A Single Dose of a DNA Vaccine Encoding Apa Coencapsulated with 6,6=-Trehalose Dimycolate in Microspheres Confers Long-Term Protection against Tuberculosis in Mycobacterium bovis BCG-Primed Mice

Made available in DSpace on 2015-09-21T17:25:10Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) joseli_vieira_etal_IOC_2013.pdf: 2121105 bytes, checksum: 5ed67f3990f4a296fb8320be5cead158 (MD5) Previous issue date: 2013Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Laboratório de Imunologia e Imunogenética. Rio de Janeiro, RJ, Brasil.Universidade de São Paulo. Escola de Medicina de Ribeirão Preto. Departamento de Bioquímica e Imunologia. Ribeirão Preto, SP, Brasil.Universidade de São Paulo. Escola de Medicina de Ribeirão Preto. Departamento de Bioquímica e Imunologia. Ribeirão Preto, SP, Brasil.Universidade de São Paulo. Escola de Medicina de Ribeirão Preto. Departamento de Bioquímica e Imunologia. Ribeirão Preto, SP, Brasil.Universidade de São Paulo. Escola de Medicina de Ribeirão Preto. Departamento de Bioquímica e Imunologia. Ribeirão Preto, SP, Brasil.Instituto Butantã. Centro de Biotecnologia. São Paulo, SP, brasil.Fonte Medicina Diagnóstica. Niterói, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia das Interações. Rio de Janeiro, RJ, Brasil.Universidade de São Paulo. Escola de Medicina de Ribeirão Preto. Departamento de Bioquímica e Imunologia. Ribeirão Preto, SP, Brasil.Universidade de São Paulo. Escola de Medicina de Ribeirão Preto. Departamento de Bioquímica e Imunologia. Ribeirão Preto, SP, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Laboratório de Imunologia e Imunogenética. Rio de Janeiro, RJ, BrasilMycobacterium bovis BCG prime DNA (Mycobacterium tuberculosis genes)-booster vaccinations have been shown to induce greater protection against tuberculosis (TB) than BCG alone. This heterologous prime-boost strategy is perhaps the most realistic vaccination for the future of TB infection control, especially in countries where TB is endemic. Moreover, a prime-boost regimen using biodegradable microspheres seems to be a promising immunization to stimulate a long-lasting immune response. The alanine proline antigen (Apa) is a highly immunogenic glycoprotein secreted by M. tuberculosis. This study investigated the immune protection of Apa DNA vaccine against intratracheal M. tuberculosis challenge in mice on the basis of a heterologous prime-boost regimen. BALB/c mice were subcutaneously primed with BCG and intramuscularly boosted with a single dose of plasmid carrying apa and 6,6=-trehalose dimycolate (TDM) adjuvant, coencapsulated in microspheres (BCG-APA), and were evaluated 30 and 70 days after challenge. This prime-boost strategy (BCG-APA) resulted in a significant reduction in the bacterial load in the lungs, thus leading to better preservation of the lung parenchyma, 70 days postinfection compared to BCG vaccinated mice. The profound effect of this heterologous prime-boost regimen in the experimental model supports its development as a feasible strategy for prevention of TB

Protection conferred by heterologous vaccination against tuberculosis is dependent on the ratio of CD4(+)/CD4(+) Foxp3(+) cells

CD4(+) Foxp3(+) regulatory T cells inhibit the production of interferon-?, which is the major mediator of protection against Mycobacterium tuberculosis infection. In this study, we evaluated whether the protection conferred by three different vaccines against tuberculosis was associated with the number of spleen and lung regulatory T cells. We observed that after homologous immunization with the 65 000 molecular weight heat-shock protein (hsp 65) DNA vaccine, there was a significantly higher number of spleen CD4(+) Foxp3(+) cells compared with non-immunized mice. Heterologous immunization using bacillus Calmette Guerin (BCG) to prime and DNA-hsp 65 to boost (BCG/DNA-hsp 65) or BCG to prime and culture filtrate proteins (CFP)-CpG to boost (BCG/CFP-CpG) induced a significantly higher ratio of spleen CD4(+)/CD4(+) Foxp3(+) cells compared with non-immunized mice. In addition, the protection conferred by either the BCG/DNA-hsp 65 or the BCG/CFP-CpG vaccines was significant compared with the DNA-hsp 65 vaccine. Despite the higher ratio of spleen CD4(+)/CD4(+) Foxp3(+) cells found in BCG/DNA-hsp 65-immunized or BCG/CFP-CpG-immunized mice, the lungs of both groups of mice were better preserved than those of DNA-hsp 65-immunized mice. These results confirm the protective efficacy of BCG/DNA-hsp 65 and BCG/CFP-CpG heterologous prime-boost vaccines and the DNA-hsp 65 homologous vaccine. Additionally, the prime-boost regimens assayed here represent a promising strategy for the development of new vaccines to protect against tuberculosis because they probably induce a proper ratio of CD4(+) and regulatory (CD4(+) Foxp3(+)) cells during the immunization regimen. In this study, this ratio was associated with a reduced number of regulatory cells and no injury to the lungs.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2007/02695-5