过敏毒素C5a和C3a在微小隐孢子虫感染中的表达分析

为明确过敏毒素C5a和C3a在小鼠感染和清除隐孢子虫(Cryptosporidium)感染过程中的作用,本研究以微小隐孢子虫(C.parvum)为研究对象,以BALB/c小鼠为感染模型,采用实时荧光定量PCR分析了C.parvum感染小鼠的小肠相关淋巴组织和脾脏中过敏毒素C3a、C5a及其相应受体(C3aR和C5aR)的mRNA水平。结果显示,在脾脏和小肠中,不仅过敏毒素C5a和C3a在感染后出现了显著上调表达,其受体C5aR和C3aR的表达水平在感染后亦显著上调表达(P<0.05),并呈现动态变化。这些研究结果提示C5a/C5aR和C3a/C3aR信号参与了宿主抗微小隐孢子虫感染的过程。     

苦参碱对微小隐孢子虫体内外感染的抑制作用

应用犬肾细胞(MDCK)模型和BALB/c小鼠模型,研究了苦参碱(MT)对隐孢子虫(C.parvum)感染的抑制作用。用C.parvum感染MDCK细胞和BALB/c小鼠,通过检测感染MDCK细胞中C.parvum的数量和BALB/c小鼠的排卵囊数来评价不同剂量的MT对C.parvum活性与感染性的体内外抑制作用。体外试验表明,MT高、中、低3个剂量组均能显著或极显著降低MDCK细胞模型中的C.parvum感染数量(P<0.05或P<0.01);体内试验表明,MT高、中、低3个剂量组均能显著减少BALB/c小鼠的排卵数(P<0.05)。     

C5a-C5aR轴在鸭疫里氏杆菌感染致鸭肝损伤中的作用

本试验旨在阐明C5a-C5aR轴在鸭疫里氏杆菌（Riemerella anatipestifer）感染致雏鸭肝损伤中的作用。将保存的鸭疫里氏杆菌复苏培养,同时制备鸭抗凝血,将鸭疫里氏杆菌与鸭抗凝血混匀,分别与抗C5a抗体和抗C5aR抗体孵育后进行全血试验,利用ELISA检测C5a及各炎性因子表达水平;利用鸭疫里氏杆菌感染雏鸭,同时分别用抗C5a抗体和抗C5aR抗体处理进行动物试验,采集主要组织进行病理组织学检查;采集雏鸭外周血和肝组织进行细菌计数;采集外周血分离血清后,进行血清酶活性检测,应用ELISA检测血清C5a及炎性因子水平;采集肝组织,利用荧光定量PCR检测主要炎性因子mRNA转录水平。结果显示,在全血试验和动物试验中,与R.anatipestifer组相比,R.anatipestifer +anti-C5a组和R.anatipestifer +anti-C5aR组C5a、TNF-α、IL-6和IL-1β表达水平显著降低（P<0.05）;阻断C5a-C5aR轴可显著降低鸭疫里氏杆菌感染雏鸭的发病率和死亡率,同时减轻雏鸭心、肝和脾组织损伤;阻断C5a-C5aR轴能显著降低鸭疫里氏杆菌感染雏鸭外周血和肝细菌数及谷丙转氨酶（alanine aminotransferase,ALT）和谷草转氨酶（aspartate aminotransferase,AST）水平;荧光定量PCR检测发现,与R.anatipestifer组相比,R.anatipestifer +anti-C5a和R.anatipestifer +anti-C5aR组C5aR、Sphk1、FGL2、TNF-α和IL-1β mRNA转录水平显著降低（P<0.05）。本研究成功证实C5a-C5aR轴激活有助于鸭疫里氏杆菌感染雏鸭,阻断C5a-C5aR轴可显著减轻雏鸭组织损伤和炎症反应,为进一步研究抗鸭疫里氏杆菌感染药物提供新思路。     

用微小隐孢子虫子孢子表面蛋白DNA疫苗免疫小鼠的实验研究

为了探讨微小隐孢子虫子孢子表面蛋白 CP15 / 60重组质粒 pc DNA3 .1- 15 / 60 DNA疫苗诱导机体产生体液和细胞免疫应答的效果。用重组的 DNA疫苗于 BAL B/ c小鼠后腿胫骨前肌肉注射免疫 ,于 0、3、6周共免疫 3次 ,10 0 μg/次。免疫后不同时间检测体液和细胞免疫应答指标。并用 1× 10 6 卵囊进行攻虫试验。结果表明 pc DNA 3 .1- 15 / 60可诱导机体产生相应的特异性抗体 ,对 C.parvum卵囊攻击具有保护作用。微小隐孢子虫子孢子表面蛋白 CP15 / 60重组质粒 pc DNA3 .1- 15 / 60有可能作为侯选的隐孢子虫 DNA疫苗 ,值得进一步深入研究     

Generation of a uniform thymic malignant lymphoma model with C57BL/6J p53 gene deficient mice

Lymphoma is the third most common cancer diagnosed in children, and T-cell lymphoma has the worst prognosis based on clinical observations. To date, a lymphoma model with uniform penetrance has not yet been developed. In this study, we generated a p53 deficient mouse model by targeting embryonic stem cells derived from a C57BL/6J mouse strain. Homozygous p53 deficient mice exhibited a higher rate of spontaneous tumorigenesis, with a high spontaneous occurrence rate (93.3%) of malignant lymphoma. Because tumor models with high phenotypic consistency are currently needed, we generated a lymphoma model by a single intraperitoneal injection of 37.5 or 75 mg/kg N-methyl-N-nitrosourea to p53 deficient mice. Lymphoma and retinal degeneration occurred in 100% of p53^+/− mice administered with higher concentrations of N-methyl-N-nitrosourea, a much greater response than those of previously reported models. The main anatomic sites of lymphoma were the thymus, spleen, bone marrow, and lymph nodes. Both induced and spontaneous lymphomas in the thymus and spleen stained positive for CD3 antigen, and flow cytometry detected positive CD4 and/or CD8 cells. Based on our observations and previous data, we hypothesize that mice with a B6 background are prone to lymphomagenesis.