RESUMO
AIMS: A regimen utilizing Bacille Calmette-Guerin (BCG) and another vaccine system as a booster may represent a promising strategy for the development of an efficient tuberculosis vaccine for adults. In a previous work, we confirmed the ability of Lactococcus lactis fibronectin-binding protein A (FnBPA+) (pValac:ESAT-6), a live mucosal DNA vaccine, to produce a specific immune response in mice after oral immunization. In this study, we examined the immunogenicity of this strain as a booster for the BCG vaccine in mice. METHODS AND RESULTS: After immunization, cytokine and immunoglobulin profiles were measured. The BCG prime L. lactis FnBPA+ (pValac:ESAT-6) boost group was the most responsive group, with a significant increase in splenic pro-inflammatory cytokines IL-17, IFN-γ, IL-6 and TNF-α compared with the negative control. CONCLUSIONS: Based on the results obtained here, we demonstrated that L. lactis FnBPA+ (pValac:ESAT-6) was able to increase the BCG vaccine general immune response. SIGNIFICANCE AND IMPACT OF THE STUDY: This work is of great scientific and social importance because it represents the first step towards the development of a booster to the BCG vaccine using L. lactis as a DNA delivery system.
Assuntos
Antígenos de Bactérias/imunologia , Vacina BCG/imunologia , Proteínas de Bactérias/imunologia , Citocinas/sangue , Interleucina-17/metabolismo , Lactococcus lactis/genética , Vacinas de DNA/imunologia , Animais , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Feminino , Interleucina-6 , Lactococcus lactis/metabolismo , Camundongos , Fator de Necrose Tumoral alfaRESUMO
In this study, Lactococcus lactis was engineered to express mutated internalin A on its surface and to secrete large amounts of listeriolysin O (LLO) in order to improve its potential as a vehicle for DNA vaccination. Western blotting experiments demonstrated that the bacterium expressed LLO in both the cytoplasmic and extracellular compartments, with higher quantities found in the culture supernatants. A hemolytic assay showed that the recombinant strain secreted 250 ng active LLO/mg total protein. This mInlA/LLO-producing strain of L. lactis may be used as an alternative tool in DNA vaccination against a number of infectious diseases or in cancer therapy.
Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Toxinas Bacterianas/genética , Toxinas Bacterianas/imunologia , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/imunologia , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/imunologia , Lactococcus lactis/genética , Listeria monocytogenes/imunologia , Mutação , Proteínas Recombinantes , Vacinas Bacterianas , Membrana Celular/metabolismo , Expressão Gênica , Hemólise , Lactococcus lactis/metabolismo , VacinaçãoRESUMO
Allergic diseases affect up to 30% of the western population, and their prevalence is increasing. Probiotics are able to modulate the mucosal immune response, and clinical trials demonstrated that specific strains, especially lactic acid bacteria (LAB) ones, reduce allergic symptoms. Moreover, the use of recombinant probiotics has been evaluated as possible strategies for the immunotherapy of allergic diseases. The production and delivery of allergens by recombinant LAB in concert with their ability to induce a Th1-type immune response have been shown to be a promising mucosal vaccination strategy in mouse model. The aim of this article is to review the applications of probiotics in allergy immunotherapy with a special focus on recombinant LAB delivering proteins or DNA.
Assuntos
Hipersensibilidade/terapia , Imunoterapia , Probióticos/uso terapêutico , Alérgenos/genética , Alérgenos/imunologia , Animais , Bifidobacterium/genética , DNA/administração & dosagem , Humanos , Hipersensibilidade/imunologia , Imunidade nas Mucosas , Lactobacillus/genética , Camundongos , Hipersensibilidade a Leite/terapia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/imunologiaRESUMO
Lactic acid bacteria (LAB) are an attractive and safe alternative for the expression of heterologous proteins, as they are nonpathogenic and endotoxin-free organisms. Lactococcus lactis, the LAB model organism, has been extensively employed in the biotechnology field for large-scale production of heterologous proteins, and its use as a "cell factory" has been widely studied. We have been particularly interested in the use of L. lactis for production of heat shock proteins (HSPs), which reportedly play important roles in the initiation of innate and adaptive immune responses. However, this activity has been questioned, as LPS contamination appears to be responsible for most, if not all, immunostimulatory activity of HSPs. In order to study the effect of pure HSPs on the immune system, we constructed recombinant L. lactis strains able to produce and properly address the Mycobacterium leprae 65-kDa HSP (Hsp65) to the cytoplasm or to the extracellular medium, using a xylose-induced expression system. Approximately 7 mg/L recombinant Hsp65 was secreted. Degradation products related to lactococcal HtrA activity were not observed, and the Limulus amebocyte lysate assay demonstrated that the amount of LPS in the recombinant Hsp65 preparations was 10-100 times lower than the permitted levels established by the U.S. Food and Drug Administration. These new L. lactis strains will allow investigation of the effects of M. leprae Hsp65 without the interference of LPS; consequently, they have potential for a variety of biotechnological, medical and therapeutic applications.
Assuntos
Proteínas de Bactérias/genética , Chaperonina 60/genética , Lactococcus lactis/metabolismo , Mycobacterium leprae/metabolismo , Sequência de Bases , Clonagem Molecular , Primers do DNA , Lactococcus lactis/genética , Mycobacterium leprae/genética , Reação em Cadeia da Polimerase , Proteínas Recombinantes/genéticaRESUMO
The G genotyping of 74 group A rotavirus samples was done by RNA-DNA hybridization (dot-blot) using oligonucleotide probes for the VP7 gene region of the human rotavirus serotypes/genotypes 1, 2, 3 and 4. Thirty-one samples could be genotyped by dot-blot showing the following results: G1 = 16, G4 = 6, G3 = 5, and G2 = 4. The data show circulation of genotypes G1-G4 and the predominance of G1. The knowledge of genotypes provides important information concerning rotavirus circulation in Central Brazil
Assuntos
Humanos , Criança , Rotavirus/genética , Brasil , Diarreia/virologia , Genótipo , Hibridização de Ácido Nucleico , Sondas de Oligonucleotídeos , Rotavirus/classificaçãoRESUMO
Um estudo seroepidemiologico para o virus da hepatite A (VHA), investigando os marcadores de infeccao passada (anti-VHA total anti-IgG e IgM) e infeccao recente (anti-VHA IgM), foi realizado entre 1991 e 1992, em criancas de creche de Goiania-Brasil central. Das 310 criancas com idade entre 03 meses e 09 anos, 69,7 por cento mostraram soropositividade ao anti-VHA total, sendo 60 por cento, na faixa etaria entre 1 e 3 anos. A prevalencia do marcador anti-VHA IgM foi de 3,2 por cento visto em idade de 1-4 anos e com distribuicao uniforme nas 10 creches estudadas. Entre as variaveis sociodemograficas estudadas, apenas o tempo de frequencia das criancas nas creches, igual ou superior a um ano, mostrou, em analise multivariada ajustada para idade, um risco de 4,7 vezes maior quando comparado com o periodo de um mes (LC 95 por cento 2,3-9,9)...
Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Creches , Hepatite A/epidemiologia , Fatores de Risco , Brasil , Hepatite A/imunologia , Testes SorológicosRESUMO
Um estudo soro epidemiológico, para anticorpos contra o virus da hepatite A (anti-VHA total-IgM e IgG), foi realizado no período de 1991-1992, em 397 "meninos de/na rua" em Goiânia. Destes, 313 apresentavam vínculo familiar e desenvolviam, em sua maioria, atividades de trabalho informal, enquanto que 84 nao possuiam vínculo familiar e se encontravam na rua ou em Instituiçoes do Governo Estadual. A taxa média de prevalência foi de 90,4 por cento, variando de 80,0 por cento a 92,9 por cento, sem contudo apresentar diferença estatística significante relativa à idade (7-21). Também nao se evidenciou qualquer diferença quando este grupo foi estratificado para presença ou ausência de vínculo familiar ou mesmo quando analisado em relaçao a outras variáveis sócio-demográficas. Estes dados sugerem que a hepatite A é endêmica na populaçao de baixa condiçao sócio-econômica da regiao e que nesta faixa etária a maioria dos indivíduos já adquiriu a infecçao. Outras investigaçoes em grupos e camadas sociais diferentes sao necessárias a fim de parametrar estratégias vacinais em países subdesenvolvidos.