NKT细胞在CFA促进的Th1型免疫应答中的作用

为探索CFA促进小鼠对蛋白质抗原产生Th1介导的特异性免疫应答的机制 ,我们用OVA +CFA和OVA +IFA免疫C5 7BL/6小鼠 ,并于第 3天、第 8天后用MACS +FACS法分离引流淋巴结中NKT细胞 ,在体外经CD3单抗刺激 2d后测定其分泌的细胞因子数量及格局。同时于免疫后第 8天分离引流淋巴结抗原特异性T细胞 ,测定其分泌细胞因子的格局 ;并于再次免疫后 2周检测小鼠血清抗体类型。ELISA结果显示 ,与OVA +IFA组相比 ,OVA +CFA免疫小鼠引流淋巴结NKT细胞和抗原特异性T细胞分泌IFN γ的能力均显著升高 (P <0 0 5 ) ,且血清抗体类型以IgG2a为主。表明CFA促进抗原特异性Th0细胞极化为Th1细胞可能是通过激活NKT细胞使之在免疫应答局部产生大量的IFN γ而实现的

Role of NKT Cells in CFA-Adjuvanted Th1 Type Immune Response to Protein Antigens

To explore the mechanism that CFA may induce mouse to produce Th1 type specific immune response to protein antigens, C57 BL/6 mice were immunized with chicken ovalbumin (OVA) emulsified with CFA or IFA. NKT cells from draining lymph node were isolatcd on day 3 and day 8 by MACS and FACS methods, then were stimulated with anti-CD3 mAb for 2 another days. The cytokines in the supernatant were quantified. Antigen specific T cells from draining lymph node were also isolated on day 8, and the cytokines in the supernatant were quantified too. The Ig isotypes in the peripheral blood were determined 2 weeks after restimulation. ELISA analyses revealed that compared with the OVA+IFA immunized group, both NKT cells and antigen specific T cells from draining lymph node produced more IFN-γ after im munization with OVA+CFA (P<0.05), and the Ig isot ype in the peripheral blood were IgG2a. Our results indicated that CFA can stim ulate NKT cells to produce IFN-γ, by which CFA may induce antigen specific Th0 cells to polarize to Th1 cells.