immunology of infectious and parasitic diseases - XXXVII Congress ...

EXPERIMENTAL ALLERGIC ASTHMA IS MODULATED BY SCHISTOSOMA
MANSONI SCHISTOSOMULA TEGUMENT (SMTEG) WITH DOWN
REGULATION OF EOSINOPHILS AND SPECIFIC ANTI-OVA IGE.
SARA CAMILA DE SOUZA(IC) (1) ; FABIO A. V. MARINHO(PG) (2) ; CRISTINA T.
FONSECA(PQ) (1) ; SERGIO C. OLIVEIRA(PQ) (2) ; LUCILA G. G.
PACIFICO(PQ) (1) .
(1) .Centro de Pesquisa René Rachou (CPqRR) - FIOCRUZ/MG; (2) .Universidade
Federal de Minas Gerais (UFMG).
Introduction: Allergic inflammations are directed by Th2 cells activation, high
levels of IgE and eosinophilia. Schistosoma mansoni infection has a negative
association with allergic disease in endemic areas, feature that is supported by
experimental models. The schistosomulum is the first pathogen stage to keep
contact with host immune system. Its tegument (Smteg) represents an
important interface host-pathogen, activating antigen presenting cells. Our
previous results showed that Smteg stimulated interleukin (IL)-10 production
and downregulated lung pathology and CCL11 levels. Our goal is to investigate
other inflammatory parameters (IgE and protein extravasation) as well as the
cell population involved in IL-10 production to better characterize the
mechanism underlying this modulation. Methods and Results: Smteg was
prepared using cercariae as described by Durães F.V. et al., 2009. Balb/C mice
were divided into three groups (n=6): PBS, Asthma and Smteg/Asthma. At days
0 and 14 all groups were immunized with 10µg of ovalbumin chicken egg (OVA)
plus alum and at 7 th day Smteg/Asthma group received 25g of Smteg,
intraperitoneally. During 21 th to 25 th days the Asthma and the Smteg/Asthma
groups were challenged by OVA aerosol. At 26 th day mice were euthanized.
Blood samples were collected for IgE measurement in sera, broncho-alveolar
lavage was performed to counting of eosinophils numbers and protein analysis.
The lungs were collected to flow cytometetry analysis. All parameters were
higher in Asthma group compared to PBS group. Importantly, the injection of
Smteg (Smteg/Asthma group) reduced the number of eosinophils (p