Interleukin 4 modulates neuroinflammatory responses in vivo.

SORIA, JA; GAVIGLIO, EA; ARROYO, DS; RODRIGUEZ-GALAN, MC; IRIBARREN, P

Mar del Plata, Argentina

Congreso; REUNIÓN ANUAL SOCIEDAD ARGENTINA DE INMUNOLOGÍA; 2009

SAI

Microglial cells (MC) are key immune cells within the central nervous system (CNS). They participate in CNS homeostasis being able to become activated once they contact exogenous and endogenous pro-inflammatory signals. After activation, MC coordinate the inflammatory responses to repair the CNS parenchyma, however, persistent activation may cause neurodegeneration. Anti-inflammatory cytokines such as IL-4 and IL-13 may induce “alternative activation” of MC which regulate neurotoxic inflammation. Here, we evaluated the effects of IL-4 on the CNS inflammatory response induced by systemic injections of lipopolysaccharide (LPS) on IL-4 KO mice. Our preliminary results indicate that MC isolated from IL-4 KO mice showed increased expression of MHC class II, CD80 and CD86 molecules than MC from wild type (WT) mice (p<0.05). After the LPS treatment the expression of costimulatory molecules on MC was higher than MC from non-treated mice (p<0.05). The expression of CD80 and CD86 in splenic CD11b+ cells was similar in IL-4 KO and WT. However, after LPS injections, the expression of MHC class II molecules was also increased in splenic CD11b+ cells from IL-4 KO mice compared to WT (p<0.05). These preliminary results suggest that IL-4 may be an important factor modulating CNS inflammatory response in vivo.in vivo..