RESUMO
The main challenge for vaccine development or improvement is the lack of safe adjuvants or immunostimulants that induce protective immune responses and can be used for mucosal immunization, which is a highly desirable strategy for vaccination against infectious diseases acquired by oral or intranasal routes. One promising alternative is the use of biodegradable and biocompatible polymeric microparticles. Recently, we developed an immobilization and delivery system with starch microparticles (SMPs) and a starch-binding domain (SBDtag) suitable for the mucosal administration of antigens and the induction of antigen-specific immune responses. Here, we explore the immunostimulant and reinforcing potential of the system using BALB/c mice with progressive pulmonary tuberculosis (PPT). The heat shock protein alpha-crystallin from Mycobacterium tuberculosis immobilized on SMPs (µAcr-SBDtag) or SMPs alone were administered nasally as boosters to BCG-vaccinated mice without any extra adjuvant. The mice were challenged intratracheally with either moderately virulent or highly virulent M. tuberculosis strains. Our results showed that the administration of either the immobilized antigen or SMPs asa booster for the BCG vaccination induced a significant reduction of bacterial loads in the lungs of mice, even more than in mice that received the BCG vaccination alone. Since no difference was observed in pulmonary bacillary burdens between the two reinforced groups, the obtained effect was most likely primarily caused by the starch. As determined by histological study, the administration of boosters did not contribute to the progress of pneumonia, which diminishes the safety concerns related to the administration of SMPs intranasally. Taken together, our findings suggest that this system may be considered asa new carbohydrate-based adjuvant suitable for mucosal vaccines against tuberculosis and other infectious diseases, and more generally, they highlight the potential of particulate α-glucans as immune response modifiers.
Assuntos
Adjuvantes Imunológicos/uso terapêutico , Vacina BCG/uso terapêutico , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/patogenicidade , Amido/química , Adjuvantes Imunológicos/administração & dosagem , Administração Intranasal , Animais , Vacina BCG/química , Vacina BCG/imunologia , Imunidade nas Mucosas/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium bovis/imunologia , Mycobacterium bovis/patogenicidade , Tuberculose/imunologia , Tuberculose/prevenção & controle , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/química , Vacinas contra a Tuberculose/imunologia , Vacinas contra a Tuberculose/uso terapêuticoRESUMO
In this study, the immune response induced by a mixture of polysaccharide and nucleic acid extracted from Bacillus Calmette-Guerin (BCG) was evaluated in chickens inoculated with infectious bursal disease virus (IBDV) vaccine. After the mixture was injected intramuscularly at a dose of 0.075, 0.15 or 0.3 mg·kg(-1)·day(-1) for 3 days, the 14-day-old chickens were inoculated with the attenuated IBDV vaccine via intranasal and ocular routes. The relative weight of bursa of Fabricius (BF) and thymus, the serum IBD antibody titer, the CD4+/CD8+ ratio, and the concentrations of IFN-γ, IL-2 and IL-6 in peripheral blood were investigated on days 5, 15 and 25. The IBD antibody titer in BCG-treated groups was higher than in the negative control and only IBD-vaccinated chickens, indicating that the mixture of BCG can significantly enhance chicken humoral response. CD4+/CD8+ and the secretions of IFN-γ, IL-2 and IL-6 were also clearly increased compared with that in the negative control and IBD-vaccinated chickens, indicating that the mixture can also enhance the cell-mediated immune response. The results also showed that the relative weights of BF and thymus increased after chickens were inoculated with BCG, indicating that the BCG mixture can clearly enhance the immunity of IBD-vaccine and can be expected to be viewed as a candidate for a new type of immune adjuvant.
Assuntos
Vacina BCG/imunologia , Infecções por Birnaviridae/veterinária , Vírus da Doença Infecciosa da Bursa/imunologia , Ácidos Nucleicos/imunologia , Polissacarídeos/imunologia , Doenças das Aves Domésticas/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Anticorpos Antivirais/sangue , Vacina BCG/química , Vacina BCG/farmacologia , Infecções por Birnaviridae/imunologia , Galinhas/imunologia , Vírus da Doença Infecciosa da Bursa/metabolismo , Masculino , Ácidos Nucleicos/isolamento & purificação , Ácidos Nucleicos/farmacologia , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Doenças das Aves Domésticas/terapia , Distribuição Aleatória , Vacinas Atenuadas/imunologia , Vacinas Atenuadas/farmacologia , Vacinas de DNA/administração & dosagem , Vacinas de DNA/farmacologia , Vacinas Virais/imunologia , Vacinas Virais/farmacologiaRESUMO
To contribute to Mycobacterium bovis BCG characterization, two substrains were analyzed using two-dimensional gel electrophoresis (2D-PAGE) and mass spectrometry (MS), based on their protective efficacy in a pulmonary-tuberculosis mouse model. Cell-fraction proteins of BCG Denmark and Phipps substrains were separated into approximately 500 spots in 2D-PAGE. The proteomes were similar in protein number, and isoelectric point (pI) and molecular mass (MM) distribution. Statistical analysis, resulted in 72 spots with no change, and 168 and 90 unique for BCG Phipps or Denmark, respectively. Two hundred and fourteen spots showed changes in intensity of >1-fold, 138 of Denmark, and 76 of Phipps. Seventeen spots were selected for MS-based identification (13 from Phipps and 4 from Denmark), including unique, as well as proteins with changes in intensity. The proteins identified participate in virulence, detoxification, adaptation, lipid metabolism, information pathways, cell wall and cell processes, intermediary metabolism and respiration, or still hypotheticals. Our findings contribute to phenotype characterization of BCG substrains and provide new elements to consider for the design of diagnostic tools, drug targets and a new vaccine against tuberculosis based upon protein expression through quantitative statistical analysis.