弓形虫急性感染小鼠血清蛋白质质谱分析的初步研究

Preliminary study on serum proteomics in mice with acute Toxoplasma gondii infection by using functionalized magnetic beads and MALDI-TOF-MS technique

目的分析弓形虫急性感染小鼠血清蛋白质组学变化。方法16只同窝配对的C57BL/6J小鼠,随机分成弓形虫急性感染组和对照组,每组8只。弓形虫急性感染组每鼠腹腔感染经CF 11纤维素纯化的RH株弓形虫速殖子（1×104/ml）0.2 ml,对照组每鼠腹腔接种0.2 ml灭菌生理盐水。感染后4 d,处死全部小鼠,应用弱阳离子（WCX）纳米磁性微球捕获小鼠血清蛋白,采用基质辅助激光解析电离飞行时间质谱（MALDI TOF MS）技术检测两组小鼠血清蛋白质变化,并采用Autoflex analysis与Clin ProTools软件进行分析与比较。结果在分子量为1 000~16 000 Da区段,与对照组小鼠血清蛋白指纹图谱比较,弓形虫急性感染小鼠血清蛋白质谱有13种蛋白表达差异有统计学意义,其中9种蛋白质表达上调,4种蛋白质表达下调。表达上调的多肽质荷比（m/z值）分别为1 932.76、1 976.85、2 090.53、5 004.5、5 776.01、5 803.05、5 847.99、5 877.51和7 501.58,表达下调的多肽m/z值分别为1 866.40、4 063.71、8 120.31和8 203.83。结论弓形虫急性感染小鼠血清蛋白质组发生显著改变,采用WCX纳米磁性微球联用MALDI TOF MS技术可检出弓形虫急性感染小鼠血清中的特异性蛋白标志物。

Objective To detect and analyze the serum protein biomarkers in mice with acute Toxoplasma gondii infection. Methods The serum samples from 8 C57BL/6J mice with acute Toxoplasma gondii infection and 8 normal healthy paired mice were prepared with WCX magnetic beads, and then analyzed on PBS II -C mass spectrometer reader. The protein spectra of the se- rum samples were normalized by the Ciphergen Protein Chip software. The peak labeling was performed by the Biomarker Wizard software. The specific protein biomarkers were screened by the Biomarker Pattern software to construct a diagnostic model for acute Toxoplasma gondii infection. Results A total of 13 distinguished proteomic peaks were detected. Nine peaks were of up-regulated expressions including m/z values of 1 932.76, 1 976.85, 2 090.53, 5 004.5, 5 776.01, 5 803.05, 5 847.99, 5 877,51 and 7 501.58, respectively; and four peaks were of down-regulated expressions including m/z values of 1 866.40,4 063.71, 8 120.31 and 8 203.83, respectively. Conclusion The potential protein biomarkers for acute Toxoplasma gondii infection are discovered in mouse serum by MALDI-TOF-MS combined with WCX magnetic beads.