Mucosal co-immunization of mice with recombinant lactococci secreting VapA antigen and leptin elicits a protective immune response against Rhodococcus equi infection.
Vaccine
; 30(1): 95-102, 2011 Dec 09.
Article
en En
| MEDLINE
| ID: mdl-22019740
ABSTRACT
Rhodococcus equi causes severe pneumonia in foals and has recently gained attention as a significant opportunistic pathogen in immunocompromised humans. However, no effective vaccine to prevent rhodococcosis is currently available. In this study, we have engineered the food-grade bacterium Lactococcus lactis to secrete the virulence-associated protein A from R. equi (LL-VapA). The immunogenic potential of LL-VapA strain was then evaluated after either intragastric or intranasal immunization in mice either alone or in combination with LL-Lep, a recombinant strain of L. lactis secreting biologically active leptin, a pleiotropic hormone with significant immunomodulatory properties. Intragastric administration of LL-VapA led to the highest VapA-specific mucosal response whereas intranasal administration led to the highest systemic immune responses. Cytokines released from in vitro-stimulated spleen cells show both a strong IFN-γ response and an increase of IL-4 level in all immunized groups, except for the group intranasally co-administered with both LL-VapA and LL-Lep. Strikingly, a significant reduction in R. equi viable counts in liver and spleen was observed four days after intravenous challenge with a virulent strain of R. equi in all immunized groups except for the group vaccinated by intragastric route with LL-VapA. Altogether, our results demonstrate that LL-VapA can evoke a T(H)1-based protective immune response in intranasally immunized mice. This response is enhanced when co-administered with LL-Lep strain, whereas only co-administration of LL-VapA and LL-Lep can induce a protective immune response in intragastric vaccinated mice, associated with a T(H)1/T(H)2 cytokine response.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Proteínas Bacterianas
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Infecciones por Actinomycetales
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Portadores de Fármacos
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Vacunas Bacterianas
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Rhodococcus equi
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Lactococcus lactis
Límite:
Animals
Idioma:
En
Revista:
Vaccine
Año:
2011
Tipo del documento:
Article
País de afiliación:
Francia