Western blot assay using recombinant p26 antigen for detection of equine infectious anemia virus-specific antibodies.
Ontology highlight
ABSTRACT:
SUBMITTER: Alvarez I
PROVIDER: S-EPMC2168377 | biostudies-literature | 2007 Dec
REPOSITORIES: biostudies-literature
Publications
Western blot assay using recombinant p26 antigen for detection of equine infectious anemia virus-specific antibodies.
Alvarez I I Gutierrez G G Ostlund E E Barrandeguy M M Trono K K
Clinical and vaccine immunology : CVI 20071024 12
We analyzed the performance of a single-band Western blot (WB) test using recombinant p26 (rp26) capsid protein of equine infectious anemia virus. According to the results obtained, the rp26 WB test is a reliable confirmatory diagnostic tool to be used as a complementary test after an enzyme-linked immunosorbent assay or agar gel immunodiffusion test yielding doubtful results. ...[more]
Similar Datasets
Project description:Thermostabilizing effect of heavy water (D2O) or deuterium oxide has been demonstrated previously on several enzymes and vaccines like oral poliovirus vaccine and influenza virus vaccine. In view of the above observations, effect of heavy water on in situ thermostabilization of recombinant p26 protein on enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of equine infectious anemia virus (EIAV) infection was investigated in the present study. The carbonate-bicarbonate coating buffer was prepared in 60% and 80% D2O for coating the p26 protein in 96-well ELISA plate and thermal stability was examined at 4 °C, 37 °C, 42 °C, and 45 °C over a storage time from 2 weeks to 10 months. A set of positive serum (n = 12) consisting of strong, medium, and weak titer strength (4 samples in each category) and negative serum (n = 30) were assessed in ELISA during the study period. At each time point, ELISA results were compared with fresh plate to assess thermal protective effect of D2O. Gradual increase in the stabilizing effect of 80% D2O at elevated temperature (37 °C < 42 °C < 45 °C) was observed. The 80% D2O provides the thermal protection to rp26 protein in ELISA plate up to 2 months of incubation at 45 °C. The findings of the present study have the future implication of adopting cost effective strategies for generating more heat tolerable ELISA reagents with extended shelf life.
| S-EPMC3913021 | biostudies-other
Project description:BackgroundEquine infectious anemia (EIA) is a viral disease, caused by the Equine Infectious Anemia virus (EIAV) belonging to the Retroviridae family, genus Lentivirus. Horses (or equids) infected with EIAV are lifelong carriers and they remain contagious for other horses even in the absence of clinical signs. So far, EIAV infection has been reported among horses in North and South America, France, Germany, Italy, Hungary and Romania, with no publication regarding the presence of EIAV in horses in Serbia. To determine the circulation of EIAV among, approximately, the 5000 horses of the Vojvodina region, northern part of Serbia, 316 serum undergone serological testing for EIA. Then, identification and full genome sequencing using next generation sequencing was performed from one EIA positive horse.Resultsthe 316 sera were tested with 3 different commercial agar gel immunodiffusion (AGID) tests and two different commercial enzyme-linked immunosorbent assay (ELISA). With the three AGID kits, 311 (98.4%) among the 316 tested sera were negative and only five (1.6%) sera were positive for EIA. Some discrepancies were seen for the two ELISA kits tested since one exhibited the same results as AGID test and the second gave 295 sera with negative results, five with a positive result and 16 with doubtful outcome. Phylogenetic analysis performed using the full genome sequence showed that EIAV characterized from a horse in Serbia is different from those identify so fare around the world and form a distinct and separate group together with another EIAV strain.ConclusionsThis study demonstrate for the first time that EIAV is circulating at a low level in the horse population from the Northern part of Serbia. Interestingly, phylogenetic data indicates that this EIAV from the western Balkan region of Europe belongs to a new cluster.
| S-EPMC8051041 | biostudies-literature
Project description:Equine infectious anemia (EIA)-a retroviral disease caused by equine infectious anemia virus (EIAV)-is a chronic, debilitating disease of horses, mules, and donkeys. EIAV infection has been reported worldwide and is recognized as pathogen of significant economic importance to the horse industry. This disease falls under regulatory control program in many countries including India. Control of EIA is based on identification of inapparent carriers by detection of antibodies to EIAV in serologic tests and "Stamping Out" policy. The current internationally accepted test for diagnosis of EIA is the agar gel immune-diffusion test (AGID), which detects antibodies to the major gag gene (p26) product. The objective of this study was to develop recombinant p26 based in-house immunoassays [enzyme linked immunosorbent assays (ELISA), and AGID] for EIA diagnosis. The synthetic p26 gene of EIAV was expressed in Escherichia coli and diagnostic potential of recombinant p26 protein were evaluated in ELISA and AGID on 7,150 and 1,200 equine serum samples, respectively, and compared with commercial standard AGID kit. The relative sensitivity and specificity of the newly developed ELISA were 100 and 98.6 %, respectively. Whereas, relative sensitivity and specificity of the newly developed AGID were in complete agreement in respect to commercial AGID kit. Here, we have reported the validation of an ELISA and AGID on large number of equine serum samples using recombinant p26 protein produced from synthetic gene which does not require handling of pathogenic EIAV. Since the indigenously developed reagents would be economical than commercial diagnostic kit, the rp26 based-immunoassays could be adopted for the sero-diagnosis and control of EIA in India.
| S-EPMC3832691 | biostudies-literature
Project description:The release of lentiviral vectors for clinical use requires the testing of vector material, production cells, and, if applicable, ex vivo-transduced cells for the presence of replication-competent lentivirus (RCL). Vectors derived from the nonprimate lentivirus equine infectious anemia virus (EIAV) have been directly administered to patients in several clinical trials, with no toxicity observed to date. Because EIAV does not replicate in human cells, and because putative RCLs derived from vector components within human vector production cells would most likely be human cell-tropic, we previously developed an RCL assay using amphotropic murine leukemia virus (MLV) as a surrogate positive control and human cells as RCL amplification/indicator cells. Here we report an additional RCL assay that tests for the presence of theoretical "equine-tropic" RCLs. This approach provides further assurance of safety by detecting putative RCLs with an equine cell-specific tropism that might not be efficiently amplified by the human cell-based RCL assay. We tested the ability of accessory gene-deficient EIAV mutant viruses to replicate in a highly permissive equine cell line to direct our choice of a suitable EIAV-derived positive control. In addition, we report for the first time the mathematical rationale for use of the Poisson distribution to calculate minimal infectious dose of positive control virus and for use in monitoring assay positive/spike control failures in accumulating data sets. No RCLs have been detected in Good Manufacturing Practice (GMP)-compliant RCL assays to date, further demonstrating that RCL formation is highly unlikely in contemporary minimal lentiviral vector systems.
| S-EPMC3732122 | biostudies-literature
Project description:The mammalian APOBEC3 (A3) proteins comprise a multigene family of cytidine deaminases that act as potent inhibitors of retroviruses and retrotransposons. The A3 locus on the chromosome 28 of the horse genome contains multiple A3 genes: two copies of A3Z1, five copies of A3Z2, and a single copy of A3Z3, indicating a complex evolution of multiple gene duplications. We have cloned and analyzed for expression the different equine A3 genes and examined as well the subcellular distribution of the corresponding proteins. Additionally, we have tested the functional antiretroviral activity of the equine and of several of the human and nonprimate A3 proteins against the Equine infectious anemia virus (EIAV), the Simian immunodeficiency virus (SIV), and the Adeno-associated virus type 2 (AAV-2). Hematopoietic cells of horses express at least five different A3s: A3Z1b, A3Z2a-Z2b, A3Z2c-Z2d, A3Z2e, and A3Z3, whereas circulating macrophages, the natural target of EIAV, express only part of the A3 repertoire. The five A3Z2 tandem copies arose after three consecutive, recent duplication events in the horse lineage, after the split between Equidae and Carnivora. The duplicated genes show different antiviral activities against different viruses: equine A3Z3 and A3Z2c-Z2d are potent inhibitors of EIAV while equine A3Z1b, A3Z2a-Z2b, A3Z2e showed only weak anti-EIAV activity. Equine A3Z1b and A3Z3 restricted AAV and all equine A3s, except A3Z1b, inhibited SIV. We hypothesize that the horse A3 genes are undergoing a process of subfunctionalization in their respective viral specificities, which might provide the evolutionary advantage for keeping five copies of the original gene.
| S-EPMC2708611 | biostudies-literature
Project description:To identify a major antigenic determinant for use in the development of a rapid serological diagnostic test for severe acute respiratory syndrome (SARS) coronavirus infection and to study the immune response during SARS coronavirus infection in humans, we cloned the full length and six truncated fragments of the nucleocapsid gene, expressed them, and purified them as glutathione S-transferase-tagged recombinant proteins. The reactivities of the recombinant proteins to a panel of antibodies containing 33 SARS coronavirus-positive sera and 66 negative sera and to antibodies against other animal coronaviruses were screened. A truncated 195-amino-acid fragment from the C terminus of the nucleocapsid protein (N195) was identified that had a strong ability to detect antibodies against SARS coronavirus. No cross-reaction was found between the N195 protein and antibodies against chicken, pig, and canine coronaviruses. The N195 protein was used to develop a Western blot assay to detect antibodies against SARS coronavirus in 274 clinically blinded samples. The specificity and sensitivity of this test were 98.3 and 90.9%, respectively. The correlation between our Western blotting assay and an immunofluorescence assay (IFA) was also analyzed. The results of our Western blot assay and IFA for the detection of SARS coronavirus-positive sera were the same. Thus, the N195 protein was identified as a suitable protein to be used as an antigen in Western blot and other possible assays for the detection of SARS coronavirus infection.
| S-EPMC371214 | biostudies-literature
Project description:In the present work, we describe and evaluate an additional step to the standard western blot protocol to increase signal strength after revealing. Weak or absence of signal is a common issue in western blot protocol leading to unexpected results. In our Antigen Retrieval for Western Blot Method (ARWB method), after transfer, the membrane was incubated in a citrate buffer following normal antigen retrieval procedure used for immunohistochemistry. Later, standard protocol was performed in order to reveal and compare with unexposed membranes to this antigen retrieval step. Signal in bands obtained by the modified protocol resulted significantly higher (in all 13 antibodies analyzed) compared to standard protocol. Some bands were only visible after citrate incubation. This method is a simple and economical way to improve results in western blot analysis. •The ARWB method significantly increases band's density in all antibodies analyzed.•Protein localization does not influence the efficacy of the ARWB method since membrane and citoplasmatic proteins bands increase their signal in a similar way after the protocol is performed.•This ARWB method is simple, safe, economical and undoubtedly helpful in immunoblotting for proteins with weak signal.
| S-EPMC6423990 | biostudies-literature
Project description:The Gag polyprotein is key to the budding of retroviruses from host cells and is cleaved upon virion maturation, the N-terminal membrane-binding domain forming the matrix protein (MA). The 2.8-A resolution crystal structure of MA of equine infectious anemia virus (EIAV), a lentivirus, reveals that, despite showing no sequence similarity, more than half of the molecule can be superimposed on the MAs of human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV). However, unlike the structures formed by HIV-1 and SIV MAs, the oligomerization state observed is not trimeric. We discuss the potential of this molecule for membrane binding in the light of conformational differences between EIAV MA and HIV or SIV MA.
| S-EPMC135893 | biostudies-literature
Project description:Hyper-immune antisera from large mammals, in particular horses, are routinely used for life-saving anti-intoxication intervention. While highly efficient, the use of these immunotherapeutics is complicated by possible recipient reactogenicity and limited availability. Accordingly, there is an urgent need for alternative improved next-generation immunotherapies to respond to this issue of high public health priority. Here, we document the development of previously unavailable tools for equine antibody engineering. A novel primer set, EquPD v2020, based on equine V-gene data, was designed for efficient and accurate amplification of rearranged horse antibody V-segments. The primer set served for generation of immune phage display libraries, representing highly diverse V-gene repertoires of horses immunized against botulinum A or B neurotoxins. Highly specific scFv clones were selected and expressed as full-length antibodies, carrying equine V-genes and human Gamma1/Lambda constant genes, to be referred as "Centaur antibodies". Preliminary assessment in a murine model of botulism established their therapeutic potential. The experimental approach detailed in the current report, represents a valuable tool for isolation and engineering of therapeutic equine antibodies.
| S-EPMC9437483 | biostudies-literature
Project description:Western blotting has proven to be an important technique in analysis of receptor-ligand interactions (i.e., by ligand blotting) and for identifying molecules mediating cell attachment (i.e., by cell blotting). Conventional ligand blotting and cell blotting methods employ nondynamic (static) incubation conditions, whereby molecules or cells of interest are placed in suspension and overlaid on membranes. However, many cell-cell and cell-matrix adhesive interactions occur under fluid shear conditions, and shear stress itself mediates and/or facilitates the engagement of these physiologically appropriate receptors and ligands. Notably, shear forces critically influence the adhesion of circulating cells and platelets to vessel walls in physiologic cell migration and hemostasis, as well as in inflammatory and thrombotic disorders, cancer metastasis, and atherosclerosis. Use of nondynamic blotting conditions to analyze such interactions can introduce bias, overtly missing relevant effectors and/or exaggerating the relative role(s) of nonphysiologic adhesion molecules. To address this shortfall, we have developed a new technique for identifying binding interactions under fluid shear conditions, the "blot rolling assay." Using this method, molecules in a complex mixture are resolved by gel electrophoresis, transferred to a membrane that is rendered semi-transparent, and the membrane is then incorporated into a parallel-plate flow chamber apparatus. Under controlled flow conditions, cells or particles bearing adhesion proteins of interest are then introduced into the chamber and interactions with individual immobilized molecules (bands) can be visualized in real-time. The substrate molecule(s) supporting adhesion under fluid shear can then be identified by staining with specific antibodies or by excising the relevant band(s) and performing mass spectrometry or microsequencing of the isolated material. This method thus allows for the identification, within a complex mixture and without prior isolation or purification, of both known and previously uncharacterized adhesion molecules operational under dynamic conditions.
| S-EPMC5571433 | biostudies-other