INVESTIGADORES
FOSSATI Carlos Alberto
congresos y reuniones científicas
Título:
ORALLY-INDUCED CD4+ CD25+ FOXP3+ TREG SUPPRESSED FOOD ALLERGIC REACTIONS
Autor/es:
SMALDINI P; ORSINI DELGADO L; FOSSATI CA; DOCENA GH,
Lugar:
Mar del Plata
Reunión:
Conferencia; LXII Reunión Anual Sociedad Argentina de Inmunología.; 2014
Institución organizadora:
SAI-SAIC
Resumen:
Food
allergy is an immune-mediated adverse reaction to food and its prevalence has
increased worldwide. Defects in Treg cells have been reported in patients with
food allergies, suggesting that an impaired tolerance may play a key role in
the intestinal allergic inflammation. We aimed to assess the suppressive effect
of regulatory T cells to alleviate food allergy in a mouse model. Balb/c mice
were orally given CMP (CMPprev) prior to oral sensitization with CMP and
cholera toxin (prevention), or after sensitization (desensitization) (CMPdes).
Mice were orally challenged with CMP and the immune response was evaluated with
in vivo (clinical score and cutaneous tests) and in vitro assays
(serum specific IgE, IgG1, IgG2a; IL-5, IL-13, IFN-γ, IL-10 and TGF-β secretion
by spleen cells, and analysis of Treg cells in the intestinal mucosa). In
vitro and in vivo induced-Treg cells were intravenously transferred
to naïve mice before sensitization. We found that symptoms were controlled with
oral administration of CMP, with a concomitant negative skin test. Accordingly,
serum specific IgE and IgG1 were abrogated (IgE: 1.57±0.2 vs 0.87±0.2 CMPdes;
0.52±0.1 CMPprev), and a substantial reduction in the secretion of IL-5 and
IL-13 by stimulated spleen cells from sensitized mice was observed.
Importantly, we found that IL-10 and TGF-β were induced with treatment along
with an induction of CD4+CD25+FoxP3+ cells (1.02±0.3% vs 10.5±0.5% CMPdes;
4.30±0.2% CMPprev) and IL-10- and TGF- β-producing regulatory T cells (Tregs)
in the lamina propria and in MLN. Mice that received Treg by adoptive transfer
showed alleviated clinical signs, low levels of serum IgE and induced a negative
skin test. We concluded that the oral administration of milk proteins pre- or
post-sensitization with CMP induced lamina propria Treg, that restored
tolerance and subsequently controlled the allergic response.