CCK-8对KLH免疫小鼠脾细胞Th1／Th2平衡的影响

Cholecystokinin octapeptide modulates Th1/Th2 imbalance in splenocytes of KLH-immunized mice

目的:探讨八肽胆囊收缩素(CCK-8)对Th1/Th2平衡的调节作用。方法:给予BALB/c小鼠钥孔戚血蓝蛋白(KLH)免疫同时体内给予不同剂量的CCK-8,酶联免疫吸附试验(ELISA)检测其脾细胞培养上清中Th1型细胞因子γ-干扰素(IFN-γ)、白细胞介素-2(IL-2)和Th2型细胞因子白细胞介素-4(IL-4)、白细胞介素-5(IL-5)水平,逆转录聚合酶链式反应(RT-PCR)法检测脾细胞中IFN-γ、IL-2、IL-4、IL-5 mRNA表达;ELISA法检测血清中Th1型抗KLH抗体IgG2a和Th2型抗KLH抗体IgG1水平。结果:①KLH免疫使小鼠脾细胞分泌Th1/Th2型细胞因子水平明显增高,mRNA表达增高,KLH免疫同时给予CCK-8可使脾细胞培养上清中IFN-γ、IL-2含量进一步增加和IFN-γ、IL-2 mRNA表达增高,而使IL-4、IL-5含量降低,IL-4、IL-5 mRNA表达减低和降低IL-4/IFN-γ比值。②KLH免疫小鼠血清中IgG2a、IgG1发生不同程度增高,CCK-8可使其血清中IgG1水平减低而使IgG2a水平增高。结论:CCK-8可促进KLH免疫小鼠体内Th1反应,使Th2优势反应向Th1方向转变。

AIM： To investigate the effects of cholecystokinin octapeptide （CCK -8） on Th1/Th2 imbalance. METHODS ： Female BALB/c mice were treated with CCK - 8 and keyhole limpet haemocyanin （ KLH）, splenocytes were acquired and incubated in vitro with KLH restimulation, the productions of Thl cytokines, interferon （IFN） -γ, interleukin （IL） -2 and Th2 cytokines, IL- 4, IL- 5 in cell culture supernatants were detected by enzyme -linked immunosorbnent assay （ELISA）. The mRNA expressions of IFN -γ, IL - 2, IL - 4 and IL - 5 in splenocytes were detected by reverse transcription -polymerase chain reaction （RT -PCT）. The levels of Thl antibody igG2a and Th2 antibodies IgGl in serum were also detected by ELISA. RESULTS：① Splenocytes derived from KLH immunized mice produced much higher level of IL- 5, IL-4, IL- 2 and IFN -γ and expressed much more mRNA than those in control mice. The IL- 4/IFN -γ ratio was elevated, in vivo treatment of CCK - 8 made KLH immunized splenocytes produced much higher IFN - γ and IL- 2, and expressed much more IFN -γ and IL- 2 mRNA, but made IL- 4 and IL- 5 productions and mRNA expres- sions reduced. ② The levels of KLH specific antibody IgG2a and IgG1, especially IgG1 were elevated in serum of KLH - immunized mice. In vivo administration of CCK - 8 reduced IgG1 production and heightened IgG2a production. CONCLUSION： CCK - 8 enhances Thl response and reduces Th2 response in KLH - immunized mice in vivo, suggesting that CCK -8 regulates adaptive immune response and it may be a useful regulator in Th1/Th2 imbalance.