WO2004008144A2 - METHODE DE DETECTION AUTOMATISABLE DE LA PrPres ET SES APPLICATIONS - Google Patents
METHODE DE DETECTION AUTOMATISABLE DE LA PrPres ET SES APPLICATIONS Download PDFInfo
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- WO2004008144A2 WO2004008144A2 PCT/FR2003/002117 FR0302117W WO2004008144A2 WO 2004008144 A2 WO2004008144 A2 WO 2004008144A2 FR 0302117 W FR0302117 W FR 0302117W WO 2004008144 A2 WO2004008144 A2 WO 2004008144A2
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- buffer
- prp
- plasminogen
- prp res
- capture
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
- G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
- G01N33/54313—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals the carrier being characterised by its particulate form
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/68—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving proteins, peptides or amino acids
- G01N33/6893—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving proteins, peptides or amino acids related to diseases not provided for elsewhere
- G01N33/6896—Neurological disorders, e.g. Alzheimer's disease
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2333/00—Assays involving biological materials from specific organisms or of a specific nature
- G01N2333/90—Enzymes; Proenzymes
- G01N2333/914—Hydrolases (3)
- G01N2333/948—Hydrolases (3) acting on peptide bonds (3.4)
- G01N2333/968—Plasmin, i.e. fibrinolysin
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2800/00—Detection or diagnosis of diseases
- G01N2800/28—Neurological disorders
- G01N2800/2814—Dementia; Cognitive disorders
- G01N2800/2828—Prion diseases
Definitions
- the present invention relates to a sensitive, rapid, simple and fully automatable detection method for PrP res in a biological sample as well as to its applications.
- Subacute transmissible spongiform encephalopathies are caused by unconventional transmissible agents (ATNC), also called prions, whose precise nature remains disputed to date.
- ESST essentially includes Creutzfeldt-Jakob disease in humans (CJD or CJD for Creutzfeldt-Jakob disease), scrapie in sheep and goats and bovine spongiform encephalopathy (BSE or BSE for bovine spongiform encephalopathy) in cattle; other encephalopathies have been demonstrated in felines, mink or certain wild ruminants, such as deer.
- PrP a host protein
- PrP res an abnormal form
- PrP res has significantly higher content in pleated ⁇ sheets, while normal PrP ( sense PrP) has a higher percentage of ' ⁇ propellers.
- the infectious isoform PrP res is capable of converting the normal protein, that is to say the sense PrP, into infectious protein.
- PrP res is partially resistant to proteases, in particular to proteinase K (PK), which causes cleavage of its N-terminal end. After action PK, PrP res is often called PrP27-30 because of the apparent molecular weight of the biglycosylated form; it is generally accepted that the PrP res cleavage site is located between amino acids 89 and 90 (Prusiner et al, Cell, 1984) for the usual strains.
- - PrP res is insoluble and aggregates in non-ionic detergents, such as Triton XI 00 or Triton 114 by forming amyloid fibers (Scrapie Associated fibrils, SAFs).
- PrP sense The normal form of the prion protein (PrP sense ) is, in principle, completely degraded by proteases and is perfectly soluble in the presence of non-ionic detergents.
- PrP res abnormal PrP
- PrP res abnormal PrP
- sense PrP differ in their physical properties, it is in fact very difficult to develop immunological tests which make it possible to reliably differentiate the two isoforms of PrP, in particular due to the absence of specific antibodies to PrP res .
- the only antibodies available recognize either sense PrP or the two forms of PrP (sense or res) after they have undergone a denaturation step. That is why in almost all immunoassays dedicated to the diagnosis of ESSTs include a denaturation step to allow the immunological detection of p r pres
- histopathology which aims to detect (mainly in central nervous tissues) the lesions characteristic of ESSTs (spongiosis, vacuolization, astrogliosis, amyloid PrP plaques); it remains a reference method for confirming a clinical diagnosis. It is very specific since it allows direct observation of the stigma of the disease. However, we now know that it is less sensitive than other techniques. This method has the disadvantage of do not allow a pre-clinical diagnosis, since anatomical lesions appear late in the history of the disease. In addition, it is not at all suitable for analysis in large series.
- bio-tests which aim to identify the infectious nature of a sample. Indeed, the most sensitive method for the diagnosis of ESSTs is, without question, experimental infection in laboratory animals. This method consists in injecting a homogenate prepared from the studied tissue into an animal and monitoring the appearance of clinical signs. The development of this experimental disease will be confirmed using conventional techniques (histology, immunohistolology, Western blot). For obvious practical reasons, these experiments are generally carried out on rodents (mice, hamsters) but in certain extreme cases, experimental infections have been carried out with sheep or cattle. The effectiveness of experimental transmission depends on many factors, including: the species barrier, the amount of transmissible agent inoculated, the prion strain, the sensitivity of the recipient species and the pathway inoculation.
- the most effective route is the intracranial route, then the intravenous route (10 times less effective).
- the least effective route is the oral route (100,000 times less effective than the intracranial route).
- the most sensitive means of detecting the transmissible agent responsible for BSE is intracranial injection in cattle.
- the main disadvantages of these methods are, on the one hand their heaviness and on the other hand their duration. Indeed, it takes between 300 and 700 days to carry out an experimental infection test in mice and between 3 and 10 years in cattle. The availability nibility of transgenic mice expressing the same PrP as that of the donor species will make it possible to shorten these times but, in all cases, these tests will last, at least three months.
- PK digestion overcomes this drawback, meaning PrP being completely digested, while PrP res is little modified.
- the specificity of this approach is due, among other things, to the fact that under the action of proteinase K, the molecular weight of PrP res is characteristically modified due to the partial degradation of the N-terminal part of the protein. Its sensitivity is of the same order of magnitude as that of immunohistology.
- the main drawback of this technique is related to its difficulty of implementation, the duration of the analysis (> 8 hours) and the impossibility of automating it.
- PrP res detection test which includes the immobilization of proteins on a nitrocellulose membrane, followed by protease digestion, denaturation and immunodetection with monoclonal antibodies.
- the Prionics test uses the Western-blot technique in an industrialized form while the tests developed by Enfer Technology and Wallac are enzyme assays of the ELISA type.
- the test developed by CEA first involves a selective purification of the PrP res which is then assayed using a sandwich assay using two monoclonal antibodies (enzymo-immunometric assay at two sites).
- the Applicant has proposed a test for the quantitative detection of PrP res , which comprises a purification step which leads to a significantly more sensitive detection; this test is described in particular in PCT International Application WO 99/41280 and in a preliminary report from Directorate General XXIV of the European Commission (Consumer policy and health protection; http: // europa.
- ligand capable of specifically recognizing PrP res .
- This ligand immobilized on an adequate solid support could allow PrP res to be concentrated in media, such as blood or urine in which it is very little concentrated. Since the interaction between the ligand and PrP res is truly specific, treatment with proteinase K will not be necessary, just as it will not be necessary to use its aggregation properties. This type of ligand was recently described by the Adriano team
- PrP res is therefore first concentrated by incubation with magnetic beads carrying plasminogen or fibrinogen, then detected by Western-blot analysis, ELISA, immunoprecipitation, BIACORE test, immunocytochemical test or histoblot test after elution of PrP res from the support. solid.
- the conditions are as follows:
- - sample preparation step homogenization and centrifugation of the homogenate; it is important to use, during the first stage of homogenization, low concentrations of ionic detergents, followed by centrifugation at low speed (500 g for 30 minutes), while in the following stages high concentrations in non-ionic detergents are used; preferably a protein concentration in the homogenate of at most 5 mg / ml is obtained;
- - proteinase K digestion preferably in the presence of 50 ⁇ g / ml of PK, at 37 ° C, for at least half an hour;
- the subject of the present invention is a method for detecting the
- PrP res in a biological sample, using a solid support, in particular magnetic beads or microtiter plates, on which is immobilized plasminogen, which process is characterized in that it comprises:
- a step of preparing the biological sample which can be constituted either by a homogenate of tissue or cells, or by serum or plasma, or by urine, during which the latter is incubated in a buffer selected from the group consisting of:
- buffers for homogenizing the biological sample comprising (1) a buffer selected from the group consisting of buffers comprising at least one surfactant selected from the group consisting of ionic surfactants and nonionic surfactants , a glucose buffer, a sucrose-based buffer and a PBS buffer and (2) optionally, proteinase K at a final concentration between 1 and 8 ⁇ g / ml, preferably at a final concentration between 2 and 4 ⁇ g / ml and
- the capture buffers comprising at least (1) a surfactant selected from the group consisting of ionic surfactants and (2) optionally a proteinase K at a final concentration of between 1 and 8 ⁇ g / ml, preferably at a final concentration between 2 and 4 ⁇ g / ml.
- the plasminogen very preferably recognizes PrP res
- a careful treatment beforehand with PK that is to say during from step (a) of preparation of the biological sample
- PK makes it possible to suppress the signal linked to a residual recognition of the sense PrP. This is the reason why we consider that the careful implementation of PK at this stage is optional; moreover, in situations where it is feared that PK treatment affects PrP res (for example in a blood or urine sample), this PK treatment step can be omitted.
- step (b) a step for capturing the PrP res on said solid support, necessarily carried out in the presence of a capture buffer as defined above, without PK, that is to say in which the surfactants are exclusively ionic surfactants, by incubation of the biological sample obtained in step (a) with said support on which plasminogen is immobilized covalently; this step comprises, if necessary, prior to incubation, a dilution of the biological sample obtained in step (a) in said capture buffer, in order to obtain the adjustment of the protein concentration, and this in particular in the case where step (a) was implemented in a homogenization buffer.
- the optimal protein concentration in the biological sample varies depending on the environment studied. In the case of a homogenate of the brain, it is preferable that it does not exceed approximately 2 g / ml (corresponding to a homogenate at 2% w / v) under penalty of observing a loss of efficiency in the capture of PrP res .
- This limitation is probably linked to the presence in the sample of uncharacterized substances which are also capable of binding to plasminogen. It is a drawback compared to other concentration methods (for example that described in PCT International Application WO 99/41280) which make it possible to treat more concentrated homogenates (homogenate at 20% w / v, ie approximately 20 mg / ml protein).
- This gentle denaturation step is compatible with the maintenance of the plasminogen / PrP res complex.
- the support on which the PrP res is optionally fixed can advantageously be washed; the washing conditions and in particular the washing buffer used, are not critical, in the process according to the invention.
- the ionic surfactant used during step (a) or step (b) is selected from the group consisting of:
- - anionic surfactants such as SDS (sodium dodecylsulfate), sarkosyl (lauroyl-sarcosine), sodium cholate, sodium deoxycholate (DOC), sodium taurocholate; and - zwitterionic surfactants, such as SB 3-10 (decyl-sulfobetaine), SB 3-12 (dodecyl-sulfobetaine), SB 3-14 (tetradecyl-sulfobetaine), SB 3-16 (hexadecyl- sulfobetaine), CHAPS and deoxyCHAPS.
- SDS sodium dodecylsulfate
- sarkosyl laauroyl-sarcosine
- sodium cholate sodium deoxycholate
- DOC sodium deoxycholate
- - zwitterionic surfactants such as SB 3-10 (decyl-sulfobetaine), SB 3-12 (dodecyl-sulfobe
- the nonionic surfactant, used during step (a) of the method according to the invention is selected from the group consisting of the C12E8
- the incubation time of step (a) is between 5 and 30 minutes at 37 ° C, preferably for 10 minutes at 37 ° C.
- the capture buffer preferably comprises sarkosyl at a final concentration of between 0.5% and 2% (w / v), even more preferred to a final sarkosyl concentration of 1% (w / v).
- the capture buffer further comprises a salt preferably selected from alkali metal salts, preferably sodium chloride, even more preferably, a ne concentration between 0.15 M and 0.5 M.
- the capture buffer further comprises a protein and even more preferably, bovine serum albumin at a concentration of 0.2 mg / ml.
- the incubation time of step (b) is between 1 hour and 4 hours at room temperature.
- the chaotropic agent used during stage (c) of gentle denaturation is selected from the group consisting of urea, a guanidine salt, such as guanidine hydrochloride or guanidine thiocyanate and sodium thiocyanate or a mixture thereof.
- the incubation time of step (c) is between 10 and 60 minutes, preferably either for 30 minutes at 37 ° C with the plates microtitration either for 10 minutes at 100 ° C with the magnetic beads.
- the tracer antibody of step (d) is a polyclonal or mono- antibody clonal selected from the group consisting of SAF antibodies and anti-recombinant PrP antibodies; more precisely, the SAF antibodies and more particularly the SAF -34, SAF-53 and SAF-61 antibodies were obtained by immunizing mice disabled for the PrP gene with denatured hamster SAFs (Demart et al., Biochem. Biophys. Res.
- Antibodies BAR-221, BAR-224 and BAR-233 were obtained by immunizing mice disabled for the PrP gene with recombinant sheep PrP.
- the antibody 8G8 was obtained by immunizing mice disabled for the PrP gene with a recombinant human PrP (Krasemann et al., J. Immunol. Methods, 1996, 199,109-118 and Mol. Med., 1996, 2, 725-734).
- the solid support is advantageously selected from the group consisting of magnetic beads and microtiter plates.
- the biological sample - is, if necessary, homogenized in a homogenization buffer optionally comprising PK, at very low concentrations (between 1 and 8 ⁇ g / ml),
- Such a method makes it possible to carry out a continuous dosing that can be fully automated, unlike the method described in international PCT application WO 99/41280 which requires a centrifugation step.
- Such an assay also has a sensitivity at least as good as that obtained with the methods implementing a purification step, as described in PCT International Application WO 99/41280.
- the present invention also relates to a diagnostic kit for implementing the method as defined above, characterized in that it comprises in combination:
- a proteinase K at a final concentration between 1 and 8 ⁇ g / ml, preferably at a final concentration between 2 and 4 ⁇ g / ml, and
- Figure 1 illustrates the effect of proteinase K concentration on the CP signal ratio (positive control) to CN (negative control).
- FIG. 2 represents a comparative study of the detection of PrP res from sheep using a conventional “sandwich” assay (BAR-224 / SAF-34) or with the plasminogen / BAR224 pair.
- FIG. 3 represents a comparative study of the assay of PrP res from sheep suffering from scrapie using the technique described in International Application WO 99/41280 or the method according to the invention: assay “plasminogen / B AR224 sandwich on microtiter plate.
- FIG. 5 illustrates the comparison of the detection of PrP res using the technique of preparation of SAFs followed by an immunometric assay (PCT International Application WO 99/41280) with that using the capture of PrP res on beads coupled to plasminogen followed by a direct assay (invention).
- FIG. 6 shows the effect of the dilution of a homogenate of sheep brain scrapie on the detection of PrP res by direct assay on plasminogen coupled to magnetic beads.
- FIG. 7 shows dilution curves of the brain of mice, cows and humans affected by ESST. It illustrates the capacity of the method according to the invention to carry out the diagnosis of all the ESSTs.
- Plasminogen is immobilized covalently on the surface of Covalink NH microtiter plates (Nunc) using a homobifunctional coupling agent, disuccinimidyl suberate (DSS).
- DSS disuccinimidyl suberate
- 100 ⁇ l of a DSS solution (12.5 mg of DSS dissolved in 50 ml of DMSO and 50 ml of 50 mM carbonate buffer pH 9.5) are incubated on the surface of the Covalink NH wells for 1 hour at room temperature.
- the wells are washed 3 times with distilled water and then 100 ⁇ l of a plasminogen solution at 2.5 ⁇ g / ml in 50 mM carbonate buffer pH 9.5 are incubated on the surface of the wells overnight at room temperature.
- the wells are emptied and saturated with EIA buffer (0.1 M phosphate buffer pH 7.4 0.15 M NaCl, 0.1% BSA and 0.01% sodium azide)
- step (a) of the process Preparation of the sample (step (a) of the process) and capture of the PrP res on the Covalink NH microtitration plates containing the plasminogen (step (b) of the process)
- CP positive control
- CN healthy
- EIA buffer pH 7.4 comprising an ionic surfactant and proteinase K at a final concentration of 1 ⁇ g / ml, for 10 minutes at 37 ° C, then 10 ⁇ l of
- Pefabloc TM proteose inhibitor corresponding to [4- (2-aminoethyl) fluoride) benzenesulfonyl] HCl
- 100 ⁇ l of sample are deposited and incubated for 2 hours at room temperature in the wells of the Covalink NH microtiter plate containing the plasminogen.
- Table I illustrates the results obtained using the antibody BAR-224 to detect PrP res associated with plasminogen after careful denaturation by treatment with guanidine / HCl.
- Table I Effect of detergents on the capture of PrP res from sheep brain scrapie by plasminogen immobilized on a solid support Covalink NH microtiter plate.
- EIA buffer 0.1M phosphate buffer pH 7.4 + 0.15 M NaCl + 0.1% BSA + 0.01% sodium azide
- the capture conditions selected for the rest of the tests are: EIA buffer + SK 1%, even if in Table I above, other conditions have a slightly higher CP / CN ratio because these conditions provide a strong CP-CN differential and in other experiments the results were reversed, the value of CN varying.
- Table II illustrates the results obtained. Table II: Effect of pH and NaCl concentration on the capture of PrP res from sheep brain scrapie by plasminogen immobilized on a Covalink NH microtiter plate.
- EIA buffer 0.1 M phosphate buffer pH 7.4 + 0.1% BSA »+ sodium azide
- the capture conditions of the PrP res preferably selected are as follows: EIA buffer + 0.5 M NaCl + 1% SK.
- EIA buffer pH 7.4 comprising 0.5 M NaCl, 1% final of sarkosyl and proteinase K at different concentrations, 0 , 0.5, 1, 2, 4, and 8 ⁇ g / ml final for 10 minutes at 37 ° C., then 10 ⁇ l of Pefabloc TM at 100 mM are added. We then proceed as described above.
- 25 ⁇ l of a homogenate of scrapie sheep brain and healthy sheep are incubated with 225 ⁇ l of EIA buffer pH 7.4 comprising 0.5 M NaCl, 1% sarkosyl and proteinase K at a final concentration of 1 ⁇ g / ml for 10 minutes at 37 ° C, then 10 ⁇ l of Pefabloc TM at 100 mM are added. 100 ⁇ l are placed in the wells of a microtiter plate containing immobilized plasminogen. After 2 hours of reaction at room temperature, the wells are washed and then incubated with 100 ⁇ l of different denaturing agents for 30 min at 37 ° C.
- Table IN Effect of the denaturing agent used after capture and before detection of sheep PrP res by a labeled antibody.
- Table N illustrates the results obtained.
- Table V Selection of the tracer antibody for the detection of sheep PrP res .
- the BAR224 tracer antibody gives the best CP / C ⁇ ratio as well as a good CP signal for the detection of sheep PrP res .
- EXAMPLE 2 Comparative study of the detection of PrP res from sheep using a conventional “sandwich” assay (BAR224 / SAF34) or with the plasminogen / BAR224 pair. This study compared the detection sensitivity of the two types of sandwich.
- a PrP res preparation (SAF) was obtained from a scrapie sheep brain:
- the preparations of SAFs (according to the rapid SAFs protocol, as described in the international PCT application WO 99/41280) from 250 ⁇ l of sheep brain homogenate with scrapie or healthy, are taken up and denatured with 25 ⁇ l of denatu- rant (buffer C, as defined in PCT International Application WO 99/41280) for 10 min at 100 ° C.
- the pellets are taken up with 250 ⁇ l of EIA buffer and successively diluted in EIA buffer. The dilutions are deposited in the wells of a microtiter plate containing the BAR224 antibody.
- the wells are washed and then incubated with 100 ⁇ l of the SAF34 tracer antibody (at 5 EU / ml) for 2 hours at room temperature. After washing, 200 ⁇ l of the developer solution are added. The absorbance at 414 nm is measured after 30 minutes of reaction.
- the SAFs preparations (identical to above) are taken up with 250 ⁇ l of EIA buffer containing final 4 mM Pefabloc TM, then treated by ultrasound until the pellet dissolves . Successive dilutions are then carried out in EIA buffer comprising Pefabloc TM. The dilutions are deposited on a solid support (microtitration plate) containing plasminogen.
- the sensitivity of the two methods is compared by including, for the method according to Application WO 99/41280, the technique for preparing the SAFs and for the plasminogen technique, the dilution which is necessary to operate. before capture, in particular to obtain a protein concentration, in the homogenate, of 20 mg / ml (2% w / v).
- Homogenate at 20% of sheep brain with scrapie is diluted or not in a homogenate of healthy sheep brain (dilution 1/5, 1/10, 1/20, 1/40, 1/80, 1/160 and 1/320).
- the SAFs are prepared from 250 ⁇ l of homogenate.
- the BAR224 and SAF34 antibodies are used as capture antibodies and tracer antibodies respectively.
- the plasminogen is immobilized on the microtitration plates as specified in Example 1;
- the assay is carried out from 25 ⁇ l of homogenate, using as capture buffer, EIA buffer comprising 0.5 M NaCl, 1% sarkosyl and 2.5 ⁇ g / ml of proteinase K, as denaturing agent of guanidine / HCl 8M and as tracer antibody BAR224.
- the results are illustrated in FIG. 3 and show that the test according to International PCT Application WO 99/41280 has a very clear advantage in terms of sensitivity because it treats 250 ⁇ l of homogenate at 20%, ie 50 mg of tissue. cerebral instead of 25 ⁇ l of the same homogenate at 20%, ie 5 mg for the test according to the invention.
- This drawback results from the use of microtiter plates, because the volume of 2% homogenate treated is limited (at most 300 ⁇ l). However, this drawback disappears when magnetic beads are used which allow very large volumes to be treated (at least 50 ml).
- plasminogen 100 ⁇ g were coupled to 1 ml of magnetic beads (Dynal M-280) according to the method described by the manufacturer.
- the beads coupled to plasminogen are washed and then incubated with 500 ⁇ l of BAR224 tracer in 1% EIA / Tween 20 buffer (at 5 EU / ml) for 2 hours at room temperature under agitation. The beads are then washed twice with 1% EIA / Tween 20 buffer and once with PBS, before adding 600 ⁇ l of EUman reagent. After 30 minutes of reaction, 200 ⁇ l of reaction medium are removed and the absorbance at 412 nm is measured.
- the denatured PrP eluted from the plasminogen is taken up with 300 ⁇ l of EIA buffer and measured using a BAR224 / SAF34 “sandwich” assay.
- SAFs are prepared from 500 ⁇ l homogenate at 20% of healthy sheep brain or scrapie (diluted or not in a homogenate of healthy sheep brain 1/10, 1/50 and 1/100).
- the SAF pellets are taken up and denatured with 50 ⁇ l of denaturation buffer (buffer C, as defined in PCT international application WO 99/41280) for 10 minutes at 100 ° C.
- the amount of PrP is then measured with the BIO-RAD Platelia TM BSE detection kit (ref. 51103) (immunoenzymatic kit for the in vitro detection of PrP res after purification according to the method described in PCT International Application WO 99 / 41280).
- the 500 ⁇ l of homogenate (the same as above) are diluted 10 times in EIA buffer comprising 0.5M NaCl and 1% sarkosyl, then incubated with 30 ⁇ l of beads containing the plasminogen immobilized for 3 hours at room temperature. After washing, gentle denaturation is carried out by treatment with a guanidine / HCl solution for 10 minutes at 100 ° C. After 3 washes with 1% EIA / Tween 20 buffer and washing with PBS, the beads are incubated with the BAR224 tracer in EIA buffer for 2 hours at room temperature. The beads are again washed 3 times with 1% EIA / Tween 20 buffer and once with PBS before adding the development solution (Ellman reagent).
- FIG. 5 shows that the plasminogen technique appears at least as sensitive as the test according to International PCT Application WO 99/41280.
- the use of magnetic beads makes it possible to work with a larger volume and to compensate for the drawback linked to the need to dilute the homogenate before capture by plasminogen.
- EXAMPLE 6 Effect of the dilution of a homogenate of sheep brain affected with scrapie on the detection of PrP res by direct assay on plasminogen coupled to the magnetic beads. Demonstration of the method's ability to concentrate PrP res diluted in a large volume of sample.
- 500 ⁇ l of a homogenate of sheep brain suffering from scrapie are diluted in 5, 10, 20 and 50 ml of EIA buffer pH 7.4 comprising 0.5 M NaCl and 1% sarkosyl, then incubated with 30 ⁇ l of balls coupled to plasminogen for 4 hours at room temperature. Then we proceed as described above.
- FIG. 6 shows the capacity of the method according to the invention to concentrate the diluted PrP res .
- EXAMPLE 7 Application of the invention to the detection of PrP res in homogenates of mouse, cow and human brains affected by ESST.
- Homogenates at 20% (w / v) obtained from a mouse brain (infected with a scrapie strain), a bovine brain (infected with BSE) or a human brain ( infected with Creutzfeldt-Jakob disease) were diluted to a concentration of 1% (w / v) in the capture buffer (EIA buffer comprising 0.5 M NaCl and 1% sarkosyl (v / v ) final). These homogenates were then brought into contact with magnetic beads containing immobilized plasminogen and analyzed under the conditions described in Example 4.
- EIA buffer comprising 0.5 M NaCl and 1% sarkosyl (v / v ) final
- a negative or positive control homogenate of the brain (50 ml or less in a negative homogenate + 50 ⁇ l of SK10%) is added to 850 ⁇ l of 0.5 M EIA / NaCl buffer + 50 ⁇ l.
- SK10% 10 ⁇ l of magnetic beads coupled to plasminogen; incubated for 2 h 30 min at room temperature under rotation; the beads are then washed, 3 times with EIA buffer comprising 1% of Tween 20, then once with PBS.
- the denaturation is carried out in the presence of 50 ⁇ l of guanidine thiocyanate (Gn / SCN) 4 M at 100 ° C for 8 min.
- the beads are washed in PBS and then incubated with 500 ⁇ l of tracer antibody 2 h at room temperature, with shaking (at 5 EU / ml). The beads are then washed twice with EIA Tween 20 1% buffer and once with PBS, before adding 1 ml of Ellman reagent. After 20 min of reaction, 200 ⁇ l of reaction medium are removed and the absorbance at 412 nm is measured.
- FIG. 7 shows that the test described works with species other than sheep and can detect other strains of prions than the scrapie strains.
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Abstract
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Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2003263271A AU2003263271A1 (en) | 2002-07-09 | 2003-07-08 | Method capable of being automated for detection of prpless thanspgreater thanresless than/spgreater than and uses thereof |
JP2004520736A JP2005537463A (ja) | 2002-07-09 | 2003-07-08 | PrPresの検出のために自動化され得る方法およびその使用 |
US10/520,397 US20060188929A1 (en) | 2002-07-09 | 2003-07-08 | Method capable of being automated for detection of prpres and uses thereof |
EP03763936A EP1523681A2 (fr) | 2002-07-09 | 2003-07-08 | Methode de detection automatisable de la prpres et ses applications |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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FR0208608A FR2842303B1 (fr) | 2002-07-09 | 2002-07-09 | Methode de detection automatisable de la prpres et ses applications |
FR02/08608 | 2002-07-09 |
Publications (2)
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WO2004008144A2 true WO2004008144A2 (fr) | 2004-01-22 |
WO2004008144A3 WO2004008144A3 (fr) | 2004-04-08 |
Family
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Family Applications (1)
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PCT/FR2003/002117 WO2004008144A2 (fr) | 2002-07-09 | 2003-07-08 | METHODE DE DETECTION AUTOMATISABLE DE LA PrPres ET SES APPLICATIONS |
Country Status (6)
Country | Link |
---|---|
US (1) | US20060188929A1 (fr) |
EP (1) | EP1523681A2 (fr) |
JP (1) | JP2005537463A (fr) |
AU (1) | AU2003263271A1 (fr) |
FR (1) | FR2842303B1 (fr) |
WO (1) | WO2004008144A2 (fr) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007531895A (ja) * | 2004-04-05 | 2007-11-08 | アイデックス ラボラトリーズ インコーポレイテッド | 伝染性海綿状脳症試験の試薬及び方法 |
CN103675115A (zh) * | 2012-12-24 | 2014-03-26 | 张文 | 海洋天然活性物质磁珠高内涵快速筛选方法 |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1596199A1 (fr) * | 2004-05-14 | 2005-11-16 | Prionics AG | Méthode de détection des formes pathogènes des protéines prions. |
ATE528649T1 (de) * | 2005-02-15 | 2011-10-15 | Adlyfe Inc | Verfahren zum nachweis falsch gefalteter proteine und prionen |
JP2010523977A (ja) * | 2007-04-04 | 2010-07-15 | ノバルティス アーゲー | プリオンアッセイ |
JP2014507649A (ja) * | 2011-01-18 | 2014-03-27 | バクスター・インターナショナル・インコーポレイテッド | ヒト血液中の抗βアミロイド抗体の測定 |
EP3420341B1 (fr) * | 2016-02-24 | 2020-11-18 | Bio-Rad Laboratories, Inc. | Procédés et systèmes de détection de fluorescence |
CN115728214A (zh) * | 2021-08-30 | 2023-03-03 | 深圳市帝迈生物技术有限公司 | 一种稀释液及应用该稀释液的网织血小板检测试剂 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2774988A1 (fr) * | 1998-02-16 | 1999-08-20 | Commissariat Energie Atomique | Procede de purification de la prpres a partir d'un echantillon biologique et ses applications |
WO2000029850A1 (fr) * | 1998-11-17 | 2000-05-25 | Wallac Oy | Immuno-essai de recherche d'encephalopathies spongiformes transmissibles chez les bovins |
WO2001023425A1 (fr) * | 1999-09-28 | 2001-04-05 | Universität Zürich | Facteurs ayant une activite de liaison au prion dans du serum ou du plasma et agents permettant de detecter l'encephalopathie spongiforme transmissible |
WO2001035104A1 (fr) * | 1999-11-12 | 2001-05-17 | Commissariat A L'energie Atomique | Procede de diagnostic d'une esst provoquee par une souche d'atnc dans un echantillon biologique |
-
2002
- 2002-07-09 FR FR0208608A patent/FR2842303B1/fr not_active Expired - Fee Related
-
2003
- 2003-07-08 WO PCT/FR2003/002117 patent/WO2004008144A2/fr not_active Application Discontinuation
- 2003-07-08 AU AU2003263271A patent/AU2003263271A1/en not_active Abandoned
- 2003-07-08 EP EP03763936A patent/EP1523681A2/fr not_active Withdrawn
- 2003-07-08 JP JP2004520736A patent/JP2005537463A/ja not_active Withdrawn
- 2003-07-08 US US10/520,397 patent/US20060188929A1/en not_active Abandoned
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2774988A1 (fr) * | 1998-02-16 | 1999-08-20 | Commissariat Energie Atomique | Procede de purification de la prpres a partir d'un echantillon biologique et ses applications |
WO2000029850A1 (fr) * | 1998-11-17 | 2000-05-25 | Wallac Oy | Immuno-essai de recherche d'encephalopathies spongiformes transmissibles chez les bovins |
WO2001023425A1 (fr) * | 1999-09-28 | 2001-04-05 | Universität Zürich | Facteurs ayant une activite de liaison au prion dans du serum ou du plasma et agents permettant de detecter l'encephalopathie spongiforme transmissible |
WO2001035104A1 (fr) * | 1999-11-12 | 2001-05-17 | Commissariat A L'energie Atomique | Procede de diagnostic d'une esst provoquee par une souche d'atnc dans un echantillon biologique |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007531895A (ja) * | 2004-04-05 | 2007-11-08 | アイデックス ラボラトリーズ インコーポレイテッド | 伝染性海綿状脳症試験の試薬及び方法 |
JP4934021B2 (ja) * | 2004-04-05 | 2012-05-16 | アイデックス ラボラトリーズ インコーポレイテッド | 伝染性海綿状脳症試験の試薬及び方法 |
CN103675115A (zh) * | 2012-12-24 | 2014-03-26 | 张文 | 海洋天然活性物质磁珠高内涵快速筛选方法 |
CN103675115B (zh) * | 2012-12-24 | 2016-04-20 | 张文 | 海洋天然活性物质磁珠高内涵快速筛选方法 |
Also Published As
Publication number | Publication date |
---|---|
FR2842303B1 (fr) | 2004-09-24 |
FR2842303A1 (fr) | 2004-01-16 |
WO2004008144A3 (fr) | 2004-04-08 |
AU2003263271A8 (en) | 2004-02-02 |
AU2003263271A1 (en) | 2004-02-02 |
US20060188929A1 (en) | 2006-08-24 |
EP1523681A2 (fr) | 2005-04-20 |
JP2005537463A (ja) | 2005-12-08 |
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