Dynamic Changes Of Murine Interfereon-gamma And Interleukin-4 During Salmonella Typhimurium Infection

OBJECTIVE To analysis the difference of dysbacteriosis, immunos-uppression and probiotics effects on T helper cell response to infection with Salmonella in mice. We investigate the immunological mechanism of interaction between state of organis and infection. METHOD 101 KunMin mice were divided into five groups, dysbacteriosis group, immunosup- pression group, probiotics group, untreat infection group and control group, respect-tively. The mice of dysbacteriosis, immunos- uppression, probiotics and untreat infection groups were infected orally S.Typhimurium by a single dose, and were sacrificed on series time points. Microscope observed pathological organ of spleen, liver and small intestine. ELISA test detected serum interferon-γ(IFN-γ) and interleukin-4(IL-4).RESULT The expression of IFN-γ was significan- tly higher in dysbacteriosis group than all other groups and increase gradually. Pathological lesion of mice in dysbacteriosis group was the most serious. IL-4 was no change in dysbacteriosis group compared with the untreat infection group. The expression of IL-4 in group immunosu-ppression was significantly higher than all other groups. but The expression of IFN-γ was lower than dysbacteriosis and probiotics groups,but non change comparing with the untreat infection group. The pathological lesions inimmunosuppression group were serious, but were lighter than dysbacteriosis group. The expression of IFN-y in group probiotics was also raised significantly comparing with immu- nosuppression and untreat infection group, the expression of IL-4 was lower than all other groups. The pathological lesions in probiotics group were the most light. Conclusion Intestinal dysbacteriosis induced excessively Thl type immunological response to salmonella infection, immunosupperssion induced excessively Th2 type immu- nological response to salmonella infection, and probiotics could cor- rect the deviation and promote immunological response to make for cleaning invasion pathogen and maintain suitable immunological response of organis.