CYTOKINE PROFILE INVOLVED ON TH17 DIFFERENTIATION IN TNFRP55-/- MICE WITH YERSINIA INDUCED-REACTIVE ARTHRITIS

CARGNELUTTI E; ELIÇABE RJ; DI GENARO MS

Mendoza

Congreso; XXVI Reunion Cientifica Anual de la Sociedad de Biologia de Cuyo; 2008

Sociedad de Biologia de Cuyo

We demonstrated that TNFRp55 deficient mice develop reactive arthritis (ReA) after oral Yersinia enterocolitica O:3 infection. The objective was to compare the cytokine profile involved in T helper (Th) 17 differentiation in mucosal and articular regional lymph nodes of infected C57BL/6 wild-type (WT) and TNFRp55-/- (KO) mice. The mice were orally infected with 1-6 x 108 colony-forming units (CFU) of Y. enterocolitica O:3. At days 7, 14 and 21 after infection, the mice were sacrificed and mesenteric (MLN) and inguinal (ILN) lymph nodes were aseptically removed. Organ homogenates were prepared and clarified by centrifugation. The supernatants were used for cytokine determinations. Interleukin (IL)-17, tumor growth factor (TGF)-â and IL-6 levels were measured by ELISA. At day 7, we found higher levels of IL-17 in KO than WT mice in MLN (p<0.01) and ILN (p<0.02). Similar results were detected but only in ILN at day 21(p< 0.05). The IL-17 levels in MLN were in parallel with IL-6 and TGF-a at day 7 (p<0.02 and p<0.005, respectively), and in ILN at days 7 (p<0.008 and p<0.003, respectively) and 21 (p<0.01 and p<0.02, respectively). Interestingly, WT mice showed higher MLN TGF-â level at day 21 after infection (p<0.01). We concluded that KO mice with Yersinia-induced ReA have higher IL-6 and TGF-â response related with Th17 differentiation, and that in contrast with MLN, ILN do not control this IL-17 response.