Trpi免疫调节功能的研究

Study on Immune Function of Trpi

利用胰蛋白酶酶解牛乳酪蛋白制备一种富含酪氨酸且具有抗菌作用的免疫活性肽(Trpi)。纯化后的产物经毛细管电泳(CE)分析,其纯度为86.45%,洋菜孔洞扩散实验结果表明粗品和纯品Trpi均具有较好的抗菌活性。通过分析小鼠体重、脾脏指数及胸腺指数的变化,表明Trpi对小鼠体重无明显影响,但能显著促进脾脏指数(p<0.01)和胸腺指数(p<0.01)的提高。淋巴细胞增殖实验结果说明Trpi在体外可以极显著地刺激小鼠脾脏淋巴细胞的增殖(p<0.001,SI=2.13)。通过口服、腹腔注射以及尾静脉注射等三种不同方式给与抗菌肽Trpi,结果发现,与对照组相比,Trpi能够明显促进IL-1β(p<0.001)、IL-6(p<0.001)及IL-10(p<0.01)的产生,对IL-4也具有微弱影响,但不影响TNF-α、IFN-γ及TGF-α的分泌。结果还表明,三种不同的给药方式对小鼠细胞因子产生的刺激强度不同,即腹腔注射给药组>尾静脉给药组>口服组。可见Trpi可能主要是通过黏膜免疫系统来影响小鼠细胞因子的变化。总之,本研究揭示,抗菌肽Trpi的免疫调节作用可能主要是通过粘膜系统的细胞因子网络。

Tyrosine-rich peptide of immunostimulating （Trpi） which is a novel casein-derived antimicrobial peptide with obvious antimicrobial and immunostimulating property was separated from tryptic casein hydrolysates. Antimicrobial activities of rude and purified Trpi were proved by the agar diffusion test, and the purity of purified Trpi which was 86.45% was analyzed by the capillary electrophoresis （CE）. The results about the effects of rude and purified Trpi on body weight, spleen index, thymus index and lymphoproliferation activity of mice, indicated that Trpi didn＇t affect body weight, but enhanced observably the spleen index （p 〈 0.01） and thymus index （p 〈 0.01）, and improved dramatically lymphoproliferation activity （p 〈 0.001, SI=2.13）. Compared to the control, Trpi promoted significantly the release of IL-1 β （p 〈 0.001）, IL-6 （p 〈 0.001）and IL-10 （p 〈 0.01）and affected faintly the level of IL-4 by three different ways： oral, intraperitoneal injection and Caudal vein injection, however, it had no effect on TNF- α, IFN- γ and TGF- α. The order of intension on cytokines was intraperitoneal injection, cudal vein injection and oral. Therefore, it was possible that Trpi affected mainly the levels of mice＇s cytokines through mucosal immune. In conclusion, the research revealed that antimicrobial peptide Trpi＇s immunostimulating function was possibly associated with the cytokine network of mucosal system.