Dichotomy between the innate immune responses by all trans-retinoic acid treatment in a model of LPS-induced immunosuppression

MARTIRE GRECO, D.; RODRIGUEZ RODRIGUES, N.; LANDONI, V.I.; CHIARELLA, P.; SCHIERLOH, P.; REARTE, B.; ISTURIZ, M.A.; FERNANDEZ, G.C.

Los Cocos, Córdoba

Congreso; LXI Reunión Anual de la Sociedad Argentina de Inmunología; 2013

SAI

Immunosuppression (IS) related to late phases of sepsis is a medical concern. The model of tolerance to LPS mimics aspects of sepsis-associated IS, as exposure to repetitive doses of LPS generates a refractory state, where animals inyected with letal dosis of LPS survive and have low amounts of LPS-induced TNF. Despite impaired immune functions in LPS-induced IS, the clearance of bacteria is increased in part due to neutrophils (PMN) activity. All-trans-retinoic acid (ATRA) is a derivative of vitamin-A with immunomodulating properties. Our objective was to study the effects of ATRA on innate an adaptive responses in LPS-induced IS. We used a murine model inyecting increasing e.v. doses of LPS for 20 days simultaneously with oral doses of ATRA (IS group: 5 to 20 µg/day/mouse of LPS, IS+ATRA group: LPS+500 µg/day/mouse of ATRA). When we studied the adptative immune response, we observed an enhanced primary humoral immune response against a particulated T-dependent antigen measured by hemagglutination in the IS+ATRA group (Titre:IS=2133±426, IS+ATRA=6827±1707, p