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

IN PREGNANT MICE, FOXP3+ CELLS ARE INVOLVED IN THE
PROTECTION AGAINST EMBRYOS RESORPTION IN CONGENITAL
TOXOPLASMOSIS
RÔMULO OLIVEIRA SOUSA 1 ; LETÍCIA DE SOUZA CASTRO-FILICE 2 ;
LOYANE BERTAGNOLLI COUTINHO 1 ; LAYANE ALENCAR COSTA
NASCIMENTO 1 ; ELOISA AMÁLIA VIEIRA FERRO 2 ; TIAGO WILSON
PATRIARCA MINEO 3 ; NEIDE MARIA SILVA 1
1. Laboratório de Imunopatologia, 2. Laboratório de Imunofisiologia da
Reprodução, 3. Laboratório de Imunoparasitologia, Universidade Federal de
Uberlândia, roolsou@hotmail.com
Introdution: Congenital toxoplasmosis is associated with adverse pregnancy
outcome. Despite the type 1 immune response, C57BL/6 is more susceptible
than BALB/c mice to Toxoplasma gondii infection. Additionally, the successful
pregnancy appears to be correlated with Th2- type maternal immunity and also
Treg cells.
Methods and Results: In order to investigate mechanisms of
susceptibility/resistance of mice with different genetic background in congenital
T. gondii infection, groups of C57BL/6 and BALB/c females were orally infected
with T. gondii ME-49 on day 1 of pregnancy and were sacrificed on day 8 post-
infection. The uterus and placenta were evaluated for resorption rate,
parasitism, histological analysis and phenotype of cell infiltrates. C57BL/6
presented inflammatory foci in the decidua in a higher frequency compared to
BALB/c mice on day 8 of pregnancy and infection, and great number of
pregnant C57BL/6 mice presented necrotic implantation sites. The C57BL/6
mice presented higher resorption rate observed on day 19 of pregnancy and
infection. Pregnant and infected C57BL/6 mice showed higher CD4, CD8 and
Mac1 positive cells in the uterus compared to BALB/c mice. Additionally, it was
verified that BALB/c mice presented statistically higher FoxP3 positive cells and
a tendency of higher IL-17 positive cells in the uterus compared to C57BL/6
mice at the same time of pregnancy and infection.
Conclusion: Our data suggest that the CD4, CD8 and Mac1 positive cells
infiltrated in the uterus are contributing to the higher resorption rate in C57BL/6
mice and FoxP3 + cells that are associated with a regulatory profile in addition to
IL-17 positive cells, are contributing to smaller resorption rate in BALB/c mice.
Financial support: FAPEMIG, CNPq