RESUMEN
Quorum Sensing and type III secretion system play an important role in the virulence of Pseudomonas (P.) aeruginosa in burn wound infections. We aimed to explore the feasibility of using 3-oxo-C12-HSL-r-PcrV conjugate as a candidate vaccine against P. aeruginosa caused infections. 3-oxo-C12-HSL-r-PcrV conjugate was prepared and used for immunization of mice (10 µg, subcutaneous, three times, at 2-week intervals). Mice were divided into five groups: I: PcrV; II: 3-oxo-C12-HSL-r-PcrV (10 µg); III: 3-oxo-C12-HSL-r-PcrV (20 µg); IV: 3-oxo-C12-HSL; and V: PBS receiving groups. After each shot of immunization, total and isotype antibody responses against corresponding antigen were measured to determine the immunization efficacy. One month after the last immunization, all groups were burned and challenged subeschar with P. aeruginosa PAO1. Survival rate and bacterial quantity in the skin and internal organs (liver and spleen) were evaluated 25-hr after burn infection. Immunization with 3-oxo-C12-HSL-r-PcrV significantly increased total IgG and specific subclass antibodies (IgG1, IgG2a, IgG2b, and IgM) in the serum of the groups II and III compared to the control group (p<0.001). While all the control mice (PBS injected group) died within 2 days after bacterial challenge, 64% of the group I, 78% of group II, and 86% of group III, survived within 14 days after challenge. Interestingly, bacterial burden in the liver and spleen of 3-oxo-C12-HSL-r-PcrV injected group (III) was significantly lower than the control group (p<0.001). The present study proposed two-component vaccine to inhibit Pseudomonas infections in burned mouse.
Asunto(s)
4-Butirolactona/análogos & derivados , Antígenos Bacterianos/uso terapéutico , Toxinas Bacterianas/uso terapéutico , Quemaduras/microbiología , Homoserina/análogos & derivados , Inmunización/métodos , Proteínas Citotóxicas Formadoras de Poros/uso terapéutico , Infecciones por Pseudomonas/mortalidad , Infecciones por Pseudomonas/prevención & control , Vacunas Conjugadas/uso terapéutico , 4-Butirolactona/farmacología , 4-Butirolactona/uso terapéutico , Animales , Anticuerpos Antibacterianos/metabolismo , Antígenos Bacterianos/farmacología , Toxinas Bacterianas/farmacología , Modelos Animales de Enfermedad , Femenino , Homoserina/farmacología , Homoserina/uso terapéutico , Inmunidad Humoral/efectos de los fármacos , Inmunidad Humoral/inmunología , Hígado/microbiología , Ratones , Ratones Endogámicos BALB C , Proteínas Citotóxicas Formadoras de Poros/farmacología , Infecciones por Pseudomonas/inmunología , Pseudomonas aeruginosa/inmunología , Pseudomonas aeruginosa/aislamiento & purificación , Piel/microbiología , Bazo/microbiología , Tasa de Supervivencia , Vacunas Conjugadas/inmunología , Vacunas Conjugadas/farmacologíaRESUMEN
Quorum sensing signal molecules (QSSMs) from the bacterium Pseudomonas aeruginosa control bacterial population density and the expression of virulence determinants. Coincidentally, and possibly to allow this pathogen to gain a foothold in the human body, certain signal molecules also downregulate immunological responses in an apparently T-helper 1-selective manner, which would suggest their application as therapeutics to some autoimmune diseases. In the present paper, experiments are described that indicate that one particular signal molecule, a synthetic N-(3-oxododecanoyl)-L-homoserine lactone, can be used to alleviate insulitis and diabetes in non-obese diabetic (NOD) mice, suggesting that bacterial signal molecules may represent a novel source of immune modulatory compounds for the treatment of type 1 diabetes, which afflicts more than 2 million individuals in Europe and North America.