Fasciola worm and egg-derived antigens:Exploring their diagnostic potential for urogenital schistosomiasis in resource-limited endemic regions

Objective:To evaluate the immunodiagnostic potential of crude Fasciola gigantica-worm(FWA)and egg antigen(FEA)in detecting anti-Schistosoma(S.)haematobium antibodies in sera and urine samples.Methods:This is a cross-sectional diagnostic study.Employing an indirect ELISA,antibodies against these antigens were assessed in samples from infected and non-infected individuals in both schistosomiasis endemic(NE)and non-endemic(NNE)areas,using microscopy as the diagnostic standard.Results:FWA-sera exhibited excellent diagnostic accuracy with an area under the curve(AUC)of 0.957,a sensitivity of 93.75%,and a specificity of 85.42%for discriminating between infected and non-infected individuals in non-endemic areas.FWA-urine also demonstrated robust performance,achieving AUC>0.95,sensitivity>97.0%,and specificity>85.0%in both NE and NNE categories.Notably,S.haematobium-specific antibody levels against FWA were significantly elevated in infected individuals in both endemic and non-endemic areas.FEA-sera exhibited outstanding diagnostic performance with sensitivity exceeding 90%and an AUC of 0.968 in non-endemic samples but not in FEA-urine.Conclusions:FWA-based ELISAs,applicable to both sera and urine,emerge as promising tools for S.haematobium diagnosis in resource-limited settings,offering advantages of high sensitivity and specificity with shared antigens with Fasciola.The superior diagnostic metrics of urine samples suggest their potential as a non-invasive biological sample for diagnostic purposes.

Cryptococcal Antigenaemia among Treatment-Naïve Adult HIV-Infected Nigerian Patients

Background: There is a high burden of HIV-related cryptococcal meningitis in Sub-Saharan Africa and it is a leading cause of morbidity and early mortality among severely immunocompromised patients. Objectives of the Study: This study was carried out to determine the prevalence of cryptococcal antigen (CrAg) and the relationship of positivity to CD4+ve T cell counts and WHO clinical stage among severely immunocompromised treatment naive adult HIV-infected Nigerian patients. Methods: This was a hospital based cross sectional and prospective study carried out among newly diagnosed and confirmed HIV infected patients. Bio data of consenting consecutive subjects was collected by the attending physician using structured questionnaire. Rapid point of care lateral flow assay kits (IMMY, USA) was used to screen plasma samples from subjects strictly following manufacturer’s instructions. Data were analysed with statistical package for social sciences (spss 15.0) software. Results were presented in simple tables with frequencies and percentages while statistical significance was taken to be p value ≤ 0.05. Results: Of 432 subjects, there were 184 (42.6%) males and 248 (57.4%) females in the study. The median CD4 count of the subjects was 74 (range 6 - 1264) cells/ul. Seven (1.6%) of the subjects were positive for cryptococcal antigen (CrAg) and all were females (100%). Six (85.7%) of CrAg positives had CD4+ T cell count less than 100 cells, while 1 (14.3%) had count above 200cells/ul. The WHO clinical stage of studied patients was;stage I 163 (37.7%), stage II 132 (30.6%) stage III 95 (22.0%) and stage IV 42 (9.7%). Among the CrAg positive subjects, 3 (42.9%) were in WHO clinical stage l while 4 (57.1%) were in stage II disease. Conclusion: The observed overall prevalence of CrAg positivity among studied patients was low but occurred most frequently among the severely immunocompromised subjects. Advancement in WHO clinical stage was not a predicting risk factor for cryptococcal antigenaemia in studied adult HIV infected patients.

No DCX-positive neurogenesis in the cerebral cortex of the adult primate

Whether endogenous neurogenesis occurs in the adult cortex remains controversial.An increasing number of reports suggest that doublecortin(DCX)-positive neurogenesis persists in the adult primate cortex,attracting enormous attention worldwide.In this study,different DCX antibodies were used together with NeuN antibodies in immunohistochemistry and western blot assays using adjacent cortical sections from adult monkeys.Antibody adsorption,antigen binding,primary antibody omission and antibody-free experiments were used to assess specificity of the signals.We found either strong fluorescent signals,medium-weak intensity signals in some cells,weak signals in a few perikarya or near complete lack of labeling in adjacent cortical sections incubated with the various DCX antibodies.The putative DCX-positive cells in the cortex were also positive for NeuN,a specific marker of mature neurons.However,further experiments showed that most of these signals were either the result of antibody cross reactivity,the non-specificity of secondary antibodies or tissue autofluorescence.No confirmed DCX-positive cells were detected in the adult macaque cortex by immunofluorescence.Our findings show that DCX-positive neurogenesis does not occur in the cerebral cortex of adult primates,and that false-positive signals(artefacts)are caused by antibody cross reactivity and autofluorescence.The experimental protocols were approved by the Institutional Animal Care and Use Committee of the Institute of Neuroscience,Beijing,China(approval No.IACUC-AMMS-2014-501).

Biliary carcinoembryonic antigen levels in diagnosis of occult hepatic metastases from colorectal carcinoma

AIM:To prospectively explore the role of carcinoembryonic antigen (CEA) in gallbladder bile in patients with colorectal carcinoma and the morphological and clinical features of neoplasia and the occurrence of hepatic metastases. METHODS:CEA levels in the gallbladder and peripheral blood were studied in 44 patients with colorectal carcinoma and 10 patients with uncomplicated cholelithiasis.CEA samples were collected from the gallbladder bile and peripheral blood during the operation,immediately before extirpating the colorectal neoplasia or cholecystectomy. Values of up to 5 ng/ml were considered normal for bile and serum CEA. RESULTS:In the 44 patients with colorectal carcinoma who underwent operation with curative intent,the average level of serum CEA was 8.5 ng/ml (range:0.1 to 111.0 ng/ ml) and for bile CEA it was 74.5 ng/ml (range:0.2 to 571.0 ng/ml).In the patients with uncomplicated cholelithiasis who underwent cholecystectomy,the average level of serum CEA was 2.9 ng/ml (range:1.0 to 3.5 ng/ml) and for bile CEA it was 1.2 ng/ml (range:0.3 to 2.9 ng/ml). The average duration of follow-up time was 16.5 months (range:6 to 48 months).Four patients who underwent extirpation of the colorectal carcinoma without evidence of hepatic metastasis and with an average bile CEA value of 213.2 ng/ml presented hepatic metastases between three and seventeen months after removal of the primary colorectal neoplasia.Three of them successfully underwent extirpation of the hepatic lesions. CONCLUSION:High CEA levels in gallbladders of patients undergoing curative operation for colorectal carcinoma may indicate the presence of hepatic metastases.Such patients must be followed up with special attention to the diagnosis of such lesions.

Isolation and Characterization of 44.6 kDa Protein from Schistosoma japonicum Male Worm

Soluble male worm antigen of Schistosoma japonicum ( Sj ) was investigated for development of new vaccine candidate. SDS-PAGE and Western blotting were performed to compare the difference between soluble antigens from worms of different sex. Mice vaccination with the testing purified protein was followed by Sj cercariae challenge to detect the protective effect against Sj . Sixteen bands were seen for the soluble male worm antigen and 12 for the female worm. In addition, a distinct band of 44.6 kDa from the male worm antigen was observed, and its antigenicity was demonstrated by Western blotting. This 44.6 kDa protein could induce significant worm and egg reduction rate in mice (39.31%, 41.98%, P <0.001). In this study a 44.6 kDa protein was isolated and partially characterized. Its antigenicity, immunogenicity and the partial immune protection suggest its potential vaccine candidte against Sj .

日本血吸虫成虫和虫卵排泄分泌抗原对Ⅰ型糖尿病模型小鼠的影响

目的观察日本血吸虫成虫排泄分泌抗原(adult-worm excretory-secretory protein,AES)和虫卵排泄分泌抗原(excretory-secretory antigen of eggs,ESA)对Ⅰ型糖尿病小鼠的影响,并初步探讨其作用机制。方法将24只雄性昆明鼠随机分为空白对照组、PBS组、AES组和ESA组,每组6只。空白对照组不作任何处理,后3组给予链脲佐菌素(streptozotocin,STZ)溶液注射制备Ⅰ型糖尿病模型,建模成功后分别用PBS、AES、ESA腹部皮下多点免疫,1周免疫1次,持续免疫4周。免疫干预1周后开始检测小鼠血糖,持续检测4周;免疫干预4周后采用ELISA法测定小鼠血清中IL-4和IFN-γ水平变化,采用HE染色法检测小鼠胰腺组织病理变化。结果与PBS组相比,AES组和ESA组小鼠血糖水平从免疫后第2周起出现下降趋势,且ESA组小鼠血糖水平低于AES组,免疫后第2、3、4周小鼠血糖水平组间差异有统计学意义(F=1214.00、1055.00、683.64,P均<0.05)。各组小鼠血清IL-4和IFN-γ水平组间差异有统计学意义(F=146.84、21.11,P均<0.05),ESA组小鼠血清中IL-4水平[(61.45±6.14)pg/mL]高于PBS组[(21.96±3.98)pg/mL]和AES组[(49.31±3.19)pg/mL],IFN-γ水平[(129.48±36.75)pg/mL]低于PBS组[(316.43±66.38)pg/mL]和AES组[(212.09±70.89)pg/mL],差异均有统计学意义(P均<0.05)。PBS组小鼠的胰岛萎缩,数量减少,空泡样变性;ESA组小鼠有轻微胰岛萎缩;AES组介于PBS组和ESA组之间。结论日本血吸虫ESA对Ⅰ型糖尿病小鼠有一定保护作用,其机制可能是ESA刺激机体导致Th1反应抑制和Th2反应增强,表现为IL-4升高和IFN-γ下降,在一定程度上减轻小鼠胰腺组织的病理损伤。

New insights on serodiagnosis of trichinellosis during window period:early diagnostic antigens from Trichinella spiralis intestinal worms

The clinical diagnosis of trichinellosis is difficult because its clinical manifestations are nonspecific.Detection of anti-Trichinella IgG by ELISA using T.spiralis muscle larval excretory-secretory(ES)antigens is the most commonly used serological method for diagnosis of trichinellosis,but the main disadvantage is false negativity during the early stage of infection.There is an obvious window period between Trichinella infection and antibody positivity.During the intestinal stage of Trichinella infection,the ES antigens of intestinal worms(intestinal infective larvae and adults)are exposed to host’s immune system at the earliest time and elicit the production of specific anti-Trichinella antibodies.Anti-Trichinella IgG antibodies in infected mice were detectable by ELISA with ES antigens of intestinal worms as soon as 8-10 days post infection(dpi),but ELISA with muscle larval ES antigens did not permit detection of infected mice before 12 dpi.Therefore,the new early antigens from T.spiralis intestinal worms should be screened,identified and characterized for early serodiagnosis of trichinellosis.

日本血吸虫尾蚴成虫及虫卵的早期诊断组分抗原分析

目的寻找具有血吸虫病早期诊断价值的组分抗原。方法以感染后不同时间的兔血清,用SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)和免疫印迹试验(Westernblotting)方法,对日本血吸虫尾蚴、成虫和虫卵中的可溶性抗原的成分进行免疫分析。结果可溶性尾蚴抗原(SCA)94、48、41、40kDa和38kDa组分抗原最早出现免疫印迹反应,能被感染后2周兔血清所识别,可被感染后3周兔血清识别的SCA71、23kDa组分抗原反应最强。可溶性成虫抗原(AWA)最早出现反应的组分抗原是71、58kDa,能被感染后3周兔血清所识别。可溶性虫卵抗原(SEA)最早出现反应的组分抗原是270、151、73、69、50kDa和24kDa,能被感染后4周兔血清所识别。结论SCA94、71、48、41、40、38、23kDa,AWA71、58kDa和SEA270、151、73、69、50、24kDa能被急性感染兔血清所识别,是具有潜在早期诊断价值的组分抗原。

旋毛虫成虫可溶性粗抗原对小鼠的免疫保护作用

本文应用人工感染的方法从大白鼠获得大量成虫。经冻融、超声粉碎、高速离心制备出成虫可溶性粗抗原。将不同剂量的抗原与等体积弗氏完全佐剂乳化后间隔1周共免疫小白鼠3次。最后一次免疫后间隔1周每鼠攻击感染130条感染性肌幼虫,攻击感染后1周剖检成虫、新生幼虫,攻击感染后35天剖检肌幼虫。试验结果表明,以每只小白鼠免疫200μg成虫可溶性粗抗原所诱导的免疫力最好,诱导成虫减虫率达94.65％,肌幼虫减虫率达95.60％。初步研究表明,旋毛虫成虫可溶性抗原是很好的免疫原。

旋毛虫成虫cDNA文库免疫筛选及序列分析

目的 为获得旋毛虫成虫抗原基因。 方法 应用免疫血清和人工感染血清对旋毛虫成虫cDNA文库进行免疫筛选、克隆测序及核苷酸序列数据库 (GenBank)查寻比较 ,采用DNAstar软件进行基因序列分析。 结果 免疫筛选成虫cDNA文库 ,获得 9个阳性克隆。对其中的Ts87进行测序 ,又采用 5′ RACE ,获取全长为 1172bp的cDNA片段 ,该基因编码 3 47个氨基酸。序列分析表明 ,克隆Ts87是个尚未见报道的旋毛虫基因序列 ,存在预测的抗原表位。 结论 获得具有抗原性的旋毛虫抗原新基因。

日本血吸虫卵与卫氏并殖吸虫成虫可溶性抗原内的共同抗原组分研究

应用凝胶电泳和免疫印斑技术对日本血吸虫卵与卫氏并殖吸虫成虫的水溶性抗原(JSEA、PAA)和尿素溶性抗原(JEA-u、PAA-u)进行了抗原蛋白组分比较分析。结果显示:两者的特异性抗原显色主带,JSEA、JEA-u分别有8条和3条,PAA、PAA-u分别有9条和2条;其中JSEA、JEA-u分别有1条和2条,PAA、PAA-u分别有1条和2条对异种抗血清呈现交叉反应显色带。表明两种吸虫的可溶性抗原均存在共同抗原组分。慢性血吸虫病患者血清与并殖吸虫成虫抗原的交叉反应仅见于PAA,而未见于PAA-u,提示PAA-u在避免交叉反应和抗原纯化方面比PAA较为优越。

纯化31/32kDa抗原和成虫粗抗原诊断日本血吸虫病的比较

用纯化的日本血吸虫成虫３１／３２ｋＤａ抗原（Ｓｊ３１／３２）与成虫粗抗原（ＡＷＡ）对不同类型日本血吸虫病患者血清抗体进行检测，结果３种不同类型（急性、慢性和晚期）血吸虫病患者血清抗Ｓｊ３１／３２抗体水平（ＯＤ值）分别为２．７７±０．２５、２．６７±０．３０和２．４６±０．１９（Ｐ＜０．０１），抗ＡＷＡ抗体水平分别为３．２７±０．１６、３．２８±０．１６和３．２０±０．１７（Ｐ＞０．０５）。慢性血吸虫病患者血清抗Ｓｊ３１／３２抗体与每克粪便虫卵数（ＥＰＧ）之间有高度的相关性（ｒ＝０．９３），明显高于抗ＡＷＡ抗体与ＥＰＧ的相关性（ｒ＝０．４５）。结果表明，利用纯化Ｓｊ３１／３２诊断血吸虫病能较好地区别不同的感染类型和感染度。

日本血吸虫成虫和虫卵可溶性抗原及其组分抗原的研究

目的:探讨日本血吸虫雄虫、雌虫、虫卵的可溶性抗原雄虫(AWA-m、雌虫AWA-f、虫卵SEA)及其组分抗原的特性。方法:用DE22纤维素层析柱对日本血吸虫AWA-m,AWA-f,SEA抗原进行纯化,得到相应组分抗原。分别以SDS-PAGE和W estern b lot对组分抗原进行全面分析,并与相应未经纯化的可溶性抗原作比较。结果:经DE22纤维素层析处理的AWA-m,AWA-f,SEA,均能获得含多种蛋白的组分抗原。SDS-PAGE结果表明,AWA-m见10条主带和9条次带,其中Mr37 000,28 000,25 000为特异性条带,出现8条免疫反应阳性带;而AWA-m组分抗原为9条蛋白带和6条免疫反应阳性带。AWA-f见15条蛋白带,其中Mr26 500为特异性条带,组分抗原为8条蛋白带。AWA-f粗抗原及其组分抗原均见9条反应带。SEA见8条主带和10条次带,13条为免疫反应阳性条带;SEA组分抗原见11条带,其中9条为免疫反应阳性带。结论:AWA-m,AWA-f,SEA经DE22纤维素层析纯化获得组分抗原,方法简单、可靠。该组分抗原含有粗抗原的主要免疫反应成分,去除了多种与日本血吸虫病免疫反应无关的蛋白。

日本血吸虫成虫及虫卵可溶性抗原的早期诊断分子筛选

为获取有效的日本血吸虫病早期诊断靶抗原分子。以感染前和感染后2周、4周、6周兔混合血清以及急性、慢性日本血吸虫病人和正常人血清,用Westernblot对日本血吸虫成虫可溶性抗原(AWA)和虫卵可溶性抗原(SEA)进行了全面的分析与筛选。SEA140kDa和AWA54kDa、21kDa、20kDa分子出现最早,能被感染后2周兔血清所识别;SEA69kDa、50kDa、45kDa、38kDa和AWA72kDa、45kDa、34kDa、15kDa相继能被感染后4周兔血清所识别;其中SEA140kDa、50kDa、45kDa、38kDa和AWA34kDa、21kDa、54kDa、15kDa与病人血清反应同6周兔血清反应效果相仿,均为免疫反应主带,且在SDS-PAGE上有对应的蛋白主带,具有潜在的早期诊断价值。进一步对SEA进行抗体类型的分析,发现SEA能刺激机体产生IgG、IgM和IgA反应,其中SEA50kDa、45kDa、38kDa三个抗原分子均能被IgG、IgM、IgA三种抗体所识别,且均为反应主带;SEA140kDa以IgM反应带最深;SEA100kDa反应带仅出现于病人血清,以IgM反应最强,且其与IgM反应带在急性病人血清明显深于慢性病人血清,表明针对IgM的SEA100kDa分子也具有一定的早期诊断和区分病程的价值。SEA140kDa、50kDa、45kDa、38kDa和AWA34kDa、21kDa、54kDa、15kDa和针对IgM的SEA100kDa分子是具有潜在早期诊断价值的优势靶抗原分子。

日本血吸虫成虫细胞培养条件的初步研究

本文报道日本血吸虫成虫细胞培养条件的初步研究.结果表明:日本血吸虫的成虫细胞,在合成培养基RPMI-1640和5%的小牛血清、台成培养基TC-199和10%或20%的小牛血清培养液中,在附加常量抗菌素、pH值为7.2—7.4、培养温度为36℃一37℃条件下,其存活时间均可超过150d.另外,成虫细胞在未加抗菌素或附加一定量(常量或两倍于常量)抗菌素的培养液中的存活天数,没有明显差别.

旋毛虫成虫抗原和肌幼虫抗原保护性免疫的比较研究

目的:比较旋毛虫成虫抗原和肌幼虫抗原诱导小鼠产生保护性免疫效果的异同。方法:制备旋毛虫成虫抗原和肌幼虫抗原,分组免疫小鼠,并于末次免疫后10d用旋毛虫感染性幼虫对各组小鼠实施攻击感染,检测攻击感染后各组小鼠肠道成虫和肌肉幼虫数并计算减虫率,同时采用ELISA法检测各组小鼠血清IgG抗体水平。结果:成虫抗原免疫组小鼠和肌幼虫抗原免疫组小鼠检获的肠道成虫数和肌幼虫数均显著少于对照组(P<0.05),其中以成虫抗原免疫组小鼠减虫率最高(P<0.01)。成虫抗原免疫组和肌幼虫抗原免疫组小鼠于实施旋毛虫感染性幼虫进行攻击感染的当日所检测的血清IgG抗体水平与其免疫前相比均升高(P<0.01,P<0.05),与对照组相比亦升高(P<0.01,P<0.05),其中也以成虫抗原免疫组小鼠血清IgG抗体升高最为显著(P<0.01)。结论:旋毛虫成虫抗原和肌幼虫抗原均能激发小鼠产生保护性免疫,其中成虫抗原免疫组小鼠显示出更好的抗感染保护性。

日本血吸虫成虫体外传代培养细胞的生物学鉴定

本研究结果显示:血吸虫成虫细胞在体外培养中呈半悬浮聚集生长状态,4代内的培养细胞及冻存复苏细胞存活率达90%,并在各代培养中均可见细胞分裂相;传5代细胞的染色体核型为8对16条。超微结构既观察到形态正常细胞,也可见形态异常细胞。表明1640-40特定培养基对血吸虫成虫中的部分细胞体外传代培养获得成功。

日本血吸虫成虫31/32 kDa蛋白的纯化及保护性免疫力的研究

本文采用制备型聚丙烯酰胺凝胶电泳(SDS-PAGE)和电渗析方法分离纯化日本血吸虫成虫 31/32 kDa 蛋白(Sj 31/32蛋白)。SDS-PAGE、免疫印迹试验(EITB)和酶联免疫吸附试验(ELISA)检测结果表明采用该方法分离纯化的 Sj 31/32 蛋白纯度高,且具有较高的活性。用纯化的 Sj 31/32 蛋白加福氏佐剂免疫的小鼠,不仅可减少虫负荷(减虫率 28.1％),还可降低血吸虫成虫的产卵量(减卵率 71.4％),抑制虫卵肉芽肿的形成。结果提示:Sj 31/32 蛋白具有较高的减卵率,可望作为混合多价疫苗候选组分。

血吸虫对吡喹酮抗药性的研究Ⅴ 吡喹酮对曼氏血吸虫吡喹酮抗性株和敏感株成虫皮层的损伤

目的 体内比较吡喹酮对曼氏血吸虫吡喹酮抗性株与敏感株成虫皮层的损伤程度。方法 用各虫株尾蚴分别感染小鼠,感染后第57天,以300mg/kg微粒化吡喹酮悬液对小鼠作灌胃治疗;在灌药后10、30min和1、12、24h后剖杀感染小鼠,门静脉灌注收集成虫,按常规方法制成扫描电镜标本,扫描电镜下观察成虫体表的变化。结果 吡喹酮诱导的皮层损伤主要为虫体表形成泡状结构的薄壁隆起;给药10min,敏感株雄虫皮层可见较多小泡状物,而抗性株则少见;1h后,敏感株虫体表可见大量的泡状物,泡状物溃破可形成皮层损伤灶,抗性株仅见少量的泡状物;24h后,敏感株雄虫体表完全受损,部分皮层剥落,暴露出肌肉层,而抗性株仅见少量泡状物和破损的泡状物。给药1h后,敏感株雌虫开始出现少量泡状物,抗性株雌虫体表未见泡状损伤;12h后,敏感株雌虫泡状物数量增加,抗性株仅在有限区域见少量泡状物。结论 抗性株和敏感株成虫体表吡喹酮诱导的皮层损伤程度存在明显差异,敏感株的损伤程度重于抗性株,雄虫重于雌虫。

旋毛虫成虫三种抗原SDS-PAGE及Western-blot比较研究

目的研究大理猪源旋毛虫(Trichinella spiralis)成虫虫体可溶性抗原、表面抗原和排泄分泌抗原3种抗原的蛋白组分及其之间的差异,比较分析其免疫反应性。方法以十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和蛋白印迹对成虫3种抗原进行蛋白组分及其免疫反应性分析。结果十二烷基硫酸钠-聚丙烯酰胺凝胶电泳结果:虫体可溶性抗原显示29条蛋白带,分子量范围在112kDa^10kDa之间,其中主带13条;表面抗原显示4条主要蛋白带,分子量分别为50、48、40、34kDa;排泄分泌抗原显示17条蛋白带,分子量范围在120~14kDa之间,其中主带6条,分子量分别为120、64、43、40、35、33kDa。蛋白印迹结果:虫体可溶性抗原出现13条反应条带,其中分子量为81、40、37、33、30kDa的条带着色明显;表面抗原出现4条反应条带,其分子量分别为50、48、40、34kDa;排泄分泌抗原显示7条反应带,其中43、40、27、18kDa着色明显。结论旋毛虫成虫虫体可溶性抗原与排泄分泌抗原较表面抗原蛋白组分复杂,3者主带部分属低分子量区;免疫反应性的强度表面抗原和排泄分泌抗原高于虫体可溶性抗原,说明前两种抗原是旋毛虫成虫刺激机体产生免疫应答的主要靶抗原。