Ethanol-induced colitis prevents oral tolerance induction in mice
Braz. j. med. biol. res
; 36(9): 1227-1232, Sept. 2003. ilus, graf
Artigo
em Inglês
| LILACS
| ID: lil-342862
Biblioteca responsável:
BR1.1
RESUMO
The gut mucosa is a major site of contact with antigens from food and microbiota. Usually, these daily contacts with natural antigens do not result in inflammatory reactions; instead they result in a state of systemic hyporesponsiveness named oral tolerance. Inflammatory bowel diseases (IBD) are associated with the breakdown of the immunoregulatory mechanisms that maintain oral tolerance. Several animal models of IBD/colitis are available. In mice, these include targeted disruptions of the genes encoding cytokines, T cell subsets or signaling proteins. Colitis can also be induced by intrarectal administration of chemical substances such as 2,4,6-trinitrobenzene sulfonic acid in 50 percent ethanol. We report here a novel model of colitis induced by intrarectal administration of 50 percent ethanol alone. Ethanol-treated mice develop an inflammatory reaction in the colon characterized by an intense inflammatory infiltrate in the mucosa and submucosa of the large intestine. They also present up-regulation of both interferon gamma (IFN-gamma) and interleukin-4 (IL-4) production by cecal lymph node and splenic cells. These results suggest a mixed type of inflammation as the substrate of the colitis. Interestingly, cells from mesenteric lymph nodes of ethanol-treated mice present an increase in IFN-gamma production and a decrease in IL-4 production indicating that the cytokine balance is altered throughout the gut mucosa. Moreover, induction of oral tolerance to ovalbumin is abolished in these animals, strongly suggesting that ethanol-induced colitis interferes with immunoregulatory mechanisms in the intestinal mucosa. This novel model of colitis resembles human IBD. It is easy to reproduce and may help us to understand the mechanisms involved in IBD pathogenesis
Texto completo:
Disponível
Coleções:
Bases de dados internacionais
Base de dados:
LILACS
Assunto principal:
Ovalbumina
/
Interleucina-4
/
Interferon gama
/
Colite
/
Modelos Animais de Doenças
/
Etanol
Tipo de estudo:
Estudo prognóstico
Limite:
Animais
/
Humanos
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
2003
Tipo de documento:
Artigo
País de afiliação:
Brasil
Instituição/País de afiliação:
Universidade Federal de Minas Gerais/BR