Experimental Study Of Th17 Related Factors Of Animal Models Infected With Mycoplasma Suis

ObjectiveTo investigate the variation of interleukin-17( IL-17),transforming growth factor-β(TGF-β),interleukin-6( IL-6) in the peripheral blood and spleen of mice, we infected the BALB/c mice with Mycoplasma suis to constitute a model..So we can explore Th17 subset in the occurrance, development and outcome of the laws, and lay the theoretical basis for further revealing the changes in immune function of the Mycoplasma suis.MethodsTwenty samples of pigs blood were collected asepticly from Institute of Animal Husbandry and Veterinary Medicine. The blood was identified positive by microscopic examination and PCR.BALB/c mice were divided randomly into group A (purified group),group B (positive group), group C(negative group) and group D(control group).They were injected intraperitoneal purified blood samples (0.5ml),positive blood samples (0.5ml), negative blood samples (0.5ml) and physiologic saline (0.5ml) respectively. We detected the concentrations of IL-17,TGF-β,IL-6 in the peripheral blood by using ELISA and expression changes of IL-17,TGF-β,IL-6 mRNA in the spleen by using RT-PCR on 1st d,3rd d,5th d,7th d,9th d after infected .Results1. The results of IL-17 concentration by using ELISA and RT-PCR showed: 1st d,3rd d,5th d,7th d,9thd after infected, group A was significantly higher than group D (P<0.05), agroup B was significantly higher than group C and D (P<0.05), and group C was significantly higher than group D (P<0.05). 5thd after infected,IL-17 concentration in the Peripheral blood of mouse raised to the highest point.2. The results of TGF-βconcentration by using ELISA and RT-PCR showed: 1st d,3rd d,5th d,7th d after infected, group A was significantly higher than group D (P<0.05), group B was significantly higher than group C and D (P<0.05), and group C was significantly higher than group D (P<0.05). 3rdd after infected, TGF-βconcentration raised to the highest point (P<0.05).9thd after infected, there were no statistically significance between the two of both in the four groups.3. The results of IL-6 concentration by using ELISA and RT-PCR showed: 1st d,3rd d,5th d,7th d,9thd after infected, group A was significantly higher than group D (P<0.05), agroup B was significantly higher than group C and D (P<0.05), and group C was significantly higher than group D (P<0.05). 7 thd after infected, IL-6 concentration raised to the highest point.4. Correlation analysis showed:By using ELISA method,the tendency of IL-17 and IL-6 was a positive correlation,group A (r=0.568),group B (r= 0.456);The tendency of TGF-βand IL-6 was a negative correlation, group A (r=-0.431) ,group B (r=-0.576). By using RT-PCR method,the tendency of IL-17 and IL-6 was a positive correlation,group A (r=0.420) ,group B (r=0.639);The tendency of TGF-βand IL-6 was a negative correlation, group A (r=-0.64 5) ,group B (r=-0.829).Conclusions1. The mice model infected with Mycoplasma suis was successfully established.The dynamic changes of IL-17,TGF-β,IL-6 concentration in the peripheral blood of mice and expression changes of IL-17,TGF-β,IL-6 mRNA in the spleen by RT-PCR2. In early stage of Mycoplasma suis, IL-17,TGF-β,IL-6 concentration increased,which indicated Mycoplasma suis may cause Th17 lymphocyte sub -set differentiate. The results assisted scientific data of proinflammatory mechanism of Mycoplasma suis . 3. IL-17,TGF-β,IL-6 concentration raised to the highest point were at 5th d,3rd d,7th d respectively.The results indicated that between the three had internal relations. Interaction of both TGF-β,IL-6 promoted the secretion of IL-6 by Th17 lymphocyte subset.Then the production of IL-17 can promote the other cells secrete IL-6.The results provided a dynamic theory of function of Th17 subset at the process of mice infected with Mycoplasma suis.