Immunization with Brucella VirB proteins reduces organ colonization in mice through a Th1-type immune response and elicits a similar immune response in dogs.

Autor:	Pollak CN; Instituto de Estudios de la Inmunidad Humoral (IDEHU, CONICET-UBA), Cátedra de Inmunología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina., Wanke MM; Servicio de Teriogenología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina., Estein SM; Laboratorio de Inmunología, Departamento de Sanidad Animal y Medicina Preventiva, Centro de Investigación Veterinaria de Tandil (CIVETAN, CONICET), Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina., Delpino MV; Instituto de Estudios de la Inmunidad Humoral (IDEHU, CONICET-UBA), Cátedra de Inmunología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina., Monachesi NE; Servicio de Teriogenología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina., Comercio EA; Servicio de Teriogenología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina., Fossati CA; Instituto de Estudios de la Inmunidad Humoral (IDEHU, CONICET-UBA), Cátedra de Inmunología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina., Baldi PC; Instituto de Estudios de la Inmunidad Humoral (IDEHU, CONICET-UBA), Cátedra de Inmunología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina pablobal@ffyb.uba.ar.
Jazyk:	angličtina
Zdroj:	Clinical and vaccine immunology : CVI [Clin Vaccine Immunol] 2015 Mar; Vol. 22 (3), pp. 274-81. Date of Electronic Publication: 2014 Dec 24.
DOI:	10.1128/CVI.00653-14
Abstrakt:	VirB proteins from Brucella spp. constitute the type IV secretion system, a key virulence factor mediating the intracellular survival of these bacteria. Here, we assessed whether a Th1-type immune response against VirB proteins may protect mice from Brucella infection and whether this response can be induced in the dog, a natural host for Brucella. Splenocytes from mice immunized with VirB7 or VirB9 responded to their respective antigens with significant and specific production of gamma interferon (IFN-γ), whereas interleukin-4 (IL-4) was not detected. Thirty days after an intraperitoneal challenge with live Brucella abortus, the spleen load of bacteria was almost 1 log lower in mice immunized with VirB proteins than in unvaccinated animals. As colonization reduction seemed to correlate with a Th1-type immune response against VirB proteins, we decided to assess whether such a response could be elicited in the dog. Peripheral blood mononuclear cells (PBMCs) from dogs immunized with VirB proteins (three subcutaneous doses in QuilA adjuvant) produced significantly higher levels of IFN-γ than cells from control animals upon in vitro stimulation with VirB proteins. A skin test to assess specific delayed-type hypersensitivity was positive in 4 out of 5 dogs immunized with either VirB7 or VirB9. As both proteins are predicted to locate in the outer membrane of Brucella organisms, the ability of anti-VirB antibodies to mediate complement-dependent bacteriolysis of B. canis was assessed in vitro. Sera from dogs immunized with either VirB7 or VirB9, but not from those receiving phosphate-buffered saline (PBS), produced significant bacteriolysis. These results suggest that VirB-specific responses that reduce organ colonization by Brucella in mice can be also elicited in dogs. (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)
Databáze:	MEDLINE
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