Function and expression of a human idiotypic network in Schistosomiasis japonica

The cross-reactive idiotype (Hu-SJ-CRI_M) is defined by polyclonal human anti-idiotypic antibodies derived from chronically S. japonicum infected patients. The present study shows that serum levels of Hu-SJ-CRI_M expressed by antibodies to S. japonicum soluble egg antigen (SEA) are associated with acute infection and hepatosplenic disease. Xenogeneic anti-idiotypic antisera (anti-Hu-SJ-CRI_M) suppressed human lymphocyte blastogenesis to SEA in vitro by 47–82% (P < 005). These anti-idiotypic antibodies also suppressed in vitro granuloma formation induced by SEA coated beads in a dose dependent manner. This immunosuppression was antigen specific in that mitogen (PHA) or non-related antigen (PPD) induced blastogenic responses were not suppressed. Surprisingly, anti-idiotypic antibodies (anti-SJ-CRI_M), which describe the mouse correlate CRI_M were not suppressive in the human blastogenesis or in vitro granuloma formation assays. These data indicate a dichotomy in the function and specificity of the idiotype/anti-idiotype human and murine immune networks in S. japonicum infection. Thus, only the patient derived molecules and serology form the basis for an immunoregulatory network in Schistosomiasis japonica.     

Natural antibodies in Microtus fortis react with antigens derived from four stages in the life-cycle of Schistosoma japonicum.

The levels of antibodies which react with the cercarial antigens (CA), schistosomulum stage antigens (SSA), adult-worm antigens (AWA) and soluble egg antigens (SEA) of Schistosoma japonicum were investigated in Microtus fortis and albino mice, using an indirect ELISA. The M. fortis studied fell into three groups: animals caught in the wild; laboratory-bred animals left unchallenged; and laboratory-bred animals that had been challenged with S. japonicum (30 cercariae/animal) 15 days previously. There were also three groups of albino mice: those without infection; those studied 15 days after challenge infection; and those investigated 42 days after infection. The antibodies detected at the highest levels in the laboratory-bred, uninfected voles and in the wild-caught animals were those reacting with SSA, followed, in descending order, by those reacting with AWA, CA and SEA. The levels of natural antibodies to SSA and AWA in these voles were significantly higher than the corresponding levels observed in the uninfected mice and even in the mice infected 15 days previously. The levels of antibodies reacting with CA, SSA, SEA and AWA in the experimentally infected M. fortis were 1.9-, 2.2-, 1.5- and 2.1-fold higher, respectively, than those in the laboratory-bred but uninfected voles. The observations indicate that even uninfected M. fortis produce antibodies which react with S. japonicum, and this presumably results in the natural resistance to infection which has been reported in these rodents.     

Cross-reactive idiotypes on rabbit anti-SEA antibodies stimulate anti-idiotype spleen and lymph node cell responses of mice infected with Schistosoma mansoni

Antibodies to Schistosoma mansoni soluble egg antigens (SEA) generated in outbred rabbits from two different sources were used to study cross-reactive idiotype/anti-idiotype (Id/anti-Id) interactions in S. mansoni -infected mice in two different locations. Immunoaffinity purified rabbit polyclonal anti-SEA antibody preparations (RabId) were predominantly Ig by SDS-PAGE and demonstrated anti-SEA activity by ELISA and Western blot. RabId prepared from three separate rabbits and used at 40 μg/ml in vitro stimulated lymphocyte proliferative responses of spleen cells from mice with eight week infections (Mean ± SEM [E–C]) of 3869 ± 764, 18 594 ± 3046 and 8962 ± 1734   cpm. Spleen cells from uninfected mice exposed to the same RabId preparations in vitro had respective [E–C] values of 206 ± 144, 494 ± 154 and 363 ± 180. Lymph node cells from mice infected for 8 weeks demonstrated [E–C] of 123 ± 400, 5073 ± 828 and 2361 ± 656 upon exposure to these 3 RabId preparations. Lymph node cells from uninfected mice had [E–C] of 220 ± 76, 194 ± 82 and 143 ± 72 when exposed to these RabId. Maximum in vitro proliferative response to Ig from unimmunized rabbits was 761 ± 400 by spleen cells from mice with eight week infections. These data indicate the presence of cross-reactive Id on rabbit anti-SEA antibodies from different rabbits that can stimulate in vitro lymphoproliferative responses of spleen or lymph node cells from S. mansoni -infected mice.     

抗日本吸虫卵单克隆抗体的制备和免疫化学的鉴定

Monoclonal antibodies (McAbs) were generated from mice immunized with soluble egg antigen (SEA) of Schistosoma japonicum. Five of which were specific to SEA of S. japonicum. The isotype of these McAbs was IgG1. Immunoblotting showed that the approximate molecule weight of the antigens recognized by the McAbs were 22 kDa, 116 kDa and greater than 200 kDa respectively. At least 3 isomorphs of the 22 kDa antigen recognized by 1E1 were found at pI 4.6-6 with 2-D Western blot. Moreover, immunoprecipitation using 125I-labeled S. japonicum SEA demonstrated that only one band corresponding to 30 kDa was recognized by 1E1.     

血吸虫感染小鼠早期诊断抗原的研究

目的对已知的6种日本血吸虫抗原的早期诊断价值进行评价,为研制用于哨鼠早期诊断的免疫试剂提供候选抗原。方法用日本血吸虫尾蚴感染小鼠,收集感染前及感染后不同时间的小鼠血清。采用重组日本血吸虫中国大陆株23kDa膜蛋白大亲水性肽段与谷胱甘肽的融合表达蛋白（GST-HD）、可溶性虫卵抗原（SEA）、血吸虫四跨膜蛋白第二亲水基团（TSP2HD）、血吸虫虫卵蛋白（IPSE）、日本血吸虫虫卵毛蚴抗原（SjMP-10）及日本血吸虫信号蛋白（Sj14-3-3）作为诊断抗原,采用酶联免疫吸附试验检测感染血吸虫后不同时间小鼠血清中特异性抗体IgM和IgG水平,通过分析感染后不同时间点抗原特异性抗体水平变化及阳性率,筛选具有血吸虫感染早期诊断价值的抗原分子。采用免疫印迹试验进一步验证其对血吸虫急性感染早期诊断的价值。结果感染后第18、21、28天,抗GST-HD抗体IgM阳性率分别为60%、70%、100%,特异性IgG阳性率分别为40%、60%、90%;抗SEA抗体IgM阳性率为50%、60%、90%,特异性IgG阳性率为20%、50%、70%;抗TSP2HD抗体IgM阳性率为30%、40%、50%,特异性IgG阳性率为20%、30%、70%;抗IPSE抗体IgM阳性率为20%、30%、50%,特异性IgG阳性率为20%、30%、60%;抗SjMP-10抗体IgM阳性率为10%、20%、20%,特异性IgG阳性率为10%、20%、30%;抗Sj14-3-3抗体IgM阳性率为0、10%、20%,特异性IgG阳性率为0、10%、30%。以GST-HD融合蛋白和SEA为抗原,检测小鼠早期感染血吸虫的敏感性高于Sj14-3-3、IPSE、TSP、MP-10,检测IgM的敏感性高于IgG。免疫印迹试验结果显示,SEA中分子量在73kDa左右的蛋白条带可被感染后1周小鼠血清所识别,并随着时间推移反应加强。GST-HD最早出现反应的血清是感染后第10天小鼠血清,反应强度在感染后第5周达到最强。结论重组GST-HD融合蛋白与SEA中分子量约73kDa的蛋白分子具有血吸虫感染早期诊断价值,免疫印迹试验的敏感性比酶联免疫吸附试验高。     

Paramyosin is a major target of the human IgA response against Schistosoma japonicum

Human resistance and susceptibility to schistosomiasis is associated with age and specific antibody isotype responses against worm (SWAP) and egg (SEA) antigens. In a cross-sectional study of 176 individuals infected with Schistosoma japonicum in the Philippines, strikingly similar isotype response patterns against SWAP and SEA was observed when compared to other endemic areas. Interestingly, IgA titres to SWAP correlated with older age among S. japonicum-infected individuals (n = 176, P < 0.01), suggesting a role for this isotype in protective immunity. To identify the molecular targets of human IgA, 17 high-IgA/SWAP responders were identified from the said population. IgA antibodies from the majority (14/17) of these individuals recognized a band of 97 kDa (Sj97), comigrating in immunoblots with the myofibrillar protein paramyosin. The antigen was confirmed as paramyosin by expressed sequence tag (EST)-analysis of four clones obtained by screening an adult S. japonicum cDNA library with pooled IgA antisera and mouse antiparamyosin polyclonal antibodies. The identification of paramyosin as a major target of human IgA raises its potential as a vaccine candidate that targets mucosal immune responses. Since this antigen is exposed on the parasite surface only during the lung stages, we propose that human IgA contributes to parasite attrition during schistosome migration in the lungs.     

Application of dipstick dye immunoassay (DDIA) kit for the diagnosis of schistosomiasis mekongi

The dipstick dye immunoassay (DDIA), developed in China for the detection of antibodies against Schistosoma japonicum, relies on soluble egg antigen (SEA) labelled with a colloidal dye. This assay is not only rapid, simple and inexpensive, but also particularly useful for screening in the field. In order to determine whether S. japonicum antigens are sufficiently cross-reactive to make the assay applicable for the diagnosis also of S. mekongi a DDIA approach based on the S. japonicum SEA was tried in cohorts of healthy and infected people living in areas non-endemic and endemic with regard to schistosomiasis mekongi in Cambodia and Laos. A sensitivity of 97.1% was recorded when testing Cambodian subjects, correctly diagnosing 33 out of 34 infected people. When the assay was applied in Laos, a sensitivity of 98.6% (69/70) was found. None of 114 residents living in a non-endemic area in Cambodia tested positive. A cross-reaction of 18.3% was found in patients infected with Opisthorchis viverrini. The results support the notion that the DDIA using S. japonicum SEA antigens can safely be implemented for the diagnosis of schistosomiasis mekongi, but care is needed in the interpretation of results obtained from areas that are co-endemic for O. viverrini.     

酶联免疫印迹术（EITB）在小鼠日本血吸虫感染早期诊断中的应用

为探讨日本血吸虫感染的早期诊断方法,本文应用酶联免疫印迹术(EITB)检测感染鼠血清的循环抗原。所用抗体由日本血吸虫成虫和虫卵的五种抗原(SEA、UEA、TA、CY、MC)免疫动物获得。SDS—PAGE和EITB显示这些抗原与华支睾吸虫、肺吸虫和蛔虫等交叉反应不明显。其中CY抗原的31KD条带是血吸虫特有。用EITB监测小鼠感染日本血吸虫后6周内各期和用吡喹酮治疗后2周的循环抗原有如下变化:UEA抗体显示的187KD抗原多肽在4周出现并逐渐加深,治疗后变淡;与TA和CY抗血清反应的40KD抗原分别在感染后3天～4周和3天～2周出现;抗MC显示的15.3KD在6周出现,治疗后消失;与成虫表膜相关的20、15、12.8KD仅在治疗后出现。对这些特异的抗原性多肽动态观察似可为早期诊断日本血吸虫病和考核疗效提供参考。     

抗日本血吸虫卵单克隆抗体的制备和免疫化学的鉴定

用可溶性日本血吸虫卵抗原(SEA)免疫小鼠制备单克隆抗体,获得5株特异的抗日本血吸虫卵单抗。免疫球蛋白亚类鉴定均为IgG_1。免疫印迹法结果表明其所识别的日本血吸虫卵抗原的分子量分别为>200kDa、116kDa和22kDa。经两维免疫印迹法(2-Dimensional Western Blot),显示被单抗IE1识别的22kDa SEA等电点pI4.6—6之间至少有3个以上同晶型体(isomorphs)。放射免疫沉淀试验表明IE1可识别30kDa抗原。     

Hybridoma proteins expressing the predominant idiotype of the antiazophenylarsonate response of A/J mice.

Hybridoma cell lines that secrete monoclonal antiazophenylarsonate antibodies were isolated from the fusion of A/J splenic lymphocytes with a myeloma cell line. A small percentage of these hybridoma proteins were recognized by rabbit antisera that detect the crossreactive idiotype characteristics of the antiazophenylarsonate response of A/J mice. The isotype, pI value, and amino-terminal sequences of four independently derived idiotype-positive hybridoma proteins were determined. These proteins were either of the IgG1 or IgG2a heavy chain class. For two mice tested, the majority of the idiotype in the immune serum was shown to be of the same isotype as the fusion-derived monoclonal antibodies. The pI values of the hybridoma proteins differed from one another and ranged from 6.9 to 7.6. Amino acid sequences of the heavy chains showed a significant degree of homology with each other, but each chain was unique in the framework or the first complementarity determining region (or both). A comparable pattern of sequence variation was evident for the light chains. The azophenylarsonate idiotype, therefore, appears to consist of a family of nonidentical but closely related molecules that are the product of more than one germline gene or the result of somatic mutation of a single germline gene.     

嗜酸粒细胞在日本血吸虫(中国大陆株)感染小鼠体内的作用

以抗嗜酸粒细胞血清(AES)对嗜酸粒细胞(Eos)在日本血吸虫(中国大陆株)感染小鼠体内的作用进行了研究。小鼠经初次感染日本血吸虫尾蚴5wk后,用200条尾蚴攻击感染,并经AES处理,肺部回收童虫数明显高于用正常兔血清(NRS)处理的对照组;正常小鼠经被动转移免疫血清后感染日本血吸虫尾蚴,用AES处理,肺部回收童虫数比NRS对照组明显增多。用日本血吸虫可溶性虫卵抗原(SEA)皮下致敏小鼠,2wk后经尾静脉注射虫卵形成肺肉芽肿反应,经AES处理后,肺虫卵肉芽肿内Eos受到明显抑制,肉芽肿平均直径明显小于NRS对照组。试验结果提示,Eos是宿主体内对日本血吸虫童虫有效的杀伤细胞之一,其杀伤作用是抗体依赖的Eos介导的细胞毒作用;AES能特异性地仰制肉芽肿内的Eos,并对不同时期肉芽肿的直径有明显的抑制作用。     

The presence of Syphacia obvelata in laboratory mice (BALB/c) — parasite antigens in immune response

Summary In conventional mice colonies, mouse pinworm, Syphacia obvelata is found very often. Several studies indicate that infection with this parasite can modulate the immune system of the host and can affect experimental final results. The aim of our study was to investigate the most immunogenic proteins of S. obvelata inducing both local and systemic immune response in naturally infected laboratory mice. Protein extracts of S. obvelata were analysed by Western blotting to examine their antigenic character. The antigens were probed with serum and mucosa of S. obvelata naturally infected mice. Surface and somatic antigens were recognized by serum and mucosal IgG, IgA and IgM antibodies. The most immunogenic and dominant proteins were observed. Proteins of Mw ∼ 70, 65 and 48 kDa showed the most evident reaction with serum and mucosa antibodies of infected animals. Surface and somatic antigens of nematode S. obvelata eliciting immune response in laboratory mice may be useful in development of a diagnostic test which could be applied for the infection control prior the experiments.     

日本血吸虫病患者体内自然抗独特型抗体的初步研究

成用杂交瘤技术所制备的鼠抗日本血吸虫可溶性抗原(SEA)单克隆抗体5B5H腹水经饱和硫酸铵提纯后制成亲和层析柱,血吸虫病人血清过此柱后获得抗Id抗体提取物。经McAb-ELISA测试,提取物与5B5H单抗特异性结合,与另一株抗SEA单抗W_(29)及抗成虫单抗W_(46)均不结合,补体结合试验表明此提取物不含有免疫复合物。SEA可显著竞争抑制Id(5B5H)-抗Id抗体的结合,提示抗Id抗体所针对的5B5H单抗的Id位于抗原结合部位或其邻近。用5B5H-ELISA检测两个不同地区血吸虫病患者的抗Id抗体,阳性率分别为35.1％和60％,与姜片虫病人血清(0/15)、华支睾吸虫病人血清(0/15)无交叉反应,在并殖吸虫病人血清中出现一例阳性(1/20),与健康人也无假阳性反应(0/50)。     

日本血吸虫24-26kDa抗原和重组Sj26抗原的抗原性和免疫原性比较研究

本文报告从日本血吸虫大陆株成虫抽提的24—26kDa抗原与源于日本血吸虫菲律宾株的重组Sj26抗原之间在抗原性和免疫原性上所进行的一系列比较研究。ELISA、IFA和Westernblotting等方法观察结果均表明,24—26kDa和rSj26抗原免疫后所诱导的特异性抗体与其对应的抗原之间具有明显的抗原交叉反应,而与其它血吸虫抗原如可溶性虫卵抗原也有交叉反应。若以两种抗原加福氏佐剂分别免疫小鼠,以日本血吸虫大陆株尾蚴攻击感染,减虫率相似(26～32％),表明两种抗原存在一定程度的交叉免疫保护性。这些研究结果为开发rSj26抗原,或是根据已知Sj26 cDNA核苷酸序列制备DNA探针,从已构建的日本血吸虫(大陆株)cDNA库筛选相关目的基因,加速血吸虫疫苗的研制起着重要作用。     

Detection of circulating antigen in serum of mice infected with Schistosoma japonicum by immunomagnetic bead ELISA based on IgY

We developed a novel immunomagnetic bead ELISA based on IgY (egg yolk immunoglobulin) for detection of circulating antigen (CA) in sera of mice infected with Schistosoma japonicum. The assay involved the use of chicken polyclonal antibodies IgY against soluble egg antigens (SEA) of S. japonicum as a capture antibody and anti-SEA mouse monoclonal antibody NP28-5B labeled horseradish peroxidase (HRP) as a detecting antibody. Two groups of BALB/c mice infected with S. japonicum cercariae were used: lightly infected mice (infected with 10 S. japonicum cercariae) and heavily infected mice (infected with 30 S. japonicum cercariae). The CA was detectable as early as 4 and 5 weeks after infection in the sera of heavily and lightly infected mice, respectively. The CA levels rose rapidly and reached a peak in 8 weeks after infection and then remained a plateau for at least another 6 weeks in both groups. Moreover, the effect of praziquantel on the CA levels was also investigated. The heavily infected mice were treated with praziquantel and the CA levels in sera increased dramatically in the first week post-treatment and then decreased to the control level by 6 weeks after treatment. The novel assay appears to be sensitive for detection of schistosomal antigenemia and valuable to judge the efficacy of chemotherapy in murine schistosomiasis.     

Comparison of immune responses of Schistosoma mansoni-infected mice with distinct chronic forms of the disease

BACKGROUND: Schistosoma mansoni-infected mice tend to present with either one of two different hepatic pathological patterns during chronic infection: periportal fibrosis (PF) with portal concentration of periovular granulomas and fibrosis or isolated granulomas (IG), with scattered periovular granulomas within the liver. These are models for the two clinical presentations of schistosomiasis, the severe hepatosplenic and the mild intestinal forms. In the present work, we examined the relationship between the development of these histopathological aspects and immunological markers in S. mansoni-infected mice. Although BALB/c mice with PF and IG had similar egg numbers in the liver, PF mice had higher liver collagen contents than mice with IG. Cultured spleen cells from mice with PF and IG had similar proliferation 20 and 40 weeks after S. mansoni infection upon stimulation with parasite egg antigen (SEA) or mitogen (Con A). Production of IL-4 upon SEA stimulation was higher in cell cultures from mice with PF, whereas IL-5 and IFN-gamma levels were not statistically different between PF and IG groups. Mice with IG had similar serum concentrations of total IgE and anti-SEA IgG1, IgG2a, IgG2b and IgG3 compared to sera from PF mice. Levels of IgG1 and IgG2a antibodies were the highest and the lowest detected, respectively. In conclusion, isogenic BALB/c mice infected with S. mansoni that develop periportal fibrosis or isolated granulomas have similar immunological patterns despite the two pathologic forms of schistosomal liver fibrosis.     

Production of IgE antibodies against the 22 kDa tegumental membrane-associated antigen of schistosomes is directed by the antigen itself

It has previously been reported that the predominant target of immunoglobulin E (IgE) recognition in sera from humans infected with Schistosoma japonicum in The Philippines or with S. mansoni in Kenya, is a 22 kDa tegumental membrane-associated schistosome antigen. In the present study, we demonstrate that the 22 kDa antigen can direct the production of antigen-specific IgE antibodies independently of schistosome infection and in the absence of any other parasite components or adjuvant. Three strains of mice were immunized using the purified, recombinant 22 kDa antigen of S. japonicum without the use of any adjuvant. Sera from all three strains of immunized mice, but not control animals, generated IgE antibodies specific for the native 22 kDa schistosome antigen in Western blots. Thus, the 22 kDa antigen itself must contain signals (presumably encoded by the primary amino acid sequence or by the secondary or tertiary structures of the molecule, or by a combination of these) which are sufficient to direct the isotype switch required for production of antigen-specific IgE .     

IL-17对日本血吸虫感染抗体及Th应答的影响

目的观察IL-17在日本血吸虫感染小鼠中对抗体及Th细胞免疫应答的影响。方法在小鼠日本血吸虫感染前后,连续多次腹腔注射rm-IL-17细胞因子（实验组1）或PBS（对照组1）,连续多次腹腔注射anti-IL-17中和抗体（实验组2）或同型抗体（对照组2）。运用流式细胞术,采用表面分子、胞内因子同时染色的三色标记法,对日本血吸虫感染小鼠脾脏、淋巴结中的Th17、Th1和Th2细胞亚群占CD4＋T细胞的比例进行观察;同时采用ELISA法检测各组小鼠血清中血吸虫抗原特异性总IgG及亚类IgG1和IgG2a的水平。结果实验组1 CD4＋T细胞中的Th17、Th1和Th2细胞亚群的比例分别是对照组1的1.09倍（P（0.05）、1.17倍（P（0.05）和1.15倍（P（0.05）;实验组2 CD4＋T细胞中的Th17、Th1和Th2细胞亚群的比例分别是对照组2的1.01倍（P（0.05）、1.11倍（P（0.05）和0.98倍（P（0.05）。rm-IL-17注射后仅可溶性虫卵抗原（SEA）特异性IgG1水平显著下降（P（0.05）、可溶性成虫抗原（SWA）特异性IgG2a的水平升高（P（0.05）,其他抗体水平均无...     

诊断家畜日本血吸虫感染胶体金免疫层析试纸条的研制

目的 目的 研制一种可用于疫区现场快速诊断家畜日本血吸虫感染的胶体金免疫层析试纸条。方法 方法 设计重组蛋 白G并在大肠杆菌中表达, 得到重组蛋白。对重组蛋白G进行胶体金标记并制备金标垫, 分别用可溶性虫卵抗原 （SEA） 和重组蛋白G划线, 作为检测线和质控线。采用组装的试纸条检测标准阴、 阳性BALB/c鼠与新西兰大白兔血清, 以及粪 检阴、 阳性的绵羊与水牛血清, 评估其灵敏度和特异度; 利用组装的试纸条检测前后盘吸虫病病牛血清, 评价其交叉反应 性。结果 结果 成功构建了重组蛋白G的原核表达质粒并在大肠杆菌中表达。以重组蛋白G制备的试纸条可用于检测日本 血吸虫感染BALB/c鼠、 新西兰大白兔、 水牛、 绵羊血清抗体。该试纸条检测日本血吸虫感染小鼠与兔血清的灵敏度、 特 异度均为100%; 检测绵羊血清的灵敏度为100%, 特异度为88.46%; 检测水牛血清的灵敏度为94.44%, 特异度为100%; 其与前后盘吸虫交叉反应率为5.88%。结论 结论 成功研制能检测多种家畜血吸虫病的胶体金免疫层析试纸条, 其检测家 畜血吸虫感染的灵敏度和特异度均较高。     

日本血吸虫可溶性虫卵抗原诱导 小鼠巨噬细胞凋亡机制

目的　观察日本血吸虫感染过程中巨噬细胞数量及其凋亡动态变化,并探讨血吸虫可溶性虫卵抗原（SEA）诱导巨噬细胞凋亡的可能机制。方法　将C57BL/6小鼠（6～8周龄）随机分为4组,其中3组作为实验组,另1组作为正常对照组。实验组每只小鼠均经腹部皮肤感染（12 ± 1）条日本血吸虫尾蚴,于感染后3、5周和8周各处死1组小鼠;正常对照组小鼠不感染血吸虫,于实验组小鼠感染当天处死。取各组小鼠肝组织和腹腔渗出细胞,检测肝脏和腹腔巨噬细胞数量及其凋亡动态变化。此外,体外用SEA、PBS及卵清蛋白（ovalbumin,OVA）处理纯化的小鼠腹腔巨噬细胞,流式细胞术检测巨噬细胞凋亡;以实时定量PCR和Western blotting技术检测巨噬细胞中BCL⁃2家族成员mRNA和蛋白表达水平;以流式细胞术和Western blotting技术检测caspase 3活化水平。同时,体外在caspase抑制剂、H2O2或N⁃乙酰⁃L⁃半胱氨酸（NAC）存在时用SEA处理巨噬细胞,以流式细胞术检测巨噬细胞凋亡水平。结果　感染日本血吸虫尾蚴后3、5周和8周,小鼠肝脏[（0.873 ± 0.106）× 106、（2.737 ± 0.460）× 106个和（3.107 ± 0.367） × 106个;F = 81.900,P < 0.01]和腹腔中巨噬细胞总数[（5.282 ± 1.136） × 105、（7.500 ± 1.200） × 105个和（12.800 ± 0.800） × 105个;F = 55.720,P < 0.01]不断增加,且感染小鼠肝脏[（0.092 ± 0.018） × 106、（0.186 ± 0.025） × 106 个和（0.173 ± 0.027）× 106 个;F = 57.780,P < 0.000 1]和腹腔中凋亡的巨噬细胞数量[（0.335 ± 0.022）× 105、（0.771 ± 0.099） × 105个和（1.094 ± 0.051） × 105个;F = 49.460,P < 0.01]亦不断增加。经SEA体外处理的巨噬细胞凋亡比例[（24.330 ± 0.784）%]高于PBS [（18.500 ± 1.077）%]及OVA[（18.900 ± 1.350）%]处理组（P均 < 0.01)。经SEA和PBS处理的巨噬细胞中,Bcl⁃2 [（1.662 ± 0.943） vs. （1.00 ± 0.00）;t = 1.215,P > 0.05]、Bax [（0.711 ± 0.200） vs. （1.00 ± 0.00）;t = 2.507,P > 0.05]、Bak [（1.255 ± 0.049） vs. （1.00 ± 0.00）;t = 0.897,P > 0.05]、BCL⁃2 [（0.068 ± 0.004） vs. （0.070 ± 0.005）;t = 0.699,P > 0.05]、BAX [（0.089 ± 0.005） vs. （0.097 ± 0.003）;t = 2.232, P > 0.05]、BAK [（0.439 ± 0.048） vs. （0.571 ± 0.091） ; t = 2.231,P > 0.05]表达水平差异均无统计学意义。在caspase抑制剂存在时,SEA仍能诱导巨噬细胞凋亡（F = 0.411,P > 0.05）;而在H2O2或NAC存在时,SEA不能诱导巨噬细胞凋亡（F = 11.880、9.897,P均< 0.05）。结论　在日本血吸虫感染过程中,SEA可能通过促进活性氧表达而诱导巨噬细胞凋亡。