Isolation and characterisation of in vivo released 41 kDa mycobacterial antigen in pulmonary and bone and joint tuberculosis and its identification with H37Ra in vitro released antigen.

OBJECTIVE: To isolate and characterise in vivo released 41 kDa mycobacterial antigen in pulmonary and bone and joint tuberculosis (TB) and its identification with in vitro released ES-41 kDa antigen. DESIGN: Circulating antigen was isolated from confirmed pulmonary tuberculosis serum (PTS) and bone and joint tuberculosis serum (BJS) by trichloroacetic acid precipitation and further fractionation by fast-protein liquid chromatography (FPLC). RESULTS: Fractionation of PTS and BJS by gel filtration column gave six protein fractions each. PTS-G3 and BJS-G3 showed maximum antigenic activity with ELISA. Further fractionation of PTS-G3 and BJS-G3 on cation exchange FPLC gave four different fractions each, of which BJS-G3B was seroreactive similarly to in vitro released 41 kDa antigen (ES-41) isolated from culture medium, whereas PTS-G3C was slightly less seroreactive. BJS-G3B could inhibit binding of in vitro released ES-41 to affinity purified antibodies in inhibition ELISA at lower concentrations than PTS-G3C (2 vs. 20 ng/ml), showing the identical nature of the antigens. Biochemical characterisation showed that circulating antigen PTS-G3C, BJS-G3B and in vitro released ES-41 antigen were lipoproteins in nature. CONCLUSION: This study helped to demonstrate the presence of 41 kDa antigen in the serum of pulmonary and bone and joint TB patients and its identification with H37Ra in vitro released 41 kDa antigen.     

Sero-reactivity of two different antigenic protein fractions of M.tb H37Ra excretory-secretory antigen in pulmonary and extra-pulmonary tuberculosis

Excretory-secretory proteins of Mycobacterium tuberculosis H37Ra, have been of diagnostic interest in pulmonary (PTB) and extrapulmonary tuberculosis (EPTB). Two different excretory-secretory antigenic proteins of M.tbH37Ra viz., EST-DE1 (a 6% TCA soluble and DEAE anion exchange purified antigen) and ESAS-7 (50% ammonium sulphate solubilized and SDS-PAGE fractionated antigen) were studied in stick-indirect penicillinase ELISA for detecting tuberculous IgG antibodies in serum samples of pulmonary as well as extrapulmonary tuberculosis (tuberculous lymphadenopathy (TBLN), tuberculous meningitis (TBM), bone & joint tuberculosis (B&J TB), abdominal tuberculosis (Abd. TB) patients. The ESAS-7 antigen has shown comparatively better seroreactivity (90%) than that of EST-DE1 antigen in pulmonary tuberculosis cases. The overall specificity of 93.2% using ESAS-7 antigen was also found better compared to 86.4% obtained using EST-DE1 antigen. Further, in extra pulmonary tuberculosis group, using ESAS-7 antigen 84% (21/25) of histopathologically confirmed TBLN cases and 90% (9/10) clinically diagnosed and ATT responded TBM cases showed positive reaction for tuberculous IgG antibody. The per cent positivity using EST-DE1 antigen was however comparatively low in TBLN and TBM cases, (76% and 80% respectively). In histopathologically proven bone and joint tuberculosis and abdominal tuberculosis cases EST-DE1 antigen showed better sensitivity of 75% and 83.3% respectively in IgG antibody detection compared to that of ESAS-7 antigen (50% and 66% respectively). From the present study, it can be envisaged that ESAS-7 antigenic fraction has a good potential in the diagnosis of pulmonary and certain extra-pulmonary tuberculosis infection (TBLN & TBM) whereas EST-DE1 was found to be better in detecting specific antibodies in bone & joint and abdominal tuberculosis.     

Purification and characterization of a 31 kDa mycobacterial excretory-secretory antigenic protein with a diagnostic potential in pulmonary tuberculosis

Proteins secreted into the culture medium by Mycobacterium tuberculosis are shown to be a source of antigens of immunodiagnostic importance. In our earlier study, we had reported a 31-37 kDa seroreactive gel-eluted antigenic fraction (ESAS-7), isolated from culture filtrate proteins of Mycobacterium tuberculosis H37Ra. In this report, we describe further purification of excretory-secretory ESAS-7 antigen fraction by fast protein liquid chromatography (FPLC) on Resource 'S' cation-exchange column and isolation of a more active and purified protein antigen fraction ESAS-7F. ESAS-7F antigen was characterized as a 31 kDa molecular weight glycoprotein containing a metallo-serine protease activity. N-terminal sequence analysis showed the first five amino acids as NTGQS (Asp-Thr-Gly-Glu-Ser). The present study helped in the isolation of a well characterized 31 kDa mycobacterial glycoprotein antigen with protease activity and diagnostic potential in detection of tuberculosis infection.     

Detection of filarial antigen using antibodies raised against Wuchereria bancrofti microfilarial SDS soluble antigen.

Polyclonal antibodies raised in mouse ascitic fluid against Wuchereria bancrofti microfilarial antigens (Wb Mf SDS S Ag) were studied for their diagnostic use in bancroftian filariasis using a dip stick, enzyme-linked immunosorbent assay. In sandwich ELISA, 100% of microfilaremic sera (30 out of 30) 53% of acute filarial sera (7/13), 40% of subacute filarial sera (6 out of 15), 13% of chronic filarial sera (2/15) and 20% of endemic area normal sera (3/15) showed the presence of filarial antigen. Determination of filarial antigen titer in microfilaremic sera showed an apparent positive correlation between microfilarial density and antigen titer. The antibody raised against Wb Mf SDS S Ag was found to be cross reactive with phosphorylcholine epitopes. The filarial antigen detected by anti Wb Mf SDS S Ag antibodies in sandwich ELISA is possibly associated with the active stage (microfilaremia) of infection.     

Penicillinase ELISA for detection of tubercular antigen in tuberculosis.

Stick sandwich enzyme linked immunosorbent assay (ELISA) using rabbit anti PPD-RT 23 immunoglobulins and enzyme penicillinase has been explored for detection of tubercular antigen in sera and CSF samples of pulmonary tuberculosis and tubercular meningitis (TBM) respectively. The analysis of sera showed 73.3% of pulmonary tuberculosis cases, 16.2% of healthy controls and 44.4% of Hansen's disease positive for tubercular antigen. The accuracies of positive and negative predictive values were 69% and 82% respectively. The analysis of CSF samples showed the presence of tubercular antigen in 76.4% of TBM, 16.6% of pyogenic meningitis cases, 19.4% of neurological diseases other than meningitis and 16.1% non-neurological disease controls. The accuracies of positive and negative predictive values were 48% and 94% respectively. Hence this simple test using economical and indigenous reagents can be applied for the diagnosis of pulmonary and extra-pulmonary tuberculosis.     

日本血吸虫感染中循环抗原动态变化及其机制研究

探讨日本血吸虫感染中循环抗原动态变化及其机制。感染日本血吸虫的ＢＡＬＢ／ｃ小鼠淋巴结Ｂ细胞和小鼠骨髓瘤细胞融合，制备抗血吸虫循环抗原不同表位的单克隆抗体组合后为探讨针，检测日本血吸虫病患者和健康人血清；晚期血吸虫病患者脾血和外周血；感染日本血吸虫兔和小鼠的门脉血和外周血。     

Antigenic profile,isolation and characterization of whole body extract of Paramphistomum gracile

An antigenic component of adult Paramphistomum gracile was characterized by means of indirect enzyme‐linked immunosorbent assay (indirect ELISA), sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS‐PAGE) and immunoblotting using sera from cattle naturally infected with P. gracile, Eurytrema pancreaticum, Fasciola gigantica, Moniezia benedeni, strongylids, Trichuris sp. and Strongyloides sp. The whole body (WB) extracts of P. gracile were fractionated by gel filtration chromatography in a Sephadex G‐200 column. It was found that the WB extract fractions, F1–F3 were highly antigenic, F5 was moderately antigenic and F4 was poorly antigenic. For SDS‐PAGE and immunoblotting, the antigenic molecules of WB extract and all five fractions were mostly at molecular weights (MW) ranging from 12 to 150 kDa. One antigenic protein of 16 kDa detected in WB extract and F1–F3 was found to give a consistent reaction with sera from infected cattle. The antigenicity of the purified 16 kDa protein was confirmed by immunoblotting and indirect ELISA using a pool of sera and individual serum samples from infected cattle (at 1 : 78 125 dilution) and hyperimmunized rabbit (at 1 : 390 625 dilution). This finding suggests that the 16 kDa protein may be a potential antigen for the immunodiagnosis of cattle paramphistomosis caused by P. gracile.     

Detection of a circulating antigen in human schistosomiasis japonica using a monoclonal antibody

A double antibody enzyme-linked immunosorbent assay (sandwich ELISA) was used for the detection of a circulating antigen from human schistosomiasis japonica infections. This assay involves the use of polyclonal rabbit Schistosoma japonicum soluble egg antigen (SEA) antiserum to bind circulating antigen and a monoclonal antibody (MabH4) to identify and quantify this antigen. Sera from 108 S. japonicum-infected patients (acute and chronic) were tested. Sera from 93 of 95 patients with chronic infection were positive for this antigen; sera from 12 of 13 patients with acute infections were also positive. Antigen was not detectable in control human sera. Sera from 35 chronic schistosomiasis patients were collected 6-12 months after praziquantel treatment. Circulating antigen was not detectable in the sera of 33 of these patients and was dramatically reduced in 2. This ELISA system may prove valuable in differentiating past and current infections.     

The effect of praziquantel on the circulating antigen SJ 70 in murine schistosomiasis japonica

A circulating schistosome 70 kDa antigen (SJ 70) has been detected in the sera of mice infected with Schistosoma japonicum. For the detection of this antigen, a double antibody sandwich enzyme-linked immunosorbent assay (ELISA) was employed. SJ 70 is first detected in the serum of S. japonicum-infected mice 4 weeks after infection. Antigen levels rise rapidly, plateau by 7 weeks after infection, and remain relatively unchanged for at least another 9 weeks. In mice infected with S. japonicum for 7 weeks and then treated with praziquantel (100 mg/kg body weight), there is a significant decrease in serum antigen levels within 2 weeks after treatment, and an almost complete disappearance of antigen from the serum 3-4 weeks after treatment.     

The serum antibody response of infected rats, rabbits, lambs and calves to Fasciola hepatica adult antigen fractions separated by preparative flatbed iso-electrofocussing

Electrofocusing of F. hepatica adult antigen in granulated gels separated the material into 22 arbitrary fractions. Polyacrylamide gel analysis demonstrated groups of proteins with similar iso-electric points in 19 of the fractions. A microplate ELISA detected antigens in all 22 fractions and was used to test the serum antibody response in infected rats, rabbits, lambs and calves to these antigen fractions. The results indicated that rat and calf sera gave a much stronger response than rabbit and lamb sera to the antigens which separated above pH 7.0. It is possible that the greater efficiency of the rat and bovine immune systems in combating re-infection with F. hepatica may be related to this response.     

Isolation and analysis of cDNA clones expressing human lupus La antigen.

Several cDNA clones of the La antigen recognized by certain lupus autoantibodies were isolated from lambda gt11 expression libraries made from human liver. Recombinant clones were used to hybrid-select HeLa cell mRNA that was subsequently translated in vitro into a single protein species that comigrated with HeLa cell La protein. The in vitro translated protein was reactive with anti-La patient sera and was identical to the authentic La protein by peptide mapping. By analyzing overlapping cDNA clones, we mapped an antigenic site of La protein at the terminal 12% of the carboxyl end of the molecule. Within this region we identified a unique decapeptide of high hydrophilicity that may constitute a La antigenic determinant. We further demonstrated that the La antigen expressed from the recombinant clones can be used in a definitive enzyme-linked assay (ELISA) for the classification of sera from patients with systemic lupus erythematosus.     

Evaluation of fractionated circulating filarial antigen in diagnosis of bancroftian filariasis.

Circulating filarial antigen (CFA) isolated from the plasma of microfilaraemic patients was fractionated on an Ultrogel ACA 34 column. The second protein peak (CFA2) showing filarial antigen was further fractionated by DEAE-cellulose column chromatography into two fractions (CFA2 DE1 and DE2). CFA2 DE1 fraction, showing antigenic activity, was further evaluated in an ELISA for its diagnostic use in bancroftian filariasis. Studies with CFA2 DE1 and anti-CFA2 DE1 antibody showed that they were highly active in the detection of filarial antibody and antigen in asymptomatic microfilaraemia sera and thus obviate the need for the tedious night blood collection and examination. Fractionated filarial plasma can be another candidate antigen for immunodiagnosis of bancroftian filariasis.     

己酮可可碱联合阿苯达唑治疗小鼠泡球蚴病的疗效观察

目的 观察己酮可可碱（PTX）和阿苯达唑（ABZ）单独及联合用药对小鼠继发性泡球蚴病的疗效。 方法 对小鼠继发性泡球蚴病进行药物治疗，各治疗组药物用量分别为：ABZ组 50 mg/（kg·d）；PTX高剂量组360 mg/（kg·d）；PTX低剂量组180 mg/（kg·d）；联合组 ABZ 50 mg/（kg·d） + PTX 180 mg/（kg·d）；感染对照组（未治疗组）和空白对照组均给予等体积生理盐水，用小鼠灌胃针经口每天灌胃给药1次，连续治疗100 d后 （其间14只死亡），检测各小鼠泡球蚴湿重、抑囊率及小鼠血清细胞因子转化生长因子?鄄β （TGF-β）、白细胞介素?鄄2 （IL-2）和IL?鄄10；并对泡球蚴组织进行病理组织学和超微结构观察。 结果 PTX在体外能有效地杀灭原头节（高剂量组为100%）, 在体内对泡球蚴抑制作用虽较弱（高剂量组为37%），但能增强小鼠的免疫力。联合用药对泡球蚴有明显的抑制作用，抑囊率为88 %，ABZ抑囊率为58 % （P<0.05）。 结论 PTX联合ABZ治疗小鼠继发性泡球蚴病疗效明显优于ABZ。     

Diagnosis of human schistosomiasis by detection of circulating cathodic antigen with a monoclonal antibody.

Monoclonal antibody (MAb) 5H11 reacted with repeating epitopes on Schistosoma mansoni circulating cathodic antigen (CCA) and detected CCA in sera of Egyptian S. mansoni-infected patients. MAb 5H11 was both capture and biotinylated detection antibody in a sandwich ELISA of trichloroacetic acid-pretreated serum samples. Sera of patients with 7-500 eggs/g of stool were positive by MAb 5H11-CCA sandwich ELISA. Stool egg counts and CCA serum levels correlated (r = .52), and CCA levels decreased by 4 weeks after praziquantel treatment in patients with pretreatment egg counts of greater than or equal to 50/g of stool (P less than .05). Sera of Schistosoma haematobium-infected patients, uninfected individuals, and most patients with other helminths were negative in this assay. The MAb 5H11-CCA sandwich ELISA appears sensitive and specific for immunodetection of active schistosomiasis mansoni and useful for monitoring its chemotherapy.     

Complement-fixing soluble antigen from rat lymphoma (C58NT)D. Preliminary characterization of the antigen and some positive human sera.

A soluble complement-fixing antigen prepared from the Gross virus-induced rat lymphoma (C58NT)D reacted in complement-fixation with the sera of some patients with different malignancies (particularly acute leukemia) and with the sera of some healthy individuals. Results of gel filtration of crude (C58NT)D antigen on Sephadex G 200 indicate that the antigenic activity is eluted with the void volume of the column, i. e. in fractions corresponding to proteins of low molecular weight. Gel filtration of some positive patient sera indicate that complement-fixing activity of tested sera is associated with fractions corresponding to IgM and/or IgG.     

适于HIV-1 p24抗原检测试剂的单抗制备与筛选

目的制备抗HIV-1p24单克隆抗体(单抗,McAb),并利用双抗体夹心ELISA法建立HIV-1p24抗原检测试剂。方法以基因工程原核重组抗原HIV-1p24蛋白免疫BALB/c小鼠,利用常规杂交瘤技术和间接ELISA法制备单克隆抗体,单抗经纯化和HRP标记后,利用双抗体夹心ELISA筛选检测p24蛋白的最佳配伍单抗以期建立HIV-1p24抗原检测试剂。结果成功筛选到16株稳定分泌抗HIV-1p24单抗的杂交瘤细胞株,并从中筛选出最佳单抗配伍组合“16G12+2F2b-HRP”,该组合对p24蛋白的检测灵敏度为20pg/mL,对感染性克隆pNL4-3表达的HIV病毒培养上清检测呈阳性,对100份HIV阴性人血清无非特异性反应,显示出良好的检测灵敏度和特异性。结论本研究初步成功地建立了HIV-1p24抗原的检测试剂,并为最终建立HIV第四代诊断试剂(HIV Ag/Ab Assay)奠定了坚实的基础。     

单克隆抗体夹心ABC-ELISA检测包虫病人循环抗原

应用生物素标记单克隆抗体进行夹心ABC-ELISA检测包虫病人血清循环抗原(HcAg),共检测包虫病人血清103份,62价呈阳性(60.19％);检测囊虫病人血清22份,其它寄生虫病血清54份,正常人血清101份,均未出现假阳性反应。常规ELISA血清抗体阴性的10例包虫病人HcAg 5例呈阳性。HcAg的检测对血清抗体阴性的包虫病人具有辅助诊断意义。     

Preparation of Toxoplasma gondii RH strain antigen,antigen analysis and antigen detection in sera: a review

The prevalence of antibodies detected by serology against Toxoplasma gondii in Indonesia is quite high. Therefore further research concerning the antigen used is important to improve the quality of the assay being used with lower cost. An attempt to prepare T. gondii strain RH antigen followed by using it in the ELISA procedure for detecting IgG showed that there was no significant difference between the local ELISA and Toxonostika quantitatively and qualitatively. Analysis of the antigen was done by Western blot, using sera collected from 30 clinically suspected toxoplasmosis cases which contained IgG only (titer ranging from 1:1,600-> or = 1:3,200); from 9 asymptomatic healthy person, from 5 cases consisted of 1 case of lymphadenitis (IgM titer > or = 1:3200 and IgG titer 1:800) and 4 cases of visual disturbances which had IgM with titer ranging from 1:800 to > or = 1:3,200 and IgG with titer ranging from 1:800 to > or = 1:3,200. It was shown that antigen components of 90, 87, 82, 72, 41, 26 and < or = 6 kDa reacted to all sera containing IgG except sera containing both IgG and IgM. Especially bands of 41 and 26 kDa showed strong reaction with all sera containing IgG, except 2 sera which contained both IgG (titer 1:800) and IgM (titer 1:800 and 1:3,200). These sera collected from 2 left eye vision disturbance cases were not reactive to all antigen components. Strong reactions against bands of 41, 26 and < or = 6 kDa were also shown in sera which contained only IgG collected from 9 healthy persons without any toxoplasmosis symptoms whereas bands of 90, 87, 82 and 72 kDa all showed moderate strong reaction. Contrasting to sera containing only IgG, of 5 sera containing both IgG and IgM 3 of them showed only reactions against bands of 41, 26 and < or = 6 kDa which were strong. It seemed that almost all sera containing IgG gave reaction to 90, 87, 82, 72, 41, 26 and < or = 6 kDa, however different pattern of reaction might occur, probably depending on the nature of infection as more antigen components would be recognized by sera containing IgG alone rather than sera containing both IgM in large quantity and IgG. In another study, an attempt to detect T. gondii antigen in 60 samples was done by using ELISA, and it was shown that circulating antigen was found in 27 (90%) from 30 samples which contained both IgG and IgM, whereas only 2 (66%) from 30 samples which contained only IgG showed positive results. Therefore, antigen detection can be used to identify the acute phase of infection.     

弓形虫循环抗原诊断试剂的研究

目的　比较弓形虫不同免疫原所制备抗体检测CAg的效果 ,优选高效价的抗体诊断试剂。 方法　制备弓形虫的细胞质抗原 (C)、代谢抗原 (S)。用抗原C、C +S、S及活虫各免疫 2只家兔 ,收集抗血清经纯化而获得IgG抗体 (多抗 )并制备酶标记抗体 ;用上述 4种多抗与多抗 -HRP组合成 16种双抗体夹心型ELISA ,检测人血清CAg和C、S抗原 ,评价试剂的敏感性 ;抗血清与疟原虫、隐孢子虫等抗原进行交叉反应性试验 ,评价试剂的特异性。结果　各种ELISA夹心法同步检测CAg阳性样本 7例 ,阴性样本 8例 ,均未出现假阴性和假阳性反应 ,其OD均值的P/N比值依次为C +C组 33 5、S +S组 2 7 8、CS +CS组 2 1 2、P +P组 13 2 ;C和S抗原的最低检出量均为 0 5 μg/ml;与其它寄生虫未出现交叉反应。 结论　 (1) 4种抗体用于检测人血清CAg、C和S抗原以及其它抗原的结果表明 ,各种抗体试剂均具有良好的敏感性和特异性 ,其中以抗C抗体试剂最为满意。 (2 ) 16种组合形式的夹心ELISA ,检测弓形虫抗原的差异无统计学意义 ,表明弓形虫C和S抗原间存在着共同抗原成分。     

双抗体夹心斑点金免疫渗滤法检测血吸虫循环抗原的现场应用

目的 探讨双抗体夹心斑点金免疫渗滤法（S－DIGFA）在现场的应用价值。方法 在原已建立的以抗26kDaGST基因重组蛋白多克隆抗体为捕获抗体兼测示抗体的S－DIGFA的基础上，应用该法检测血吸虫病中度流行区和传播阻断地区人群的血清共1388份，并以双抗体夹心ELISA（S－ELISA）作对照。结果 用S－DIGFA和S－ELISA平行检测血吸虫病中度流行区人群血清300份，阳性检出率分别为15．7％和17．3％；两法检测血吸虫病传播阻断地区人群血清1088份，阳性检出率分别为3．9％和3．7％。结论 S－DIGFA检测循环抗原可在现场扩大和作血清流行病学调查。