Effect of tumor necrosis factor receptor p55 deficiency on the response of peritoneal macrophages to Yersinia antigens

ELIÇABE J.; DI GENARO S.

Potreros de los Funes, San Luis

Congreso; XXIV Reunión Científica Anual de la Sociedad de Biología de Cuyo, IV Reunión Científica de la Sociedad Argentina de Microscopía (SAMIC); 2006

Sociedad de Biología de Cuyo

We demonstrated that TNFRp55 has a protective role in Yersinia enterocolitica O:3 reactive arthritis (ReA). The objective was to study the role of TNFRp55 on the macrophage response to Yersinia arthritogenic antigens. Thioglycollate elicited peritoneal macrophages from wild-type and TNFRp55-/- C57BL/6 mice were obtained. For killing assays, adherent cells were infected with Yersinia (moi 1:100) and intracellular bacteria were counted at 0 and 90 min. Lipopolysaccharide (LPS) and outer membrane proteins (OMP) were prepared. Macrophages were stimulated with LPS O:3, O:5, O:8 (10 µg/ml) or OMP O:3 (50 µg/ml). Nitric oxide (NO) production, as nitrite, was measured in 6, 48 and 72 h supernatants using Griess reagent. Morphological changes of the cells were evaluated. TNFRp55-/- macrophages showed impaired intracellular Yersinia killing (p<0.05). The NO concentration was higher at 72 h (p<0.01) and lower with LPS O:3 (p<0.05). NO production was increased in TNFRp55-/- macrophages (p<0.001 and p<0.003 with LPS or OMP stimulation, respectively). Differential morphological changes were detected in wild-type and TNFRp55-/- macrophages, and after LPS or OMP stimulation. We concluded that TNFRp55 influences the response of macrophages to Yersinia antigens.