Detection of apoptosis induced by Yersinia enterocolitica infection in immunodeficent mice.

GUTIÉRREZ J; GÓMEZ N; STEFANINI DE GUZMÁN A; DI GENARO S

Mendoza

Congreso; XXIII Reunión Anual de la Sociedad de Biología de Cuyo-2005; 2005

Sociedad de Biología de Cuyo

Yersinia enterocolitica is a Gram negative pathogen that causes enteritis and enterocolitis in humans and rodents. Interleukin 12 (IL-12) by induction of IFN-g mediates protective mechanisms against the Yersinia infection. Interleukin 4 (IL-4) antagonizes the protective response against this pathogen. Apoptosis can play a role in infections. The purpose of this work was to study the impact of IL-12 and IL-4 deficiency in apoptosis induced by Yersinia infection. IL-12 knockout (IL-12 -/-), IL-4 knockout (IL-4 -/-) mice and wild type C57BL/6 mice were orogastrically infected with 2x108 colony-forming units (CFU) of Y. enterocolitica 0:3. Mice were sacrificed at day 3 postinfection.  Fluorescent dye staining with ethidium bromide-acridine orange (early and late stages of apoptosis), DNA fragmentation (late stages of apoptosis) and the mRNA expression of pro-apoptotic (Bax) and anti-apoptotic (Bcl2) genes were measured. We observed differences in the induction of apoptosis between the groups of mice and in different organs and methods. Lower apoptosis in the spleen of IL-4 -/- mice (p<0,05) was detected. Higher DNA fragmentation and Bax expression were observed in Peyer’s patches of IL-12 -/- mice. We concluded that IL-12  deficiency increases apoptosis induction in mucosa of oral Yersinia infected mice.