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

KINETIC OF THE SPECIFIC HUMMORAL IMMUNE RESPONSE IN SHEEP
IMMUNIZED WITH Toxoplasma gondii SURFACE GLYCOCONJUGATES
PATRÍCIA OLIVEIRA MEIRA SANTOS (PG)(1,2); MARIA TEREZA BARRETO
GUEDES (PG)(1); DAN LOUREIRO (PG)(1); BRUNO LOPES BASTOS (1);
JOSE TADEU RAYNAL (PG)(1); CIRO DE OLIVEIRA LIMA (2); DANIEL
FACUNDO DA SILVA (2); ROBERTO MEYER (1); RICARDO WAGNER
PORTELA (1)
(1) Laboratory of Immunology and Molecular Biology, Health Sciences
Institute, Federal University of Bahia
(2) Medical School, Federal University of Ceará – Cariri
Introduction: Toxoplasmosis is a relevant disease in human and animal
medicine; the infection with the parasite can lead to cause abortion and
neonatal death, as well as neurologic symptoms at immunosuppressed
individuals. With the growth of Brazilian sheep industry, the knowledge of the
immune response against this protozoan and the development of diagnostic
assays could significantly contribute to the infection control and productivity
improvement. This study had the objective to evaluate the specific humoral
immune response kinetics in sheep immunized with Toxoplasma gondii surface
glycoconjugates (GlyC) or challenged with parasite tachyzoites. Methods and
Results: Sheep (n=16) were injected with saline (G1), GlyC+saponin (G2) or T.
gondii tachyzoites (G3). An ELISA was developed to evaluate the specific
immunoglobulin production; GLyC specific IgG was measured in several
moments pos-inoculation (p.i.). The ELISA developed presented repeatability
and reproducibility of 94.3% and 96.2%, respectively. Anti-GlyC IgG levels in
the G2 and G3 groups began to rise by 10 days p.i., and the highest levels were
found at day 12. At G3, higher IgG levels were found at day 30 p.i. There is a
significant difference at IgG seric levels in sheep immunized with T. gondii
derived glycoconjugates and infected with the parasite between the 10 th and
60 th days p.i. Conclusion: The ELISA anti-GlyC seems to be a promising tool in
the diagnostic if infected sheep.
Financial Support: Northwest Bank and FAPEX.