MXPA06001922A - Peptides which can bind to transforming growth factor beta 1 (tgf-beta1) - Google Patents

Abstract

The invention relates to peptides which can bind to transforming growth factor TGF-&bgr;1 (TGF-&bgr;1) and which are potential inhibitors of the biological activity of TGF-&bgr;1 by means of direct binding to the aforementioned cytokine. The inventive peptides can be used in the treatment of pathological alterations or diseases based on a deregulated or excessive expression of TGF-&bgr;1.

Description

PEPTIDES WITH ABILITY TO JOIN THE TRANSFORMING GROWTH FACTOR BETA1 (TGF-BETAl) FIELD OF THE INVENTION The invention relates, in general, to peptides that have the ability to bind transforming growth factor β1 (TGF-β1) and its applications. In particular, the invention relates to peptides inhibiting the biological activity of TGF-β1 by its direct binding to TGF-β1, and its use in the treatment of diseases or pathological alterations based on an excessive or deregulated expression of TGF-β1. BACKGROUND OF THE INVENTION TGF-β1 is a glycoprotein belonging to a superfamily of structurally related regulatory proteins (cytokines) included within one of the three isoforms described in mammals (TGF-beta 1, 2 and 3). The most abundant isoform is TGF-β1, which consists of a 25-kDa homodimer co-deposited by 2 subunits linked by a disulfide bridge. The amino acid sequence of human TGF-β1 has been described by, for example, Derynck K et al. , "Human transforming growth factor-beta complementary DNA sequence and expression in normal and transformed cells". Nature 316 (6030), 701-705 (1985). TGF-ßl is a molecule whose sequence is highly conserved in evolutionary terms. Although originally Ref.:170275 defined by its ability to induce adhesion-independent proliferation and morphological changes in rat fibroblasts, further investigations have revealed that TGF-β1 is a general inhibitor of proliferation in a large number of cell types. It is produced by a wide variety of cell types and in different tissues during all phases of cell differentiation. It produces a wide variety of biological effects, generates powerful and very often opposing effects on the development, physiology and immune response. Information on the role of TGF-ßl in liver differentiation and regeneration, and in hepatic fibrosis, as well as the effects of TGF-β1 on the extracellular matrix, can be found in the Spanish patent application ES 2146552 Al. Having as objective the study of the mechanisms of action of TGF-ßl, a dozen proteins (membrane receptors and extracellular matrix proteins) that interact with this cytokine have been described. On the other hand, because numerous diseases or pathological alterations are associated with an excessive or deregulated expression of TGF-β1, for example, fibrosis associated with loss of function of an organ or tissue, or surgical or aesthetic complications, results interesting to look for products capable of inhibiting the biological activity of TGF-β1, since such products could potentially be used in human or animal therapy as blockers of the pathological consequences of an excessive or deregulated expression of TGF-β1. Strategies commonly used to inhibit the biological activity of TGF-β1 include, among others, the use of (i) neutralizing specific antibodies, (ii) antisense oligos of the gene encoding TGF-β1 that block its expression, or (iii) receptors soluble of TGF-ßl that act in a similar way to antibodies. The use of antibodies allows a total and specific blockade of this cytokine (TGF-ßl) although certain side effects are potentiated both by the presence of exogenous immunoglobulins in blood and by the effects derived from the systemic blockade of TGF-ßl. In addition, the stability over time of immunoglobulins does not allow a control at short times of blockade in the activity of this cytokine. The antisense oligo inhibit the production of TGF-β1 at the level of gene expression, which can generate important deregulations in all the processes in which this cytokine intervenes. Recently, another strategy based on the use of peptides inhibiting the biological activity of TGF-β1 has been developed. In this sense, the Spanish patent application ES 2146552 Al describes synthetic peptides derived from both TGF-β1 and its receptors, or proteins capable of binding to TGF-β1, which can be used as inhibitors of the biological activity of TGF-β1. SUMMARY OF THE INVENTION The invention is faced, in general, with the problem of searching for new compounds capable of inhibiting the biological activity of TGF-β1. The solution provided by the present invention is based on the fact that the inventors have identified peptides capable not only of binding to TGF-β1, but also capable of inhibiting the biological activity of TGF-β1 by direct binding to TGF-β1 itself. Some of these peptides have been identified through the use of the technology associated with the phage libraries that allows to determine peptides, with a size typically comprised between 6 and 15 amino acids, which have a high affinity binding with TGF-β1, quantifying , subsequently, through in vitro and in vivo tests, the capacity of inhibition of the biological activity of TGF-β1 of the different peptides. Other peptides have been obtained by truncation of peptides previously identified by said technology associated with phage libraries. Peptides capable of binding to TGF-β1, in particular, those capable of inhibiting the biological activity of TGF-β1 by direct binding to TGF-β1 are potentially useful for the treatment of diseases and pathological disorders associated with over expression or deregulated of TGF-ßl. Likewise, peptides capable of binding to TGF-ßl provide a tool for the study of the biological role of TGF-ßl (still to be elucidated in many fields of regulation of different biological processes). Therefore, one aspect of this invention relates to peptides that possess the ability to bind to TGF-β1. In a particular and preferred embodiment, said peptides have, in addition, the ability to inhibit the biological activity of TGF-β1. In another aspect, the invention relates to a pharmaceutical composition comprising at least one of said peptides. In another aspect, the invention relates to the use of said peptides in the preparation of a medicament for the treatment of diseases and pathological alterations associated with an excessive or deregulated expression of TGF-β1. Illustrative examples of such diseases or pathological alterations associated with an excess or deregulated expression of TGF-β1 include fibrosis associated with loss of function of an organ or tissue as well as surgical and / or aesthetic complications. In another aspect, the invention relates to DNA sequences encoding said peptides. In another aspect, the invention relates to a DNA construct comprising a DNA sequence encoding a peptide provided by this invention. In another aspect, the invention relates to a vector comprising said DNA sequence or said DNA construct.

In another aspect, the invention relates to a host cell, such as a transformed host cell, comprising said DNA construct or said vector. In another aspect, the invention relates to a method for producing a peptide provided by this invention which comprises culturing said host cells under conditions that allow the expression of said peptide and, if desired, recovering the obtained peptide. In another aspect, the invention relates to the use of said DNA sequences and DNA constructs in the manufacture of vectors and cells for the treatment of diseases and pathological alterations associated with an excessive or deregulated expression of TGF-β1 by gene therapy. . BRIEF DESCRIPTION OF THE FIGURES Figure 1 shows schematically the position of a 15 amino acid (aa) peptide, genetically fused to the pIII protein, on the surface of the filamentous bacteriophage M13. Figure 2 schematically shows the gene position of the insert, which codes for a 15 aa peptide, in the bacteriophage M13 genome and the position of the peptide in the pIII protein sequence.

Figure 3 shows schematically the selection of peptides by the "Biopanning" technique. The biotinylated TGF-β1 is immobilized on streptavidin-containing plates (through the biotin-strept avidin linkage). The phage library is selected on the basis of the interaction between TGF-β1 and the peptides presented by the phages. Phages with low affinity for TGF-β1 are eliminated by washing. The phages retained in the plate are eluted by decreasing pH. After three cycles of phage enrichment with high affinity for TGF-β1, the phages are isolated and sequenced (see Exercise 1) [Legends of Figure 3: "a": Phage library displaying 15 aa peptides; ?? b ": Infection in E. coli (K91Kan) (amplification);" c ": Purification of phages;" d ": Incubation of phages with decreasing concentrations of TGF-ßl;" e ": Washes;" f ": Elution of the phages bound UpH);" g ": Infection in E. coli strain;" h ": Selection of infected colonies (tetracline);" i ": Amplification of the selected phages; and" j ": Sequencing of DNA (corresponding to the peptide) after three cycles of "biopanning".] Figure 4 is a representation of a tree of sequence analogies between the peptides of 15 amino acids identified by a phage library Figure 5 is a diagram showing the effect of the concentration of TGF-β1 on the growth of the cell line Mv-1-Lu, expressed as tritiated thymidine uptake in counts per minute (C. p.m.).

Figure 6 is a diagram illustrating the protocol for induction of acute liver damage (see Example 3). DETAILED DESCRIPTION OF THE INVENTION In one aspect, the invention relates to a peptide, hereinafter, peptide of the invention, whose amino acid sequence comprises between 3 and 15 consecutive amino acid residues of an amino acid sequence selected from SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21 and SEQ ID NO: 22, and their pharmaceutically acceptable salts. The peptides of the invention have the ability to bind to TGF-β1. Some of said peptides also have the ability to inhibit, in vitro and / or in vivo, the biological activity of TGF-β1. The ability of the peptides of the invention to bind to TGF-β1 can be determined by any appropriate method that allows determining the binding between two molecules, for example, by an affinity assay, which comprises contacting TGF-β1 with the peptide to be tested under conditions that allow the binding of said peptide to TGF-β1 and evaluate the binding between the peptide and TGF-β1. In a particular embodiment, said affinity assay can be performed using radiolabeled TGF-β1, for example, human 125I-TGF-β1, as described in ES 2146552 Al. Alternatively, the compound that can be labeled is the peptide to be tested. In general, this type of affinity assays comprises contacting TGF-β1, for example, immobilized on a plate blocked with streptavidin, with the peptide whose binding capacity to TGF-β1 is desired to be known, and, after incubating for a period of time. of appropriate time, analyze the binding of the peptide to TGF-β1. Peptides with low affinity for TGF-β1 are eliminated by washing while peptides with higher affinity remain bound to TGF-β1 and can be released by breaking the molecular interactions between both molecules, which can be done, for example, by lowering the pH . By assaying the peptide against different concentrations of TGF-β1 or vice versa, one can obtain an idea of the affinity of the peptide in question against TGF-β1. The ability of the peptides of the invention to inhibit the biological activity of TGF-β1 in vitro can be evaluated and, if desired, quantified, using a growth inhibition assay of the Mv-l-Lu cell line, a cell line derived from mink lung epithelium whose proliferation is inhibited by TGF-β1 (see Example 2). The ability of the peptides of the invention to inhibit the biological activity of TGF-β1 in vivo can be evaluated and, if desired, quantified by an animal model assay of acute liver injury induced, for example, by administration of tetrachloride of carbon (CC14) (see Example 3). As is known, acute liver damage generates a cascade of effects and physiological responses that includes the elevation of TGF-β1 levels, responsible, among other effects, for the expression of the type I collagen gene, among others. Within the scope of this invention are pharmaceutically acceptable salts of the peptide of the invention. The term "pharmaceutically acceptable salts" includes the salts usually used to form metal salts or acid addition salts. The nature of the salt is not critical as long as it is pharmaceutically acceptable. The pharmaceutically acceptable salts of the peptide of the invention can be obtained from acids or bases, organic or inorganic. Said salts can be obtained by conventional methods well known to those skilled in the art. In a particular embodiment, the invention provides a peptide comprising 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 consecutive amino acid residues of an amino acid sequence selected from SEQ. ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO : 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17 , SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21 and SEQ ID NO: 22, and their pharmaceutically acceptable salts. In a specific embodiment, the invention provides a peptide selected from the group consisting of the peptides identified by SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21 and SEQ ID NO: 22, and its pharmaceutically acceptable salts. In another specific embodiment, the invention provides a peptide selected from the group consisting of the peptides identified by SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO 30, SEQ ID NO: 31, SEQ ID NO: 32, SEQ ID NO: 33, SEQ ID NO 34, SEQ ID NO: 35 and SEQ ID NO: 36, and their pharmaceutically acceptable salts . These peptides comprise between 9 and 14 consecutive amino acid residues of the amino acid sequence of the peptide identified by SEQ ID NO: 17 and have been obtained by truncation of said peptide (Example 4).

In another specific embodiment, the invention provides a peptide selected from the group consisting of the peptides identified by SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 6, SEQ ID NO: 11, SEQ ID NO: 14, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 33 and SEQ ID NO: 34 and their pharmaceutically acceptable salts. The peptides identified by SEQ ID NO: 4, SEQ ID NO: 6, SEQ ID NO: 11, SEQ ID NO: 14 and SEQ ID NO: 17, exhibit activity inhibiting the biological activity of TGF-β1, both in vitro as in vivo; the peptide identified by SEQ ID NO: 2 exhibits only inhibitory activity of the biological activity of TGF-β1 in vivo; and the peptides identified by SEQ ID NO: 3 and SEQ ID NO: 18, have only inhibitory activity of the biological activity of TGF-β1 in vitro. The peptides identified by SEQ ID NO: 33 and SEQ ID NO: 34 exhibit activity inhibiting the biological activity of TGF-β1 in vitro. For the initial identification of peptides capable of binding to TGF-β1, the technology associated with the phage libraries has been used to determine peptides that have a high affinity binding with TGF-β1, and subsequently quantify them by means of in vitro assays. In vitro and in vivo, the capacity of inhibition of the biological activity of the TGF-ßl of the different peptides. The sequence of the peptides that bind to TGF-β1, inhibiting in vitro or in vivo the biological activity of TGF-β1, can be deduced from the corresponding DNA sequence after several cycles of "biopanning", generally 3 The use of phage libraries to identify inhibitors of certain products has been described, for example, by Chirinos-Rojas CL et al., in Immunology, 1999, Jan. 96 (1): 109-113; McConnell S.J., et al., In Gene 1994, Dec. 30, 151 (1-2): 115-118; or Smith G.P., Science, 1985, Jun. 14, 228 (4705): 1315-1317. Therefore, the invention provides a method for the identification of peptides having the ability to bind to TGF-β1 comprising: (i) using a phage library comprising a plurality of filamentous phages, containing the genome of each of said phage a nucleotide sequence that codes for a different peptide linked to the gene of a phage coat protein, whereby each phage contains a different peptide genetically fused to a phage coat protein; (ii) selecting, by affinity assay, the phages containing the peptides that bind with the highest affinity to TGF-β1; and (iii) determining the sequence of the peptides that bind to TGF-β1, from the corresponding DNA sequences inserted into the phage selected in step (ii) and coding for said peptides that bind to TGF-β1 . In a particular embodiment, in order to obtain peptides of 15 amino acids capable of binding with high affinity to TGF-β1 and with possible inhibitory activity of the biological activity of said cytokine, a phage library composed of a plurality of filamentous bacteriophages was used (M13) each containing a different peptide, 15 amino acids, genetically fused to a phage coat protein, in this case bound to the N-terminal end of the pIII coat protein. In this way, the phage presents on its surface a peptide of 15 amino acids, in each of the five molecules of the surface protein, while inside it contains the DNA that codes for said peptide sequence. In phage libraries the coding sequence for the peptide comes from a degenerate sequence in each of the 15 positions with the 20 natural amino acids, which allows the presentation of l, lxl012 possible sequences of 15 amino acids in different phages. The physical relationship, I to l, between the peptide sequence and the DNA encoding it in the bacteriophage makes it possible to select, from a large number of variants, those sequences that specifically bind to TGF-β1. This process is carried out through an affinity test.

In a particular embodiment, said affinity assay consists of an in vitro selection protocol termed "biopanning". Briefly, said technique consists of the incubation of a set of phages representing, for practical purposes, all the variants of peptides of 15 amino acids (in this case), in a plate blocked with streptavidin to which biotinylated TGF-βl is added. . The biotinylated TGF-ßl is anchored to the plate through the biotin-streptavidin interaction, which is correctly presented for its interaction with the peptides carried by the phages. After an incubation, unbound phages are removed by washing and then the phages bound specifically are eluted by a pH decrease that breaks the molecular interactions between TGF-β1 and the peptides presented by the phages. The eluted phages are then amplified by infection in a bacterial strain. The process is repeated a total of 3 rounds, so that the content of phages that bind specifically and with high affinity to TGF-ßl is enriched. The concentration of biotinylated TGF-βl used to block the plates is progressively reduced in each round, for example, from 2.5 to 0.01 and finally 0.001 μg / ml. In this way, the phages selected in each round present an increasing degree of affinity for TGF-β1. At the end of the process the phages that have been selected for their affinity with TGF-β1 are sequenced with primers. This allows to obtain the sequences of the peptides presented in the phages. Example 1 illustrates the selection of peptides that bind to TGF-β1 by phage library, selection by "biopanning" and sequencing of peptides with high affinity binding to TGF-β1. The invention also provides a method for the identification of peptides having the ability to bind TGF-β1 comprising truncating peptides possessing the ability to bind to TGF-β1 and assaying the ability of such truncated peptides to bind to TGF-β1. The truncated peptides can be obtained by any conventional method, for example, by chemical synthesis (given their size) of the truncated versions of the peptide by their N-terminal, C-terminal or both ends. The ability of said truncated peptides to bind to TGF-β1 can be determined by any suitable method that allows to determine the binding between two molecules, for example, by an affinity assay, which comprises contacting TGF-β1 with the peptide to be tested. under conditions that allow the binding of said peptide to TGF-β1 and evaluate the binding between the peptide and TGF-β1, as previously mentioned. Also, the ability of said truncated peptides to inhibit, in vitro and / or in vivo, the biological activity of TGF-β1 can be assayed by any of the assays mentioned in this disclosure. Due to the role of TGF-β1 in numerous biological processes, a consequence of the inhibitory activity of TGF-β1 of the peptides of the invention has to do with the potential development of a new family of drugs useful for the treatment of diseases and diseases. pathological alterations associated with an excessive or deregulated expression of TGF-β1, since such peptides allow to block the excess or deregulation of said cytokine that causes damage. The peptides of the invention, therefore, can be used in the treatment of diseases or pathological disorders associated with an excess or deregulated expression of TGF-β1, such as (i) fibrosis associated with loss of function of an organ or a tissue, for example, pulmonary fibrosis, hepatic fibrosis (cirrhosis), renal fibrosis, corneal fibrosis, etc., as well as (ii) surgical and / or aesthetic complications, for example, fibrosis associated with cutaneous and peritoneal surgery, associated fibrosis with burns, osteo-articular fibrosis, keloids, etc. Therefore, in another aspect, the invention relates to a pharmaceutical composition comprising a therapeutically effective amount of a peptide of the invention together with, at least one pharmaceutically acceptable excipient. The pharmaceutical composition provided by this invention may contain one or more peptides of the invention, together with, optionally, one or more, alternative TGF-βl inhibitory compounds. Said pharmaceutical composition is useful for its administration and / or application in the human or animal body, preferably in the human body. The use of peptides, such as the peptides of the invention, instead of using antibodies or antisense oligos, has numerous advantages, since they are small molecules, with greater diffusion capacity and shorter half-life. The peptides may have a high affinity for TGF-β1, but they degrade more rapidly than the antibodies, and the adverse side effects can be controlled by dosing. The vehiculization of the peptides to target organs or tissues in comparison with other types of compounds is also more accessible. The peptides of the invention can be administered to treat the diseases and pathological alterations associated with an excessive or deregulated expression of TGF-β1 by any means that produces the contact of the peptide of the invention with the site of action thereof in the human body. or animal The amount of peptide, derivative or pharmaceutically acceptable salt thereof that may be present in the pharmaceutical composition provided by this invention may vary within a wide range.

The dosage for treating a disease or pathological disorder associated with an excessive or deregulated expression of TGF-β1 with the peptides and / or pharmaceutical compositions of the invention will depend on numerous factors, including age, condition of the patient, severity of the disease or pathological alteration, the route and frequency of administration and the peptide of the invention to be administered. The pharmaceutical compositions containing the peptides of the invention can be presented in any form of administration, for example, solid or liquid, and can be administered by any appropriate route, for example, orally, parenterally, rectally or topically, for which they will include the pharmaceutically acceptable excipients necessary for the formulation of the desired administration form, for example, ointments (lipogels, hydrogels, etc.), eye drops, aerosol sprays, injectable solutions, osmotic pumps, etc. A review of the different pharmaceutical forms of administration of drugs and of the excipients necessary to obtain them can be found, for example, in the "Galenic Pharmacy Treaty", C. Faulí i Trillo, 1993, Luzán 5, S.A. Editions, Madrid. The use of the peptides of the invention in the manufacture of said pharmaceutical composition constitutes a further aspect of this invention. Therefore, in another aspect, the invention relates to the use of a peptide of the invention in the preparation of a medicament for the treatment of diseases or pathological alterations associated with an excess or deregulated expression of TGF-β1, such as fibrosis associated with loss of function of an organ or tissue, for example, pulmonary fibrosis, hepatic fibrosis (cirrhosis), renal fibrosis, cal fibrosis, etc .; or surgical and / or aesthetic complications, for example, fibrosis associated with skin and peritoneal surgery, fibrosis associated with burns, osteoarticular fibrosis, keloids, etc. The peptides of the invention can be obtained by conventional methods, for example, by chemical synthesis techniques on solid phase; purify by high performance liquid chromatography (HPLC); and, if desired, they can be analyzed by conventional techniques, for example, by sequencing and mass spectrometry, amino acid analysis, nuclear magnetic resonance, etc. Alternatively, the peptides of the invention can be obtained by recombinant DNA technology. Therefore, in another aspect, the invention provides a DNA sequence encoding a peptide of the invention. Said DNA sequence can be easily deduced from the sequence of the peptide.

Said DNA sequence can be contained in a DNA construct. Thus, the invention provides a DNA construct comprising a DNA sequence encoding a peptide of the invention. Said DNA construct may incorporate, operatively linked, a sequence regulating the expression of the DNA sequence encoding the peptide of the invention. The control sequences are sequences that control and regulate the transcription and, where appropriate, the translation of the peptide of the invention, and include promoter, terminator, etc., functional sequences in transformed host cells comprising said DNA sequence or construction. In a particular embodiment, said expression control sequence is functional in bacteria. Advantageously, said DNA construct further comprises a marker or gene coding for a motif or for a phenotype that allows selection of the host cell transformed with said DNA construct. The DNA construct provided by this invention can be obtained by employing techniques well known in the state of the art [Sambrook et al., "Molecular cloning, a Laboratory Manual", 2nd ed., Cold Spring Harbor Laboratory Press, N.Y., 1989 Vol 1-3]. The DNA sequence or the DNA construct provided by this invention can be inserted into an appropriate vector. Therefore, in another aspect, the invention relates to a vector, such as an expression vector, comprising said DNA sequence or construct. The choice of vector will depend on the host cell into which it will be introduced later. By way of example, the vector where said DNA sequence is introduced can be a plasmid or a vector that, when introduced into a host cell, is integrated or not into the genome of said cell. The obtaining of said vector can be carried out by conventional methods known to those skilled in the art [Sambrok et al. , 1989, cited above]. In another aspect, the invention relates to a host cell, such as a transformed host cell, comprising a DNA sequence or a DNA construct provided by this invention. In another aspect, the invention relates to a method for producing a peptide of the invention comprising growing a host cell comprising the DNA sequence or construction provided by this invention under conditions that allow the production of said peptide of the invention and, if desired, recover said peptide of the invention. The conditions for optimizing the culture of said host cell will depend on the host cell used. If desired, the method for producing the peptide of the invention further includes the isolation and purification of said peptide. In another aspect, the invention relates to the use of said DNA sequences and DNA constructs in the manufacture of vectors and cells for the treatment of diseases and pathological alterations associated with an excessive or deregulated expression of TGF-β1 by gene therapy. . In accordance with this aspect of the invention, said DNA sequence or construct is contacted with a gene transfer vector, such as a viral or non-viral vector. Viral vectors suitable for practicing this embodiment of the invention include, but are not limited to the following, adenoviral vectors, adeno-associated vectors, retroviral vectors, lenti-iral vectors, alphaviral vectors, herpesviral vectors, vectors derived from coronaviruses, etc. Non-viral type vectors suitable for practicing this embodiment of the invention include, but are not limited to the following: naked DNA, liposomes, polyamines, dendrimers, cationic glycol copolymers, liposome-polycation complexes, proteins, mid gene transfer systems by receiver, etc. The following examples illustrate the invention and should not be considered as limiting the scope of the invention. EXAMPLE 1 Selection of peptides that bind to TGF-β1 by phage library To obtain sequences of 15 amino acids capable of binding with high affinity to TGF-β1 and with possible inhibitory activity of the biological activity of this cytokine, a In vitro selection technique based on technology developed from phage libraries. These libraries consist of filamentous bacteriophages (M13) that contain a peptide genetically fused to a virus coat protein, in this case bound to the N-terminal end of the pIII coat protein (Figure 1). In this way the phage presents on its surface a peptide of 15 amino acids, in each of the 5 molecules of this protein that has the phage on its surface, while inside it contains the DNA that codes for said peptide sequence. In the phage libraries the coding sequence for the peptide comes from a degenerate sequence in each of the 15 positions with the 20 natural amino acids. This allows the presentation of l, lxl012 possible sequences of 15 amino acids in different phages. The physical relationship, I to l, between the peptide sequence and the DNA encoding it in the bacteriophage allows selection, from a large number of variants, those sequences that bind specifically to TGF-ßl. This process is carried out through an in vitro selection protocol called "biopanning". The phage library used to carry out this example comes from a second amplification of the primary library described by T. Nishi, H. Tsuri and H. Saya [Exp. Med. (Japan) 11, 1759 (1993)], assigned by the laboratory of George P. Smith. Additional information about this technology can be found at the following web page: http: // ww. biosci .missouri. edu / smithgp / PhageDisplayWebsite / Ph agePisplayWebsitelndex. html Selection technique (Biopanning) This technique involves the incubation of a phage cluster, representatives (for practical purposes) of all variants of 15 amino acids, in a plate blocked with streptavidin (10 μg / ml in NaHCO3 0, 1 M, 2h at room temperature) to which biotinylated TGF-βl is added. The biotinylated TGF-ßl is anchored to the plate through the biotin-streptavidin interaction, which is correctly presented for its interaction with the peptides carried by the phages. The TGF-β1 is contacted with the peptides carried by the phage at a concentration of 3 × 10 4 virus / ml and allowed to incubate for approximately 12 hours. After incubation, the unbound phages are removed by 5 washes with PBS / Tween (phosphate-buffered saline / polyoxyalkylene derivatives of sorbitan fatty acid esters) and then the phages are specifically bound by a decrease in pH (elution buffer). ) that breaks down the molecular interactions between TGF-β1 and the peptides presented by phages. The eluted phages are then amplified by infection in a bacterial strain [E. coli). The process is repeated a total of 3 rounds, so that the content of phages that bind specifically and with high affinity to TGF-β1 is enriched (Figure 3). The concentration of biotinylated TGF-βl used to block the plates is progressively reduced in each round from 2.5 to 0.01 and finally 0, OOlμg / ml. In this way, the phages selected in each round present an increasing degree of affinity for TGF-β1. At the end of the process the phages that have been selected for their affinity with TGF-β1 are sequenced with primers, after being isolated by resistance to tetracycline that the genetically modified phages confer after infecting E. coli cells. This allows to obtain the sequences of the peptides presented in the phage of a number of clones obtained from isolated colonies. The number of times a sequence is repeated, corresponding to a peptide of 15 amino acids carried by each clone, of the total of sequenced clones gives an idea of the degree of relative affinity that said 15 amino acid sequence has for TGF-β1. Sequence of the peptides In order to obtain phage clones, obtained from "biopanning", a selection is made in the presence of an antibiotic from bacterial colonies infected by these phages, whose resistance is given by a tetracycline resistance gene present. in the phage genome. With this method only colonies infected with bacteriophages grow. Thus each colony contains the genome of a single phage that corresponds to the sequence of a single peptide presented on its surface.

Of the 108 bacterial colonies infected by phage, derived from the last round of selection by "biopanning, the portion of the genome encompassing the region corresponding to the peptides presented in the pIII protein was sequenced using the primer identified by SEQ ID NO: 23. In this way, the sequences shown in Table 1 were obtained, where the number of colonies (clones) carrying said sequences are also indicated Table 1. Sequences of amino acids from the phages that interact with TGF-β1, The number of clones (colonies) of each sequence gives a relative idea of the degree of affinity between the peptides and TGF-β1, that is, the greater the number of clones, the higher the binding affinity. However, the degree of affinity does not correspond to the ability to block the activity of TGF-β1 since the most active peptide, the peptide identified with SEQ ID NO: 17 (see Tables 2 and 3) gives 3 clones, while the peptide identified with SEQ ID NO: 3, which gives 41 clones, is much less active in the acute liver damage assay (Table 3). Although not wishing to be bound by any theory, this question could be explained on the basis that the most active peptide would probably block the binding of TGF-β1 to its receptor. Comparison of peptide sequences The sequences obtained were analyzed with the CLUSTAL W program (1.81). This program generates a multiple grouping of sequences according to their amino acid sequence analogies. The peptides are thus grouped by structural families (Figure 4). Based on the analogies presented by these peptides, minor motifs of binding to TGF-β1 or groups of peptides that bind to different regions of TGF-β1 can be suggested. EXAMPLE 2 Inhibition of biological activity ± nv ± tro of TGF-βl by peptides in proliferation assays with Mv-l-Lu cells The Mv-l-Lu cell line (CCL-64, American Type Cell Culture, Virginia, United States ) derived from mink lung epithelium, grows in monolayer and responds to exogenous TGF-ßl with a decrease in its proliferation (Figure 5). The inhibition by peptides of this cytokine is capable of restoring its growth and reflects the ability of different peptides as inhibitors of biological activity within TGF-β1. The peptides tested were obtained by peptide synthesis following conventional procedures (Merrifield RB J Am Chem Soc 1963; 85: 2149-2154; Atherton E et al., J Chem Soc Perkin Trans 1981; 1: 538-546). Mv-l-Lu cells are cultured to subconfluence in complete medium [RPMI-1640 supplemented with L-glutamine, sodium pyruvate, antibiotics and 10% fetal calf serum (FBS)] at 37 ° C and 5% C02 in bottles of 162 cm2 (Costar Corporation, CA, USA). The cells, after trypsinization, are cultured in 200 μl of complete medium in 96-well plates at an initial density of 5,000 cells / well, at 37 ° C and 5% C02 / for 6 hours to allow their adhesion. Subsequently, the treatments of the different peptides are added at different concentrations, starting with 200 μg / ml and TGF-ßl (Human Transforming Growth Factor-ßl, Roche) is added at a concentration of 200 μg / ml. After 12 hours of incubation, 1 μCi of methyl-3H-thymidine (Amersham Life Science, Buckinghamshire, UK) is added per well in 25 μl of clean medium (RPMI-1640) and the plate is incubated for 12 hours under the same conditions . Finally, the cells are harvested (Filtermate 196 Harvester, Packard) by transferring the tritiated thymidine, incorporated in the DNA synthesis, to plates (UniFilter-96 GF / C®, Perkin Elmer) and the radioactivity is quantified, after addition of liquid from scintillation, in a scintillation counter (Top Count, Microplate Scintillation Counter, Packard). The incorporation of tritiated thymidine in the absence and presence of TGF-β1, respectively, was used as positive and negative control. The inhibition of TGF-β1 activity in this assay was calculated by the following formula: lOOx (cpm with peptide - cpm negative control)% Inhibition = - -:: - r- (cpm positive control - cpm negative control) The negative control represents the incorporation of tritiated thymidine in the presence of TGF-β1, but in the absence of peptide, while the positive control refers to the same parameter in the absence of TGF-β1 and peptide. Thus, the percentage inhibition of the peptides can be measured on the biological activity of TGF-β1, due to its ability to reverse the repressing effect of this cytokine on the proliferation of the Mv-l-Lu cell line (Table 2).

Table 2 Effect of the peptides obtained by selection by "biopanning" on the inhibition of the in vitro biological activity of TGF-β1, calculated from the restoration of the growth of the Mv-l-Lu line The peptides identified as SEQ ID NO: 3, 11, 17 and 18 inhibit the in vitro biological activity of TGF-β1 with a percentage of inhibition of more than 20%. Additionally, the activity of the peptide identified as P144 has been compared in the Spanish patent application ES 2146552 Al with the activity of the peptide identified by SEQ ID NO: 17 as regards its ability to reverse the repressor effect of TGF-β1 on the proliferation of the previously described Mv-l-Lu cell line, observing a better activity of the peptide identified as SEQ ID NO: 17. EXAMPLE 3 Inhibition of the in vivo biological activity of TGF-β1 by peptides in a model of acute liver damage, induced by CC1 Acute liver damage generates a cascade of effects and physiological responses that includes the elevation of TGF-ßl levels. This elevation is responsible for inducing the expression, among others, of the type I collagen gene. In this model of acute liver damage in female Balb / C mice weighing 25 to 30 g, 2 μl of CC14 per gram of mouse in volumetric ratio of 1: 1 with corn oil. The control group receives an equivalent volume of corn oil, and the treated groups receive, after the initial dose of CC14, 50 μg of peptide in 500 μl of 1% physiological saline in DMSO (dimethylsulfoxide) every 24 h. After 72 hours all the animals are sacrificed and the liver samples are processed; to evaluate mRNA expression, liver tissue was frozen in liquid nitrogen and stored at -80 ° C until used. Other samples of liver tissue were preserved in OCT® or Tissue-Tek® (Sakura Finetek BV), processed in the same way as samples destined for mRNA extraction, and samples were also preserved in 10% buffered formalin, for later inclusion in paraffin and histological evaluation. Subsequently, the level of type I collagen mRNA of all groups is quantified by quantitative PCR. Figure 6 shows a flow diagram corresponding to the induction, sampling and quantification of the results in the acute liver injury assay. The ability of the peptides studied to block acute damage, measured in accordance with the levels of induced type I collagen mRNA, was determined by quantifying this RNA by real-time PCR. The degree of inhibition of collagen expression corresponding to each of the peptides is shown in Table 3. The peptides tested were obtained by peptide synthesis following conventional procedures (Merrifield RB J Am Chem Soc 1963; 85: 2149-2154; Atherton E et al., J Chem Soc Perkin Trans 1981; 1: 538-546).

Table 3 Effect of the peptides obtained by selection by "biopanning" on the inhibition of the in vivo biological activity of TGF-β1, calculated on the inhibition of type I collagen mRNA induction in a model of acute liver damage (Neg: negative) The peptides identified as SEQ ID NO: 2, 4, 6, 11, 14 and 17 inhibit the in vivo biological activity of TGF-β1 with a percentage of inhibition greater than 35%. Additionally, the activity of the peptide identified as P144 in the Spanish patent application ES 2146552 Al has been compared with that of the peptide identified by SEQ ID NO: 17 in terms of its ability to inhibit the expression of type I collagen mRNA in the assay of acute liver damage in previously defined mice. In this comparative test, it is observed that the peptide identified as SEQ ID NO: 17 inhibits the expression of mRNA of type I collagen much more than the peptide identified as P144 in the Spanish patent application ES 2146552 Al which has no activity. The results obtained with the comparative tests (Examples 2 and 3) show that a peptide illustrative of the peptides of this invention (the peptide identified by SEQ ID NO: 17) is more active than a peptide illustrative of the patent application Spanish ES 2146552 Al (the peptide identified as P144) in the proliferation assays with Mv-1-Lu cells and in a model of acute liver damage.

EXAMPLE 4 Inhibition of in vitro biological activity of TGF-β1 by truncated peptides of the SEQ peptide sequence ID NO: 17, in proliferation assays with Mv-l-Lu cells. In this example the inhibitory activity of some peptides whose amino acid sequence comprises between 3 and 15 consecutive amino acid residues of one of the amino acid sequences of the invention is shown. .

The activity of truncated peptides (derived from the peptide sequence SEQ ID NO: 17) with respect to the complete sequence has been compared in terms of its ability to reverse the repressing effect of TGF-β1 on the proliferation of the Mv-cell line. l-Lu For this, and with the intention of identifying the minimum sequence of the peptide SEQ ID NO: 17 able to inhibit the biological activity of TGF-β1 in vi tro, truncated versions of this peptide were synthesized, by the N-terminal end, C- ter inal or both ends. The peptides tested were obtained by peptide synthesis following conventional procedures (Merrifield RB J Am Chem Soc 1963; 85: 2149-2154; Atherton E et al., J Chem Soc Perkin Trans 1981; 1: 538-546). Following the same methodology described in Example 2, the activity of the truncated peptides was quantified in the proliferation assay with Mv-1-Lu cells, compared to the activity of the complete sequence of peptide SEQ ID NO: 17.

Table 4 Effect of the truncated peptides obtained from the peptide sequence SEQ ID NO: 17 on the inhibition of the in vitro biological activity of TGF-β1, calculated from the restoration of the growth of the Mv-l-Lu line SEQ ID NO: Sequence% Inhibition 17 KRIWFIPRSS YERA 28.5 ± 3.9 24 (TI) RI FIPRSS YERA 9.4 + 0.4 25 (T2) RIWFIPRSSWYER 6.2 ± 1.5 26 (T3) I FIPRSSWYERA 4 , 5 + 1/8 27 (T4) IWFIPRSS YE 1.4 ± 2.5 28 (T5) WFIPRSSWY 3.1 ± 0.9 29 (T6) WFIPRSSWYERA 2.7 + 1.8 30 (T7) FIPRSSWYERA -0 , 3 ± 3.0 31 (T8) IPRSSWYERA 3.4 ± 1.4 32 (T9) PRSS YERA 3.8 + 1.6 33 (UNCLE) KRIWFIPRSSWYER 31.4 ± 7.0 34 (Til) KRI FIPRSSWY 34 , 4 ± 7.9 35 (T12) KRIWFIPRSS 6.0 + 0.4 36 (T13) KRIWFIPRS 6.2 ± 2.5 As shown in Table 4, in this comparative test, the elimination of lysine (K) from the N-terminal end, leads to a loss of activity of the peptide SEQ ID NO: 17, from 28.5% to 9.4% . In contrast, removal of up to 3 amino acids from the C-terminal end does not affect the activity of the peptide. On the other hand, the elimination of the aromatic amino acids, tyrosine (Y) and tryptophan (), eliminates the activity of the peptide. This allows to reduce the original sequence of the peptide SEQ ID NO: 17 to a sequence of 12 amino acids (KRIWFIPRSSWY) [SEQ ID NO: 34] without affecting its inhibitory activity of TGF-βl in vi tro. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (17)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A peptide characterized by its ability to bind to TGB-ßl whose amino acid sequence is selected from any of SEQ ID No .: 1-SEQ ID No .: 6, SEQ ID No .: 9 SEQ ID No .: 22, and SEQ ID No .: 24-SEQ ID No .: 36, or fragments of said peptides, comprising 3 to 15 amino acids, and their salts pharmaceutically acceptable 2. The peptide according to claim 1, characterized in that it also has the ability to inhibit the biological activity of TGF-β1 in Vitro and / or in vivo. 3. The peptide according to claim 1 or 2, characterized in that it is selected from the group consisting of the peptides identified as SEQ ID No .: 2, SEQ ID No .: 3, SEQ ID No .: 4, SEQ ID No. : 6, SEQ ID No.:11, SEQ ID No.:14, SEQ ID No.:17, SEQ ID No.:18, SEQ ID No.:33, SEQ ID No.:34, and their pharmaceutically acceptable salts . 4. The use of a peptide whose amino acid sequence is selected from any of the sequences SEQ ID No .: 1 to SEQ ID No .: 22, and SEQ ID No .: 24 to SEQ ID No .: 36, or fragments of said peptides, comprising 3 to 15 amino acids, and their pharmaceutically acceptable salts, in the manufacture of a pharmaceutical composition with the ability to inhibit the biological activity of TGF-β1. 5. The use of a peptide according to claim 4, in the manufacture of a medicament for the treatment of diseases or pathological alterations associated with excess or deregulated expression of TGF-β1. 6. The use of a peptide according to claim 5, characterized in that diseases or pathological alterations associated with excess or deregulated expression of TGF-β1, comprise fibrosis associated with loss of function in organs or tissues, and surgical complications and / or aesthetic. The use of a peptide according to any of claims 5 or 6, wherein the diseases or pathological alterations associated with excess or deregulated expression of TGF-β1, is selected from pulmonary fibrosis, liver fibrosis (cirrhosis) , renal fibrosis, corneal fibrosis, fibrosis associated with the skin and peritoneal surgery, fibrosis associated with burns, osteoarticular fibrosis or keloids. 8. A pharmaceutical composition, characterized in that it comprises a therapeutically effective amount of a peptide according to any of claims I to 3, with at least one pharmaceutically acceptable excipient. 9. A pharmaceutical composition according to claim 8, characterized in that it comprises at least one peptide according to any of claims 1 to 3, with one or more TGF-β1 inhibitor compounds, different from those which are the subject of this invention. 10. A DNA sequence, characterized in that it encodes a peptide according to any of claims 1 to 3. 11. A DNA construct, characterized in that it comprises a DNA sequence according to claim 10. 12. A construction of DNA according to claim 11, characterized in that it comprises an operably linked expression regulatory sequence of the DNA sequence. 13. A vector, characterized in that it comprises a DNA sequence according to claim 10, or a DNA construct according to the claim II or 12. 14. A host cell, characterized in that it comprises a DNA sequence according to claim 10, or a DNA construct according to claim 11 or 12, or a vector according to claim 13. 15. A process for the production of a peptide according to any of claims 1 to 3, characterized in that it comprises the development of a host cell according to claim 14, under conditions that allow the production of the peptide, and his recovery. 16. The use of a DNA sequence according to claim 10, or a DNA construct according to any of claims 11 or 12, for inhibiting the biological activity of TGF-.beta. By gene therapy. The use of a DNA sequence according to claim 10, or a DNA construct according to any of claims 11 or 12, in the manufacture of vectors and cells for the treatment of diseases and pathological disorders associated with expression in excess or deregulated TGF-β1.