根据华支睾吸虫死亡细胞释放的高迁移率族蛋白1（CsHMGB1）同源分子编码序列构建pET-28a（+）表达质粒并转化至Rosetta（DE3）感受态细胞,异丙基-β-D-硫代半乳糖苷（IPTG）诱导CsHMGB1-His融合蛋白表达;Ni-TED琼脂糖树脂纯化蛋白后,蛋白质免疫印迹（Western blotting）分析鉴定His标签融合蛋白表达情况。用含不同浓度（1 μg/ml和10 μg/ml）CsHMGB1-159/127的培养液与小鼠巨噬细胞RAW264.7共培养,同时设立无刺激物的空白对照组,培养24 h和48 h。用pNiFty2-SEAP质粒和HEK-Blue^TM培养基检测SEAP活性代表核转录因子-κB（NF-κB）活化,用酶标仪检测培养上清吸光度（A₆₂₀值）,并在显微镜下观察细胞内蓝色显色反应。结果显示,分别表达出编码159和127个氨基酸的CsHMGB1-159/127蛋白,相对分子质量（M_r）约为23 500和20 000。1和10 μg/ml CsHMGB1-159蛋白刺激小鼠巨噬细胞24 h后的A₆₂₀值分别为0.66 ± 0.08和0.65 ± 0.03,均高于对照组（0.29 ± 0.02）（t = 11.1、28.5,P < 0.01）,且胞浆均出现明显蓝色;48 h后的A₆₂₀值分别达1.02 ± 0.08和1.07 ± 0.08,均高于对照组（0.62 ± 0.035）（t = 11.2、12.9,P < 0.01）,且胞浆蓝色加深。用1和10 μg/ml CsHMGB1-127蛋白刺激24 h后的A₆₂₀值分别为0.52 ± 0.08和0.56 ± 0.08,均高于对照组（t = 7.39、8.37,P < 0.01）,胞浆也出现明显蓝色;48 h后的A₆₂₀值分别达到1.10 ± 0.05和0.90 ± 0.10,均高于对照组（t = 20.30、6.26,P < 0.01）,胞浆蓝色也明显加深。1和10 μg/ml CsHMGB1-159蛋白刺激24 h后的A₆₂₀值高于相应浓度的CsHMGB1-127蛋白（t = 2.98、2.75,P < 0.05）;48 h后两种蛋白的A₆₂₀值的差异有统计学意义（t = -2.07,P < 0.01;t = 3.40,P < 0.05）。CsHMGB1-159比CsHMGB1-127蛋白在体外均能够刺激小鼠巨噬细胞NF-κB活化,CsHMGB1-159比CsHMGB1-127蛋白的作用更强。

The PET-28a(+)expression plasmids were constructed according to the identified HMGB1 homologous gene sequences (CDSs)of Clonorchis sinensis and cloned into Rosetta (DE3) competent cells. Isopropyl-β-D-thiogalactoside (IPTG) was used to induce the expression of CsHMGB1-His fusion proteins. After purification by Ni-TED agarose resin, the expression of His-tagged fusion proteins was confirmed by Western blotting analysis. The mouse macrophage RAW264.7 cells were cultured with mediums supplemented with CsHMGB1-159/127 at a concentration of 1 μg/ml and 10 μg/ml, for 24 h and 48 h, respectively. The cells cultured without stimulants were used as the blank control. The SEAP activity, which indicates NF-κB activation, was detected by using pNiFty2-SEAP plasmid and HEK-Blue^TM culture medium. The A₆₂₀ value of culture supernatant was detected by microplate a reader, and the intracellular NF-κB activation was also observed under a microscope. Our results showed that the CsHMGB1-159/127 proteins encoding 159 and 127 amino acids were expressed, and the relative molecular weights (M_r) were approximately 23 500 and 20 000, respectively. The A₆₂₀ values of supernatant from mouse macrophage stimulated with CsHMGB1-159 protein (1 and 10 μg/ml)for 24 hours were 0.66 ± 0.08 and 0.65 ± 0.03, respectively, which were higher than those in the control group (0.29 ± 0.02)(t = 11.1, 28.5; P < 0.01), and blue staining was observed in the cytoplasm. The A₆₂₀ values after 48 h reached 1.02 ± 0.08 and 1.07 ± 0.08, respectively, which were higher than those in the control group (0.62 ± 0.035)(t = 11.2, 12.9; P < 0.01), and the blue staining in the cytoplasm was stronger. Similarly, the A₆₂₀ values after 24 h stimulation with CsHMGB1-127 protein (1 and 10 μg/ml) were 0.52 ± 0.08 and 0.56 ± 0.08, respectively, which were higher than those in the control group(t =7.39, 8.37; P < 0.01), and the blue staining was observed in the cytoplasm. The A₆₂₀ values after 48 h reached 1.10 ± 0.05 and 0.90 ± 0.10, respectively, which were also higher than those in the control group (t = 20.30, 6.26; P < 0.01), and stronger blue staining was also observed in the cytoplasm. The A₆₂₀ values of CsHMGB1-159 protein (1 and 10 μg/ml) after 24 hours of stimulation were significantly higher than that of CsHMGB1-127 protein (t = 2.98, 2.75; P < 0.05). There were also significant differences in A₆₂₀ value after 48 h stimulation (t = 3.40, P < 0.01). The HMGB1 homologous proteins of Clonorchis sinensis encoding 159 and 127 amino acids can stimulate mouse macrophage NF-κB activation in vitro. The CsHMGB1-159 has stronger stimulatory effect than CsHMGB1-127 protein.