SUPPRESSION OF ALLERGIC AIRWAY INFLAMMATION BY ADMINISTRATION OF TOXOPLASMA GONDII TOTAL LYSATE ANTIGENS.

MARÍA DE LOS ANGELES ALDIRICO; MATIAS PERRONE SIBILIA; ARIADNA SOTO; VANESA R. SÁNCHEZA; MARIANO S. PICCHIO; NADIA ARCÓN; IGNACIO FENOY; VALENTINA MARTÍN; ALEJANDRA GOLDMAN

Congreso; First LASID-SAI-FAIC; 2015

The pathogenesis of asthma reflects the influences of multiple risk factors. Between them, the lack of some infections would be mainly responsible for the growing prevalence. Using a mouse model of experimental asthma, we previously showed that T. gondii infection before sensitization blocked the development of airway inflammation. The aim of the present work was to study whether administration of total lysate antigens (TLA) of this parasite replicates the suppression of pathology seen with live T. gondii infection. C57BL/6 mice were ip sensitized and aerosol challenged with OVA (O). During sensitization, experimental group received via ip. TLA 25 (OT25) or 50µg (OT50) along with the allergen. Negative controls include non-sensitized mice ip injected with PBS (P) or TLA (T), both challenged with PBS. Addition of TLA resulted in profound suppression of airway allergic inflammation measured by total cell numbers (P:16±1; T:15±4; O:124±22; OT25:14±11*; OT50:28±10*;X±SEMx104) and eosinophils infiltrate in bronchoalveolar lavage (P:0.9±0.9; T:0.8±0.8; O:456±123; OT25:177±39; OT50:59±28*; X±SEMx103). H&E and PAS staining of lung sections showed reduced inflammatory infiltrate and mucus production with TLA administration. Anti-OVA IgG1-isotype was significantly diminished (P:0,006±0.002; T:0.006±0.001; O:151±0.058; OT25:0.116±0.036; OT50:0.033±0.023*; OD±SEM) and IgE completely ablated (P:0,047±0,010; T:0,035±0,003; O:0,084±0,010; OT25:0,0438±0,010*; OT50:0,039±0,005*;OD±SEM). An increase in anti-OVA IgG2a-antibodies was not detected indicating that a Th1 shift had not occurred. BAL fluid contained lower levels of IL-5 (P:106±28; T:83±8; O:166±33; OT25:145±20; OT50:52±11*; pg/ml±SEM). *p