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

IMMUNOMODULATORY MECHANISMS OF SOLUBLE ANTIGEN OF
TACHYZOITES (STAg) IN THE INTESTINAL INFLAMMATORY LESIONS
INDUCED BY ORAL INFECTION WITH Toxoplasma gondii
LUCIANA ALVES DE SOUSA 1 ; ALEXSANDRA ALVES BEZERRA MARTINS 1 ;
ESTER CRISTINA BORGES ARAÚJO 1 ; PAULO VICTOR CZARNEWSKI
BARENCO 1 ; DEISE APARECIDA OLIVEIRA SILVA 2 ; JOSÉ ROBERTO
MINEO 2 ; NEIDE MARIA SILVA 1
1
Laboratory of Immunopathology, Institute of Biomedical Sciences, Federal
University of Uberlândia
2
Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal
University of Uberlândia
Introduction: C57BL/6 mice orally infected with 100 cysts of Toxoplasma
gondii ME-49 strain are highly susceptible to acute infection, with massive
necrosis of the intestinal villi and mucosal cells, as well as intense influx of
inflammatory cells in the small intestine. Intraperitoneal treatment with STAg 48
hours prior oral infection with high parasitic load of T.gondii is able to reduce the
intestinal inflammatory response caused by parasites in the susceptible mice,
C57BL/6.
Methods and Results: In order to verify the role of STAg in oral infection with
T.gondii, resistant, BALB/c, and susceptible, C57BL/6 mice were treated with
phosphate buffered saline (PBS) or STAg 48 hours before oral infection with 30
cysts of T.gondii ME-49 strain and sacrificed on day 8 after infection.
Pretreatment with STAg attenuated the intestinal inflammatory immune
response induced by the parasite and increased the Goblet, Paneth and IgA
positive cell numbers in the small intestine of susceptible and resistant animals.
Conclusion: The results suggest that the prior injection of STAg is able to
promote protective mechanisms in the small intestine of orally T. gondii infected
animals, which are mediated by goblet and Paneth cells and local secretion of
IgA.
Financial Support: CAPES, CNPq, FAPEMIG