Chlamydia pneumoniae infection significantly exacerbates aortic atherosclerosis in an LDLR–/– mouse model within six months

We have previously shown that infection with the C. pneumoniae AR39 strain once monthly for 9 consecutive months significantly exacerbated atherosclerosis in mice with LDL receptor deficiency (LDLR–/–) in the presence of a high cholesterol diet. To further optimize the LDLR–/– mouse model for studying the mechanisms of C. pneumoniae atherogenesis, we have tested a different infection protocol with intranasal inoculation twice monthly for 6 consecutive months in the present study. We found that C. pneumoniae infection for 6 months was sufficient to produce a 130%, significantly greater exacerbation of aortic atherosclerosis in LDLR–/– mice in the presence of a high cholesterol diet. Mice receiving a high cholesterol diet alone displayed a lesion area index of 18.2 ± 6.1 (S.D.) while mice treated with both the high cholesterol diet and C. pneumoniae infection had a lesion area index of 41.8 ± 15.2 (S.D.). However, the chlamydial infection did not significantly alter the mouse serum total cholesterol or the LDL levels induced by the high cholesterol diet. This study not only confirms our previous findings that C. pneumoniae infection can exacerbate aortic atherosclerosis lesion in the LDLR–/– mice, but also further optimizes the LDLR–/– mouse model for future mechanism studies.     

肥大细胞在大鼠输卵管急性沙眼衣原体感染中的作用

目的　为研究肥大细胞在大鼠输卵管急性沙眼衣原体 (Chlamydialtrachomatis,CT)感染中的作用。方法　选择成年雌性SD大鼠 6 0只 ,通过手术从一侧卵巢囊接种沙眼衣原体D型株 ,对照组接种 2 -SPA缓冲液。分别于感染后第 1/ 2d、第 7d、第 14d将大鼠处死 ,取手术侧的输卵管常规固定、脱水、包埋。结果　S -P法显示 :输卵管局部的CD4 + T细胞和血管内皮细胞粘附分子 (VCAM - 1)的表达均较对照组明显增强 (P <0 0 1)。改良的甲苯胺蓝染色法显示 :感染组肥大细胞较对照组数量有显著性增高 (P <0 0 5 ) ,并且其变化趋势与CD4 + T细胞和VCAM - 1表达的变化趋势一致。结论　可以推测 ,沙眼衣原体感染引起急性输卵管炎时 ,肥大细胞通过促进炎症局部小静脉内皮细胞上VCAM -1的表达 ,诱导CD4 + T细胞的浸润 ;然后分泌IL - 4等细胞因子促进CD4 + T细胞向TH2 细胞方向转化 ,不利于机体清除沙眼衣原体 ,从而使发生局部输卵管病理损伤的可能性增加。     

Redirection of host vesicle trafficking pathways by intracellular parasites

Bacterial and protozooan intracellular parasites have evolved diverse mechanisms for evasion of host cellular defenses associated with adaptations for survival in distinct intracellular compartments. As the reagents identifying discrete steps in vesicle maturation and trafficking have become increasingly available, it has become clear that the vacuoles occupied by intracellular parasites are much more diverse than had been previously appreciated. Many parasites induce selective fusion competence with the vacuoles they occupy, without affecting vesicular trafficking elsewhere in the cell. A likely means of controlling vesicular interactions is modification of the parasitophorous vacuole membrane by the insertion of parasite-specific proteins. A rapidly expanding class of bacterial proteins that modify the vacuolar membrane are the chlamydial inclusion membrane proteins. Although the functions of most of these proteins remain to be defined, the majority are expressed early in the infectious process, suggesting that modification of the vacuole is critical to the outcome of the host–parasite interaction.     

大鼠输卵管沙眼衣原体感染后体内树突状细胞的变化

目的观察大鼠输卵管沙眼衣原体(CT)感染后体内树突状细胞(DC)的变化.方法选择成年雌性Wistar大鼠,从卵巢囊接种沙眼衣原体E型株.于感染后第1/2d、7d、14d、21d、28d和第35d处死动物取材,显示输卵管和脾内DC的变化.结果 1. 实验1/2d组输卵管未出现S-100 DC,在实验第7d、14d、21d、28d和第35d组输卵管均有S-100 DC出现;2.感染后脾淋巴小结数量增多,体积较大,淋巴小结内S-100 DC密集,动脉周围淋巴鞘内S-100 DC增多.结论输卵管CT感染后,输卵管和脾内S-100 DC增加,提示在体内DC对CT具有抗原提呈和启动机体免疫应答的作用,DC具有作为CT治疗性疫苗基础构建的潜力.     

In silico synteny based comparative genomics approach for identification and characterization of novel therapeutic targets in Chlamydophila pneumoniae

Chlamydophila pneumoniae is one of the most important and well studied gram negative bacterial strain with respect to community acquired pneumonia and other respiratory diseases like Chronic obstructive pulmonary disease (COPD), Chronic asthma, Alzheimer''s disease, Atherosclerosis and Multisclerosis which have a great potential to infect humans and many other mammals. According to WHO prediction, COPD is to become the third leading cause of death by 2030. Unfortunately, the molecular mechanisms leading to chronic infections are poorly understood and the difficulty in culturing C pneumoniae in experimental conditions and lack of entirely satisfactory serological methods for diagnosis is also a hurdle for drug discovery and development. We have performed an insilico synteny based comparative genomics analysis of C pneumoniae and other eight Chlamydial organisms to know the potential of C pneumoniae which cause COPD but other Chlamydial organisms lack in potential to cause COPD though some are involved in human pathogenesis. We have identified total 354 protein sequences as non-orthologous to other Chlamydial organisms, except hypothetical proteins 70 were found functional out of which 60 are non homologous to Homo sapiens proteome and among them 18 protein sequences are found to be essential for survival of the C pneumoniae based on BLASTP search against DEG database of essential genes. CELLO analysis results showed that about 80% proteins are found to be cytoplasmic, Among which 5 were found as bacterial exotoxins and 2 as bacterial endotoxins, remaining 11 proteins were found to be involved in DNA binding, RNA binding, catalytic activity, ATP binding, oxidoreductase activity, hydrolase activity and proteolysis activity. It is expected that our data will facilitate selection of C pneumoniae proteins for successful entry into drug design pipelines.     

沙眼衣原体感染后大鼠输卵管糖蛋白的变化

目的：研究沙眼衣原体（chlamydial trachomatis,CT）感染后,输卵管粘膜的结构及糖蛋白的变化。方法：60只成年Wistar雌性大鼠随机分为实验组和对照组,实验组单侧卵巢囊接种沙眼衣原体E型株,对照组接种2SP代替沙眼衣原体,分别于接种后第0.5、7、14天取材,在光镜下观察输卵管的结构变化,并采用PAS-Alcian blue染色显示输卵管内糖蛋白组分的变化。结果：对照组输卵管粘膜结构和糖蛋白组分无明显变化;实验组输卵管受损部位主要局限于粘膜层,PAS-Alcian blue染色显示沙眼衣原体感染可导致中性糖蛋白分泌减少。结论：沙眼衣原体的感染可使输卵管糖蛋白组分发生改变,这可能与反复感染的宫外孕、输卵管性不孕的发生有关。     

人工感染羊嗜流产衣原体豚鼠流产模型的建立

目的通过人工感染怀孕豚鼠建立嗜流产衣原体发病模型,观察流产病理学变化的差异,确定豚鼠是否可以作为嗜流产衣原体的动物模型。方法35只清洁级怀孕40d的豚鼠随机分为7组,每组5只。将羊嗜流产衣原体分离株B10011、CG1株分别以三个剂量组（10^-1,10^-2,10^-3）腹腔攻毒1次,每只0．5mL,以灭菌生理盐水为阴性对照。攻毒后观察豚鼠的临床体征、流产和死亡数量。攻毒后20d安乐死处理剩余的大小豚鼠,无菌摘取组织,分成2份。一份-20℃冷冻保存,PCR检测病原在组织中的分布;另外一份固定于10％中性甲醛溶液,组织切片和免疫组化观察。结果（1）羊嗜流产衣原体分离株B10011和CG1均可造成怀孕豚鼠流产、产弱胎、畸形胎或死胎。2种分离株感染不同剂量造成豚鼠平均流产时间、流产数量、豚鼠死亡数量均有显著差异,且CG1株敏感性高于B10011株。（2）2个分离株均可造成肾脏、肝脏肿大,肺脏呈局灶性出血,卵巢出血坏死,胎盘子宫阜水肿;病理组织学显示肾小管上皮细胞变性、坏死,单核细胞大量增生;肝细胞颗粒样病变。脾髓质弥漫性出血,皮质区淋巴小结生发中心萎缩。（3）免疫组化结果显示衣原体包涵体主要分布于肾脏近曲小管、远曲小管,以及脾脏的髓质区。（4）PCR检测显示分离株感染后,肾脏、脾脏、肺脏、肝脏中均呈阳性。在卵巢组织中,高剂量组呈阳性。结论以B10011和CGl分离株人工感染怀孕豚鼠均可导致豚鼠出现流产,且CG1分离株敏感性较高,呈剂量一效应关系;感染豚鼠病理学变化与临床羊流产相似。因此,人工感染豚鼠流产模型可以用于反刍动物嗜流产衣原体病的研究。     

沙眼衣原体感染后大鼠输卵管与植物凝集素BS-1结合的糖蛋白的变化

目的研究沙眼衣原体感染后输卵管与植物凝集素BS-1结合的糖蛋白的变化.方法取25只成熟Wistar雌性大鼠随机分为实验组和对照组,每组5只.对照组接种2SP代替沙眼衣原体,其余每组大鼠均在卵巢囊接种沙眼衣原体D型株.分别于感染后3,5,7,14d处死动物,取输卵管,观察大鼠输卵管与植物凝集素BS-1结合的糖蛋白在感染后不同天数发生的改变,其变化可通过荧光显微镜观察与植物凝集素BS-1结合后的荧光强度来检测,并采用HPIAS-1000图文分析系统进行定量分析和SPSS11.0统计软件作统计分析.结果输卵管受损部位主要在粘膜层,富含N-乙酰-D-半乳糖胺的糖蛋白随感染的天数不同,其变化有所不同,尤其以输卵管峡部变化明显.图像分析结果显示:感染第7d时其分泌量最低,感染后第14d其分泌量逐渐恢复,且各组间差异有显著性意义(P<0.05).结论输卵管是精子与卵子结合的地方,也是胚胎早期发育的场所.富含N-乙酰-D-半乳糖胺的糖蛋白可通过参与精卵结合、受精卵卵裂和早期胚胎发育等方式,对受精卵及早期胚胎发挥保护作用.     

阿奇霉素对沙眼衣原体感染后生殖道黏膜免疫反应的影响

目的 研究阿奇霉素治疗生殖道沙眼衣原体感染过程中对局部黏膜免疫反应的影响,为其临床应用提供新的实验依据.方法 构建小鼠生殖道沙眼衣原体感染模型,随机分为生理盐水组和阿奇霉素组.阿奇霉素组一次性给予阿奇霉素（80mg/kg）,生理盐水组给予等量生理盐水.给药当天、给药第7天、给药第14天和给药第21天,阴道拭子取宫颈脱落细胞,分离沙眼衣原体.给药21天,处死动物.收集血清,ELISA测定血清IL-6和TNF-α水平,同时进行阴道、宫颈黏膜常规HE染色和肥大细胞甲苯胺蓝染色、树突状细胞免疫组织化学分析.结果 1.阿奇霉素组沙眼衣原体感染率明显低于生理盐水组,且未出现上行感染（P〈0.05）.2.阿奇霉素组生殖道黏膜内树突状细胞数量增加（P〈0.05）,肥大细胞数量无明显变化（P〈0.05）.3.阿奇霉素组血清内IL-6和TNF-α的水平,均高于对照组和生理盐水组（P〈0.05）.结论 阿奇霉素除了有效清除生殖道沙眼衣原体感染,亦可以调节生殖道黏膜的免疫反应,减轻免疫病理损伤,使沙眼衣原体感染有较好的预后.     

沙眼衣原体分泌性蛋白Pgp3滴鼻免疫增强小鼠对衣原体生殖道感染的保护作用

【目的】探讨不同免疫途径沙眼衣原体(Chlamydia trachomatis,Ct)分泌性蛋白Pgp3的免疫保护效果,分析其可能的保护机制,以确定Pgp3蛋白疫苗在Ct疫苗研制中的应用价值。【方法】分泌性蛋白Pgp3经滴鼻或肌注途径免疫雌性Balb/c小鼠,免疫60 d后,阴道接种鼠沙眼衣原体(Chlamydia muridarum,Cm)建立生殖道感染动物模型,在该模型中评价Pgp3蛋白疫苗抗Cm感染的保护效果,并探讨其机制。【结果】滴鼻或肌注免疫后,小鼠血清及生殖道中检测到了特异性抗体;小鼠脾淋巴细胞产生IFN-γ、IL-17及IL-5水平均明显高于对照组,且滴鼻免疫组IFN-γ水平升高较肌注组更显著(P<0.05);Pgp3蛋白滴鼻免疫组小鼠经Cm生殖道感染后,阴道带菌时间明显缩短,输卵管病理改变轻而肌注免疫组其保护作用不明显。【结论】Pgp3蛋白经滴鼻免疫可有效诱导小鼠产生明显的抗Cm保护效应。其可能的免疫保护机制与诱导Th1型为主的细胞免疫应答及高效价的特异性抗体有关,提示Pgp3蛋白疫苗具有潜在的疫苗研究与开发价值。     

The protective efficacy of chlamydial protease-like activity factor vaccination is dependent upon CD4+ T cells

We have previously determined the protective efficacy of intranasal vaccination with chlamydial protease-like activity factor (CPAF) against genital chlamydial infection. Since T-helper 1 (Th1) responses are important for anti-chlamydial immunity, we examined the contribution of CD4(+) T cells in CPAF mediated immunity against intravaginal (i.vag.) Chlamydia muridarum infection in C57BL/6 mice. CPAF+IL-12 vaccination induced antigen-specific CD4(+) T cells that secreted elevated levels of IFN-gamma, and generated strong humoral responses. The protective effects of CPAF vaccination against genital chlamydial challenge were abrogated by anti-CD4 neutralizing antibody treatment. Moreover, anti-chlamydial immunity could be adoptively transferred to na?ve recipients using CPAF-specific CD4(+) T cells. Therefore, CPAF mediated anti-chlamydial immunity is highly dependent upon antigen-specific CD4(+) T cells.     

Chlamydial symbionts in the enigmatic Xenoturbella (Deuterostomia)

Ultrastructural observations of the gastrodermal cells in the enigmatic Xenoturbella revealed numerous chlamydiae. They are related to "Candidatus Fritschea" and Simkania (Simkaniaceae) based on 16S and 23S rRNA. Their 23S rRNA gene contains an intron encoding a putative homing endonuclease. The chlamydiae were pleomorphic and formed intravacuolar colonies. They have flattened disk-shaped elementary bodies, either oval or bow tie-shaped in cross-section, and reticulate bodies that are spherical, polygonal or irregularly shaped. All stages have five-layered cell wall with rippled appearance. Bacteria were not observed in the nuclei. The association between the chlamydiae and Xenoturbella is characterized by absence of cytopathological effects; limited host cell response against the chlamydiae; the confinement of the chlamydiae to inclusions in some part of the host cell; and complete and uniform infection of all examined hosts.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.