转染MIP-lα和B7-1基因增强小鼠的抗淋巴瘤效应

目的观察转染趋化因子MIP-lα和共刺激分子B7-1基因增强小鼠抗淋巴瘤的效应。方法将MIP-1α和B7-1基因慢病毒重组载体转染小鼠EL-4淋巴瘤细胞,应用RT-PCR检测MIP-1et和B7-l基因mRNA表达,Westernblot法检测MIP-lα和B7-1蛋白表达;转基因EL-4细胞注入小鼠右腋皮下,观察成瘤情况;灭活的转基因EL_4细胞注入成瘤小鼠体内,观察其增强小鼠抗淋巴瘤效应。结果RT．PCR检测发现EL-4／MIP-lα＋B7—1细胞内有MIP-1α及B7—1mRNA表达,Westernblot显示MIP-1α及B7-1蛋白表达;MIP-lα组、B7-1组较对照组成瘤时间延长,成瘤率降低,肿瘤平均体积较小,而联合组成瘤性消失;MIP-1俚和B7-1治疗组的肿瘤平均体积、重量及肿瘤器官转移率明显小于对照组（P〈0．05）,而联合组的肿瘤平均体积及重量明显小于MIP-lα和B7-1组（P〈0．05）,而且联合组小鼠平均生存期,均较单基因组、对照组明显延长（P〈0．05）。结论转染MIP-1d和B7-1基因能够明显增强小鼠机体抗淋巴瘤效应,明显延长荷瘤小鼠的平均生存期,为淋巴瘤的基因治疗提供了新的思路。     

不同接种量荧光素酶标记小鼠乳腺癌细胞4T1在小鼠体内生长及肺转移的比较

目的 采用活体成像技术比较四种剂量荧光素酶标记肿瘤细胞在小鼠体内生长及肺转移情况,为光学标记肿瘤模型的药物筛选或机制研究提供参考资料.方法 以荧光素酶作为报告基因导人小鼠乳腺癌细胞4T1中,经G418筛选获得稳定表达荧光素酶的细胞克隆并扩大培养.标记细胞稀释成1×107细胞/mL,2×107细胞/mL,5×107细胞/mL和1×108细胞/mL四种剂量,取0.1 mL接种子BALB/c小鼠右侧第二对乳腺脂肪垫内,制作小鼠原位乳腺癌模型,比较肿瘤细胞在小鼠体内生长及肺转移情况.结果获得稳定表达荧光素酶基因的细胞克隆,在致瘤性方面和亲代细胞无明显差别,四种剂量细胞接种BALB/c小鼠后,均有肿瘤生长,接种第28天时,四种剂量接种的原位移植瘤大小没有明显差别,但接种两个高剂量肿瘤细胞的小鼠组各有2只小鼠死亡;接种后31 d,发现四种剂量接种的原位移植瘤均发生不同程度的转移,随着观察天数的增加,转移程度逐渐严重,接种后42 d,小鼠陆续发生死亡.结论 根据转移和死亡情况,确定接种1×106个细胞/只不仅肺转移明显,而且存活时间一般超过45 d,比高剂量接种存活时间长,为最佳肺转移剂量.     

特比萘芬和伊曲康唑联合应用对暗色孢科真菌的体外药敏试验研究

目的本试验探讨特比萘芬和伊曲康唑单独及联合应用对54株暗色孢科真菌的体外相互作用。方法应用美国国家临床和实验室标准研究所(CLSI)的M38-A方案。菌悬液终浓度为(0.4～5)×106CFU/ml,孵育温度35℃,培养时间5～7d。各药单独和联合应用时的MIC值均为与生长对照孔相比100%生长抑制的最低药物浓度;药物间相互作用用分数抑菌浓度(FIC值)表示;FIC<1认为有协同作用,1≤FIC<2认为有相加作用,FIC=2认为无相关性,FIC>2认为有拮抗作用。结果单独用药时特比萘芬在紧密着色霉、裴氏着色霉、卡氏支孢霉和疣状瓶霉组中MIC的几何均数分别为0.198μg/ml,0.372μg/ml,0.215μg/ml,0.456μg/ml,伊曲康唑在紧密着色霉、裴氏着色霉、卡氏支孢霉和疣状瓶霉组中MIC的几何均数分别为0.232μg/ml,0.323μg/ml,0.186μg/ml和0.315μg/ml。体外联合用药时二者MIC几何均数低于其单独应用时的MIC值。在54株受试菌中,联合用药时协同作用为29.6%(16/54),相加作用为68.5%(37/54),拮抗作用为1.9%(1/54)。结论特比萘芬和伊曲康唑联合应用时表现以协同和相加作用为主,很少菌株表现拮抗现象。     

伊曲康唑联合特比萘芬治愈着色芽生菌病1例

报告1例由卡氏枝孢瓶霉引起的着色芽生菌病。患者男性,43岁,因右上臂局限性红色斑块性皮损5 a就诊。皮损组织病理为慢性炎性肉芽肿改变,可见硬壳细胞。真菌培养鉴定为卡氏枝孢瓶霉。给予伊曲康唑(200 mg/d)和特比萘芬(250 mg/d)联合治疗12周痊愈。     

重组表达小鼠MIP-1α和B7-1基因的慢病毒载体的构建及鉴定

目的构建重组表达小鼠MIP-1α和B7-1基因的慢病毒载体,为淋巴瘤基因治疗的实验研究奠定基础。方法设计引物扩增获得目的基因小鼠MIP-1α和B7-1基因的全长编码序列cDNA,将目的基因与经酶切线性化的慢病毒载体进行定向连接,其产物转化感受态细胞,对长出的阳性克隆进行PCR鉴定和直接测序序列分析。MIP-1α和B7-1目的基因质粒转染293T细胞,观察绿色荧光蛋白（GFP）表达,采用Western Blot法检测其蛋白表达,实时荧光定量PCR,检测慢病毒浓缩液的滴度。结果成功构建了重组表达小鼠MIP-1α和B7-1基因的慢病毒载体,实时荧光定量PCR证实MIP-1α、B7-1基因重组慢病毒载体的滴度均达2.00E＋8 TU/mL。结论本研究成功构建并包装出高滴度的小鼠MIP-1α和B7-1基因重组慢病毒载体,为淋巴瘤基因治疗的实验研究奠定了基础。     

孢悬液浓度和宿主体型大小对球孢白僵菌对松墨天牛幼虫的致病力的影响

【目的】球孢白僵菌Beauveria bassiana是一种被广泛用于害虫生物防治的生防菌。本研究探讨了孢悬液浓度和宿主体型大小对球孢白僵菌对松墨天牛Monochamus alternatus 幼虫的致病力的影响,旨在为松墨天牛的生物防治提供科学基础。【方法】分别用0.5% 吐温-80(CK)以及1×10⁵, 1×10⁶, 1×10⁷, 1×10⁸和1×10⁹孢子/mL的球孢白僵菌孢悬液接种松墨天牛4龄幼虫,统计接种后15 d内幼虫死亡率和染菌率。同时用最佳浓度(1×10⁹孢子/mL)的球孢白僵菌孢悬液接种体型大小分别为100~150, 200~220, 300~320, 400~420, 500~520和600~650 mg/头的松墨天牛幼虫,测定接种后20 d内幼虫的死亡率和染菌率。【结果】接种1×10⁵~1×10⁹孢子/mL的球孢白僵菌后,松墨天牛4龄幼虫起初活动自如,后在头部出现烧灼状伤并且体色逐渐变红,最后周身长满菌丝。不同浓度下,随球孢白僵菌孢子浓度升高,松墨天牛4龄幼虫校正死亡率和校正染菌率增加。接种1×10⁶~1×10⁹孢子/mL球孢白僵菌孢悬液15 d的松墨天牛4龄幼虫累计校正死亡率均可达到100%,1×10⁷, 1×10⁸和1×10⁹孢子/mL浓度下,松墨天牛达到100%校正死亡率所需时间最少。接种0 (CK), 1×10⁵, 1×10⁶, 1×10⁷, 1×10⁸和1×10⁹孢子/mL球孢白僵菌孢悬液的松墨天牛4龄幼虫校正染菌率在第15天分别为0, 20.00%, 86.67%, 90.00%, 96.67%和100.00%,表现为白僵菌孢子浓度越高,染菌率越高。1×10⁹孢子/mL的接种浓度下,松墨天牛幼虫个体越大,天牛幼虫死亡率和染菌率越高。表现在第20天时,体型大小为100~150, 200~220, 300~320, 400~420, 500~520和600~650 mg/头的幼虫的死亡率分别为76.67%, 76.67%, 66.67%, 93.33%, 100.00%和100.00%,染菌率分别为60.00%, 63.33%, 60.00%, 86.67%, 96.67%和100.00%。【结论】球孢白僵菌悬浮液浓度对松墨天牛幼虫的死亡和侵染有显著影响,表现为随孢子浓度的增加而增加;同时,松墨天牛幼虫个体越大,死亡率和染菌率越高。研究结果对开展利用球孢白僵菌防治松墨天牛具重要借鉴和指导意义。     

沙眼衣原体感染诱导小鼠生殖道局部促炎性细胞因子的表达情况

建立小鼠生殖道沙眼衣原体感染模型,观察小鼠生殖道局部促炎性细胞因子的表达。将小鼠生物型沙眼衣原体C. muridarum 1＆#215;104 IFU阴道接种于C57B6背景雌性小鼠,取感染后阴道拭子做沙眼衣原体培养,计算IFU,监测小鼠感染和病原体清除情况;80 d后处死小鼠,检测子宫输卵管病理改变;ELISA检测感染过程中小鼠生殖道促炎性细胞因子IL-1α、IL-6、MIP-2和TNF-α产生情况。小鼠感染在第3至第15天维持较高水平,然后病原体被逐渐清除,整个病程约3~5周;病理检测显示子宫输卵有严重炎症、管腔扩张积水,狭窄等;于感染后第3天检测到局部IL-1α、IL-6、MIP-2分泌,第7天达高峰,然后逐渐下降至正常水平（ IL-6于11 d恢复正常,IL-1α和 MIP-2于15 d恢复正常）。 TNF-α仅在第7天检测到高水平表达。相对于TNF-α和IL-6,IL-1α和MIP-2维持时间较长。成功建立沙眼衣原体感染小鼠生殖道模型,沙眼衣原体急性感染可诱导小鼠生殖道局部分泌IL-1α、IL-6、MIP-2和TNF-α。     

孢悬液浓度和宿主体型大小对球孢白僵菌对松墨天牛幼虫的致病力的影响

【目的】球孢白僵菌Beauveria bassiana是一种被广泛用于害虫生物防治的生防菌。本研究探讨了孢悬液浓度和宿主体型大小对球孢白僵菌对松墨天牛Monochamus alternatus幼虫的致病力的影响,旨在为松墨天牛的生物防治提供科学基础。【方法】分别用0.5%吐温-80(CK)以及1×10~5, 1×10~6, 1×10~7, 1×10~8和1×10~9孢子/mL的球孢白僵菌孢悬液接种松墨天牛4龄幼虫,统计接种后15 d内幼虫死亡率和染菌率。同时用最佳浓度(1×10~9孢子/mL)的球孢白僵菌孢悬液接种体型大小分别为100～150, 200～220, 300～320, 400～420, 500～520和600～650 mg/头的松墨天牛幼虫,测定接种后20 d内幼虫的死亡率和染菌率。【结果】接种1×10~5～1×10~9孢子/mL的球孢白僵菌后,松墨天牛4龄幼虫起初活动自如,后在头部出现烧灼状伤并且体色逐渐变红,最后周身长满菌丝。不同浓度下,随球孢白僵菌孢子浓度升高,松墨天牛4龄幼虫校正死亡率和校正染菌率增加。接种1×10~6～1×10~9孢子/mL球孢白僵菌孢悬液15 d的松墨天牛4龄幼虫累计校正死亡率均可达到100%,1×10~7, 1×10~8和1×10~9孢子/mL浓度下,松墨天牛达到100%校正死亡率所需时间最少。接种0 (CK), 1×10~5, 1×10~6, 1×10~7, 1×10~8和1×10~9孢子/mL球孢白僵菌孢悬液的松墨天牛4龄幼虫校正染菌率在第15天分别为0, 20.00%, 86.67%, 90.00%, 96.67%和100.00%,表现为白僵菌孢子浓度越高,染菌率越高。1×10~9孢子/mL的接种浓度下,松墨天牛幼虫个体越大,天牛幼虫死亡率和染菌率越高。表现在第20天时,体型大小为100～150, 200～220, 300～320, 400～420, 500～520和600～650 mg/头的幼虫的死亡率分别为76.67%, 76.67%, 66.67%, 93.33%, 100.00%和100.00%,染菌率分别为60.00%, 63.33%, 60.00%, 86.67%, 96.67%和100.00%。【结论】球孢白僵菌悬浮液浓度对松墨天牛幼虫的死亡和侵染有显著影响,表现为随孢子浓度的增加而增加;同时,松墨天牛幼虫个体越大,死亡率和染菌率越高。研究结果对开展利用球孢白僵菌防治松墨天牛具重要借鉴和指导意义。     

重组IL-33在致死型约氏疟原虫感染中对细胞因子表达的影响及意义

探讨IL-33作为外源性细胞因子对致死型约氏疟原虫感染的细胞因子表达的影响及意义。以致死型约氏疟原虫(Plasmodium yoelii 17XL,P.y 17XL)感染BALB/c小鼠为研究对象,感染D0-D5腹腔注射重组IL-33,动态观察原虫血症。感染后3 d和5 d,无菌制备脾细胞悬液,P.y 17XL原虫裂解物体外刺激脾细胞培养72 h。采用多因子检测方法对脾细胞培养上清多种细胞因子进行定量分析。与对照组相比,IL-33给药组原虫血症上升缓慢,原虫血症峰值延迟出现。与对照组相比,IL-33给药组脾细胞培养上清IFN-γ、IL-6、TNF-α和IL-18表达明显下调,而IL-5表达水平明显增加。趋化因子MIP-1β、MIP-1α、RANTES和GRO-α表达明显降低。重组IL-33在P.y 17XL感染过程中通过下调趋化因子表达,减少炎症细胞浸润进而降低前炎症细胞因子表达。通过上调IL-5表达,增强嗜酸性粒细胞活性进而发挥控制P.y 17XL原虫增殖的作用。     

茄病镰刀菌致ICR小鼠局部皮肤感染的实验研究

目的建立茄病镰刀菌感染皮肤的ICR小鼠模型。方法将茄病镰刀菌三个不同浓度的菌悬液分别接种于正常和免疫抑制ICR小鼠受损及正常未受损的皮肤,于接种后第7、14、21、28天处死动物,取皮疹和各脏器进行真菌镜检、培养和组织病理学检查。结果正常和免疫抑制组皮肤受损的小鼠均出现皮疹,而免疫抑制组皮疹程度重,持续时间长,且真菌镜检、培养及组织病理学大都可见菌丝。皮肤未受损的小鼠不发生皮疹。实验小鼠均未出现系统播散。结论接种109CFU/mL或1010CFU/mL茄病镰刀菌的孢子悬液于免疫抑制ICR小鼠擦伤的皮肤,可有效造成ICR小鼠的茄病镰刀菌皮肤感染。     

MCP-1 and MIP-2 levels during Echinococcus granulosus infections in mice

Ten BALB/c mice were infected with the cestode Echinococcus granulosus. After the infection, serum was collected at different periods of time and monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2) were determined. The level of MCP-1 increased from at day 20 post infection (p.i.), to a maximum of on day 60 p.i., then decreased to on day 130 p.i. A second peak was observed at day 150 p.i. In addition, MIP-2 was detectable in serum as late as day 100 p.i. The highest level was observed on day 130 p.i., and decreased thereafter. Serum from noninfected animals (controls) contained no detectable levels of either MCP-1 or MIP-2. However, MCP-1 and MIP-2 appear to be implicated in E. granulosus infections, but their exact role during the disease is under determination.     

Enhanced production of macrophage inflammatory protein 2 (MIP-2) by in vitro and in vivo infections with encephalomyocarditis virus and modulation of myocarditis with an antibody against MIP-2

Interleukin-8 (IL-8) is a chemotactic cytokine for neutrophils and lymphocytes. Macrophage inflammatory protein 2 (MIP-2) is a murine counterpart of IL-8. The present study was performed to determine whether MIP-2 aggravates murine myocarditis. We examined (i) the MIP-2-producing activity of encephalomyocarditis (EMC) virus-infected cultured macrophages, (ii) serial plasma MIP-2 levels in EMC virus-induced mice by enzyme-linked immunosorbent assay, and (iii) the effects of antimouse MIP-2 monoclonal antibody (MAb) in vivo upon myocarditis. The production of MIP-2 increased in an infection dose- and time-dependent manner in virus-infected RAW 264. 7 macrophages. Five-week-old C(3)H/He mice were inoculated with EMC virus. Plasma MIP-2 levels were significantly elevated in mice on days 7 and 14 postinfection. Mice were injected subcutaneously with anti-MIP-2 MAb at 10 microg/day (group 2) or 100 microg/day (group 3) on days 0 to 5 and were observed until day 21. Uninfected control mice (group 1) were prepared. The survival rate was higher in the anti-MIP-2-treated group (group 3), but not in group 2, than in the control group. Histopathological analysis revealed that cellular infiltration and myocardial necrosis with macrophage and T-cell accumulation were less prominent in the anti-MIP-2 MAb-treated group, but not in group 2, compared to the level in the controls. MIP-2 is an important naturally occurring inflammatory cytokine in myocarditis, and anti-MIP-2 MAb treatment may prevent the inflammatory response.     

Inducible expression of inflammatory chemokines in respiratory syncytial virus-infected mice: role of MIP-1alpha in lung pathology

Lower respiratory tract disease caused by respiratory syncytial virus (RSV) is characterized by profound airway mucosa inflammation, both in infants with naturally acquired infection and in experimentally inoculated animal models. Chemokines are central regulatory molecules in inflammatory, immune, and infectious processes of the lung. In this study, we demonstrate that intranasal infection of BALB/c mice with RSV A results in inducible expression of lung chemokines belonging to the CXC (MIP-2 and IP-10), CC (RANTES, eotaxin, MIP-1beta, MIP-1alpha, MCP-1, TCA-3) and C (lymphotactin) families. Chemokine mRNA expression occurred as early as 24 h following inoculation and persisted for at least 5 days in mice inoculated with the highest dose of virus (10(7) PFU). In general, levels of chemokine mRNA and protein were dependent on the dose of RSV inoculum and paralleled the intensity of lung cellular inflammation. Immunohisthochemical studies indicated that RSV-induced expression of MIP-1alpha, one of the most abundantly expressed chemokines, was primarily localized in epithelial cells of the alveoli and bronchioles, as well as in adjoining capillary endothelium. Genetically altered mice with a selective deletion of the MIP-1alpha gene (-/- mice) demonstrated a significant reduction in lung inflammation following RSV infection, compared to control littermates (+/+ mice). Despite the paucity of infiltrating cells, the peak RSV titer in the lung of -/- mice was not significantly different from that observed in +/+ mice. These results provide the first direct evidence that RSV infection may induce lung inflammation via the early production of inflammatory chemokines.     

趋化因子MCP-1、MIP-1α的表达与TAM计数在胆囊癌中的临床病理意义

目的：检测胆囊腺癌组织中趋化因子MCP-1和MIP-1α的表达、TAM计数并探讨其临床病理意义。方法：收集中南大学湘雅二医院及湖南省人民医院近五年胆囊腺癌手术切除标本36例及慢性胆囊炎手术切除标本10例,采用原位分子杂交方法检测MCP-1和MIP-1α的表达,免疫组化法进行TAM计数。结果：胆囊腺癌组织中MCP-1、MIP-1αmRNA表达阳性率及评分均明显高于慢性胆囊炎（P〈0．01）;高分化胆囊腺癌中二者的阳性率及评分均低于低分化胆囊腺癌,其中MCP-1mRNA比较有显著性差异（P〈0．05）;MCP-1、MIP-1α mRNA的表达呈显著正相关。胆囊腺癌组织MCP-1mRNA表达阳性率及其评分与侵犯胆总管及发生淋巴结转移显著相关;MIP-1α mRNA表达阳性率及其评分与侵犯肝脏显著相关。胆囊腺癌组织中,TAM计数（24．89±0．84）明显高于慢性胆囊炎组织（16．19±0．66）,有显著性差异（P〈0．01）。TAM与MCP-1、MIP-1α mRNA表达评分值均呈显著正相关（r分别为0．580,0．567）。MCP-1 mRNA与MIP-1α mRNA评分值之间呈显著正相关（r=0．638）。结论：MCP-1、MIP-1α的表达增加及TAM计数升高可能调控和影响胆囊癌的发生和发展,MCP-1、MIP-1α可能促进TAM向胆囊癌组织迁移浸润。     

内源性IL-17诱导MIP-2与IL-6表达在衣原体肺炎中促进中性粒细胞循环

目的 探讨衣原体肺炎中白细胞介素-17（interleukin -17,IL-17）对中性粒细胞（polymorphonuclear leucocyte,PMN）循环的调节作用及机制.方法 用40 μl含1×10^3包涵体形成单位（inclusion-forming units,IFU）的衣原体鼠肺炎株（Chlamydia muridarum,Cm）呼吸道感染BALB/c小鼠,诱导鼠衣原体肺炎.用抗鼠IL-17单克隆抗体吸入中和内源性IL-17,以相应独特型抗体（IgG2α）作为对照.用RT-PCR检测小鼠肺组织及肺上皮细胞系巨噬细胞炎性蛋白-2 （macrophage inflammatory protein-2,MIP-2）和IL-6 mRNA的表达.取小鼠支气管肺泡灌洗液细胞染色计数PMN,感染肺组织进行病理染色.结果 衣原体肺炎中,内源性IL-17中和小鼠肺组织PMN浸润显著降低,支气管肺泡灌洗液PMN数量显著低于对照组.IL-17与TNF-α协同可上调肺上皮细胞MIP-2和IL-6 mRNA表达,且内源性IL-17中和小鼠肺组织MIP-2和IL-6表达显著降低.结论 衣原体肺炎中IL-17通过促进肺组织细胞分泌趋化性细胞因子MIP-2和前症性细胞因子IL-6,诱导PMN循环,参与宿主抗衣原体炎性应答.     

Regulation of macrophage chemokine expression by lipopolysaccharide in vitro and in vivo.

The host response to Gram-negative LPS is characterized by an influx of inflammatory cells into host tissues, which is mediated, in part, by localized production of chemokines. The expression and function of chemokines in vivo appears to be highly selective, though the molecular mechanisms responsible are not well understood. All CXC (IFN-gamma-inducible protein (IP-10), macrophage inflammatory protein (MIP)-2, and KC) and CC (JE/monocyte chemoattractant protein (MCP)-1, MCP-5, MIP-1alpha, MIP-1beta, and RANTES) chemokine genes evaluated were sensitive to stimulation by LPS in vitro and in vivo. While IL-10 suppressed the expression of all LPS-induced chemokine genes evaluated in vitro, treatment with IFN-gamma selectively induced IP-10 and MCP-5 mRNAs, but inhibited LPS-induced MIP-2, KC, JE/MCP-1, MIP-1alpha, and MIP-1beta mRNA and/or protein. Like the response to IFN-gamma, LPS-mediated induction of IP-10 and MCP-5 was Stat1 dependent. Interestingly, only the IFN-gamma-mediated suppression of LPS-induced KC gene expression was IFN regulatory factor-2 dependent. Treatment of mice with LPS in vivo also induced high levels of chemokine mRNA in the liver and lung, with a concomitant increase in circulating protein. Hepatic expression of MIP-1alpha, MIP-1beta, RANTES, and MCP-5 mRNAs were dramatically reduced in Kupffer cell-depleted mice, while IP-10, KC, MIP-2, and MCP-1 were unaffected or enhanced. These findings indicate that selective regulation of chemokine expression in vivo may result from differential response of macrophages to pro- and antiinflammatory stimuli and to cell type-specific patterns of stimulus sensitivity. Moreover, the data suggest that individual chemokine genes are differentially regulated in response to LPS, suggesting unique roles during the sepsis cascade.     

甲型H1N1流感病毒感染不同免疫缺陷小鼠的比较

目的宿主免疫系统的功能状态在病毒的感染中起着至关重要的作用,本实验观察了不同免疫缺陷小鼠感染甲型H1N1流感病毒的差异。方法使用六个品系的近交系小鼠,经乙醚麻醉后进行滴鼻攻毒,分析其在病毒感染后存活率、体重变化和肺组织病理改变的异同。结果感染H1N1病毒的6种小鼠在观察的14d内,野生型的C57BL／6小鼠感染开始体重缓慢下降,感染后期有所回升,有半数存活;BALB／c小鼠和四种免疫缺陷品系小鼠感染病毒后体重随病情发展快速下降,死亡率均为100％。野生型C57BL／6小鼠感染初期为较弥漫的间质性肺炎,后期病变逐渐局限;BALB／c小鼠和四种免疫缺陷品系小鼠感染病毒后出现弥漫的中重度间质性肺炎,细支气管上皮有变性坏死,但炎症细胞明显少于C57BL／6小鼠。结论在甲型H1N1流感病毒的初次感染中固有免疫和特异性免疫分别在感染的初期和后期起主要作用,宿主免疫系统的功能状态影响着甲型H1N1病毒感染和预后。     

Expression and function of C5a receptor in mouse microvascular endothelial cells

The complement-derived anaphylatoxin, C5a, is a potent phlogistic molecule that mediates its effects by binding to C5a receptor (C5aR; CD88). We now demonstrate specific binding of radiolabeled recombinant mouse C5a to mouse dermal microvascular endothelial cells (MDMEC) with a K(d50) of 3.6 nM and to approximately 15,000-20,000 receptors/cell. Recombinant mC5a competed effectively with binding of [(125)I]rmC5a to MDMEC. Enhanced binding of C5a occurred, as well as increased mRNA for C5aR, after in vitro exposure of MDMEC to LPS, IFN-gamma, or IL-6 in a time- and dose-dependent manner. By confocal microscopy, C5aR could be detected on surfaces of MDMEC using anti-C5aR Ab. In vitro expression of macrophage inflammatory protein-2 (MIP-2) and monocyte chemoattractant protein-1 (MCP-1) by MDMEC was also measured. Exposure of MDMEC to C5a or IL-6 did not result in changes in MIP-2 or MCP-1 production, but initial exposure of MDMEC to IL-6, followed by exposure to C5a, resulted in significantly enhanced production of MIP-2 and MCP-1 (but not TNF-alpha and MIP-1alpha). Although LPS or IFN-gamma alone induced some release of MCP-1 and MIP-2, pre-exposure of these monolayers to LPS or IFN-gamma, followed by addition of C5a, resulted in synergistic production of MIP-2 and MCP-1. Following i.v. infusion of LPS into mice, up-regulation of C5aR occurred in the capillary endothelium of mouse lung, as determined by immunostaining. These results support the hypothesis that C5aR expression on MDMEC and on the microvascular endothelium of lung can be up-regulated, suggesting that C5a in the co-presence of additional agonists may mediate pro-inflammatory effects of endothelial cells.     

A/California/7/2009与A/California/4/2009病毒感染力比较

目的甲型H1N1流感病毒A/California/7/2009与A/California/4/2009病毒序列比较同源性在99%以上,本实验旨在比较两株病毒感染BALB/c小鼠研究感染力强弱。方法分别将A/California/7/2009（CA7）与A/California/4/2009（CA4）两株病毒分别连续10倍稀释后,对4~6周龄雌性BALB/c小鼠经乙醚麻醉后进行滴鼻攻毒,每个稀释度接种10只实验小鼠,测定CA7 MLD50为101.24/0.05 mL,检测小鼠感染、致病的多项指标,观察期为14 d。结果相同TCID50的CA7和CA4病毒感染小鼠,CA4感染小鼠后14 d内死亡率为20%,而CA7感染小鼠后8 d内死亡率为100%。CA7 106TCID50感染的小鼠病理表现为重度弥漫性间质性肺炎,CA4 106TCID50感染的小鼠病理表现为中度-重度间质性肺炎。结论在相同条件下,CA7感染力明显强于CA4。