INVESTIGADORES
GOLDMAN Alejandra
congresos y reuniones científicas
Título:
Further analysis of protection induced by the rTgPI-1 vaccine against Toxoplasma gondii: characterization of the vaccine-induced immune responses in C57BL/6 mice
Autor/es:
SÁNCHEZ, VANESA R1; RODRIGUEZ, FACUNDO M; FENOY, IGNACIO M; GONZÁLEZ COBIELLO, P2; GOLDMAN ALEJANDRA; MARTIN VALENTINA
Reunión:
Congreso; First French-Argentine Immunology Congress FAIC; 2010
Resumen:
We previously showed that the recombinant
protein rTgPI-1 (PI) used as an immunogen, resulted a potent vaccine against
toxoplasmosis in two mouse strains. Vaccination of highly susceptible C57BL/6
mice induced a reduction of 49% in the parasite load after an oral infection.
This protection was achieved only when a prime-boost protocol combining
intradermical (ID) and intranasal (IN) immunizations were used. This strategy
that included Alum (A) ID and ODN-CpG (C) IN induced the elicitation of a Th1
specific humoral response. The present study was conducted to further
characterize the cellular immune response generated by the PI-based protective
vaccine. B6 mice were inoculated with 2 doses of [PI+A] ID and boosted with 2
doses of [PI+C] IN (G4) and the control groups received 4 doses of [PI+C] IN
(G3) or [PI+A] ID (G2) or 2 [A]id + 2 [PI+C] IN (G5) or 2 [PI+A]ID + [C]IN (G6)
and a naïve control group was also included (G1). Two weeks after the last
inoculation, some groups of animals were sacrificed for in vitro splenocyte culture studies (G1-4). After 5 days of in vitro PI stimulation, only G4 showed
a significant lymphoproliferative response (Δcpm G4:24813±4209 vs G1:94±1,3a),
and a significant increment in both CD4+ (absolute cell number G4:169667±28312
vs. G1:62550±1703a) and CD8+ lymphocytes (G4:92767±16372 vs. G1:
30300±462a) as measured by flow-cytometry. In order to test if both
id and in administration of PI (G4) was necessary for protection, a challenge
assay was performed including control G1, G5 and G6 groups. We observed that
only G4 mice presented a significant brain parasite load reduction (G4:562±131
vs. G1:1910±153b) with an in vivo
specific cellular response measured by a DTH assay (mm G4:0,089±0,016 vs.
G1:0,031±0,009a) (Data: mean±SEM; ap<0.05; bp<0.01).
These results indicate that this PI-based protective immunization strategy, in
which PI is administrated by both the ID and IN routes, elicited a humoral and
also a strong cellular immune response