Mifepristone (RU486) restores the humoral immune response in bacterial endotoxins-induced immunosuppressed mice

REARTE B; MAGLIOCO A; BALBOA L; FERNANDEZ G; ISTURIZ M

Viña del Mar

Congreso; 9th Latin American Congress of Immunology; 2009

Introduction: Endotoxin tolerance, defined as a reduced responsiveness to lipopolysaccharide (LPS) after a first encounter with endotoxin, could be involved in sepsis-associated immunosuppression. Previously, we demonstrate that RU486, a glucocorticoid-receptor antagonist, induces the disruption of tolerance in mice. Objective: The aim of this study was to evaluate the effect of RU486 on immune response in LPS-induced immunosuppressed mice. Methods: BALB/c mice were immunosuppressed with LPS and then were treated with RU486 and immunized with sheep red blood cells. Parameters of immunosuppression and immune response were evaluated by flow citometry and hemagglutination on day 7. Results: splenocytes CD11b+ of immunosuppressed mice showed a decreased MHC-II and TLR4 expression (control: MHCII = 317±28; TLR4= 16±2 vs immunosuppresed: MHCII=153±16; TLR4= 6±1; MFI±SEM, p