PATTERN OF PROINFLAMMATORY CYTOKINE MESSENGER-RNA EXPRESSION DURING TRICHINELLA-SPIRALIS INFECTION OF THE RAT

Trichinella spiralis occupies an intramulticellular niche in the small intestinal epithelium, and thus we examined the intestine and gut-ass ociated tissues for proinflammatory cytokines during the infection, We document the patterns of interleukin-l (IL-1), IL-6, gamma interferon , and tumor necrosis factor alpha mRNA expression in the duodenum, jej unum, Peyer's patches, mesenteric lymph node, spleen, and liver in T. spiralis-infected rats. By reverse transcription-PCR detection of mRNA s, IL-1 beta was found increased in the jejunum but only on day 2. The jejunal IL-1 beta increase was attributed to the epithelium by isolat ing epithelial cells and then depleting them of intraepithelial lympho cytes prior to analysis, The only cytokine for which mRNA was substant ially increased in tissues later in infection was tumor necrosis facto r alpha in the spleen and, to a lesser extent, in the mesenteric lymph node, In fact mRNA levels for some cytokines declined below uninfecte d levels in some organs during the infection, IL-1 may be important in the initiation of the intestinal inflammatory response to this infect ion.