Detection of Plasmodium falciparum using a radioimmunoassay based on a crossreacting, monoclonal anti-P. berghei antibody-P. berghei antigen system

An antibody binding-inhibition test is described, which allows the detection of P. falciparum in red blood cells (RBC) infected in vitro, using a crossreacting, monoclonal anti-P. berghei antibody and P. berghei coated microtiter plates. Experiments carried out to determine the coating efficiency of various P. berghei and P. falciparum derived antigen preparations showed that intact, saponin freed P. berghei parasites and sonicated, RBC parasitized with P. falciparum had the highest binding activity. Binding of the monoclonal antibody to the antigen coated plates was effectively inhibited by preincubation with sonicated, P. falciparum infected RBC. The minimal degree of infection detectable was about 0.008% parasitemia (400 parasitized RBC/microliters blood). The sensitivity of detection was not appreciably affected by the source of the coating antigen. We conclude that the difficulty and expense involved in the use of P. falciparum based immunodiagnostic tests for large scale screening for malaria can be obviated by making use of P. berghei based assays.     

Use of monoclonal antibody in an ELISA test for the detection of antibodies to bovine leukaemia virus

A variant of the ELISA technique, involving a monoclonal anti-gp51 antibody yields a highly sensitive method for the detection of bovine leukaemia virus (BLV) antibodies. The gp51 antigen-coated microtitre plates are obtained by incubation of plastic-adsorbed monoclonal antibodies with a non-purified mixture of BLV antigens. Sera to be tested are incubated in the wells of the gp51-coated plates and bound antibodies are revealed by an enzyme-linked antibovine immunoglobulin reagent. This test is as sensitive as liquid phase radioimmunoassay using the same gp51 antigen and thus appears as a highly sensitive, practical, rapid and cheap method for the detection of BLV antibodies.     

Development of a double monoclonal antibody sandwich ELISA test for Verticillium dahliae Kleb.

Verticillium dahliae causes wilt diseases in a wide range of horticultural and field crops in many parts of Turkey. In the Aegean region it has been a serious problem in cotton and vegetables for many years. More recently, it has become a major problem for olive growers in relatively newly established orchards. The fact that the only possible control methods of Verticillium wilt disease is the use of healthy and pathogen free propagating material has directed us to produce monoclonal antibodies against V. dahliae in order to apply rapid, sensitive and reliable serological detection methods. Verticillium spp. isolates were obtained from olive plantations, as well as from cotton and tomato fields in the Aegean and Marmara Regions. All suspected isolates were obtained as V. dahliae after determining microscopic morphological characteristics and pathogenicity tests on cotton seedlings. Immunizing antigens were prepared by three different methods including surface washing system, czapek dox agar and gel filtration methods. BALB/c mice were immunized with each antigenic form. Lymph node, spleen and bone marrow cells were used as sources of B-lymphocytes and 8D2 (IgM) and 7D6 (IgG1) were obtained from the spleen and lymph node fusion. The monoclonal antibodies were purified and immunoglobulin types were identified. 8D2 monoclonal antibody gave positive reaction with the V.dahliae isolates from olive, cotton, tomato and watermelon; however, it didn't give any cross reactivity with other epiphytic fungi. 7D6 antibody displayed cross-reactions with a few fungi. The monoclonal antibody (8D2) was conjugated with horseradish peroxidase (HRP). These monoclonal antibodies were characterized for use in the development of diagnostic kits based on double-monoclonal antibody sandwich ELISA test system for detecting V. dahliae in Turkish isolates. In this test, the first antibody was used as capture antibody and the second one was used for detection of antigens.     

Reactivity of a monoclonal antibody produced to the histidine-rich protein of Plasmodium lophurae with Plasmodium falciparum

Monoclonal antibodies were produced against the histidine-rich protein of Plasmodium lophurae and tested for reactivity with Plasmodium falciparum antigens. One anti-histidine-rich protein monoclonal antibody showed immunological cross-reactivity with polypeptides of P. falciparum synthesized in vivo and in vitro.     

Gold nanoparticle-based paper sensor for multiple detection of 12 Listeria spp. by P60-mediated monoclonal antibody

The genus of Listeria consists of heterologous species and its presence in the food chain is an indicator of poor hygiene. However, a portable and simple paper sensor for detection of listeria spp. with high accuracy was still unknown. In this study, we prepared a pair of monoclonal antibodies (mAbs) that specifically recognize the P60 protein on the cell surface of Listeria spp. The selected pair was found to be sensitive to both the P60 protein and cell body of the genus Listeria. On this basis, a rapid paper sensor was established for sensitive Listeria spp. detection. The developed paper sensor broadly cross-reacted with the 12 tested strains of Listeria and the sensitivity in PBS buffer was 10³–10⁴ colony-forming units (CFU) judged by the gray values of the test line. No cross-reaction with any other gram-positive or gram-negative strains tested was observed. A study using milk samples showed that this paper sensor could detect samples contaminated with low levels of the tested Listeria spp. (1–9 CFU/mL) after 8?h of enrichment and further concentrate for approximately 10 times by centrifugation. The results were in accordance with those obtained using the polymerase chain reaction method.     

Preparation of anti-T idiotype monoclonal antibody reacting with human T leukaemic cell lines and with a small percentage of peripheral T lymphocytes.

Monoclonal antibody (MoAb) KT38 raised against a human T leukaemic cell line TALL-1, reacted with another T leukaemic cell line Jurkat, but not with any other cell lines tested. The co-modulation of CD3 and KT38 antigen was observed with stimulations of either MoAb T3 or KT38 on both TALL-1 and Jurkat. Upon radioimmunoprecipitation and SDS-PAGE analysis, MoAb KT38 precipitated the heterodimer of 40-60 kD from Jurkat and TALL-1 under reducing conditions. Thus, MoAb KT38 is considered to be an anti-T idiotype (Ti) antibody to TALL-1 and Jurkat cells. MoAb KT38 was also shown to react with a minor population of peripheral blood lymphocytes (PBL) and with very few cells (0.5-2.0%) in the paracortical area of the lymph node. When PBL were stimulated in a KT38-coated culture flask for 5 days, the percentage of KT38-positive PBL was markedly increased. The CD3 antigen on these cultured PBL in the flask was modulated by the stimulation with MoAb KT38. Thus, it is suggested that a common idiotope exists on the T cell receptor of Jurkat, TALL-1 and a small percentage (1.9-6.1%) of PBL.     

[125I]protein a solid-phase assay for detection of monoclonal antibody

Summary The production of monoclonal antibodies involves testing hundreds of hybridoma supernatant samples for antibody content. This necessitates a rapid detection assay which can separate antibody of interest from antibodies that react nonspecifically. Solid-phase radioimmunoassay is one such method.     

Use of a monoclonal antibody in a double-sandwich ELISA for detection of IgM antibodies to Toxoplasma gondii major surface protein (P30)

A double-sandwich ELISA, developed for detection of IgM antibodies to the major surface protein of Toxoplasma gondii (P30), is proposed for the diagnosis of acute acquired toxoplasmosis. The method is based on the capture of serum IgM antibodies, which are revealed indirectly by the sequential addition of a Toxoplasma extract and a beta-galactosidase-conjugated anti-P30 monoclonal antibody. All 57 patients tested with serological characteristics of recently acquired toxoplasmosis showed high levels of IgM anti-P30 antibodies. In addition, 5 out of the 24 patients with chronic toxoplasmosis and all 7 patients with a clinical acute infection in which the classical IgM serology was negative, also presented significant anti-P30 IgM antibodies. Patients with either rheumatoid factor or antinuclear antibodies were all negative. In view of its simplicity, specificity and sensitivity, this method is recommended for the current diagnosis of T. gondii infection.     

An indirect competitive enzyme-linked immunosorbent assay for acrylamide detection based on a monoclonal antibody

Acrylamide (AA) is formed spontaneously in heated foodstuffs and is a focus of concern in many people due to safety. In this study, we developed an indirect competitive enzyme-linked immunosorbent assay (icELISA) based on a monoclonal antibody (MAb) to detect a derivative, which was generated from 4-mercaptobenzoic acid (4-MBA). As AA is a very small molecule (71.08?Da) and cannot elicit a homologous monoclonal antibody, we coupled the AA derivative (AA-4-MBA) to a carrier protein such as bovine serum albumin (BSA) and ovalbumin (OVA). The conjugates were used as the immunogen and coating antigen. A rapid and sensitive icELISA against AA-4-MBA was obtained by optimizing the experimental parameters. The MAb which had no specificity for AA or 4-MBA, but had high affinity for AA-4-MBA, had a satisfactory IC₅₀ of 32?ng/ml and a limit of detection of 8.87?ng/ml. The quantitative working range was 8.87–112.92?ng/ml (IC₂₀ to IC₈₀). Cross-reactivity with other analogues was lower than 10%. These results indicated that the developed icELISA was a fast and efficient method for detecting AA in food.     

Evaluation of trophoblast HLA-G antigen with a specific monoclonal antibody

A monoclonal antibody to HLA-G has been generated by immunizing HLA-A2.1/human β²-microglobulin (β²m) double transgenic mice with murine L cells transfected with both human β²m and HLA-G. This monoclonal antibody, designated as G233, has been found not to cross-react with other HLA class I antigens when tested on numerous cell lines by flow cytometry. With immunohistology, all populations of extravillous trophoblast (cell columns, interstitial trophoblast, endovascular trophoblast, placental bed giant cells) were stained. An extensive range of adult and fetal tissues was also tested but none reacted with monoclonal antibody G233, including those previously reported to express HLA-G mRNA, indicating that the protein has a highly restricted distribution. Failure to detect HLA-G in the fetal thymus raises the question as to how T-cell tolerance to this antigen is induced. Immunoprecipitation of trophoblast surface proteins with monoclonal antibody G233 revealed a heavy chain of 39 kDa and a light chain of 12 kDa, indicating that HLA-G expressed on the surface of trophoblast is complexed with p2m. However, sequential immunoprecipitation with monoclonal antibody W6/32 followed by monoclonal antibody G233 continued to detect a residual band of 39 kDa, suggesting that trophoblast surface HLA-G may also occur as free heavy chains not associated with p2m. Immunoprecipitation followed by two dimensional gel electrophoresis showed that monoclonal antibody G233 recognizes several iso-forms of HLA-G from trophoblast similar to the characteristic spot array previously described for HLA-G. This monoclonal antibody G233 will be highly useful in future experiments to elucidate the function of HLA-G.     

An enzyme-linked immunoassay for the detection of medroxyprogesterone acetate in intestines based on monoclonal antibody

A competitive indirect enzyme-linked immunoassay (ciELISA) based on a monoclonal antibody was developed to detect medroxyprogesterone acetate (MPA) in sheep intestines, which are used as sausage casings. MPA has a relative molecular mass of only 344.5, and it has no immunogenicity. By activating MPA with o-carboxymethyl hydroxylamine hemi HCl, a hapten of MPA (3-CMO-MPA) was synthesised and linked to bovine serum albumin (BSA) and ovalbumin (OVA) to prepare artificial antigens. The monoclonal antibody was prepared from mice immunised with MPA-BSA. The ELISA method allowed MPA detection in a range of 0.1–24.3 ng/ml with an average IC₅₀ value of 1.7 ng/ml. The recoveries of MPA from spiked intestinal tissues at levels of 0.5–5 ng/g ranged from 85.2% to 115.1% with CVs of 8.8–11.2%, and the detection limits were 0.5 ng/g in intestinal tissues. The ciELISA test proved to be a rapid, sensitive, economical and reliable method for screening MPA residues in intestinal tissues.     

Use of monoclonal antibody in a blocking ELISA to detect group specific antibodies to bluetongue virus

An enzyme-linked immunosorbent assay (ELISA) in the form of a blocking test is described for the detection of group specific antibodies to bluetongue virus (BTV). The test relies upon interruption of the reaction between BTV antigen and a group specific murine monoclonal antibody against BTV by addition of serial dilutions of bovine or ovine test sera containing specific antibodies to BTV which inhibit binding of the monoclonal antibody to the BTV antigen. This is detected as a reduction in the optical density (O.D.) reading obtained with the monoclonal antibody alone. The test is capable of specific detection of antibodies to all 22 serotypes of BTV but, unlike the agar gel precipitin (AGP) test, does not show cross-reactions with antibodies to epizootic haemorrhagic disease of deer (EHD) viruses. Furthermore, antibodies to cellular proteins which complicate interpretation of the AGP test and the indirect ELISA are not detected in the blocking ELISA. The high sensitivity and specificity of the blocking ELISA make it an ideal alternative to the AGP test. The use of a monoclonal antibody would facilitate standardisation of diagnostic testing between laboratories.     

Immunohistochemical detection of cd1a antigen in formalin-fixed and paraffin-embedded tissue sections with monoclonal antibody 010

The immunoreactivity of a CD1a monoclonal antibody (MAb), denoted 010, was investigated by means of the streptavidin-biotin-peroxidase method in formalin-fixed and paraffin-embedded tissues from 47 cases. The samples comprised reactive lymphoid proliferations of skin, tonsil, and lymph node including dermatopathic lymphadenopathy and Langerhans' cell histiocytosis, Hodgkin's and non-Hodgkin's lymphomas, and thymomas. Interdigitating and dermal dendritic cells, veiled cells, Langerhans' cells, and also cortical thymocytes and their neoplastic counterparts displayed immunostaining with MAb 010 in paraffin sections. These results are identical to previous ones reported for other CD1a MAbs in fresh or frozen specimens. The findings suggest that the binding site of 010 is a fixation-resistant epitope of CD1a antigen which has not been previously identified.     

Competitive direct ELISA based on a monoclonal antibody for detection of Ochratoxin A in dried fig samples

A monoclonal antibody (MAb) generated against Ochratoxin A (OTA) has been used in a competitive direct enzyme linked immunosorbent assay (cdELISA) for the detection of OTA in dried figs obtained from the Spanish retail market. Fifty per cent inhibition of the maximum binding was obtained with an OTA concentration of 2 ng/mL, and the detection limit for OTA in solution was 0.18 ng/mL, corresponding to 3.15 ng OTA per gram of sample. OTA was detected in 19 (54.3%) out of 35 samples of dried figs analysed, with concentrations that ranged from 3.15 to 277 ng/g. Five samples contained OTA concentrations above the tolerable level set by EC regulations for dried vine fruits (10 ng/g). The MAb-based cdELISA assay developed in this work could be effectively applied for OTA screening in dried figs.     

Detection and quantitation of rotavirus using monoclonal antibody coupled red blood cells: comparison with ELISA

A total of 125 faecal extracts from infants were tested by reverse passive haemagglutination (RPH) using red cells coated with a monoclonal antibody against the major group-specific rotavirus antigen (VP 6). Results were compared with those obtained using a rabbit anti-rotavirus capture, guinea pig anti-rotavirus detector-based ELISA. The specificity of the assay was confirmed by use of 'normal' immunoglobulin coupled red cells and by inhibition with rabbit antiserum. The antibody-coated red cells could be stabilised by treatment with glutaraldehyde and subsequent freeze-drying with no detectable loss of activity even after storage at 45 degrees C for 4 wk. Good correlation was obtained between RPH and ELISA. Purified bovine rotavirus could be detected by RPH down to approximately 10(5) particles in a 25 microliters vol. Similar results were obtained with polyclonal antibody coupled cells and an ELISA using monoclonal antibody. Experiments using subgroup-specific monoclonal antibodies indicated the feasibility of rapid subgroup determination.     

Pre-neutralization of C5a-mediated effects by the monoclonal antibody 137-26 reacting with the C5a moiety of native C5 without preventing C5 cleavage

Complement C5a is aetiologically linked to inflammatory tissue damage in conditions like septicaemia, immune complex diseases and ischaemia-reperfusion injury. We here describe a monoclonal antibody (mAb), 137-26, that binds to the C5a moiety of human C5 and neutralizes the effects of C5a without interfering with C5 cleavage and the subsequent formation of lytic C5b-9 complex. Mouse anti-human C5 mAbs were generated and the reactivity with C5 and C5a was detected by ELISA and surface plasmon resonance. The inhibition of C5a binding to C5a receptor was studied using a radioligand binding assay. The effects of the antibody on C5a functions were examined using isolated neutrophils and a novel human whole blood model of inflammation. Haemolytic assays were used to study the effect on complement-mediated lysis. mAb 137-26 reacted with both solid- and solution-phase C5 and C5a in a dose-dependent manner with high affinity. The antibody competed C5a binding to C5a receptor and inhibited C5a-mediated chemotaxis of neutrophils. Furthermore, the antibody effectively abrogated complement-dependent E. coli-induced CD11b up-regulation and oxidative burst in neutrophils of human whole blood. mAb 137-26 was more potent than a C5a receptor antagonist and a previously described anti-C5a antibody. mAb 137-26 did not inhibit complement-mediated lysis, nor did it activate complement itself. Together, mAb 137-26 binds both the C5a moiety of native C5 and free C5a, thereby effectively neutralizing the biological effects of C5a. The antibody may have therapeutic potential in inflammatory diseases where C5a inhibition combined with an operative lytic pathway of C5b-9 is particularly desired.     

General immunoassay for pyrethroids based on a monoclonal antibody

For the development of class-specific antibody against pyrethroids, four haptens were designed and synthesised. A hybridoma 3E9 was successfully selected for production of antibody, which originated from mouse immunised with conjugates of hapten 1 [(RS)-cyano-3-phenoxybenzyl-2, 2, 3, 3-tetramethylcyclopropane-carboxylic acid] and keyhole limpet hemocyanin. A sensitive general immunoassay was developed with a monoclonal antibody from 3E9 cell line and coating antigen from conjugates of hapten 4 [N-(3-phenoxybenzoyl)-4-amino-L-phenylalanine] and bovine serum albumin. Under the optimised conditions, the antibody has good recognition to cypermethrin with 50% inhibition concentration (IC₅₀) value of 1.7±0.76 ng mL^?1. The cross-reaction to analogues was calculated as 12% for fenpropathrin, 4% for esfenvalerate. Besides, the antibody showed affinity to bifenthrin, deltamethrin and fenvalerate in different degrees with IC₅₀ value ranging from 191.8 to 298.5 ng mL^?1. The performance of this immunoassay was evaluated by fortified real water samples with three representative compounds. Recoveries were 76–118%, and the results showed that this immunoassay could be applied to monitor pyrethroid residues.     

Delineation of human cord blood hematopoietic progenitor cell subsets with a unique monoclonal antibody AY19

Abstract: AY19, a unique mAb was used to better characterize the umbilical cord blood hematopoietic progenitor subpopulations. This mAb identifies an 85 kDa cell surface glycoprotein. In this present study we showed that AY19 mAb is reactive with 50–60% of the CD34+ cord blood cells. Extensive phenotypical studies revealed that AY19 mAb defines a novel CD34+ subset different from the ones defined by anti-CD90, anti-CD38, anti-CD33, anti-CD71, anti-CD19, anti-CD7 or anti-HLA-DR mAbs. We show that AY19 mAb reacts with both primitive and committed progenitors including my-eloid and lymphoid progenitors. In addition, sorted CD34+^high/AY19+ cells contain an increased number of CFU-GM and a decreased number of BFU-E compared with sorted CD34+^high/AY19— cells. We show that AY19 mAb exhibits agonistic properties by inducing a significant increase in the size of CFU-GM colonies when added to serum-free liquid cultures of hematopoietic progenitors. This suggests that AY19 mAb identifies a cell surface receptor which may be involved in the regulation of hematopoietic cell proliferation.     

制备单克隆抗体检测PES1的表达

目的:制备PES1单克隆抗体(mAb)并用所制备的抗体检测PES1在多种肿瘤细胞中的表达及其在成年大鼠不同组织中的表达分布。方法:纯化GST-PES1(1-322aa)融合蛋白后注入小鼠进行免疫,经过细胞融合、筛选以及用Western blot进行特异性鉴定后获得mAb。再用制备的mAb检测PES1在不同的人肿瘤细胞和大鼠不同组织中的表达。结果:所制备的PES1 mAb能特异地识别PES1。用所制备的mAb检测发现,在所检测的人乳腺癌、卵巢癌、肝癌以及肺癌等细胞中均有不同程度的表达;PES1类似物pescadillo在大鼠的乳腺和卵巢组织中表达,但在其他组织中没有被检测到。结论:成功地制备了PES1的mAb。PES1可能与肿瘤的发生发展有一定的关系;由于PES1明显表达于雌激素重要的靶器官,所以可能参与雌激素信号通路。     

抗人IgG-抗HRP双特异性单克隆抗体细胞株的建立与鉴定

目的 制备人ＩｇＧ检测用双特异性单克隆抗体诊断试制。方法 用人ＩｇＧ免疫ＢＡＬＢ／ｃ小鼠脾细胞与抗ＨＲＰＭｃＡｂ杂交瘤细胞ＨＡＴ敏感株进行第２次融合。结果 获得５株能稳定分泌抗人Ｉｇ－抗ＨＲＰ的双特异性单克隆抗体的杂交－杂交瘤细胞,分泌的抗体亚类其中１株为ＩｇＧ２ａ／ＩｇＧ１,余为ＩｇＧ１／ＩｇＧ１。培养上清与腹水效价分别为２＾７、１０＾０４以上,经ＨＲＰ亲和层析有２个蛋白吸ＢｓＭｃＡｂ存在于第２