IDEHU   05542
INSTITUTO DE ESTUDIOS DE LA INMUNIDAD HUMORAL PROF. RICARDO A. MARGNI
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Immunomodulatory properties of a Brucella abortus protein in a food allergy mouse model
Autor/es:
SMALDINI P; IBAÑEZ A; FOSSATI, CA; CASSATARO J,; DOCENA GH,
Reunión:
Congreso; First French-Argentine Immunology Congress. LVIII Reunión Anual de la Sociedad Argentina de Inmunología; 2010
Resumen:
Immunomodulation constitutes a potential
therapy for food allergy. It has been reported that a protein from Brucella
abortus (Bp) produced a Th1
in vitro and in vivo immune response in mice immunized by oral or
intraperitoneal routes. The aim of this work was to use Bp as a mucosal
immunomodulator in a cow`s milk allergy mouse model. Balb/c mice were
intragastrically immunized with cow`s milk protein (CMP) using cholera toxin (CT)
as a Th2 mucosal adjuvant. Mice were simultaneously treated with recombinant Bp
intranasally (Bp in), with Bp intragastrically (Bp ig), with E. coli LPS in
(control group), with synthetic ODN CpG ig (control group) or with saline
(control group). Finally, mice were orally challenged with CMP. Immune response
was evaluated with in vitro (serum specific IgE, IgG1 and IgG2a, histamine,
IL-5 and IFN-g secretion by splenocytes) and in vivo assays (clinical score, cutaneous
tests and DTH). IL-5 and IFN-g mRNA expression was assessed in intestinal tissue. We found lower
clinical scores and plasma histamine levels in treated mice after the oral
challenge than in sensitized animals. Cutaneous tests were positive e in
sensitized mice, while negative or mild in the treated groups. DTH was
statistically higher in Bp and LPS treated animals (0.20±0.07; 0.16±0.09 vs
0.074±0.04, p<0.05). Besides, specific IgE was suppressed [1.06±0.30 vs
0.54±0.21 (Bp in); 0.22±0.2 (LPS); 0.87±0.23 (Bp ig); 0.45±0.18 (CPG)], while
IgG2a was increased, in treated mice. IL-5 and IFN-g were modulated by the different immunomodulators at
the protein and mRNA levels. In conclusion, a protein from Brucella abortus,
LPS and CpG, were found to modulate the specific Th2 immune response elicited
with CMP plus CT, by mucosal administration in Balb/c mice. These results may
constitute the basis for a potential immunomodulatory therapy in food allergy.