Study On Recombinant Chicken Interleukin-2 Used As Immunopotentiator

Chicken IL-2 was expressed using mammalian cell expression system. Four series experiments were carried out to study its dynamic expression and its reserve condition and its effect on immunity system in IBDV and E.tenella infection as immunopotentiator. Series 1 Dynamic expression of chicken IL-2 expressed using mammalian cell expression. IL-2 was expressed in COS-7 cell transfected with recombinant shuttle plasmid pSV. SPORT I and its biological activity and dynamic expression were assayed by chicken T cell proliferation test. The result suggests that IL-2 was expressed 72hr and reached peak 96 hr after transfection. Series 2 Reserve conditions of chicken recombinant interleukin-2. After stored at different temperature for different time, the activity of IL-2 was assayed using chicken T cell proliferation test. The results show that the optimal store condition for chicken recombinant interleukin-2 is under ?0 C, in which IL-2 can keep its activity a~ long as 7 months. Series 3 Effect of chicken recombinant interleukin-2 for IBDV vaccine as immunopotentiator. Chickens were divided into control group, inactived [BDV vaccine group and inactived LBDV vaccine +IL-2 group. Spleen lymphocyte transfonr~ation levels were tested and pathological changes of burs~l were observed after inoculation and challenge. The results shows that IL-2 can elevate significantly the level of lymphocyte transformation and decrease pathological changes by 20%, so that improve immune protection of inactived [BDV vaccine. Series 4 Effect of chicken recombinant interleukin-2 on immunity system of chicken in E.tenella infection. Chickens were divided into control groups groups infected by different doses oocyst and groups infected by different doses oocyst +IL- 2. IL-2 induced activity of lymphocyte and lymphocyte transformation level of ceacal tonsils and spleen were assayed in different days after first infection and challenge. Caecal tonsils lymphocyte transformation was inhibited continuously after first infection. Spleen lymphocyte transformation level of infected groups decreased 4 day after infection. Caecal tonsils lymphocyte [L-2 induced activity in iO~ and 2 X i0~ doses of oocyst groups increased 4 day after infection, then the 37 ~W ~Wfl~3r-%-2 f~J~Th)I~ ability of produce IL-2 decreased. Spleen lymphocyte IL-2 induced activity was lower than that of control group except for i04 group 4 day and 2,5 X io~ group 6 day after infectioit In infection+IL-2 groups, caecal tonsils lymphocyte transformation level was superior to inThttion group; spleen lymphocyte transformation level increase in low dose+IL-2 group. In these groups, caecal tonsils lymphocyte IL-2 induced activity was superior to infected and control group, spleen lymphocyte IL-2 induced activity in iO~ group elevate to a certain extent. After challenge, caecal tonsils and spleen lymphocyte transformation was inhibited continuous in infected groups; caecal tonsils lymphocyte IL-2 induced activity was supenor to control group 4 day and decreased 9 day after challenge. Spleen lymphocyte IL-2 induced activity was lower than that of control group at 4th day and increased at 9th day after challenge. In infectbn+IL-2 groups, caecal tonsils lymphocyte transformatior. was superior to infection group after challenge. Spleen lymphocyte transformation was superior to infection group and superior to control group 9 day after challenge. Caecal tonsils lymphocyte IL-2 i...