Expression Of Interleukin-12 In Chinese Hamster Ovary(CHO)cells And Its Biological Activities

Interleukin?2(IL---12)is a newly discovered g]vcoprotein produced mainly by phagocytic cells, B lymphocytes and ant igcrr-prescnl ng cells, It acts as a growth factor for activated \I( and cci is and enhances the cytotoxic activity of NK and T cells. it is a key cytokine that induces Thl ccldifferentiation and imitiates cellediated immune responses. It appears promising in the antiumor and antinfection fields. Of all the cvtokines that have been cloned now, 11?2 is the only heterodimer that formed by two covaientiy linked giyeosylated chains of p35 and p40 subumits. Because of the complex structure of Jf..?2, it can not be expressed by B. Co] i. So the eukarvot Ic expression oF IL is the on. way to acquire lh?2 m vitro 1ev the (rher exji oration of its theory and ch.inical reserch. In order to acquire high expression and hio1ogic.iliv active I] 12, We dissected p35 and p40 suhunLs scparatlv tom [i?2/PACUW 42 plasmid by excisionase. Then we conducted plasmid rccombination using p35 arid p40 separatly with vector p1114 thai. can he expressed in eukarvocyte. Then the recombined pasmids and were transfected together to Chinese hamster ovary (C[lO) cells. To induce IL?2 with MSX screening for positive 11?2 cLones, ELISA method was used to test the prodution of IL?2. ~H桾dR aduitorment method was used to examine the JL?2抯 enhancing proliferation effects to peripheral blood granulocytes. The conclusions are as to] lcows: 1. The two subuwnits of IL?2梡35 and p40 can he r)htsmid recombined with eukaryotic expression vector梡EE1抣. 2. High copies of positive clones oY IL?2 can he acquired through p35/pEE14 and p40/pEE1I co梕xpression. 3. The two subunits of TL?2梡35 and p40 can he expressed together with plasmids of pEEJ4 in CHO cells. 4. IL條2 expressed in CI-10 cells can enhance the pro] i feration. of peripheral blood granulocvtcs. The results above showed that using pEELI as an expression vector, biologically active 1L?2 can be SLICCesstuliv expressed. It i~ a new way to get IL?2 for further studvsug its biological function and mechanism.