathogen interactions.
Assuntos
Epitopos/imunologia , Biblioteca de Peptídeos , Vacinas Sintéticas/imunologia , Sequência de Aminoácidos , Animais , Epitopos/química , Citometria de Fluxo , Humanos , Imunidade Celular/imunologia , Imunização , Memória Imunológica/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , FenótipoRESUMO
In search of reducing vaccine production costs', a recombinant M13 phage version of the anti-cysticercosis tripeptide vaccine (S3Pvac) was developed. The efficacy of S3Pvac-Phage vs. placebo was evaluated in a randomized trial that included 1,047 rural pigs in 16 villages of Central Mexico. Three to five months after vaccination 530 pigs were examined by tongue inspection. At 5-27 months of age, 331 pigs (197 vaccinated/134 controls) were inspected at necropsy. Vaccination reduced 70% the frequency of tongue cysticercosis and, based on necropsy, 54% of muscle-cysticercosis and by 87% the number of cysticerci.
Assuntos
Antígenos de Helmintos/imunologia , Bacteriófago M13/imunologia , Cisticercose/imunologia , Cisticercose/veterinária , Doenças dos Suínos/imunologia , Doenças dos Suínos/prevenção & controle , Taenia solium/imunologia , Vacinas/imunologia , Vacinas/uso terapêutico , Envelhecimento/imunologia , Animais , Antígenos de Helmintos/biossíntese , Bacteriófago M13/metabolismo , Cisticercose/prevenção & controle , México , População Rural , Suínos , Doenças dos Suínos/parasitologia , Vacinas de Produtos Inativados/imunologia , Aumento de Peso/efeitos dos fármacosRESUMO
Vaccination of pigs may curtail Taenia solium transmission by reducing the number of cysticerci, the precursors of adult intestinal tapeworms in humans. Several antigen preparations induce protection against porcine cysticercosis in experimental settings but only one subunit vaccine (S3Pvac) has been tested and proved effective in the field against naturally acquired disease. Besides improving of the vaccine's effectiveness, significant reductions in production costs and in the logistics of its administration are necessary for the feasibility of nationwide control programs. This review highlights the development of several versions of S3Pvac aimed to increase effectiveness, reduce costs and increase feasibility by novel delivery systems and alternative routes of administration.
Assuntos
Cisticercose/veterinária , Doenças dos Suínos/prevenção & controle , Taenia solium/imunologia , Vacinação/veterinária , Vacinas de Subunidades Antigênicas/uso terapêutico , Animais , Cisticercose/parasitologia , Cisticercose/prevenção & controle , Cisticercose/transmissão , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/parasitologia , Doenças dos Suínos/transmissão , Vacinação/economia , Vacinação/métodos , Vacinas de Subunidades Antigênicas/economia , Vacinas de Subunidades Antigênicas/imunologia , Vacinas Sintéticas/economia , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/uso terapêuticoRESUMO
Extracellular and intraneuronal formation of amyloid-beta (Abeta) deposits have been demonstrated to be involved in the pathogenesis of Alzheimer's disease (AD). However, the precise mechanism of Abeta neurotoxicity is not completely understood. Previous studies suggest that binding of Abeta with a number of targets have deleterious effects on cellular functions. It has been shown that Abeta directly interacted with intracellular protein ERAB (endoplasmic reticulum amyloid beta-peptide-binding protein) also known as ABAD (Abeta-binding alcohol dehydrogenase) resulting in mitochondrial dysfunction and cell death. In the present study we have identified another mitochondrial enzyme, ND3 of the human complex I, that binds to Abeta1-42 by the screening of a human brain cDNA library expressed on M13 phage. Our results indicated a strong interaction between Abeta and a phage-displayed 25 amino acid long peptide TTNLPLMVMSSLLLIIILALSLAYE corresponding to C-terminal peptide domain of NADH dehydrogenase, subunit 3 (MTND3) encoded by mitochondrial DNA (mtDNA). This interaction may explain, in part, the inhibition of complex I activity in astrocytes and neurons in the presence of Abeta, described recently. To our knowledge, the present study is the first demonstration of interaction between Abeta and one of the subunits of the human complex I.
Assuntos
Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Biblioteca Gênica , Testes Genéticos/métodos , Fragmentos de Peptídeos/metabolismo , Proteínas/metabolismo , Southern Blotting/métodos , Fragmentação do DNA/fisiologia , Complexo I de Transporte de Elétrons , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Reação em Cadeia da Polimerase/métodosRESUMO
Cell-surface saccharides of Mycobacterium tuberculosis appear to be crucial factors in tuberculosis pathogenicity and could be useful antigens in tuberculosis immunodiagnosis. In the present study, we report the successful antigenic and immunogenic mimicry of mannose-containing cell-wall compounds of M. tuberculosis by dodecamer peptides identified by phage-display technology. Using a rabbit antiserum raised against M. tuberculosis cell-surface saccharides as a target for biopanning, peptides with three different consensus sequences were identified. Phage-displayed and chemically synthesized peptides bound to the anticarbohydrate antiserum. Rabbit antibodies elicited against the peptide QEPLMGTVPIRAGGGS recognize the mannosylated M. tuberculosis cell-wall antigens arabinomannan and lipoarabinomannan, and the glycosylated recombinant protein alanine/proline-rich antigen. Furthermore, antibodies were also able to react with mannan from Saccharomyces cerevisiae, but not with phosphatidylinositol dimannosides or arabinogalactan from mycobacteria. These results suggest that the immunogenic peptide mimics oligomannosidic epitopes. Interestingly, this report provides evidence that, in contrast with previously known carbohydrate mimotopes, no aromatic residues are necessary in a peptide sequence for mimicking unusual glycoconjugates synthesized by mycobacteria. The possible usefulness of the identified peptide mimotopes as surrogate reagents for immunodiagnosis and for the study of functional roles of the native non-peptide epitopes is discussed.
Assuntos
Mimetismo Molecular/imunologia , Mycobacterium tuberculosis/imunologia , Peptídeos/química , Peptídeos/imunologia , Polissacarídeos Bacterianos/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Antibacterianos/biossíntese , Ensaio de Imunoadsorção Enzimática , Epitopos/química , Humanos , Dados de Sequência Molecular , Mycobacterium tuberculosis/química , Biblioteca de Peptídeos , CoelhosRESUMO
The aim of this study was to test the capacity of recombinant phages to deliver antigens for vaccination against porcine cysticercosis. Thus, three peptides (KETc1, KETc12, GK1) and a recombinant antigen KETc7, previously proven to induce high levels of protection against pig cysticercosis, were expressed on the surface of the M13 bacteriophage at multiple copies. The pool of these four recombinant phages induced high levels of protection against an experimental murine cysticercosis. The immunogenicity of the phage vaccine preparation was therefore, tested in pigs, the natural host of Taenia solium. Subcutaneous or oral vaccination with these phages induced antigen-specific cellular immune responses in pigs. Preliminary data also points to the protective capacity of this recombinant phage vaccine against pig cysticercosis. The immunogenicity of these recombinant phages, together with the low cost of their production, make them a realistic candidate to be tested in pigs as an anti-cysticercus phage vaccine for field trials. This is the first report describing the application of a filamentous bacteriophage as a vaccine in large animals such as pigs, the only intermediate hosts of T. solium, a parasite of major medical importance in developing countries. The potential application of phages as a modern platform for vaccines for human and animal diseases is discussed.
Assuntos
Bacteriófago M13/imunologia , Cisticercose/veterinária , Doenças dos Suínos/parasitologia , Taenia solium/imunologia , Vacinação/veterinária , Vacinas Sintéticas/imunologia , Administração Oral , Animais , Anticorpos Anti-Helmínticos/sangue , Antígenos/genética , Antígenos/imunologia , Bacteriófago M13/genética , Cisticercose/imunologia , Cisticercose/parasitologia , Cisticercose/prevenção & controle , Epitopos/genética , Epitopos/imunologia , Feminino , Histocitoquímica , Injeções Subcutâneas/veterinária , Fígado/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Músculo Esquelético/parasitologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/prevenção & controle , Vacinação/métodos , Vacinas Sintéticas/economia , Vacinas Sintéticas/genéticaRESUMO
Cysticercosis caused by Taenia solium frequently affects human health and rustic porciculture. Cysticerci may localize in the central nervous system of humans causing neurocysticercosis, a major health problem in undeveloped countries. Prevalence and intensity of this disease in pigs and humans are related to social factors (poor personal hygiene, low sanitary conditions, rustic rearing of pigs, open fecalism) and possibly to biological factors such as immunity, genetic background, and gender. The indispensable role of pigs as an obligatory intermediate host in the life cycle offers the possibility of interfering with transmission through vaccination of pigs. An effective vaccine based on three synthetic peptides against pig cysticercosis has been successfully developed and proved effective in experimental and field conditions. The well-defined peptides that constitute the cysticercosis vaccine offer the possibility to explore alternative forms of antigen production and delivery systems that may improve the cost/benefit of this and other vaccines. Encouraging results were obtained in attempts to produce large amounts of these peptides and increased its immunogenicity by expression in recombinant filamentous phage (M13), in transgenic plants (carrots and papaya), and associated to bacterial immunogenic carrier proteins.