Immunoglobulin and cytokine profile in murine secondary hydatidosis

We have investigated specific immune responses in BALB/c mice with experimentally induced secondary hydatidosis. Following intraperitoneal inoculation of brood capsules containing Echinococcus granulosus-protoscoleces, the course of the infection was followed for 513 days. The sera of the mice were screened for the presence of a number of cytokines, and for specific antibodies. During the first 129 days of infection, high levels of cytokines TNFα, IL-α, IFNγ, IL-6, andIL-10 and specific IgGl andIgG3 isotypes were detected, as compared to uninfected controls. The levels oflgM and IgG2a were slightly increased following infection, and remained elevated throughout the period of observation. The levels of IL-lα and specific immunoglobulin of all isotypes except IgM and IgG2α, were significantly decreased 103 days post infection fp.i.), whereas TNFα was sharply decreased 129 days p.i. During the period of 129 to 209 days of infection there was an increase in secreted IL-10, and a slow decrease in the levels of IL-6 andlFN-γ. Levels of IgM, IgG, IgGl, and IgG2a plateaud during this period, whereas IgG3 and TNFα showed a peak at day 190 p.i. These data suggest the induction of Th2 antibody-mediated immunity with a parallel expansion of Thl-mediated inflammatory responses as important mechanism of host defence against the metacestode.     

Antibody response of Echinococcus granulosus infected mice: Protoscolex specific response during infection is associated with decreasing specific IgG1/IgG3 ratio as well as decreasing avidity

The antibody response was followed during 68 weeks in 17 Balb/c mice intraperitoneally (i.p.) infected with Echinococcus granulosus protoscoleces (PSC) and in three mice i.p. immunized with dead PSC. Titres of antibodies recognizing peptidic and glucidic PSC epitopes, as well as their isotypic and avidity profiles were followed by ELISA. In addition, antigen recognition patterns were analysed by immunoblot. The response against carbohydrate epitopes was dominant in infected and immunized mice but stronger in the first group. Infected mice showed similar profiles of specific IgG and IgM with maximum titres from week 38 to 53. Although IgG1 and IgG3 were the predominant antibody subclasses, the ratio of IgG1/IgG3 antibody titres as well as antibody avidity decreased during the experiment, encompassing a decrease in recognition of peptidic epitopes. Immunized mice did not show significant levels of specific IgM and, after week 15, showed IgG titres lower than the infected mice. IgG1 was the predominant IgG subclass during all the experiment with background levels of IgG3. The mean Ab avidity was high and showed no significant changes during immunization. Different patterns of response were thus produced by dead and developing live parasites. Although high avidity IgG1 antibodies were early found in both cases, lower avidity IgG3 antibodies were increasingly produced afterwards only in infected animals. The isotype switch and avidity decrease observed only during infection are consistent with a possible parasitic mechanism to evade host immunity .     

2种棘球绦虫IgG抗体检测试剂盒应用效果比较

目的 观察不同厂家生产的2种棘球绦虫IgG抗体检测试剂盒的检测效果。 方法 采用2种不同厂家生产的棘 球绦虫IgG抗体检测试剂盒检测相同数量的棘球蚴病人、 正常人血清, 以及卫氏并殖吸虫、 华支睾吸虫、 日本血吸虫和猪囊 尾蚴病人血清, 统计2种方法的特异性、 敏感性和交叉反应性。 结果 2个厂家生产的棘球绦虫IgG抗体检测试剂盒的特 异性和敏感性均为100％。深圳康百得公司生产的试剂盒与卫氏并殖吸虫病、 华支睾吸虫病、 日本血吸虫病和猪囊尾蚴病 的交叉反应率分别为25.00％、 26.09％、 10.00％和87.50％; 珠海海泰公司生产的试剂盒的交叉反应率分别为5.00％、 13.04％、 20.00％和93.75％。2种试剂盒间, 卫氏并殖吸虫病检出率差异有统计学意义 （P ＜ 0.05）, 其他检出率差异均无统 计学意义 （P均 ＞ 0.05）。结论 2个厂家生产的棘球绦虫IgG抗体检测试剂盒均具有敏感性高、 特异性强、 简便快速等优 点; 但需进一步解决与其他寄生虫病的交叉反应问题, 以提高早期诊断的准确性。     

Immunoglobulin profiles in a murine intermediate host model of resistance for Echinococcus granulosus infection

We have shown previously that primary infection of Chinese Kunming (CKM) mice with Echinococcus granulosus oncospheres is protective against subsequent challenge. Nine groups of mice were infected with the oncospheres of E. granulosus by different routes (intraperitoneal, subcutaneous or intravenous injection). After infection, serum was collected after different periods of time and serum antibodies were tested by ELISA against oncospheral proteins and hydatid cyst fluid antigens. The results indicated that CKM mice produced low levels of antibodies before a secondary challenge infection given 3 weeks later by a different route. Most mice did not evoke significant antibody responses against oncospheral antigens until 5 weeks after infection. The level of IgG, especially IgG1 against oncospheral antigens increased from week 4 post-infection (p.i.), to a maximum at week 9 p.i. In addition, antibodies against hydatid cyst fluid antigens increased at the same time as the recognition of oncospheral antigens. Immunoblots using hydatid cyst fluid showed that the first antigen that was recognized - an 8-kDa protein, possibly the smallest subunit of Antigen B - appeared 5-6 weeks p.i. and reactivity to this molecule was intensive at week 9 p.i. The results suggest that protection against secondary infection was not principally antibody-mediated during the initial phases of infection, when cellular immune responses may play a pivotal role in the protective mechanism.     

Detection of specific circulating antigen, immune complexes and antibodies in human hydatidosis from Turkana (Kenya) and Great Britain, by enzyme-immunoassay

Circulating antigen, specific immune complexes (IgG and IgM) and specific antibodies (IgG, IgM, IgE and IgA) were detected by enzyme-linked immunosorbent assay (ELISA) in the sera of hydatid (Echinococcus granulosus) patients from Turkana (Kenya) and the UK. Specific IgG and IgM antibodies predominated in current UK hydatid infections, while all classes of specific antibodies were lower in the Turkana patients. Circulating antigen, detected in 3% polyethylene glycol (PEG) precipitated complexes, using peroxidase conjugated hyperimmune human hydatid IgG (Fab) was more specific in ELISA than either antibody or immune complex assays where peroxidase conjugated anti-human IgG was used. Anti-human immunoglobulin ('rheumatoid' factor) was not detected in hydatid sera. Serum antigen, specific IgM immune complexes and specific IgM antibodies were associated with UK cases of current hydatid infection in contrast to patients with previous histories of hydatidosis. In 3 hydatid patients (from UK) levels of circulating antigen and specific IgM immune complexes rapidly declined within 1-4 months after surgical cyst removal. The detection of specific IgG and antigen in PEG precipitated immune complexes from false-negative/low responder Turkana hydatid sera, suggests that antibody 'mopping' by specific antigen may be occurring. After SDS-PAGE/immunoblotting analysis, antigen of mol. wt 67 000, present in hydatid cyst fluid and protoscoleces, was identified as putative circulating antigen in 3% PEG precipitates of sera from albendazole treated hydatid patients.     

感染细粒棘球蚴绵羊诱发过敏性休克期间IgG、IgG1和IgE水平的探讨

目的　测定感染细粒棘球蚴(E.g)绵羊诱发过敏性休克期间特异性IgG、IgG1和IgE抗体水平。了解抗原B对人工感染E.g绵羊IgG抗体的反应性。　方法　从绵羊E.g囊液中制备抗原B和E.g囊液粗制抗原,ELISA测定感染E.g绵羊诱发休克期间特异性IgG、IgG1和IgE抗体的动态变化。　结果　感染E.g绵羊6个月,特异性IgG、IgG1和IgE抗体水平较正常绵羊显著升高;诱发休克后特异性IgE抗体水平显著下降,尤其因休克致死的绵羊下降更为明显;IgG及IgG1抗体的衰减时间不同,趋势各不相同;抗原B和E.g囊液粗制抗原与血清IgG抗体反应阳性率分别为91%、32%。　结论　特异性IgE是导致棘球蚴病所致过敏性休克的主要抗体,而IgG和IgG1抗体也起着重要作用。抗原B与感染E.g绵羊IgG抗体的血清反应性较好,可作为一种血清免疫学诊断方法监测绵羊感染E.g的状况。     

微囊法棘球蚴继发感染小鼠动物模型的建立

目的 通过体外培养原头蚴发育成微囊,经腹腔注射建立稳定的细粒棘球蚴和多房棘球蚴继发感染小鼠动物模型。方法 无菌条件下采集羊源细粒棘球绦虫原头蚴和鼠源多房棘球绦虫原头蚴,经胃蛋白酶消化后检测虫体活力并计数,于37℃、5%CO₂条件下进行体外培养至发育成微囊,以每鼠50个微囊的剂量经腹腔注射的途径分别接种BALB/c小鼠。接种6个月后,通过腹部解剖大体观察和病理检测分析各组小鼠的感染情况及包虫囊的生长情况。结果 原头蚴在体外培养60d时发育成微囊,显微镜下观察Eg具有明显的透明角质层结构,而Em微囊角质层较薄。小鼠细粒棘球蚴和多房棘球蚴的感染率均为100%,Eg包虫囊为游离单囊,成囊率达70%,囊内无原头蚴;Em包虫囊为类似肿瘤的团块状组织,病灶内有生发囊及原头蚴。结论 采用微囊法可建立稳定的棘球蚴继发感染小鼠动物模型,为疫苗研制、药物筛选和疗效判定提供研究动物模型。     

Epitope specificities and antibody responses to the EG95 hydatid vaccine

Antibody isotype and epitope specificities were examined in sheep immunized with EG95, a protective recombinant vaccine against hydatid disease. All sheep immunized with EG95 as a fusion protein with glutathione S-transferase (GST) produced prominent IgG antibodies against the EG95 portion of the protein. Linear, antibody-binding epitope specificities of EG95 were mapped using a series of 25 overlapping synthetic peptides. Three immunodominant regions were identified which generated specific IgG₁ and IgG₂ antibodies in the majority of vaccinated sheep. These regions corresponded to the EG95-derived sequences SLKAVNPSDPLVYKRQTAKF, DIETPRAGKKESTVMTSGSA and SALTSAIAGFVFSC. An additional immunogenic region was identified which induced almost exclusively IgG₂ antibody. This epitope was located within the sequence TETPLRKHFNLTPV. The anti-parasitic, protective effects of the EG95 vaccine correlated with the detection of specific antibody to two or more of the four linear immunogenic regions. The identification of these immunogenic peptides of EG95 maybe useful in the development of a synthetic peptide vaccine as a derivative of the EG95 recombinant.     

Antibody response of Echinococcus granulosus infected mice: recognition of glucidic and peptidic epitopes and lack of avidity maturation

The antibody response was followed weekly during 68 weeks in 17 Balb/c mice intraperitoneally (i.p.) infected with 2000 Echinococcus granulosus protoscoleces (PSC) and in three mice i.p. immunized with 2000 dead PSC. Antibodies against hydatid cyst fluid (HCFA) and its peptidic (periodate-resistant) and carbohydrate (periodate-sensitive) epitopes were titrated by ELISA. Avidity and the antigen recognition pattern of antibodies were also analysed during infection and immunization by ELISA and immunoblot, respectively.
The antibody response of infected mice showed quantitative and qualitative variations during infection, since both titre as well as recognition of peptide and carbohydrate epitopes in HCFA depended on time post infection. No avidity maturation was evident during the course of infection. Sera from infected mice recognized the 38 kDa subunit of Ag5 but did not react with the 8 kDa subunit of AgB. On the contrary, the antibody response of immunized mice showed only one peak of antibodies that recognized both peptidic and carbohydrate epitopes of HCFA. In addition, sera from these mice recognized mainly 60 and 110 kDa bands. Our results suggest that: a) avidity and antigen recognition patterns of antibodies in mice treated with live PSC are different from those treated with dead PSC; b) antibodies against HCFA glucidic or peptidic epitopes appear at different times post infection.     

抗细粒棘球蚴B抗原人源单链可变区抗体临床诊断价值的初步研究

目的评价人源单链可变区抗体(ScFv)诊断细粒棘球蚴病的临床价值.方法用Western-blot检测ScFv识别的抗原表位,并检测该抗体与包虫病病人囊液、血清中循环抗原的结合,与其它肝占位疾病患者血清、正常人血清的交叉反应.结果 ScFv识别囊液抗原位点单一,特异性优于多克隆抗体,交叉反应低,但检测囊液及血清循环抗原的敏感性低于多克隆抗体.结论对临床使用ScFv诊断进行了初步尝试,直接ELISA法检出率不高,应改进为双抗体夹心法或多种抗体铺底捕获法来检测循环抗原.     

Immunosuppression in murine malaria. IV. The secondary response to bovine serum albumin

The anamnestic antibody response of CBA mice to bovine serum albumin was characterized by a rapid production of high-avidity antibody. After 3 weeks both the total amount of antibody and its avidity declined but still remained above those seen in the primary response for at least 6 weeks. The effects of acute Plasmodium berghei and Plasmodium yoelii yoelii infections upon the induction and the expression of this anamnestic response were studied. Mice infected with these malaria parasites responded poorly to primary immunization and the immunological memory generated was quantitatively subnormal. In addition, presence of the infection during a period between approximately the second and third weeks of the primary response prejudiced the development of high-avidity memory. Optimally primed mice, challenged during a subsequent acute infection, responded well initially, but were unable to maintain the secondary response at a normal level in terms of both quantity and avidity of the antibody. However, if challenge was delayed until after recovery from the infection, a normal secondary response ensued. Antibody concentrations in the sera of primed animals declined rapidly during infection. This was at least partly due to increased catabolism.     

细粒棘球绦虫p38蛋白原核表达及其多克隆抗体制备

目的 制备细粒棘球绦虫(Eg)p38蛋白的多克隆抗体,为进一步研究Egp38蛋白的功能提供检测抗体。方法 将Egp38蛋白基因序列克隆至原核表达载体pET28a,转化E. coli BL21株,IPTG诱导蛋白表达,以Ni亲和层析纯化Egp38蛋白,免疫家兔,收集免疫血清,ELISA 测定抗体效价,Western blotting检测所制备抗体与Eg虫体天然Egp38蛋白的反应性。结果 经0.2 mmol/L IPTG诱导,表达出约46 kDa的Egp38重组蛋白,制备获得效价在2.56×10⁵以上的多克隆抗体,该抗体能够与Egp38重组蛋白和Eg蚴虫体内的Egp38蛋白发生特异性反应。结论 成功制备获得兔抗Egp38多克隆抗体,为研究Egp38在Eg与宿主间的交互作用中的功能和作为药物靶标等研究奠定基础。     

酶联免疫吸附试验检测梅毒患者血清中抗苍白螺旋体IgM抗体

目的评价抗苍白螺旋体IgM抗体检测对梅毒的临床意义.方法用酶联免疫吸附试验(ELISA)对72例梅毒患者检测了特异性IgM抗体,并与快速血浆反应素环状卡片试验(RPR)、梅毒螺旋体明胶颗粒凝集试验(TPPA)的检测结果进行比较分析.结果血清抗苍白螺旋体IgM抗体在一期梅毒的阳性率为73.3%(11/15),在二期梅毒的阳性率为88.9%(16/18),二者差异无显著的统计学意义(χ2＝1.6363,P＞0.10).在潜伏梅毒,IgM抗体阳性率为26.1%(6/23),非常显著地低于早期显性梅毒(χ2＝17.6189,P＜0.005).在一期、二期和潜伏梅毒,RPR和TPPA的阳性率均为100%.入组前2～24个月已经正规抗梅治疗的梅毒16例,其中IgM抗体阳性2例.结论 ELISA法检测特异性IgM抗体诊断一期梅毒并不优于RPR和TPPA.IgM抗体在潜伏梅毒敏感性低,其诊断应依靠RPR和TPPA.目前不推荐单独检测抗梅毒IgM抗体来监测病情和判断疗效.抗苍白螺旋体IgM抗体的临床意义有待更深入的研究.     

细粒棘球蚴egG1Y162疫苗对小鼠免疫应答的研究

目的 观察细粒棘球蚴egG1Y162疫苗免疫小鼠后机体的免疫应答状况。方法 实验组、GST对照组、佐剂组和正常组小鼠分别注射egG1Y162疫苗、谷胱甘肽巯基转移酶(GSTs)、佐剂(FCA)和生理盐水(NS),在免疫第0、2、4、6、8和10周,收集各组血清用酶联免疫吸附法(ELISA法)检测抗体滴度,并检测各组血清抗体IgG的动态变化。第10周用四甲基偶氮唑蓝实验(MTT法)检测免疫小鼠脾淋巴细胞体外刺激后的增殖反应,用AnnexinV-FITC和碘化丙啶(PI)双染色法检测脾细胞凋亡率。结果 egG1Y162疫苗免疫组小鼠在第2周免疫后检测到抗体,在免疫第10周,抗体滴度可达到1∶25 600。血清抗体IgG在免疫第2~10周不断升高,并在免疫第10周达到最高水平。MTT法显示egG1Y162疫苗免疫组小鼠脾淋巴细胞在体外能被egG1Y162疫苗特异性刺激增生。疫苗刺激后疫苗组增殖水平显著高于对照组、佐剂组和正常组(P<0.05)。AnnexinV-FITC和PI双染色法结果显示实验组小鼠脾细胞原液和ConA刺激细胞凋亡发生率均显著低于对照组(P< 0.01),每组ConA刺激脾细胞凋亡发生率显著高于相应的原液培养(P< 0.01)。结论 细粒棘球绦虫egG1Y162疫苗可诱导小鼠产生高效价抗体并可刺激脾淋巴细胞增殖活化、抑制脾细胞凋亡,特异性抗体反应和脾淋巴细胞增殖活化促进机体产生体液免疫反应和细胞免疫反应,共同协调诱导机体产生免疫应答反应。     

Modulation of the cellular immune response by a carbohydrate rich fraction from Echinococcus granulosus protoscoleces in infected or immunized Balb/c mice

Infection of Balb/c mice with Echinococcus granulosus protoscoleces constitutes the model for secondary hydatid infection. The immune response of Balb/c mice infected with E. granulosus is characterized by secretion of antibodies specific for carbohydrate epitopes and production of type-2 cytokines. A role for glycoconjugates in the induction of type-2 responses has been suggested in other host--parasite systems. Although glycoconjugates are immunogenic in E. granulosus infection, the role of these molecules in the establishment of the type-2 response has never been analysed. In this study, a carbohydrate rich fraction (E4+) from E. granulosus protoscoleces was obtained using the monoclonal antibody E492/G1 specific for the moiety Galalpha(1,4)Gal which is widely represented in protoscoleces and other E. granulosus antigenic preparations. The results showed that E4+ was immunogenic in Balb/c mice evoking an antibody response mainly directed against carbohydrate epitopes. In addition, splenocytes from E4+-immunized mice showed suppressed proliferative responses to Con A and E4+ induced IL-10 secretion by E4+-primed and naive splenocytes. The fraction E4+ also was immunogenic in infected mice during early infection. In this case also, splenocytes from infected mice as well as peritoneal cells from infected or naive mice, when stimulated in vitro with E4+, secreted IL-10. Collectively, these results suggest that E4+ may be involved in immunosuppression phenomena and, by stimulating IL-10 secretion, may contribute to the induction and sustaining of the type-2 cytokine response established in early experimental infection.     

Relevance of circulating antigen detection to follow-up experimental and human cystic hydatid infections

We analysed specific antibody (Ab) and circulating antigen (CAg) profiles along experimental mouse infection using as control a group of mice immunized with intact but dead parasites. Results from this experiment showed an early major CAg peak followed by a larger Ab peak which partially overlaps with other minor CAg peaks. These results suggest that CAg may be a marker of early mouse infection. In order to study the relevance of these findings in humans we similarly analysed by ELISA 148 sera provided by retrospective post-surgical follow-up of 19 patients. Available records showed that 14 patients developed new cysts one to ten years after surgery while no new disease was observed in the other five. Some of the former patients showed CAg as early as two months after surgery while no CAg was observed in the other five patients at any time. In addition, a collection of 38 sera obtained before surgery were similarly tested and five of them showed only CAg, while 18 showed only Ab and 12 sera showed Ab&CAg. These results in humans are consistent with the findings in the mouse experimental model and suggest that CAg may be an early marker of hydatid infection, thus being relevant for post-surgical follow-up.     

Diagnostic evaluation of a synthetic peptide derived from a novel antigen B subunit as related to other available peptides and native antigens used for serology of cystic hydatidosis

A synthetic peptide (GU4) derived from an antigen B (AgB) subunit was serologically compared with crude antigen (HCFA); immunopurified AgB and antigen 5 (Ag5), and two other synthetic peptides, for diagnosis of human cystic hydatidosis. GU4 was derived from the sequence of AgB/2, the novel AgB subunit described by us. The other two peptides: 65 (AgB mimotope) and 89–122 (Ag5 mimotope), were described by others. Antigens B and 5 showed higher diagnostic sensitivity than corresponding peptides. All sera reacting with peptides 89–122 and GU4 also reacted with 65. The latter provided three to four times higher sensitivity than the former two peptides, but 30% lower specificity. The diagnostic efficiency of AgB (82%) was higher than those of Ag5 (74%) and HCFA (71%). Interestingly, 89–122 only reacted with hydatid sera, some of which did not react with AgB. Considering positive those reacting with 89–122 or AgB, sensitivity increases from 77% (with AgB) to 82% (combined), while specificity is the same as with AgB (86%). Our results suggest that hydatid serology may be improved by: a) combining several defined antigens (including synthetic peptides), b) design of new E. granulosus-specific mimotopes, which react with the false negative sera (16/90; 18%).     

Ultrastructural localization of major hydatid fluid antigens in brood capsules and protoscoleces of Echinococcus granulosus of human origin

Monospecific rabbit antisera obtained through experimental immunization with previously purified proteins were used in the ultrastructural localization of two hydatid fluid antigens, in brood capsules and protoscoleces of Echinococcus granulosus of human origin. The antigen-antibody reaction was revealed by a colloidal gold based method. Reaction was evident in the connective region of the germinal membrane and in the parenchyma of the protoscoleces. Both antigen 5 and antigen B were located in the interstitial material between the parenchymal cells and precisely associated with disorganized areas. The brood capsule wall and the brood capsule contents, the tegument of the protoscoleces, the parenchymal cells, the muscle cells, the calcareous corpuscles and the hooks did not contain antigen 5 or antigen B. Label was not observed in the lumen of the collecting ducts or in the flame cells, although antigen 5 was evident in the periluminal cytoplasm. The origin of the antigens and their release are discussed.     

Quantitative review of antibody response to inactivated seasonal influenza vaccines

Please cite this paper as: Seidman et al. (2012) Quantitative review of antibody response to inactivated seasonal influenza vaccines. Influenza and Other Respiratory Viruses 6(1), 52–62. Background Seasonal influenza epidemics are associated with significant morbidity and mortality each year, particularly amongst young children and the elderly. Seasonal influenza vaccines have been available for decades, yet influenza remains a major public health threat in the US, sparking interest in studies evaluating the effectiveness of vaccination. Objectives We sought to identify determinants of serological responses to inactivated seasonal influenza vaccines including number of doses, adjuvant, and subject characteristics. Methods We reviewed 60 articles published between 1987 and 2006. We used weighted multiple logistic regression and random‐effects models to evaluate how seroconversion and seroprotection rates varied with host and vaccine factors. Results Both children and seniors tended to have poorer immune responses compared to adults whereas use of adjuvant and a second vaccine dose tended to improve immune response. Pre‐vaccination serological status had a large impact on the immune response to vaccination. We found substantial heterogeneity among studies, even with similar population settings and vaccination regimen. Conclusions Future studies should stratify their results by pre‐vaccination serological status in an effort to produce more precise summary estimates of vaccine response.     

''Arc 5'' antibodies in sera of sheep infected with Echinococcus granulosus, Taenia hydatigena and Taenia ovis

The 'arc 5' precipitin band, formed when test human serum is reacted against immunoelectophoresed hydatid cyst fluid antigen, has provided a positive diagnosis of Echinococcus granulosus infection. These antibodies to 'arc 5' antigen have now been found in the sera of sheep. They appear 2 weeks after infection with Taenia ovis, after 3 weeks with T. hydatigena and after 16 weeks with E. granulosus. An antigen similar to the 'arc 5' antigen of E. granulosus cyst fluid was also demonstrated in cyst fluid from T. hydatigena, but it would not be positively identified in T. ovis cyst fluid. The presence of 'arc 5' in immunoelectrophoresis tests is not suitable for specific immunodiagnosis of E. granulosus infections in sheep in New Zealand. 'Arc 5' antibodies were only associated with living E. granulosus cysts and were not present if cysts were dead. The location of the cysts in either liver or lungs and the onset of brood capsule production did not influence the presence of 'arc 5' antibodies.