WO2003005032A2 - Procede de criblage de molecules aptes a se lier a la proteine gp120 du virus de l'immunodeficience - Google Patents
Procede de criblage de molecules aptes a se lier a la proteine gp120 du virus de l'immunodeficience Download PDFInfo
- Publication number
- WO2003005032A2 WO2003005032A2 PCT/FR2002/002349 FR0202349W WO03005032A2 WO 2003005032 A2 WO2003005032 A2 WO 2003005032A2 FR 0202349 W FR0202349 W FR 0202349W WO 03005032 A2 WO03005032 A2 WO 03005032A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- gpl20
- peptide
- sequence
- protein
- present
- Prior art date
Links
Classifications
-
- 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
- G01N33/569—Immunoassay; Biospecific binding assay; Materials therefor for microorganisms, e.g. protozoa, bacteria, viruses
- G01N33/56983—Viruses
- G01N33/56988—HIV or HTLV
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2500/00—Screening for compounds of potential therapeutic value
- G01N2500/02—Screening involving studying the effect of compounds C on the interaction between interacting molecules A and B (e.g. A = enzyme and B = substrate for A, or A = receptor and B = ligand for the receptor)
Definitions
- the present invention relates to a method for screening for molecules capable of binding to the gpl20 protein of the immunodeficiency virus or to its analogues. It uses a fluorescence anisotropy technique and a particular family of peptides with high affinity and specificity for the viral protein gpl20.
- immunodeficiency viruses comprising a gpl20 viral envelope protein or a protein analogous thereto.
- HAV human immunodeficiency virus
- VIS simian immunodeficiency virus
- VISNA ovine immunodeficiency virus
- VIB bovine immunodeficiency virus
- VF Feline Immunodeficiency Virus
- Some of the peptides of the present invention are capable of binding to the viral protein gpl20 or its analogs, of inhibiting the binding of the viral protein gpl20 to the CD4 receptor, with IC 50 values between 0.1 and 400 nM in according to their sequence. Some of these molecules are capable of inhibiting the infection of T lymphocytes by the AIDS virus with, for example, an ED 50 (Effective Dose 50%) of 100 to 900 nM. In addition, the binding of these molecules to the recombinant viral protein gpl20 induces a variation conformity in it which unmasks new epitopes, with the same efficiency as the soluble CD4 molecule.
- the screening method of the present invention is a powerful research tool for selecting new molecules useful for the manufacture of new anti-AIDS drugs.
- HIV human immunodeficiency virus
- the structural elements of CD4 critical for its binding to the viral glycoprotein gpl20 include the amino acids Gly38, Gln40, Gly41, Ser42, Phe43, Thr45, which are included in region 36-47, and CD4 arginine-59.
- the CD4 region 36-47 has been assimilated to the CDR2 region of the immunoglobulins and has a pin-like structure hair.
- This structure is formed by a ⁇ (C) strand, corresponding to the sequence 36-40, followed by an elbow corresponding to the 40-43 sequence which allows a second ⁇ (C ") strand, corresponding to the sequence 43 -47, to form with the first an antiparallel ⁇ structure.
- This structure is stabilized by hydrogen bonds between the amide nitrogen of the residues
- This hairpin structure plays a central role in the interaction of CD4 with the viral protein gpl20 and performs a dual function: first, it allows the amino acids Gly38, Gln40, Gly41, Ser42, Phe43 and Thr45 to form a molecular surface complementary to the interaction surface of the viral protein gpl20 and, in particular, allows the side chain of Phe43 to be inserted at the entry of a hydrophobic cavity into the molecular surface of the viral protein gpl20; secondly, it allows a ⁇ -sheet type interaction between the polypeptide skeletons of the ⁇ C "strand of CD4 and the ⁇ 15 strand
- Arginine 59 also plays a critical role in the CD4-gpl20 interaction, since the guanidinium group of its side chain forms a double hydrogen bridge with the side chain of the Asp368 residue of the viral protein gpl20, allowing the stabilization of the interaction of the ⁇ structure type between the C "strands of CD4 and ⁇ 15 of the viral protein gpl20. Site-directed mutagenesis experiments have demonstrated that all of these CD4 residues play a critical role in the interaction with the viral protein gpl20 [2], [3].
- CD4 interacts with a broad depression of the molecular surface (800 A 2 ) of the viral protein gpl20, using a large molecular surface (742 A 2 ), which is centered around the region which has been assimilated to the CDR2 region of immunoglobulins.
- a narrow and deep cavity opens, the "Phe43 cavity", in which the side chain of Phe43, at the top of the CDR2 region of CD4, occupies the entrance.
- the resolution of this structure confirms the previous mutagenesis data, which indicate the residue Phe43 and the entire CDR2 loop as functionally very important, and proposes the latter as a possible target for the inhibition of the attachment of HIV-1 virions to cells.
- the gpl20-CD4 interaction allows the virus to bind to the membrane of target cells and represents the first protein-protein interaction in the mechanism of infection.
- other co-receptors are necessary for efficient entry of the AIDS virus into cells. These are CXCR-4 [5], [6], which is involved in the entry of lymphotropic viral strains (X4) and CCR-5 [7], [8], which is involved in the entry M-tropic strains (R5) and most primary isolates.
- the crystallographic structure of the viral protein gpl20 complexed with CD4 has made it possible to elucidate one of the mechanisms used by the AIDS virus to escape the immune response.
- the gpl20 envelope protein had hypervariable and highly glycosylated regions.
- the crystallographic structure has in fact demonstrated that the hypervariable regions and the highly glycosylated regions form the exposed molecular surface of the viral protein gpl20, which also corresponds to the accessible surface of the virions. Only a few regions of the molecular surface of the viral protein gpl20 are conserved and can be the target of antibodies. These regions are not normally accessible and are probably protected by hypervariable loops
- V1-V2-V3 which in the crystallized protein have been deleted, and are therefore invisible.
- One of these regions is a surface close to the interaction site for the chemokine receptors, and accessible to CD4i antibodies, after binding of the envelope to CD4.
- the CD4 binding site is another exposed and conserved surface: however, this surface is present in a cavity of the viral protein gpl20 and is therefore not accessible to antibodies, but can accommodate CD4 which has a single domain- d immunoglobulin unlike antibodies that use two domains for molecular recognition.
- Peptide constructs derived from CD4 have been proposed as inhibitors of viral infection: it is a structural mimic peptide of the CDR2 loop of CD4 which incorporates a phenyl group mimicking Phe43 [14] and a cyclic peptide corresponding to the CDR3 loop of CD4 and incorporating additional aromatic residues [15].
- these constructions have a weak antiviral activity limited to a laboratory isolate and, even if they were initially designed as CD4 structural mimetics, they are not active in the entry stage [16].
- a bis-azo dye FP21399 [18] identified by a combinatorial approach, phosphorothioate oligonucleotide zintevir (AR177) [19], a polymer based on naphthalene sulfonate, PRO2000 [20] and d a starch derivative, dextrin 2-sulfate (D2S) [21], which inhibit HIV-1 chemical isolates in cell cultures, but require high concentrations.
- entry inhibitors there is also SPC3 [22], a multi-branched synthetic peptide construct, which, originally proposed as an inhibitor of the CD4-gpl20 interaction, is then shown to be active in a next step attachment of virions to cells.
- Other small molecules have been proposed as entry inhibitors: bicycla AMD3100 [23], NSC651016 [24],
- T140 [26] and TAK779 [27].
- These molecules are viral entry inhibitors, active on the CXCR4 and CCR5 entry co-receptors, but have no activity in the CD4-gpl20 interaction.
- Peptides derived from the sequence of the C-terminal region of the gp41 glycoprotein, the peptide T20 (or DP178) [28] and its most recent improved version DT1249 [29] are other inhibitors of infection which target a transient phase of entry, after the attachment of the viral envelope to CD4 and before the fusion of virus cell membranes: these peptides are inactive in the gpl20-CD4 interaction.
- Most of these products are currently in phase I / II clinical trials, but their therapeutic efficacy • remains to be verified.
- the anti-AIDS therapeutic regime currently used in clinics, tritherapy includes a combination of three inhibitors that target two viral enzymes, reverse transcriptase and protease. Even if triple therapy has succeeded in significantly reducing the viral load of many patients, it is not capable even in the most favorable cases of eradicating the disease, because dormant reservoirs of infection still persist [30].
- the partial success of tritherapy on the one hand and the impossibility of stopping AIDS infection with current therapeutic protocols on the other hand have increased the demand for new drugs which can be active at the level of other viral targets and increase the repertoire and efficacy of current clinical drugs.
- the libraries of molecules currently available and potentially active in inhibiting entry and infection by the AIDS virus are enormous.
- the object of the present invention is precisely to provide a method for screening for molecules capable of binding with a determined affinity to the gpl20 protein of the AIDS virus, in particular of human immunodeficiency (HIV).
- HIV human immunodeficiency
- the screening method of the present invention includes at least one screening cycle comprising the following steps: a) covalent labeling with a fluorescent probe of a peptide having said determined affinity for the gpl20 protein, said peptide comprising the sequence (A) defined below, b) bringing the labeled peptide into contact with the gpl20 protein, at a concentration of gpl20 which allows between 20 and 50% of binding of the labeled peptide, so as to form a reversible complex [labeled peptide-gpl20], c ) standard measurement of the fluorescence polarization of the complex [labeled peptide-gpl20], d) screening test by placing in competition the complex [labeled peptide-gpl20] formed with at least one candidate molecule capable of binding to the protein gpl20 to a determined concentration of said molecule (s) and under physicochemical conditions making it possible for competition between said molecule and the labeled peptide to form e possibly
- the molecules sought by means of the screening method of the present invention are therefore those which compete with the peptide of the present invention.
- the method of the present invention is characterized in particular in that it uses a family of particular peptides which mimic CD4 and overcome the aforementioned drawbacks of the prior art. Indeed, it uses a stable peptide, having a very strong affinity for the envelope of the AIDS virus, in particular for the protein gpl20.
- the peptide of the present invention is characterized in that it comprises the following sequence (A):
- the peptide of the present, invention is characterized in that it comprises the Sequence (I):
- Xaa j Cys - Thr or Ala -Cys - Xaa k ⁇ -NH 2 , 25 in which TPA represents thiopropionic acid, Xaa a , Xaa b , Xaa c , Xaa, Xaa e , Xaa f , Xaa 9 , Xaa h , and Xaa 1 , are amino acids, natural or unnatural, identical or different, Xaa? represents Nal, Phe or Bip, and Xaa k represents Gly, Val or Ile.
- Asp represents the optical isomer D of aspartic acid
- Nal represents ⁇ -naphthylalanine
- Bip represents bi-phenylalanine.
- (I) comprising a thiopropionic acid at the position 1 of the sequence, a Phe, Nal, or Bip residue in position 23 of the sequence (Xaa j ), and a Gly, Val or Ile residue in position 27 of the sequence (Xaa) has a high affinity and a high specificity for binding for the gpl20 protein of the viral envelope of the immunodeficiency virus.
- This peptide has only 27 or 28 residues, and has a hairpin structure consisting of two antiparallel ⁇ strands connected by a ⁇ elbow of four residues.
- the two antiparallel strands being at a distance which can give interactions with intramolecular hydrogen bridges, stabilize the structure.
- the distance between the amide nitrogen and carbonyl oxygen atoms of the peptide bond is from 2.5 to 3.6 A. This well defined and stable structure reproduces structural elements of CD4 critical for its binding to the gpl20 glycoprotein.
- the side chain of Xaa J 23 points to the hairpin pattern in a conformation similar to that of the Phe 43 of CD4 to be inserted at the entrance of a hydrophobic cavity of the viral protein gpl20, thus strengthening the link with gpl20.
- Arg and Lys at positions 9 and 18 are topologically equivalent to the Arg59 and Lys35 residues of the CD4 protein.
- the hairpin structural motif has a surface accessible to the solvent and / or to a larger molecule such as a protein, which can favor its interaction with the protein of the viral envelope.
- the amino acid side chains of the surface accessible to the solvent of this motif are close in space and form a continuous molecular surface which reproduces the structure of several residues important for the CD4-gpl20 bond.
- the structural platform which contains the hairpin structural motif also contains other structural regions capable of accommodating additional chemical functionalities in a well-defined spatial position relative to the structural hairpin motif, which can thus reinforce its biological function. and / or present labeling groups.
- a biotin group or a fluorescein group has been incorporated at the side chain of lysine 11, without causing loss of the biological activity of the derivative.
- the incorporation of these groups allowed the use of these derivatives in tests for interaction with the envelope protein, as described below.
- the sequence (A), for example the sequence, (I) can also comprise a proline residue linked to the residue Xaa k .
- a proline residue added in position 28 stabilizes the C-terminal end and makes the ⁇ C-terminal strand of the hairpin structural motif less flexible.
- Xaa 1 in the sequence (I), can be Gly.
- the peptide of the present invention can comprise a sequence chosen from the sequences ID no. 4, ID no. 5, ID no. 6, ID no. 7, ID no. 8, ID no. 9, ID no. 10, ID # ll, ID # 12, ID # 13, ID # 14, ID # 15, ID # 16, ID # 17, ID # 18, ID # 19 and ID # 20 of the attached sequence list.
- the peptide of the present invention can be obtained by chemical synthesis in solid phase or by genetic recombination.
- the chemical synthesis can be carried out for example with an automatic peptide synthesizer of the Applied Biosystems type, mod.433A (trademark). It can be carried out, for example, in Fmoc chemistry which uses the fluoromethyloxycarbonyl group for the temporary protection of the ⁇ -amino function of amino acids.
- the peptide of the invention can also be manufactured by means of a method comprising the following steps: a) integration of a nucleic acid sequence into an expression vector, said nucleic acid sequence coding for the peptide of the present invention, b) introduction of the expression vector comprising said nucleic acid sequence into a host cell, c) culture of the host cell comprising said nucleic acid under culture conditions allowing the synthesis of said peptide, d) recovery of the peptide synthesized, and e) grafting the TPA in the N-terminal position.
- the grafting of a TPA in the C-terminal position of the peptide can be carried out by means of a conventional organic chemistry method applicable to a peptide.
- the inventors have synthesized a family of peptides reproducing part of the structure of the CD4 region resembling the CDR2 region of immunoglobulins, which, as demonstrated by mutagenesis and crystallographic analysis results, are among the critical regions of the CD4 binding to the viral protein gpl20.
- the peptides of the present invention are capable of binding to the region of the gpl20 glycoprotein which interacts with CD4, the main receptor for the entry of the AIDS virus, in particular HIV-1, into CD4 target cells.
- These peptides constitute a family of inhibitors whose affinity for the viral glycoprotein gpl20 monomeric recombinant, varies between IC 50 values ranging from 0.1 nM to 400 nM. They are specific and potent inhibitors of the CD4-gpl20 interaction based on the structure of CD4.
- the binding with the recombinant viral protein gpl20 is in competition with the soluble CD4 and is specific for the well-structured form
- they can be labeled, for example with a fluorescent probe, without the protein binding affinity of the gpl20 viral envelope being altered.
- peptides can therefore be used as tracers in the screening method using a fluorescence anisotropy technique according to the present invention.
- This method uses the fluorescence polarization of said peptide covalently labeled by a fluorescent probe.
- the peptide used is that which has an affinity in the range of that of the molecules sought. For example, if one seeks to screen for molecules having an affinity greater than or equal to 10 s M "1 , one will use a labeled peptide having an affinity of 10 6 M " 1 . Also, for example, if one seeks to screen for molecules having a higher affinity, for example 10 9 M ⁇ 1, a peptide exhibiting a similar affinity will be used.
- the screening method of the present invention can be granted according to the desired affinity by choosing the peptide used.
- the affinity for the viral protein Gpl20 of the molecules detected by the screening method of the present invention can be determined from that of the peptide according to the invention chosen for the screening.
- the fluorescent probe should preferably have a high quantum yield and fluorescence in the visible for a high detection sensitivity.
- Other fluorescent probes exhibiting the properties specified above can of course be used.
- the fluorescence polarization is calculated from two measurements, the emission intensity of the fluorescence polarized in parallel and perpendicular, with an excitation in parallel.
- parallel polarization is defined in the z direction of the laboratory axis.
- Ao / A-1 ⁇ / ⁇ c (4), in which Ao is the limit anisotropy of the fluorophore, a physical constant determined by the angle between the absorption and emission dipoles, ⁇ is the lifetime fluorescence, and ⁇ c is the rotational correlation time.
- V h the hydrated volume of the molecule or molecular complex according to the relation (5):
- ⁇ c ⁇ V h / RT (5), in which ⁇ is the viscosity of the solution, R is the constant of gas and T, the temperature in Kelvin.
- any molecule capable of inhibiting the interaction between a peptide of the present invention and a viral protein gpl20 can represent an inhibitor of the CD4-gpl20 interaction, and therefore an inhibitor of the viral infection. It is therefore possible, thanks to the peptides of the present invention to screen in a library of molecules any molecule capable of interacting with the protein gpl20 or a protein analogous to gpl20, in particular molecules with antiviral activity or molecules useful for the manufacture. of medicine.
- the screening method of the present invention operates by competition.
- the peptide of the present invention, chosen and labeled, is brought into the presence of gpl20 at a concentration which allows between 20 and 50% of fixation.
- the amount of gpl20 should not be saturated, otherwise, a large amount of molecules to be screened should be used to allow competition.
- the complex [labeled peptide-gpl20] formed must be reversible to allow competition.
- concentration of the candidate molecules in the screening assays of the process of the present invention are determined in the same way as in the conventional tests of competition of molecules for a receptor used in molecular biology.
- concentration of the candidate molecule (s) is preferably 10 to 100 times higher at the concentration of the labeled peptide of the present invention.
- the method of the present invention is a method which is both rapid, in particular because it uses the fluorescence anisotropy techniques, and precise because it uses the peptides of the present invention. In addition, it requires very small quantities of reagents as shown in the examples below, which reduces the costs incurred in the search for molecules capable of being used for the manufacture of drugs intended for the treatment of AIDS compared to the methods of prior art.
- the screening method of the present invention is quite suitable for screening libraries of molecules currently available and potentially active in inhibiting the entry and infection of the AIDS virus. It therefore constitutes a rapid and efficient search tool for molecules that are effectively active in order to inhibit the gpl20-CD4 interaction necessary for effective infection by the AIDS virus.
- a single candidate molecule is tested in a screening cycle.
- the candidate molecule tested will be considered as a molecule capable of binding to the viral protein Gpl20.
- the fluorescence polarization measurement of step e) is unchanged compared to the standard measurement of step c)
- the candidate molecule tested will not be considered to be able to bind to the viral protein Gpl20.
- the cycles will have to follow each other as many times as there are different candidate molecules to be tested, at the rate of one molecule per cycle.
- a sample comprising several different candidate molecules can be tested in a single screening cycle.
- the fluorescence polarization measurement of step e) is less than the standard measurement of step c)
- the sample will be considered as comprising at least one molecule capable of binding to the viral protein gpl20.
- the fluorescence polarization measurement of step e) is unchanged compared to the standard measurement of step c)
- the sample will not be considered as comprising at least one molecule capable of binding to the viral protein Gpl20 .
- a single cycle makes it possible to test a sample comprising several different candidate molecules. If for one of the samples the fluorescence polarization measurement of step e) is less than the standard measurement of step c), then at least one of the candidate molecules of said sample will be considered as capable of binding to the viral protein gpl20.
- the screening can then be refined on the molecules of said sample according to the first embodiment of the present invention to identify the molecule or molecules of the sample capable of binding to the viral protein Gpl20.
- This second mode of embodiment of the present invention allows very rapid screening of candidate molecules.
- first and second embodiments of the present invention can be carried out on known candidate molecules currently available and potentially active in inhibiting entry and infection by the AIDS virus.
- the method of the present invention can be applied to unpurified biological liquids such as urine, cell extracts, bacteria, etc.
- this extract can be analyzed by the traditional methods of analysis in chemistry to identify the molecules which it contains.
- a more precise screening can then be carried out to highlight, among all the molecules identified in the extract, the molecule (s) capable (s) of binding to the viral protein Gpl20.
- the process of the present invention therefore constitutes a powerful screening tool, rapid, reproducible, sensitive and tunable to a wide range of affinity. It is practiced in solution and does not require separating the complexes from the free molecules.
- the screening method of the present invention has many advantages that those skilled in the art can readily identify.
- Another advantage is that the labeling of the peptide of the present invention can be carried out with different compounds such as Rhodamine green, fluorescein, etc.
- compounds such as fluorophores which absorption and emission properties in the visible can be particularly advantageous for the detection of molecules in non-purified extracts such as urine, cellular extracts, bacteria, etc.
- this method makes it possible to use little viral protein gpl20, since it can take place in the presence of a concentration of unsaturated gpl20, or even preferably at a concentration which allows 20 to 50% of binding.
- the method of the present invention using the peptides and the anisotropy measurements defined above makes it possible to carry out measurements entirely in solution.
- the method of the present invention can be adapted to very small volumes of a few microliters, and thus measures microwells. It also allows very quick measurements, one or two minutes for competitions.
- Another advantage of the process of the present invention lies in the reproducibility of the results.
- the anisotropy value for a labeled peptide of the present invention for example under the conditions defined in the examples below, is always the same.
- Another advantage of the process of the present invention lies in the fact that the temperature and solution conditions can easily be modified and controlled.
- Yet another advantage lies in the fact that the signal / noise ratio being very high, the method of the present invention makes it possible to detect very low rates of fixation.
- sequence ID no.1 sequence sCD4.
- sequence ID No. 2 sequence of scyllatoxin (ScTx).
- CD4M9 sequence peptide derived from scyllatoxin, not having TPA in position 1 of the sequence.
- sequences ID n ° 4-16 and 19 and 20 sequences named CD4M9T, CD4M26, CD4M27, CD4M27A, CD4M27B, CD4M27C, CD4M30, CD4M31, CD4M32, CD4M33, CD4M35, K15, K16 and CD4M9BIP and CD4M9V respectively of the present invention.
- sequence ID No. 17 sequence named CD4M3 derived from scyllatoxin not having TPA in position 1 of the sequence.
- sequence ID No. 18 sequence called CD4MO derived from charybdotoxin.
- Figure 1 Curves of inhibition of the binding of CD4 to the viral protein gpl20, by peptides of the present invention, obtained by competitive ELISA.
- the peptides tested are: CD4M9, CD4M9T, CD4M27, CD4M32, CD4M33 and CD4M35.
- the experimental data are reported as a percentage of binding (% F) as a function of the concentration of the peptides.
- Figure 2 Curve of inhibition of the binding of CD4 to the viral protein gpl20, by the peptide labeled CD4M33-fluorescein, CD4M33-F, obtained by competitive ELISA.
- the curves of the peptides CD4M9 (sequence ID n ° 3), CD4M33 (sequence ID n ° 13) and CD4M35 (sequence ID n ° 14) are also shown for comparison.
- the experimental data are reported as a percentage of binding (% F) as a function of the concentration of the peptides.
- Figure 3 Interaction curves of the recombinant viral protein gpl20-HXB2 with the peptide CD4M33 (sequence ID No. 13) attached to the surface of a chip of a surface plasmon resonance instrument, The association curves ( 0-300 s) and dissociation (300-800 s) were recorded after injection of the viral protein gpl20 at concentrations 13.2 (1), 19.8 (2), 29.6 (3), 44.4 (4), 66.6 ( 5) and 100 (6) nM. The data are reported in resonance units (RU) as a function of time (t) in seconds.
- RU resonance units
- the data are represented as a percentage inhibition (% I) of reverse transcriptase (TI) activity in the culture supernatants as a function of the nM concentration of the peptides.
- the association (0-180 s) and dissociation (180-400, 180-450 s) curves are reported for the viral protein gpl20 alone and the viral protein gpl20 in the presence of CD4M27 (1.5 equivalent, sequence ID n ° 6), CD4M9 (1.5 equivalent), the inactive mutant (Ala23) CD4M9 (1.5 equivalent) and soluble CD4 (1.5 equivalent).
- the data are reported in resonance units (RU) as a function of time (t) in seconds.
- FIG. 7 Examples of peptide sequences of the present invention shown with the letter codes of the amino acid residues.
- TPA and B represent thio-propionic acid and bi-phenylalanine respectively and "d" the optical form D of aspartic acid.
- FIGS. 8 a), b) and c) curves illustrating fluorescence anisotropy measurements (An), expressed in millianisotropy (mA), of the peptide K16 of the present invention labeled with rhodamine green, in solution at a concentration of 2 nM, and placed in the presence of viral protein gpl20 of strain HXB2 at different concentrations [GP120] nanomolar (nM).
- FIGS. 9 and 10 curves illustrating fluorescence anisotropy measurements (An), expressed as millianisotropy (mA), respectively of the peptides CD4M33 and K15 of the present invention labeled with rhodamine green, in solution at a concentration of 2 nM, and placed in the presence of viral protein gpl20 of strain HXB2 at different concentrations [GP120] nanomolar (nM).
- FIG. 9 curves illustrating fluorescence anisotropy measurements (An), expressed as millianisotropy (mA), respectively of the peptides CD4M33 and K15 of the present invention labeled with rhodamine green, in solution at a concentration of 2 nM, and placed in the presence of viral protein gpl20 of strain HXB2 at different concentrations [GP120] nanomolar (nM).
- FIGS. 12a) and 12b) curves illustrating fluorescence anisotropy measurements (An), expressed in millianisotropy (mA), of the peptide CD4M33 of the present invention labeled with rhodamine green, in solution at a concentration of 6 nM, and put in the presence of viral protein gpl20 respectively of strains HXB2 and SF2 at different concentrations [HXB2] and [SF2] nanomolar (nM).
- Figure 13 Theoretical curves illustrating theoretical values of fluorescence anisotropy (An), expressed in millianisotropy (mA), of a competition between a labeled CD4M33 peptide and an unlabeled CD4M33 peptide, as a function of the nanomolar concentration
- Kd 14nM of CD4M33 determined by direct titration.
- the peptides of the present invention were produced in this example by solid phase chemical synthesis with an automatic peptide synthesizer Applied Biosystems, mod. 433A, and in chemistry Fmoc, which uses the group Fluorenylmethyloxycarbonyle (Fmoc) for the temporary protection of the ⁇ -amino function of amino acids.
- the protective groups used to prevent side reactions of the amino acid side chains, in this Fmoc strategy, were tert-butyl ether (tBu) for the residues Ser, Thr and Tyr; tert-butyl ester (OtBu) for Asp, Glu; trityl (Trt) for Gin, Asn, Cys, His; tert-butyloxycarbonyl (Boc) for Lys and 2, 2, 5, 7, 8-pentametylchromane-6-sulfonyl (Pmc) for Arg.
- tBu tert-butyl ether
- OtBu tert-butyl ester
- Trt trityl
- Pmc tert-butyloxycarbonyl
- the coupling reaction takes place with an excess of 10 equivalents of amino acids (1 mmol) relative to the resin (0.1 mmol).
- the protected amino acid is dissolved in 1 ml of N-methylpyrollidone (NMP) and 1 ml of a 1M solution of 1N-hydroxy-7-azabenzotriazole (HOAt) in NMP solvent.
- 1 ml of a 1M solution of N, N '-dicyclohexylcarbodiimide (DCC) is then added.
- the active ester formed is transferred to the reactor which contains resin.
- the resin is deprotected from its Fmoc group by a solution of 20% piperidine in NMP. The excess piperidine is removed by washing with NMP after approximately 5 to 10 minutes.
- the detection of the dibenzofulven-piperidine adducts at 305 nm makes it possible to follow the good progress of the synthesis. Indeed, the quantification of the adduct makes it possible to estimate the efficiency of the deprotection of the Fmoc group and as a result of the coupling of the last incorporated amino acid.
- a fluorescent probe and a biotin group were coupled to two of the peptides studied of the present invention, CD4M9T (sequence ID no. 4) and CD4M33 (sequence ID no. 13). The incorporation into these two compounds was carried out on the lysine 11 residue, at a face opposite the binding site of the viral protein gpl20.
- This choice of a lysine was conditioned by its possibilities of protecting its side chain with a protective group, said to be orthogonal, such as the group of (1- (4, 4-dimethyl-2, 6-dioxo-cyclohexylidene) ethyl) (or Dde group).
- a protective group said to be orthogonal, such as the group of (1- (4, 4-dimethyl-2, 6-dioxo-cyclohexylidene) ethyl) (or Dde group).
- a protective group such as the group of (1- (4, 4-dimethyl-2, 6-dioxo-cyclohexylidene) ethyl) (or Dde group).
- a protective group such as the group of (1- (4, 4-dimethyl-2, 6-dioxo-cyclohexylidene) ethyl) (or Dde group).
- the fluorescent group was introduced on the side chain of lysine 11 of the peptide of the present invention CD4M33 and of lysine 15 or 16 of peptides K15 (sequence ID no. 15) or K16 (sequence sequence no. 16), respectively, of the present invention.
- the Dde group was therefore used for the protection of the lysine side chain during the synthesis of the peptide, and then released by two treatments of 5 min with 2% hydrazine in dimethylformamide (DMF).
- the fluorescein molecule was coupled directly to the synthesized peptide. The coupling of the probe was carried out using the fluorescein- (5- (6) -N-hydroxysuccinimidylcarboxylate ester.
- the CD4M9 peptide is synthesized according to the procedure described above with Lysine in position 11 having, as a protective group for the side chain, a Dde group. After synthesis of the peptide, the peptide-resin is treated 5 times with a solution of 2% hydrazine in DMF. The coupling of a link arm is carried out for one hour at room temperature in DMF with 10 equivalents of Fmoc-8-amino-3, 6-dioxaoctanoic using the reagent HBTU in the presence of diisopropylethylamine. The Fmoc group is then deprotected with 20% piperidine in DMF.
- the peptide-resin is therefore treated with 10 equivalents of Traut's reagent (2-iminothiolane hydrochloride (Sigma) in the presence of DIEA.
- the peptide is finally released and deprotected as described below. FINAL DEPROTECTION OF THE RESIN.
- the cleavage of the resin and of the protective groups present on the side chains were carried out simultaneously by treatment of the peptide linked to the resin with trifluoroacetic acid (TFA).
- TFA trifluoroacetic acid
- the reagent used during the cleavage is an acid mixture containing 81.5% of TFA and the trappers phenol (5%), thioanisole (5%), water (5%), ethanedithiol (2.5%) and tri-isopropylsilane ( 1%).
- the resin was treated with this mixture for three hours with stirring and room temperature, at a rate of 100 ml of solution per gram of resin.
- the free peptide in solution was recovered by filtration.
- the peptide was then precipitated and washed cold in diisopropyl ether then dissolved in 20% acetic acid and lyophilized.
- the peptide recovered after lyophilization, the crude synthesis, is in reduced form, that is to say that the intrachain disulfide bridges are not formed.
- the formation of these covalent bonds was carried out using the redox cystamine / cysteamine pair.
- the crude synthesis was taken up in water added with 0.1% TFA (v / v) and guanidinium chloride 6M to facilitate its dissolution, at a rate of 2.0 g.ml "1. This solution then was added dropwise, diluted to 0.2 mg / ml ⁇ 1 , to the reduction buffer, composed of 100 mM Tris / HCl, pH 7.8, and 5 mM cysteamine.
- the 0.5 mM cystamine (oxidant) was finally added after 45 minutes of reaction at room temperature. The medium is brought to pH 3.0 after 30 minutes.
- Cysteamine makes it possible to reduce the thiol groups present on the peptide. In the open air, it oxidizes and allows the oxidation of cysteines and therefore the folding of the peptide by formation of intrachain disulfide bridges. The cystamine added at the end of handling makes it possible to perfect the folding. The good progress of the oxidation is verified by analytical chromatography by comparing the times of retention of raw and oxidized products, more important for the former.
- the reactional folding medium composed of a 20 mM phosphate buffer, 200 mM NaCl, adjusted to pH 7.8 is degassed for a long time with argon and then added with 5 mM of cysteamine, 5 mM cytamine.
- the peptide comprising seven free SH functions is then added and the oxidation reaction is stopped by adding acid after only 10 minutes, sufficient time for folding and the formation of the three natural disulfide bridges and short enough to limit the formation of product. secondary corresponding to higher oxidation states.
- the peptides of the present invention were purified by reverse phase high performance liquid chromatography on a Vydac C18 preparative column.
- the inhibition of the rgpl20-CD4 interaction was measured by indirect ELISA (Enzyme Linked ImmunoSorbent Assay). 50 ng per well of anti-gpl20 antibody, D7324, were immobilized on a 96-well plate (Maxisorb, Nunc) overnight at 4 ° C. After passivation with Bovine Serum Albumin and three washes with the washing buffer (10 mM Tris, pH 7.8, 0.05% Tween 20), 15 ng of rgpl20 HXB2 per well were added. Different concentrations of competitors were then added, after three washes, as well as 0.4 ng of soluble CD4 per well. 100% controls containing only soluble CD4 are carried out. After overnight at 4 ° C.
- the tests were conducted in duplicates and the results expressed as the average of experimental duplicates.
- the biological activities of the CD4MO peptide (sequence ID no. 18) derived from charybdotoxin and of the CD4M3 peptide (sequence sequence No. 17), derived from scyllatoxin (sequence sequence No. 2) were tested in the indirect ELISA test.
- FIG. 1 groups together the results obtained in this example with the peptides of the present invention.
- % F percentage of fixation
- C (M) molar concentration
- CD4M9 (sequence ID No. 3) was tested in ELISA by competition. It has the capacity to inhibit the soluble rgpl20 LA ⁇ -CD4 interaction with a 50% inhibition concentration (or IC 50 ) of 4.10 "7 M (Table I), ie an increase in the inhibition capacity by a factor of 50 compared to the peptide of the present invention CD4M3 (sequence ID No. 17).
- the peptide of the present invention CD4M9 in competitive ELISA test, is also capable of inhibiting the interaction of CD4 with other recombinant gpl20 proteins, originating from T- and M-tropic viruses: HIV-1n IB , HIV-IMH, HIV-1 Ba -L, HIV-1 JR . FL , HIV-1 W61D , with a 50% inhibition concentration (IC 50 ) between 0.1 and 1.0 x 10 "6 M [4].
- This peptide inhibits the interaction gpl20 ⁇ x soluble B2 -CD4 at an IC 50 of 9 x 10 "8 M ( Figure 1, Table I).
- a CD4M9V mutant comprising the substitution of the C-terminal Gly-Pro sequence of CD4M9 by Val, has an IC 5 o of 3.0 ⁇ 10 ⁇ 7 M in the inhibition of the gpl20 A i-CD4 interaction (Table 1) , which represents a slight increase in inhibitory capacity.
- the mutant CD4M9Bip has the substitution Phe23Bip compared to CD4M9; this peptide has an IC 50 of 1.0 ⁇ 10 ⁇ 7 M in the inhibition of the interaction g l20 LA i- CD4 (Table 1), which represents a further increase in inhibitory capacity.
- the mutant CD4M9T (sequence ID No.
- the peptide of the present invention CD4M27 (sequence ID No. 6) contains the Arg5Phe mutations (to remove a non-essential arginine and protect the disulfide bridge 6-24), Gly27Val and the deletion of the C-terminal proline residue (to better stabilize the ⁇ structure). It has an increase in the capacity to inhibit the CD4 - gpl20 ⁇ B2 CI 5 o binding by 7.10 "9 M, (FIG. 1, Table I).
- the peptides CD4M27 A, B and C are obtained respectively by a Gly21Ser mutation ( a), Ser22His (b) and Ser22Asn (c) from the CD4M27 peptide They have an inhibition capacity comparable to that of the CD4M27 peptide.
- the peptide of the present invention CD4M32 (sequence ID No. 12), compared to CD4M9T, comprises the deletion of the C-terminal proline residue, the Gly27Val mutation and the mutation of Phe23 to biphenylalanine (Bip): the Phe23Bip mutation adds an extension hydrophobic to the side chain of Phe23, to increase the interaction with the hydrophobic cavity of the viral protein gpl20.
- CD4M32 shows an increase in the inhibition of CD4-gpl20 ⁇ B2 binding (IC 50 of 8.10 "10 M, FIG. 1).
- the mutant CD4M30 (sequence ID No. 10), compared to CD4M32, contains the mutation Arg5Phe
- This peptide of the present invention has an IC 50 of 3.0 nM, in the tests for inhibition of the CD4-gpl20 LA i interaction.
- the mutant CD4M33 (sequence ID No. 13) groups together the mutations present in the two preceding peptides, in particular CyslTPA, Arg5Phe, Phe23Bip, Gly27Val, the deletion of a residue in the C-terminal position and in addition the Ala4His mutation (to increase the solubility of the molecule).
- Two other peptides K15 (sequence ID No. 15) and K16 (sequence ID No. 16) have been synthesized: they contain the substitutions Gln7Val, Leu8Gln, LysllHis, relative to the CD4M33 peptide of the present invention, and a Lys residue in position 15 or 16, respectively.
- a fluorescent fluorescein group was then covalently attached to the side chain of this lysine residue, according to the protocol described in Example 1.
- the fluorescent peptides K15 and K16 have an IC 50 of 5, 0.10 ⁇ 8 M and 6.0.10 "9 M in the inhibition of the interaction gpl20 LAI -CD4, whose affinity for the viral protein gpl20 is not modified by labeling.
- the present invention provides a family of peptides which represent potent inhibitors of the CD4-gpl20 interaction.
- Table 1
- IC 50 50% inhibition concentration (IC 50 ) of CD4 mimetic peptides in the interaction of soluble recombinant CD4 for the viral envelope protein gpl20 LAI and gpl20 ⁇ B2-
- IC 50 50% inhibition concentration of CD4 mimetic peptides in the interaction of soluble recombinant CD4 for the viral envelope protein gpl20 LAI and gpl20 ⁇ B2-
- the standard deviation for each value is less than 30%.
- Streptavidin was immobilized on the chip as follows: the surface of the chip was first activated by the injection of 50 ⁇ L of coupling agent provided by the manufacturer and which can form amide bonds: N-ethyl-N '- (dimethylaminopropyl) carbodiimide (EDC) / N-hydroxysuccinimide (NHS), 50/50; then 20 ⁇ L of streptavidin, 0.2 mg.mL "1 in 10 mM sodium acetate, pH 4.5, were injected at 5 ⁇ L.min " 1 , followed by neutralization of the carboxylic groups activated by 2 x 20 ⁇ L of 1.0 M ethanolamine, pH 8.5.
- coupling agent provided by the manufacturer and which can form amide bonds: N-ethyl-N '- (dimethylaminopropyl) carbodiimide (EDC) / N-hydroxysuccinimide (NHS), 50/50; then 20 ⁇ L of streptavidin, 0.2
- the biotinylated molecules were then injected (10 ⁇ L.min “1 in 10 mM Hepes buffer, 0.3 M NaCl, pH 7.4) on three of the four tracks of the chip.
- CD4M9 (10 "7 M) has been immobilized up to a value RU (resonance unit) 100; the second runway was left blank (witness); the third track was covered with soluble CD4 (10 "7 M) up to a value of 450 RU; on the fourth track, the CD4M33 (10 ⁇ 7 M) was immobilized at a value of 100 RU.
- CMSP peripheral blood mononuclear cells
- Medium A is composed of RPMI 1640 cell culture medium (Life Technologies) supplemented with 10% fetal calf serum (SVF, Roche Product) decomplemented by heat at + 56 ° C for 30 min, with 2 mM L- Glutamine (Roche Product), and a 100 ⁇ g / ml solution of three antibiotics (penicillin, streptomycin, neomycin; PSN, Life Technologies).
- Medium B consists of medium A supplemented with 20 IU / ml of recombinant human IL-2 (Roche Product). Isolation and activation of PBMCs
- the PBMCs are separated from the other figured elements of the blood by centrifugation in a ficoll gradient (MSL 2000, Eurobio): 30 ml of blood, from a healthy donor, diluted by a third are placed on a cushion of 20 ml of ficoll. After 20 min of centrifugation at 850 g, the ring of. CMSP is removed and then washed twice using RPMI 1640, after 10 min of centrifugation at 750 g and 5 min at 400 g. The PBMCs are then activated for 48 h with 1 ⁇ g / ml of phytohemagglutinin-P (PHA-P; Difco Laboratories).
- PHA-P phytohemagglutinin-P
- the CMSP are cultivated at + 37 ° C., in an atmosphere saturated with humidity, under 5% of CO 2. At the end of the 48 hours of mitogenic activation, they are cultured in medium B. Throughout the culture, the culture supernatants are removed, and the culture media are renewed all three. or four days. At each renewal of the culture media, the cell viability is evaluated by microscopic observation.
- the compounds of the present invention CD4M30, CD4M33 and CD4M35 were solubilized in sterile ppi water (Aguettant), aliquoted then stored at -20 ° C.
- the compound SAH-CD4 soluble CD4 coupled to human albumin serum supplied by Aventis (Vitry-sur-Seine) was stored at -80 ° C. until its use. The solutions and dilutions were then carried out extemporaneously in medium A.
- the PBMCs were pretreated with the compounds for 1 hour and then infected with the reference isol t with lymphocytic tropism HIV-I LM or with the clinical isolate HIV-1 LEN -
- the biological characteristics of this isolate are: rapid / high, scyncitia inducing (SI), X4: it is therefore preferably capable of infecting lymphocytes.
- the viral stock was constituted by amplifying this strain in vitro using mononuclear cord blood cells (CMSO) activated beforehand by 1 ⁇ g / ml PHA-P and cultured in medium B.
- CMSO mononuclear cord blood cells
- TCID 50 50% Tissue Culture Infectious Dose was calculated using Kârber's formula.
- Viral replication was measured, on day 7 of the culture, by assaying the reverse transcriptase activity in the culture supernatants using the RetroSys assay kit (registered trademark) according to the recommendations of the company Innovagen. Analysis of results and determination "of 50% effective doses
- the 50% effective doses (ED 50 ) are calculated using the "Dose-effects analysis ith microcomputers" software developed by J. Chou & TC Chou.
- the fragment encoding the viral protein gpl20 (amino acid V12 to R481) was amplified by PCR in the plasmid HIVIIIB / HXB2R, using two primers making it possible to generate a fragment containing the BamHI sites (upstream of the Kpnl site of the gpl20 viral protein) and PstI (downstream of the stop codon added to the end of the gpl20 viral protein sequence).
- the BamHI / PstI fragment thus obtained was cloned into the Bluescript vector (pBS, Stratagene), leading to the plasmid pBSml.
- the BamHI-PstI fragment from pBSm2 was then inserted between the BglII-PstI sites of the baculovirus P10 transfer vector pl19P.
- Sf9 insect cells were cotransfected with the purified viral DNA of the modified baculovirus AcSLP10 and the DNA of the recombinant vector pl19P gpl20. Recombinant viruses are purified by a standard method.
- the Sf9 scia cells (line adapted to growth without serum, deposited in the collection of the Institut Pasteur) are maintained in a spinner in a serum-free medium.
- These cells (5.10 5 cells / ml) are then infected with the recombinant viruses at a multiplicity of infection of 1 PFU (Beach-forming Unit) per cell and incubated at 28 ° C. After six days of infection, the cells are centrifuged (500 g), and the wild-type gpl20 viral protein is concentrated and directly purified from the culture supernatant by affinity chromatography on a column of Sepharose-bromacetyle coupled to the antibody anti-gpl20 D7324.
- PFU Beach-forming Unit
- sequence ID No. 13 was labeled with biotin and with the fluorescein fluorescent probe as described in example 1, at the level of Lys-11 positioned on the opposite surface of the active surface of the peptide of the present invention CD4M33. Its activity remains unchanged in ELISA tests ( Figure 2).
- Figure 2 combines the results obtained in this example. These are curves showing the evolution of the percentage of attachment (% F) of peptides of the present invention to the viral protein gpl20 ⁇ B2 as a function of the molar concentration of these peptides
- CD4M33 for the viral protein gpl20
- an analysis of biospecific interactions (described in example 3), based on detection by surface plasmon resonance, has been used.
- the CD4M33 peptide of the present biotinylated invention (prepared as in Example 1) was specifically fixed on the carboxylated dextran matrix of a chip which has been pre-grafted with streptavidin. Solutions of different gpl20 recombinant proteins
- FIG. 3 shows the evolution of the plasmon resonance signal as a function of time, after interaction of the gpl 0 ⁇ B2 protein (at different concentrations) with the CD4M33 peptide of the present invention.
- FIG. 4 shows that the presence of the CD4M33 peptide is essential for the interaction of the viral envelope with the 48d and CG10 antibodies, specific for the viral envelope, and that HIV-1 does not bind to the antibodies in its absence. : this is an indirect demonstration of the binding of the CD4M33 peptide to the HIV-1 viral envelope.
- the inventors carried out infection experiments, with the HIV-I LAI virus and with the chemical isolate HIV-1 LEK / of primary cultures of blood mononucleosis cells peripheral (CMSP) human. In all experiments, the effects of the new molecules were compared to those of AZT.
- the HIV-I LAI virus was added at different viral doses (10-100 TCID 50 , Table 2) in the presence of varying concentrations of CD4M30, CD4M33, CD4M35 and SAH-CD4.
- the HIV-1 LEN virus was added to TCID 50 (Table 4) in the presence of CD4M33.
- CD4 mimetic toxicity tests were also carried out on the same cells.
- the HIV-I A strain replicates at high level in PHA-P activated PBMCs. The peak of viral replication is on day 7 of the culture, and the effects of the peptides CD4M30, CD4M33 and CD4M35 were quantified at this post-infection time.
- C. ANTIRETROVIRAL ACTIVITY OF THE CD4M33 COMPOUND TOWARDS HIV-1 LEN CLINICAL ISOLATE cl. Effects of AZT on the replication of the HIV-ILEN isolate in PBMCs.
- AZT strongly inhibits the replication of the HIV-1 LEN strain in the PBPAs activated by PHA-P and infected with the HIV-1 LEN / isolate with an ED 50 equal to 2.2 nM (Table 4). The degree of inhibition is identical to that observed with respect to the reference strain with lymphocytic tropism HIV-ILAI-c2. Effects of the CD4M33 mimetic on the replication of the HIV-1 LEN clinical isolate in PBMCs. The retroviral activity of the mimetic CD4M33 vis-à-vis the PBMCs activated by PHA-P and infected with the isolate HIV-1 LEN results in a dose-dependent decrease in viral replication and an ED 50 equal to 367 nM ( table 4). The mimetic CD4M33 therefore retains a significant anti-HIV-1 activity, even if it turns out to be slightly weaker compared to that observed with the HIV-I LAI strain.
- CD4M33 peptide has an antiretroviral activity greater than 1 base 10 logarithm than that observed with another derivative of CD4 receptor, SAH-CD4, and above all showed significant anti-HIV activity vis-à-vis a clinical isolate (Table 4).
- the peptide of the present invention CD4M33 which is capable of binding to the recombinant viral protein gpl20 with a Kd of 2.4-8.0 nM (surface plasmon resonance experiments) and of inhibiting the interaction between the recombinant proteins CD4-gpl20 in ELISA, with an IC 50 of 120-250 pM, also has the capacity to inhibit this interaction in primary cultures of human cells, to inhibit the initial step of entry and therefore to block the even an HIV-1 clinical isolate infection.
- CMSP phytohemoagglutinin-P
- PHA-P The cells were infected with 50 TCID50 viruses:
- EXAMPLE 8 EXPOSURE OF ANTIGENIC SITES OF THE ENVELOPE.
- CD4M33 When CD4M33 is added to the viral protein gpl20 ⁇ B2 / with a molar excess of 1.5 and 20 times, the viral protein shows a strong interaction with the antibodies ( Figures 6a-b); on the other hand, in its absence (and in the absence of soluble CD4) the envelope protein interacts with the antibodies very weakly (Fig. 6a-b).
- the effect of adding CD4M33 on the increase in the interaction affinity of the viral protein gpl20 for antibodies is comparable to that obtained by adding equivalent amounts of soluble CD4.
- FIG. 4 shows the results obtained in these experiments and demonstrates the evolution of the plasmon resonance signal as a function of time after interaction of a suspension of HIV-1 HXB2 viral particles with a chip presenting the immobilized 48d and CG10 antibodies: HIV-1 interacts with the antibodies only after incubation with the CD4M33 peptide of the present invention and, on the other hand, in its absence or in the presence of the peptide [ Ala23] CD4M9 inactive, the interaction is practically zero.
- the surface plasmon resonance technique has therefore made it possible to demonstrate that the binding of CD4M33 to the envelope protein gpl20 is capable of inducing a modification of the viral protein, which, consequently, preferentially exposes certain molecular surfaces to neutralizing antibodies (17b, CG10), isolated from people affected by HIV-1 [11], [12], [13].
- CD4M33 has the property of unmasking epitopes of the viral protein gpl20, as does soluble CD4, with the advantage that it will not be able to induce an immune response against CD4 and that, from more, because of its small size, it will allow an even more favorable access to the epitopes exposed of the viral protein gpl20.
- Peptides of the present invention labeled or unlabeled, in the form of 50 ⁇ g lyophilized (powder) were solubilized by adding in an Eppendorf (trademark) containing the powder, 50 ⁇ l of a potassium phosphate buffer, 10 mM , 100 mM KC1, pH 7.0 in order to obtain a concentrated solution at between 300 and 750 ⁇ M.
- the labeling is carried out with fluorescein (F) or with rhodamine green (R).
- the gpl20 viral proteins were prepared in the form of solutions at a concentration of -1 mg / ml.
- the titrations were carried out in the "reverse" direction.
- 4 ml of a peptide solution of the present invention, labeled and at a concentration of 6 nM in the phosphate buffer cited above was prepared.
- 200 ⁇ m of a solution containing 10 ⁇ l of gpl20 at a concentration of 0.421 ⁇ M, 4 ⁇ l of peptide of the present invention labeled with fluorescein and at a concentration of 6 nM, and 186 ⁇ l of buffer was prepared.
- the anisotropy of 200 ⁇ l of the labeled peptide solution alone was first tested. Depending on the probe used on the peptide and the settings of the apparatus, in particular the gain, the anisotropy of the peptide of the present invention labeled alone varies between 80 and 110 units of millianisotropy. Then, the anisotropy of the tube containing the labeled peptide and the gp120 at 410 nM was measured.
- the value of the labeled peptide in the presence of this high concentration of gpl20 was of the order of 200 millianisotropy.
- the titration was carried out by taking 40 ⁇ l of the solution and then adding 40 ⁇ l of the labeled peptide solution alone at 6 nM. In this way, gpl20 was diluted, by a value of 0.1 log unit per dilution, while keeping the concentration of labeled peptide constant.
- This reverse titration protocol uses as little gpl20 as possible.
- the labeled peptides have shown a tendency to stick to the walls of the containers.
- Several dilution solutions have therefore been made in order to avoid a gradual decrease in the concentration of labeled peptide.
- the competition was then carried out between 10 and 100 nM of unlabeled CD4M33 peptide.
- the competitions were carried out experimentally by adding to 200 ⁇ l of a 6 nM solution of CD4M33-F peptide and 20 nM gpl20 aliquots of 1 ⁇ l of unlabeled competitor CD4M33 peptide in the above phosphate buffer in order to cover concentrations between 10 and 100 nM. The anisotropy values were then measured after each addition.
- a third preparation was therefore carried out (III K16 / GP120).
- the measurements carried out on this preparation are shown in Figure 8c).
- the affinity (Kd) measured is 97nM.
- Their affinity for the viral protein gpl20 was 14 nM, 195 nM, and 323 nM, respectively. 2) AFFINITY MEASUREMENTS TAKEN WITH A PEPTIDE OF THE PRESENT INVENTION FOR DIFFERENT GP120 VIRAL PROTEINS
- the 8nM affinity for gpl20 HXB2 is very close to the value determined from the results shown in FIG. 9, ie 14 nM.
- a displacement of a labeled peptide having a determined affinity, represented by the CD4M33 peptide, by an unlabeled CD4M33 peptide was carried out to simulate screening according to the method of the present invention.
- the results of this example are represented in FIG. 13. These results show that a concentration of 20 nM of gpl20 allows a fixation approaching 50%, and therefore a relatively high starting anisotropy of approximately 180 millianisotropy.
- the affinity of the labeled CD4M33 for gpl20 HXB2 was 11 + 3 nM.
- this screening test can demonstrate any molecule, whatever its chemical structure, which would bind to gpl20 competitively with this peptide.
- the peptides of the present invention therefore represent in vitro inhibitors of infection by the AIDS virus, in particular HIV-I.
- the screening method of the present invention which uses fluorescence anisotropy of a peptide
- the present invention therefore, constitutes a new tool for screening candidate molecules for the manufacture of drugs for treating AIDS.
- Retroviruses. 11, 533-539 [18] Ono, M., Wada, Y., Wu, Y., Nemori, R., Jinbo, Y.,
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Immunology (AREA)
- Engineering & Computer Science (AREA)
- Molecular Biology (AREA)
- Hematology (AREA)
- Virology (AREA)
- Biomedical Technology (AREA)
- Chemical & Material Sciences (AREA)
- Urology & Nephrology (AREA)
- Food Science & Technology (AREA)
- Physics & Mathematics (AREA)
- AIDS & HIV (AREA)
- Cell Biology (AREA)
- Biotechnology (AREA)
- Tropical Medicine & Parasitology (AREA)
- Medicinal Chemistry (AREA)
- Microbiology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Pathology (AREA)
- Peptides Or Proteins (AREA)
- Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)
- Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)
Abstract
Description
Claims
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA002452663A CA2452663A1 (fr) | 2001-07-06 | 2002-07-04 | Procede de criblage de molecules aptes a se lier a la proteine gp120 du virus de l'immunodeficience |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR01/09015 | 2001-07-06 | ||
FR0109015A FR2827046B1 (fr) | 2001-07-06 | 2001-07-06 | Procede de criblage de molecules aptes a se lier a la proteine gp120 du virus de l'immunodeficience |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2003005032A2 true WO2003005032A2 (fr) | 2003-01-16 |
WO2003005032A3 WO2003005032A3 (fr) | 2003-12-04 |
Family
ID=8865218
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/FR2002/002349 WO2003005032A2 (fr) | 2001-07-06 | 2002-07-04 | Procede de criblage de molecules aptes a se lier a la proteine gp120 du virus de l'immunodeficience |
Country Status (3)
Country | Link |
---|---|
CA (1) | CA2452663A1 (fr) |
FR (1) | FR2827046B1 (fr) |
WO (1) | WO2003005032A2 (fr) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2000023474A1 (fr) * | 1998-10-21 | 2000-04-27 | The University Of Queensland | Ingenierie des proteines |
-
2001
- 2001-07-06 FR FR0109015A patent/FR2827046B1/fr not_active Expired - Fee Related
-
2002
- 2002-07-04 CA CA002452663A patent/CA2452663A1/fr not_active Abandoned
- 2002-07-04 WO PCT/FR2002/002349 patent/WO2003005032A2/fr active Application Filing
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2000023474A1 (fr) * | 1998-10-21 | 2000-04-27 | The University Of Queensland | Ingenierie des proteines |
Non-Patent Citations (4)
Title |
---|
DRAKOPOULOU EUGENIA ET AL: "Engineering a CD4 mimetic inhibiting the binding of the human immunodeficiency virus-1 (HIV-1) envelope glycoprotein gp120 to human lymphocyte CD4 by the transfer of a CD4 functional site to a small natural scaffold." LETTERS IN PEPTIDE SCIENCE, vol. 5, no. 2-3, mai 1998 (1998-05), pages 241-245, XP008003798 ISSN: 0929-5666 * |
DRAKOPOULOU, EUGENIA ET AL: "Engineering a CDR2 sequence of hCD4 into the.alpha./.beta. scaffold of charybdotoxin" PEPTIDES 1996, PROCEEDINGS OF THE EUROPEAN PEPTIDE SYMPOSIUM, 24TH, EDINBURGH, SEPT. 8-13, 1996 (1998), MEETING DATE 1996, 345-346. EDITOR(S): RAMAGE, ROBERT;EPTON, ROGER. PUBLISHER: MAYFLOWER SCIENTIFIC, KINGSWINFORD, UK., 1998, XP001073762 * |
MARTIN L ET AL: "Engineering Novel Bioactive Mini-Proteins on Natural Scaffolds" TETRAHEDRON, ELSEVIER SCIENCE PUBLISHERS, AMSTERDAM, NL, vol. 56, no. 48, 24 novembre 2000 (2000-11-24), pages 9451-9460, XP004220792 ISSN: 0040-4020 * |
VITA CLAUDIO ET AL: "RATIONAL ENGINEERING OF A MINIPROTEIN THAT REPRODUCES THE CORE OF THE CD4 SITE INTERACTING WITH HIV-1 ENVELOPE GLYCOPROTEIN" PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF USA, NATIONAL ACADEMY OF SCIENCE. WASHINGTON, US, vol. 96, no. 23, 9 novembre 1999 (1999-11-09), pages 13091-13096, XP002181795 ISSN: 0027-8424 * |
Also Published As
Publication number | Publication date |
---|---|
WO2003005032A3 (fr) | 2003-12-04 |
FR2827046A1 (fr) | 2003-01-10 |
FR2827046B1 (fr) | 2004-01-23 |
CA2452663A1 (fr) | 2003-01-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1497467B1 (fr) | Oligonucleotide issus des sequences codant pour la composante de surface des proteines d'enveloppe des ptlv et leurs utilisations | |
EP1001815B1 (fr) | Vecteurs derives d'anticorps pour le transfert de substances dans les cellules | |
CA2202408C (fr) | Sequences nucleotidiques d'antigenes retroviraux vih-1 groupe (ou sous-groupe) o | |
CA2370563C (fr) | Vaccin anti-vih-1 comprenant tout ou partie de la proteine tat de vih-1 | |
EP1368372B1 (fr) | Peptides presentant une affinite pour la proteine virale gp120, et utilisation de ces peptides | |
CA2416761A1 (fr) | Procede de criblage de peptides utilisables en immunotherapie | |
EP0569309B2 (fr) | Polypeptides de synthèse appartenant au virus de l'hépatite C (VHC) et utilisables notamment pour détecter ce dernier | |
CA2561163A1 (fr) | Antigene tat stabilise et ses applications pour la vaccination anti-vih | |
WO2003005032A2 (fr) | Procede de criblage de molecules aptes a se lier a la proteine gp120 du virus de l'immunodeficience | |
EP0349354A1 (fr) | Peptides PF10 à PF19 d'un rétrovirus HIV, procédé de synthèse de ces peptides, leur utilisation notamment pour le diagnostic | |
EP0439601B1 (fr) | Composition contenant un epitope b de la glycoproteine d'enveloppe d'un retrovirus et un epitope t d'une proteine distincte de ce retrovirus | |
JPH09501143A (ja) | 治療用化合物 | |
CA2540520A1 (fr) | Polypeptide d'interaction comprenant un motif heptapeptidique et un domaine de penetration cellulaire | |
FR2792204A1 (fr) | Vaccin anti-vih-1 comprenant tout en partie de la proteine tat de vih-1 | |
JP4481404B2 (ja) | Hiv−1o群の検出用のペプチド | |
FR2671554A1 (fr) | Peptides synthetiques derivant de l'antigene hbc du virus de l'hepatite b, leurs applications a la detection d'une infection par ce virus et a la vaccination contre l'hepatite b. | |
WO2005097180A1 (fr) | Antigene tat dimerique et ses applications pour la vaccination anti-vih. | |
OA19487A (en) | Potent HIV inhibiting lipopeptide, derivative thereof, pharmaceutical composition thereof and use thereof. | |
FR2698271A1 (fr) | Vaccin contre le virus de la leucémie bovine, nouveau peptide immunogène et kit de vaccination. |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A2 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SI SK SL TJ TM TN TR TT TZ UA UG US UZ VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A2 Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LU MC NL PT SE SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2003510957 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2452663 Country of ref document: CA |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
122 | Ep: pct application non-entry in european phase | ||
NENP | Non-entry into the national phase |
Ref country code: JP |