RESUMO
We evaluated the use of a vaccine formulation based on a mixture of two different PLGA microspheres, composed by faster and slower release profiles, containing DNA encoding hsp65 and the recombinant hsp65 protein, respectively, aiming to DNA priming and protein boost after a single dose vaccination. The combination of PLGA50:50 microspheres containing DNA-hsp65 and trehalose dimycolate (TDM) with PLGA75:25 microspheres containing recombinant hsp65 (prime-boost Me) was able to induce high levels of anti-hsp65 specific antibodies. The serum levels of these specific antibodies remained high during 90 days after vaccination, whereas the DNA Me formulation based only in DNA-hsp65 plus TDM-loaded microspheres was not able to sustain the high antibody levels during the same period. Production of IFN-gamma was significant in animals vaccinated with both formulations, while the prime-boost Me vaccinated mice sustained higher levels of this cytokine during all the evaluation period. Thus, prime-boost strategy by using biodegradable microspheres seems to be a promising strategy to stimulate long-lasting immune response.
Assuntos
Proteínas de Bactérias/administração & dosagem , Chaperoninas/administração & dosagem , Imunização Secundária/métodos , Ácido Láctico/química , Ácido Poliglicólico/química , Polímeros/química , Tuberculose Pulmonar/prevenção & controle , Vacinas de DNA/administração & dosagem , Animais , Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Chaperonina 60 , Chaperoninas/genética , Chaperoninas/imunologia , Citocinas/sangue , Interferon gama/biossíntese , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Microesferas , Mycobacterium tuberculosis/patogenicidade , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/imunologia , Baço/metabolismo , Fatores de Tempo , Tuberculose Pulmonar/imunologia , Tuberculose Pulmonar/microbiologiaRESUMO
In this work we describe the development and characterization of a new formulation of insulin (INS). Insulin was complexed with cyclodextrins (CD) in order to improve its solubility and stability being available as a dry powder, after encapsulation into poly (D,L-lactic-co-glycolic acid) (PLGA) microspheres. The complex INS : CD was encapsulated into microspheres in order to obtain particles with an average diameter between 2 and 6 microm. This system was able to induce significant reduction of the plasma glucose level in two rodent models, normal mice and diabetic rats, after intratracheal administration.
