AU697910C - Peptides and methods against psoriasis - Google Patents

Description

PEPTIDES AND METHODS AGAINST PSORIASIS

BACKGROUND OF THE INVENTION

This invention relates to the immune system and, more specifically, to methods of modifying pathological immune responses in psoriasis.

Higher organisms are characterized by an immune system which protects them against invasion by potentially deleterious substances or microorganisms. When a substance, termed an antigen, enters the body, and is recognized as foreign, the immune system mounts both an antibody-mediated response and a cell-mediated response. Cells of the immune system termed B lymphocytes, or B cells, produce antibodies that specifically recognize and bind to the foreign substance. Other lymphocytes termed T lymphocytes, or T cells, both effect and regulate the cell-mediated response resulting eventually in the elimination of the antigen.

A variety of T cells are involved in the cell- mediated response. Some induce particular B cell clones to proliferate and produce antibodies specific for the antigen. Others recognize and destroy cells presenting foreign antigens on their surfaces. Certain T cells regulate the response by either stimulating or suppressing other cells.

While the normal immune system is closely regulated, aberrations in immune response are not uncommon. In some instances, the immune system functions inappropriately and reacts to a component of the host as if it were, in fact, foreign. Such a response results in an autoimmune disease, in which the host's immune system attacks the host's own tissue. T cells, as the primary regulators of the immune system, directly or indirectly effect such autoimmune pathologies. Psoriasis is characterized by epidermal keratinocyte hyperprolifera ion, coupled with an inflammatory infiltrate. The pathogenesis of this disease is not fully understood. T cell activation appears to play a vital role in triggering and/or maintaining the disease. As evidence, cyclosporin A works effectively on improving the patient's condition.

A need exists for improved and effective means of curing or ameliorating psoriasis. Such a treatment should ideally control the inappropriate T cell response, rather than merely reducing the symptoms. The present invention satisfies this need and provides related advantages as well .

SUMMARY OF THE INVENTION

This invention provides methods of preventing or reducing the severity of psoriasis in an individual by administering a peptide having substantially the sequence of a T cell receptor present on the surface of T cells mediating psoriasis which is capable of causing an effect on the immune system to regulate the T cells.

This invention provides methods of preventing or reducing the severity of psoriasis in an individual by administering a peptide having substantially the sequence of a non-conserved region sequence of a T cell receptor present on the surface of T cells mediating psoriasis or a fragment thereof, wherein the peptide or fragment is capable of causing an effect on the immune system to regulate the T cells.

This invention also provides compositions for preventing or reducing the severity of psoriasis in an individual having a peptide having substantially the sequence of a non-conserved region of a T cell receptor present on the surface of T cells mediating psoriasis or a fragment thereof, wherein the peptide or fragment is capable of causing an effect on the immune system to regulate the T cells.

In another embodiment, this invention concerns methods of preventing the proliferation of T cells associated with psoriasis in an individual by determining a T cell receptor binding partner for a T cell receptor present on the surface of T cells mediating psoriasis and administering the T cell binding partner to the individual .

According to another embodiment, the method involves preventing or reducing the severity of psoriasis by inhibiting the binding of a T cell receptor to its TCR binding partner in order to prevent the proliferation of T cells associated with psoriasis.

This invention also provides methods of preventing or reducing the severity of psoriasis in an individual by contacting T cells specifically associated with psoriasis with an effective amount of a cytotoxic or cytostatic agent specifically reactive with such T cells to inhibit their activity.

This invention further provides methods of diagnosing or predicting susceptibility to psoriasis in an individual by detecting T cells having a T cell receptor associated with psoriasis in a sample from the individual, the presence of abnormal expression of T cells containing the T cell receptor indicating the pathology or susceptibility to psoriasis. This invention provides methods of preventing or reducing the severity of psoriasis in an individual by preventing the attachment of a psoriasis-associated T- cell receptor to its binding partner.

Another method of this invention involves preventing or reducing the severity of psoriasis in an individual by administering to the individual a vector having an expression. -control sequence operatively linked to a nucleic acid encoding a T cell receptor or a peptide having substantially the sequence of a non-conserved region sequence of a T cell receptor present on the surface of T cells mediating psoriasis or a fragment thereof, wherein the peptide or fragment is capable of causing an effect on the immune system to regulate the T cells.

This invention also provides vectors having an expression control sequence operatively linked to a nucleic acid encoding a T cell receptor or a peptide having substantially the sequence of a non-conserved region sequence of a T cell receptor present on the surface of T cells mediating psoriasis.

BRIEF DESCRIPTION OF THE FIGURE

Figure 1 shows the variable region sequences of Vβ3 (SEQ ID NO: 1), VS13.1 (SEQ ID NO: 2) and VS17 (SEQ ID NO: 3) . The underlined segments depict the CDR1, CDR2 and CDR4 hypervariable regions of each Vβ chain. The sequences between the CDR2 and CDR4 regions represent an overlap between these two hypervariable regions. DETAILED DESCRIPTION OF THE INVENTION

This invention provides compositions and methods for preventing or reducing the severity of psoriasis. The invention results from the discovery that psoriasis is characterized by the predominant usage of certain T cell receptors in the psoriatic plaque lesion. In particular, Vβ3 , Vβl3.1 and Vβl7 predominate. Treatment according to the method of the invention provides a specific and sustained amelioration which avoids problems associated with other potential avenues of therapy.

As used herein, "substantially the amino acid sequence, " or "substantially the sequence" when referring to an amino acid sequence means the described sequence or other sequences having any additions, deletions or substitutions that do not substantially effect the ability of the sequence to cause an effect on the immune system which regulates T cells having the desired T cell receptor. Such sequences commonly have many other sequences adjacent to the described sequence.

A portion or segment of the described sequence can be used so long as it is sufficiently characteristic of the desired T cell receptor or fragment thereof to cause an effect on the immune system which regulates T cells having the desired T cell receptors, but not against T cells not having desired T cell receptors. Such variations in the sequence can easily be made, for example by synthesizing an alternative sequence. The alternate sequence can then be tested, for example by administration to a vertebrate, to determine its effectiveness. As used herein, the term "fragment" means a subset of the non-conserved amino acid sequence of a TCR that can cause an effect on the immune system which regulates T cells. As used herein, the term "non- conserved region" refers to variable and VDJ regions. The term is intended to include such fragments in conjunction with or combined with additional sequences or moieties, as for example where the peptide is coupled to other amino acid sequences or to a carrier. The terms "fragment" and "peptide" can, therefore, be used interchangeably since a peptide will be the most common fragment of the T cell receptor. Each fragment of the invention can have an altered sequence, as described above for the term "substantially the sequence."

Reference herein to a "fragment," "portion" or

"segment" of a T cell receptor does not mean that the composition must be derived from intact T cell receptors. Such "fragments," portions" or "segments" can be produced by various means well-known to those skilled in the art, such as, for example, manual or automatic peptide synthesis, various methods of cloning or enzymatic treatment of a whole TCR.

As used herein, the phrase to "cause an effect on the immune system which regulates T cells" means to cause the immune system to modify the activity in. response to their ligands of T cells bearing particular T cell receptors. Such an effect can include either wholly or partially a T cell response. For example, the down regulation of an autoreactive T cell may be a result of the recognition by a regulatory T cell of the T cell receptor peptide in the groove of an MHC molecule on the surface of an autoreactive T cell. Alternatively, the regulatory effect can be caused by the interference by a T cell receptor peptide of the interaction of a T cell recptor on an autoreactive T cell and its MHC/peptide ligand. Such modification of activity can be evidenced by amelioration of the severity of inflammation in the target tissue. The amount of such a peptide necessary to cause such an effect will vary between species and individuals depending on many factors which one skilled in the art can determine.

As used herein, "binding partner" means a compound which is reactive with a TCR. Generally, this compound will be a Major Histocompatibility Antigen (MHO but can be any compound capable of directly or indirectly stimulating T cell activation or proliferation when bound to the TCR. Such compounds can also be, for example, a superantigen that binds to a superantigen binding site on the TCR.

As used herein, "superantigens" means antigens or fragments thereof that bind preferentially to T cells at specific sites on the β chain of a TCR and stimulate T cells at very high frequency rate. Such superantigens can be endogenous or exogenous. "Frequency" refers to the proportion of T cells responding to antigens and ranges from about 1/5 to 1/100 in response to superantigens. Thus, superantigens are distinguishable from conventional antigens, which have a much lower T cell response frequency rate ranging from about 1/10⁴ to 1/10⁶. Superantigens activate T cells by binding-to specific Vβs. The superantigen binding sites of various TCRs have been distinguished from the conventional hypervariable regions (CDRs) of TCRs. These CDRs represent the regions of TCRs thought to be responsible for binding conventional antigens that are complexed to MHC.

As used herein, "ligand" means any molecule that reacts with another molecule to form a complex. As used herein, "selectively binds" means that a molecule binds to one type of molecule or related group of molecules, but not substantially to other types of molecules. In relation to Vβs, "selective binding" indicates binding to TCRs or fragments thereof containing a specific Vβ without substantial cross-reactivity with other TCRs that lack the specific Vβ.

As used herein, "individual" means any vertebrate, including human, capable of having psoriasis.

As used herein, "reduce the severity of psoriasis" means improving the condition of psoriatic lesions or decreasing the percentage of T cells in a lesion bearing a preferential T cell receptor.

The immune system is the primary biological defense of the host (self) against potentially pernicious agents (non-self) . These pernicious agents may be pathogens, such as bacteria or viruses, as well as modified self cells, including virus-infected cells, tumor cells or other abnormal cells of the host. Collectively, these targets of the immune system are referred to as antigens. The recognition of antigen by the immune system rapidly mobilizes immune mechanisms to destroy that antigen, thus preserving the sanctity of the host environment.

T cells owe their antigen specificity to the T cell receptor (TCR) which is expressed on the cell surface. The TCR is a heterodimeric glycoprotein, composed of two polypeptide chains, each with a molecular weight of approximately 45 kD. Two forms of the TCR have been identified. One is composed of an alpha chain and a beta chain, while the second consists of a gamma chain and a delta chain. Each of these four TCR polypeptide chains is encoded by a distinct genetic locus containing multiple discontinuous gene segments. These include variable (V) region ger segments, joining (J) region gene segments and const- ; (C) region gene segments. Beta and delta chains contain an additional element termed the diversity (D) gene segment. Since D segments and elements are found in only some of the TCR genetic loci, and polypeptides, further references herein to D segments and elements will be ir parentheses to indicate the inclusion of these regions <- ly in the appropriate TCR chains. Thus, V(D)J refers either to VDJ sequences of chains which have a D region or refers to VJ sequences of chains lacking D regions .

With respect to the variable region of the beta chain, referred to as a Vβ, the nomenclature used herein to identify specific Vβs follows that of Kimura et al . , Eur. J. Immuno. 17:375-383 (1987) .

During lymphocyte maturation, single V, (D) and J gene segments are rearranged to form a functional gene that determines the amino acid sequence of the TCR expressed by that cell. Since the pool of V, (D) and J genes which may be rearranged is multi-membered and since individual members of these pools may be rearranged in virtually any combination, the complete TCR repertoire is highly diverse and capable of specifically recognizing and binding the vast array of binding partners to.which an organism may be exposed. However, a particular T cell will have only one TCR molecule and that TCR molecule, to a large degree if not singly, determines the specificity of that T cell for its binding partner.

Animal models have contributed significantly to the understanding of the immunological mechanisms of autoimmune disease. One such animal model, experimental allergic encephalomyelitis (EAE) , is an autoimmune disease of the central nervous system that can be induced in mice and rats by immunization with myelin basic protein (MBP) . The disease is characterized clinically by paralysis and mild wasting and histologically by a perivascular mononuclear cell infiltration of the central nervous system parenchyma. The disease pathogenesis is mediated by T cells having specificity for MBP. Multiple clones of MBP-specific T cells have been isolated from animals suffering from EAE and have been propagated in continuous culture. After _______ vitro stimulation with MBP, these T cell clones rapidly induce EAE when adoptively transferred to healthy hosts. Importantly, these EAE- inducing T cells are specific not only for the same antigen (MBP) , but usually also for a single epitope on that antigen. These observations indicate that discrete populations of autoaggressive T cells are responsible for the pathogenesis of EAE.

Analysis of the TCRs of EAE-inducing T cells has revealed restricted heterogeneity in the structure of these disease-associated receptors. In one analysis of 33 MBP-reactive T cells, only two alpha chain V region gene segments and a single alpha chain J region gene segment were found. Similar restriction of beta chain TCR gene usage was also observed in this T cell population. Only two beta chain V region segments and two J region gene segments were found. More importantly, approximately eighty percent of the T cell clones, had identical amino acid sequences across the region of beta chain V-D-J joining. These findings confirm the notion of common TCR structure among T cells with similar antigen specificities and indicate that the TCR is an effective target for immunotherapeutic strategies aimed at eliminating the pathogenesis of EAE. An alternative mechanism for T cell activation has been suggested in which endogenous and exogenous superantigens have been shown to mediate T-cell stimulation as described, for example, in White et al . , Cell 56:27-35 (1989) and Janeway, Cell 63:659-661 (1990) .

The present invention provides an effective method of immunotherapy for psoriasis which avoids many of the problems associated with previously suggested methods of treatment . By administering the peptides of this invention rather than passively administering heterologous antibodies, the host's own immune system is mobilized to suppress the autoaggressive T cells. Thus, the suppression is persistent and may involve any or all immunological mechanisms in effecting that suppression. This multi-faceted response is more effective than the uni-dimensional suppression achieved by passive administration of monoclonal antibodies or ≤x. vivo- derived regulatory T cell clones which requires a highly individualized therapeutic approach because of MHC non- identity among humans in order to avoid graft versus host reactions. The methods of the present invention are also more effective than vaccination with attenuated disease- inducing T cells that lack specificity for the protective antigen on the surface of a particular T cell as well as the variable induction of immunity to that antigen. In addition, vaccination with attenuated T cells is plagued by the same labor intensiveness and need for individualized therapies as noted above for ___χ vivo derived regulatory T cell clones.

As they relate to psoriasis, the compositions of the present invention comprise TCR fragments from specific T cells that mediate psoriasis. The peptides can be whole TCRs substantially purified from T cell clones, individual T cell receptor chains (for example, alpha, beta, etc.) or portions of such chains, either alone or in combination. The compositions can be homogenous, for example, a single peptide, or can be composed of more than one type of peptide, each of which corresponds to a different portion of the TCR. Further, these peptides can be from different TCRs that contribute to psoriasis. These peptides can be of variable length so long as they can elicit or affect a regulatory response. Preferably, such peptides are between about 5 - 100 amino acids in length, and more preferably between about 6 - 25 amino acids in length.

In a further specific embodiment, T cell receptors, whole T cells or fragments of TCRs that contain Vβ3 , Vβl3.1 or Vβl7 can be administered to an individual having psoriasis . The effect on the immune system generated in the individual can neutralize or kill T cells having Vβ3 , VS13.1 or Vβl7 and, thus, prevent or treat the deleterious effects of such Vβ-bearing T cells. Moreover, to the extent that Vβ3 , Vβl3.1 or Vβl7 is common to T cell receptors on pathogenic T cells mediating other autoimmune diseases or autoimmune diseases in general, such compositions can also be effective in preventing or reducing the severity of such other autoimmune diseases .

As used herein, "Vβ3" refers to a family of specific human β-chain variable region. Vβ3 has the following amino acid sequence: DVKVTQSSRY LVKRTGEKVF LECVQDMDHE NMFWYRQDPG LGLRLIYFSY DVKMKEKGDI PEGYSVSREK KERFSLILES ASTNQTSMYL CASS (SEQ ID NO: 1) . Kimura, N. et al., Eur. J. Immunol . 17:375-383 (1987) . As used herein, "V313.1" refers to a specific human β-chain variable region. Vβl3.1 has the following amino acid sequence NAGVTQTPKF QVLKTGQSMT LQCAQDMNHE YMSWYRQDPG MGLRLIHYSV GAGITDQGEV PNGYNVSRST TEDFPLRL S AAPSQTSVYF CASS (SEQ ID NO: 2) . Li, Y. et al . , J. Exp . Medicine, 174:1537-1547 (1991) .

As used herein, "Vβl7" refers to a specific human β-chain variable region of three T cell receptors. Vβl7 has the following amino acid sequence: DGGITQSPKY LFRKEGQNVT LSCEQNLNHD AMYWYRQDPG QGLRLIYYSQ IVNDFQKGDI AEGYSVSREK KESFPLTVTS AQKNPTAFYL CASS (SEQ ID NO: 3) . Kimura, N. et al . , Eur. J. Immunol . , 17:375-383 (1987) .

The hypervariable or junctional regions are useful for the compositions of the present invention. Hypervariable regions useful in the present invention include CDR1, CDR2, CDR3 and CDR4. The amino acid sequences of the CDR1, CDR2 and CDR4 hypervariable regions for Vβ3, Vβl3.1 and Vβl7 are shown in Figure 1.

The CDR3 , also known as the V(D)J region, is useful as a composition of the present invention since T cell immunity elicited by peptides corresponding to this region is expected to be highly specific for a particular antigen. Due to the recombination of the V, D and J region genes prior to maturation, the amino acid sequence across these regions is virtually unique to each T cell and its clones.

However, as a germ-line element, the CDR2 region is also useful in psoriasis. In psoriasis studies, the results indicate a limited number of Vβs among the activated T cells infiltrating the epidermis. Thus, peptides corresponding to the CDR2 region are viable alternatives for use as compositions of the present invention. For example, the CDR2 region of Vβ3 : DPGLGLRLIY FSYDVKMKEK G (fragment of SEQ ID NO: 1) ,^' of VS13.1: DPGMGLRLIH YSVGAGITDQ G (fragment of SEQ ID NO: 2) , or of Vβl7: DPGQGLRLIY YSQIVNKFQK G (fragment of SEQ ID NO: 3) , can be used.

Modifications in these sequences that do not affect the ability of the receptor or a fragment thereof to act as an immunogen to stimulate the desired effect on the immune system are contemplated and are included in the definition of TCR fragment. The variable region can be joined with any D and J segment of the TCR. Further, representative fragments of Vβ3, Vβl3.1 and Vβl7 are also included in the definition of "Vβ3," "Vβl3.1" and "Vβl7," respectively.

In another embodiment, peptides can correspond to the Vβ regions that contain sequences of high homology which are conserved among pathogenic TCRs. These regions of conserved homology include the conventional CDRs, such as CDR1 and CDR2, which are common to T cells bearing the same Vβ, and also the superantigen binding site, which can be common to pathogenic TCRs bearing different Vβs. The superantigen binding site is also known to be in or around the CDR4 hypervariable region.

The compositions of the present invention comprise peptides of varying lengths corresponding to the TCR or fragments thereof capable of causing an effect on the immune system. The peptides can correspond to regions of the TCR which distinguish that TCR from other nonpathogenic TCRs. Such specific regions can, for example, be located within the various region(s) of the respective TCR polypeptide chains, for example, a short sequence spanning the V(D)J junction, thus restricting the effect on the immune system solely to those T cells bearing this single determinant. The compositions are administered to an individual exhibiting or at risk of exhibiting psoriasis. Definite clinical diagnosis of psoriasis warrants the administration of the relevant disease-specific TCR compositions. Prophylactic applications are warranted in diseases where the autoimmune mechanisms precede the onset of overt clinical disease. Thus, individuals with familial history of disease and predicted to be at risk by reliable prognostic indicators could be treated prophylactically to interdict autoimmune mechanisms prior to their onset.

TCR peptides can be administered in many possible formulations, including pharmaceutically acceptable media. In the case of a short peptide, the peptide can be conjugated to a carrier, such as KLH, in order to increase its ability to cause an effect on the immune system. The composition can include or be administered in conjunction with an adjuvant, of which several are known to those skilled in the art. After initial immunization with the vaccine, further boosters can be provided. The compositions are administered by conventional methods, in dosages which are sufficient to cause an effect on the immune system. Such dosages can be easily determined by those skilled in the art .

Appropriate peptides to be used for administration can be determined as follows. Disease- inducing T cell clones reactive with the target antigens are isolated from affected individuals. Such T cells are obtained preferably from the site of active autoaggressive activity such as a psoriatic lesion.

Alternatively, such T cells can be obtained from blood of affected individuals. The TCR genes from these autoaggressive T cells are then sequenced. Polypeptides corresponding to TCRs or portions thereof that are selectively represented among disease inducing T cells (relative to non-pathogenic T cells) can then be selected as vaccines and made and used as described above. An alternative method for isolating pathogenic T cells is provided by Albertini in PCT Publication No. WO88/10314, published on December 29, 1988.

Alternatively, the compositions can comprise anti-idiotypic antibodies which are internal images of the peptides described above. Methods of making, selecting and administering such anti-idiotype vaccines are well known in the art. See, for example, Eichmann, et al., CRC Critical Reviews in Immunology 7:193-227 (1987) , which is incorporated herein by reference.

In a further aspect of the present invention, methods of preventing the proliferation of T cells associated with psoriasis are also contemplated. Such methods include determining a T cell receptor binding partner according to the above methods and administering an effective amount of such binding partner in an appropriate form to prevent the proliferation of the T cells. The methods can be used, for example, to build a tolerance to self antigens as in the case of an autoimmune disease.

The present invention also relates to methods of preventing or reducing the severity of psoriasis by inhibiting the binding of a T cell receptor to its TCR binding partner in order to prevent the proliferation of T cells associated with psoriasis. Ligands that are reactive with the T cell receptor or its binding partner at binding sites that inhibit the T cell receptor attachment to the binding partner can be used. Such ligands can be, for example, antibodies having specificity for the T cell receptor or its binding partner. The invention also provides a method of preventing or reducing the severity of psoriasis in an individual comprising cytotoxically or cytostatically treating Vβ-containing T-cells, particularly Vβ3 , Vβl3.1 and Vβl7, in the individual. The Vβ-contaming T cells are treated with a cytotoxic or cytostatic agent that selectively binds to the Vβ region of a T cell receptor that mediates psoriasis . The agent can be an antibody attached to a radioactive or chemotherapeutic moiety. Such attachment and effective agents are well known in the art. See, for example, Harlow, E. and Lane, Antibodies. A Laboratory Manual. Cold Spring Harbor Laboratory (1988) , which is incorporated herein by reference.

As noted, the invention provides the disc ^~rγ that specific variable regions of the β-chains of three TCRs, designated Vβ3, Vβl3.1, and Vβl7, are closely associated with psoriasis in human subjects. This discovery allows for the detection, prevention and treatment of psoriasis using the methodology set out in this invention.

Specifically, the invention provides a method of diagnosing or predicting susceptibility to psoriasis in an individual comprising detecting T cells having the β-chain variable region from Vβ3, Vβl3.1 or Vβl7 in a sample from the individual, the presence of abnormal levels of such Vβ-containing T cells indicating the pathology or susceptibility to the pathology. The Vβ- containing T cells can be qualitatively or quantitatively compared to that of normal individuals. Such diagnosis can be performed, for example, by detecting a portion of the Vβs that does not occur on non-psoriasis associated β-chain variable region T-cell receptors. The Vβs of the present invention can be detected, for example, by contacting the Vβs with a detectable ligand capable of specifically binding to the individual Vβs. Many such detectable ligands are known in the art, e.g. an enzyme linked antibody. Alternatively, nucleotide probes, complementary to the individual Vβ of interest, encoding nucleic acid sequences can be utilized to detect such Vβ- containing T cells.

The invention also provides a method of preventing or reducing the severity of psoriasis comprising preventing the attachment of a Vβ3-, Vβl3.1- or Vβl7-containing T-cell receptor to its binding partner. In one embodiment, attachment is prevented by binding a ligand to Vβ3 , VS13.1 or Vβl7. In an alternative embodiment, attachment is prevented by binding a ligand to the Vβ3, VS13.1 or Vβl7 binding partner. Attachment can be prevented by known methods, e.g. binding an antibody to the individual Vβs or to its binding partner in order to physically block attachment.

The present invention further relates to a method of preventing or reducing the severity of psoriasis by gene therapy. This method involves the use of vectors having an expression control sequence operatively linked to a nucleic acid molecule encoding a polypeptide. The nucleic acid molecule can be DNA or RNA. The polypeptide can be a TCR or a fragment thereof capable of causing an effect on the immune system_^ or an anti-idiotype antibody that can be used as a composition in the present invention. Such DNA or RNA can be isolated by standard methods known in the art. The isolated nucleic acid can then be inserted into a suitable vector by known methods. An expression control sequence is operatively linked to a nucleic acid molecule when it directs the transcription and translation of that molecule in an appropriate host cell. This includes provision of appropriate start and stop codons. Expression vectors and their use are well known to the art. Such methods are described, for example, in Sambrook et al . , Molecular Cloning - - A Labora tory Manual , Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, (1989) which is incorporated herein by reference.

The vector is subsequently administered directly into a tissue of an individual. Preferably, the DNA or RNA-containing vector is injected into the skeletal muscle of the individual. For example, a 1.5 cm incision can be made to expose the quadricep muscles of the subject. A 0.1 ml solution containing from 10-100 μg of a DNA or RNA plasmid and 5-20% sucrose is injected over 1 minute into the exposed quadricep muscles about 0.2 cm deep. The skin is thereafter closed. The amount of DNA or RNA vector can range from 10 to 100 μl of hypotonic, isotonic or hypertonic sucrose solutions or sucrose solutions containing 2 mM CaCl₃. The plasmid containing solutions can also be administered over a longer period of time, for example, 20 minutes, by infusion. The in vivo expression of the desired gene can be tested by determining an increased production of the encoded polypeptide by the subject according to methods known in the art or as described, for example, in Wolff et al., Science 247:1465-1468 (1990) .

It is believed that the treated cells will respond to the direct injection of DNA or RNA by expressing the encoded polypeptide for at least about 60 days. Thus, the desired TCR, fragment capable of causing an effect on the immune system or anti-idiotype antibody can be effectively expressed by the cells of the individual as an alternative to vaccinating with such polypeptides. The present invention also relates to vectors useful in the gene therapy methods and can be prepared by methods known in the art. Compositions containing such vectors and a pharmaceutically acceptable medium are also provided. The pharmaceutically acceptable medium should not contain elements that would degrade the desired nucleic acids.

The following example is intended to illustrate but not limit the invention.

EXAMPLE

PREFERENTIAL USAGE OF Vβ3, VB13.1 AND V17 IN PSORIASIS

All psoriasis patients for this study were enrolled at the Psoriasis Research Institute (Palo Alto, CA) . The clinical background information is provided in Table I . None of the patients were treated by any topical medications for at least two weeks before sampling. Epidermal shavings measuring 0.4 mm thickness by 6 cm² were taken from a clinically active lesion from back, arm or abdomen using a Castroviejo keratotome (Storz Instruments Inc., St. Louis, MO.) Samples were shipped overnight in RPMI containing 1% human AB serum at 4°C.

Skin samples were cut with a scalpel and treated with No-zyme cell dissociation buffer (GIBCO BRL, Gaithersburg, MD) with 0.1% DNase for 15 minutes at 37°C. Undigested pieces were further treated with 0.25% trypsin with 0.1% DNase for 10 minutes. Cells released were spun down, resuspended in ice-cold PBS (with DNase) to lyse keratinocytes (Foster CA. et al. , J. Exp. Med. , 171:997- 1013 (1990) ) . Further enrichment of lymphocytes was done by collecting interface cells after separating on Ficoll-Hypague gradient. Peripheral blood leukocytes (PBLs) were isolated by Ficoll Hypague as suggested by the manufacturers .

Lymphocyte enriched population was stained with monoclonal mouse anti-human CD4, CD8 , CD25 antibodies and sorted on FACStar Plus (Becton-Dickinson, Mountain View, CA) . Cytochrome conjugated normal mouse immunoglobulins were used as control antibodies to set the gates. CD8⁺ (or CD8⁺CD25^*) , CD4⁺ (or CD4⁺CD25^*) cells were collected, spun down and to the pellet RNazol was added, samples vortexed and then frozen at -70°C.

Total RNA was isolated using RNazol B (Biotecx Laboratories, Inc., Houston, TX) according to the manufacturer's directions. Twenty micrograms (μg) of glycogen (Boehringer Mannheim, Indianapolis, IN) was added to coprecipitate the RNA. Mock RNA tubes containing no nucleic acids were simultaneously processed to ensure there was no reagent contamination. RNA was collected after overnight precipitation at -20°C by centrifugation at 14,000 rpm for 25 minutes, followed by a 75% ethanol wash. After aspirating all ethanol, the air-dried RNA pellet was resuspended in DEPC-water and taken for cDNA synthesis. cDNA synthesis was performed in a 10 μl volume using an antisense Cβ primer, GCGGCTGCT CAGGCAGTA (SEQ ID NO: 4) , which binds approximately 220 nucleotides downstream from the Jβ) at a final concentration of 100 nM. The Superscript Preamplification System was used for all cDNA syntheses as suggested by the manufacturer (BRL, Gaithersburg, MD) Since such small amounts of RNA cannot be quantitated by absorbance at 260 nm, blood lymphocyte RNA sample was equilibrated to contain the same amount of cell- equivalent ' s worth of total RNA as that in skin in order to compare the relative signals obtained in the PCR. In addition, RNA extraction and further analysis was performed on only samples that contained at least 1000 sorted cells .

PCR amplifications of cDNA for the skin and blood samples were prepared and run simultaneously in the same block using a Perkin Elmer Cetus Thermal cycler (Perkin Elmer Cetus, Norwalk, CT) . "Water blank" controls were included to run through the PCR and all previous protocols to ensure no contamination. The thermal cycling profiles were as follows: One time at 94°C for 5 minutes to denature all RNA:DNA hybrids, followed by cyclings of 94°C for 1 minute, 55°C for 1 minute, and 72°C for 1 minute. Number of cycles (mean = 33) varied depending on the amount of input template. Hot start PCR was employed to minimize spurious priming by using AmpliWax gems (Perkin Elmer Cetus) .

Twenty-two individual PCR reactions were set up in 50 μl in GeneAmp tubes (Perkin Elmer Cetus) with each tube containing the appropriate Vβ-specific primer. Most sense primers were taken from Choi, Y. , et al . , Proc . Natl . Acad. Sci . USA. , 86:8941-8945 (1989) or

Wucherpfeennig, K.W. , et al. , Science, 248:1016-1019 (1990) (Vβs 1, 11, 15, and 19) which are incorporated herein by reference although a few others were changed as follows (5 '-3') : Vβ6- TCAGGTGTGA TCCAATTTC (SEQ ID NO: 5) ; Vβ8- TCTGGTACAG ACAGACCATG AT (SEQ ID NO: -6) ;

Vβl2- GATACTGACA AAGGAGAAGT CTCAGAT (SEQ ID NO: 7) ; Vβl7- TCACAGATAG TAAATGACTT TCAG

(SEQ ID NO: 8) . These primers were changed from those previously published in order to capture all subfamily members (i.e., Vβ6, 8) or to prevent cross-priming onto closely related subfamilies ' members (Vβl2 and 13 are closely related) . All 22 primers have been extensively tested by sequencing to ensure that they are specific for only the desired/predicted subfamily. At the 3 '-end, a ³³P-γATP end labeled antisense Cβ (TTGGGTGTGG GAGATCTCTG C (SEQ ID NO: 9) , which primes approximately 55 nucleotides from the Jβ) was used.

Upon completion of the PCR reaction, 15 μl of each PCR reaction was run on a 6% non-denaturing polyacrylamide gel to resolve the specific PCR products. The radioactivity of each PCR product was then directly scanned from each dried gel using an Ambis Radioanalytic System (Ambix, San Diego, CA) . The total cpms of all Vβ PCR products on each gel was summed and divided into each individual cpm value to establish a value for each Vβ expressed as a percentage. Both skin and blood samples were treated as identically as possible (equilibrated templates, identical cycling conditions, and equivalent cycle number in many instances) . A relative compariscn between the percentage of each Vβ in the skin to that in the blood was made throughout this study.

To sequence the Vβ PCR products, PUC18 plasmid was used and dideoxy cycle sequencing was performed as suggested by the manufacturers (Applied Biosystems Inc., Foster City, CA) using the ABI 373 Sequencer (Applied

Biosystems, Foster City, CA) . Each sequence obtained was scanned against the panel of known human Vβ and Jβ genes to establish identity using PC Gene (Intelligenetics, Mountainview, CA) . Each nucleotide sequence was translated and reported as the predicted amino acid sequence.

To examine if there is a preferential usage of a certain Vβ gene in psoriatic plaque lesion, we isolated CD8^* T cells from both the psoriatic epidermis and the PBL, and the percent of expression of Vβl to Vβ20 was determined as described above. It is reasoned that T cells which are involved in plaque formation should be stimulated in si tu by antigen or superantigen on the skin elements. Therefore, one criteria for preferential usage of a Vβ in the skin was that it had to represent at least 10% of the total Vβs in the skin and its relative expression of skin to PBL levels was at least 2. We also included Vβs of which the expression was very high (greater than 30%) in the skin, although the relative expression of skin to PBL level was less than 2 as a result of an unusually high expression in the PBL. These Vβs were included since otherwise an active systemic response to superantigens, relevant or irrelevant to psoriasis, would mask the significance of a highly expressed Vβ in the skin.

As shown in Table II, among the thirteen patients for which TCR Vβ analysis of skin and PBL were performed, a total of eleven patients preferentially used either Vβl3.1 or Vβ3. For example, three patients used only Vβl3.1, four patients used only Vβ3 and four patients showed preferential usage of both Vβl3.1 or Vβ3. In the two patients that did not show preferential expression of Vβl3.1 and Vβ3, a common usage of Vβl7 was detected. It should be noted here, CD8⁺CD25^* T cells were studied in some patients and CD8⁺ T cells were studied in others when samples showed a low number of double positive cells (on FACS screen) and a decision was made to sort all CD8⁺ T cells in order to obtain enough cells (at least 1000) to study.

To determine if these TcR Vβ-bearing cells persisted in these chronic plagues, four of the patients that used Vβl3.1 (with or without Vβ3) were sampled for the second time. The second sample was taken either from the original lesion or at a different site (see Table I) , a different amount of time elapsed between the first and second sampling for different patients. The results of these repeat patients are given in Table III. As shown, patient #5019, which used Vβl3.1 (Table II) in the first sampling, was again shown to use Vβl3.1. Patients #5022 and #5026, which preferentially used Vβ3 and Vβl3.1, were also again shown to use these two Vβs. Patient #5029, which used Vβ3 and Vβl3.1, upon the second shaving, retained the Vβ3 usage. The Vβl3.1 for #5029, according to the criteria that we set, was not preferentially used; nevertheless, the absolute percent of expression was still above 10%. It is noted here that among the repeat samples, two were from the original lesion (#5026, #5029) , two were from different sites (#5019, #5022) . Therefore, these data not only suggest the persistence of these Vβs in the lesion, but also their common presence at different sites.

Analysis of CD8^TCD25⁺ T cells isolated from two atopic dermatitis as shown in Table IV, does not demonstrate an elevated Vβ3 or Vβl3.1 expression in the skin compared to that of PBL. Therefore, repeat findings of elevated level of Vβ3 and Vβl3.1 TCR genes in psoriatic lesions, and the absence of such findings in atopic dermatitis patients, both indicate an in si tu expansion of these T cells to either skin antigens or superantigens in the psoriatic plaques.

To address the question if antigens or superantigens were seen in the skin by these T cells, we analyzed their clonality by sequencing the V-D-J junctions. As shown in Table V, monoclonality (or nearly) of Vβl3.1-bearing CD8⁺ T cells in the skin was observed in patients #5019 and #5022, a marked oligoclonality was seen in patients #5026 and #5029. Vβl3.1 sequences found in PBL were much more polyclonal . These results, therefore, strongly suggest the involvement of limited numbers of antigenic epitopes rather than superantigens in the stimulation of Vβl3.1- bearing CD8^T T cells in these lesions. Vβ3 sequences in the skin, except in patient #5029 where a nearly monoclonality was observed, were less oligoclonal than Vβl3.1 sequences. However, skin antigen rather than superantigen still seems to be responsible for the in si tu expansion of Vβ3-bearing CD8^T T cells since superantigen would have also stimulated Vβ-bearing CD4^* T cells, (Kotzin, B. L. et al . , Proc . Natl . Acad. Sci .

(USA) , 88:9161-9165 (1991) ; Miethke T., et al . , Int . J. Med. Microbiol . , 275:264-268 (1991)) in the skin, in contrast to our finding, as shown in Table VI. As for Vβl3.1 CD4⁺ T cells in the skin, in the two patients that had a lesser (as compared to CD8⁺ T cells) elevation over the PBL, sequence analysis (Table V) showed much diverse junctional sequences than that of Vβl3.1-bearing CD8^* T cells .

Stimulation of Vβ3 and Vβl3.1 CD8^* T cells by antigen in the skin is further supported by sequence data obtained from repeated patients. As shown in Table VII, in two (#5022, #5029) out of three repeat patients that we had obtained sequences of the V-D-J junction, same sequences were obtained, either in the repeat shave of the same lesion (patient #5029) or of a different site. Persistence of T cells with the same antigenic specificity (same V-D-J sequence) in a lesion and the presence of them in different lesions, both reflected an antigenic selection in the skin.

Table I. Clinical History of Psoriasis Patients

Table II. Percentage of Vβ Gene Expression in Skin and PBL CD8⁺ Cells from Psoriasis Patients

* Vβs of which the % expression in skin is above 10 and is at least 2X of that in PBL, or Vβs of which the % expression is equal to or above 30.

Table II (CONTINUED) Percentage of VB Gene Expression in Skin and PBL CD8 Cells from Psoiasis Patients

* VBs of which the % expression in skin is above 10 and is at least 2X of that in PBL, or VBs of which the % expression is equal to or above 30.

Table III. TcR Vβ Gene Expression in Skin and PBL CD8^* T Cells of Psoriasis Repeat Patients

* See Table II

Table IV. TcR VS Gene Usage by Skin and PBL CD8^*T Cells from Atopic Dermatitis Patients

* See Table II

Table V. Analysis of β-Chain Sequences on CD8^* T Cells from Psoriatic Lesions and PBL

Radioactivity of the PCR product of a specific Vβ divided by radioactivity of all Vβ products from a given sample.

Table V. (CONTINUED) Analysis of β-Chain Sequences on CD8^* T Cells from Psoriatic Lesions and PBL

Table VII: Analysis of β-Chain Sequences on CD8^* T Cells from Skins of Repeat Psoriasis Patients

See Table V

"Although the invention has been described with reference to the presently-preferred embodiments, it should be understood that various modifications can be made without departing from the spirit of the invention. Accordingly, the invention is limited only by the claims that follow.

Claims (34)

We claim :

1. A method of preventing or reducing the severity of psoriasis in an individual comprising administering a peptide having substantially the sequence of a T cell receptor present on the surface of T cells mediating psoriasis and capable of causing an effect on the immune system to regulate the T cells.

2. A method of preventing or reducing the severity of psoriasis in an individual comprising administering a peptide having substantially the sequence of a non-conserved region of a T cell receptor present on the surface of T cells mediating psoriasis, or a fragment thereof, wherein the peptide or fragment is capable of causing an effect on the immune system to regulate the T cells.

3. The method of claim 2 wherein the peptide comprises substantially the variable region of a β-chain of a T cell receptor.

4. The method of claim 3 wherein the β-chain variable region is substantially Vβ3, Vβl3.1 or Vβl7.

5. The method of claim 2 wherein the peptide comprises substantially the amino acid sequence of the CDR1, CDR2 or CDR4 region of β-chain variable region of the T cell receptor.

6. The method of claim 5 wherein the β-chain variable region is Vβ3, Vβl3.1 or Vβl7.

7. The method of claim 6 wherein the peptide comprises substantially the Vβ3 sequence DPGLGLRLIY FSYDVKMKEK G (fragment of SEQ ID NO: 1) or a fragment thereof.

8. The method of claim 6 wherein the peptide comprises substantially the Vβl3.1 sequence DPGMGLRLIH YSVGAGITDQ G (fragment of SEQ ID NO: 2) , or a fragment thereof.

9. The method of claim 6 wherein the peptide comprises substantially the Vβl7 sequence DPGQGLRLI YYSQIVNKFQ KG (fragment of SEQ ID NO: 3) or a fragment thereof .

10. The method of claim 2 wherein the peptide comprises substantially the CDR3 region of a β-chain.

11. The method of claim 10 wherein the β-chain comprises Vβ3, Vβl3.1 or Vβl7.

12. A composition for preventing or reducing the severity of psoriasis in an individual comprising a peptide having substantially the sequence of a non- conserved region of the β-chain of a T cell receptor comprising Vβl3.1 or a fragment thereof, wherein the peptide or fragment is capable of causing an effect on the immune system to regulate the T cells.

13. A method of preventing the proliferation of T cells associated with psoriasis in an individual comprising determining a T cell receptor binding partner for a T cell receptor present on the surface of T cells mediating psoriasis and administering the T cell binding partner to the individual, wherein the peptide or fragment is capable of causing an effect on the immune system to regulate the T cells.

14. The method of claim 13 wherein the T cell receptor β-chain comprises Vβ3, Vβl3.1 or Vβl7.

15. A method of preventing or reducing the severity of psoriasis in an individual comprising inhibiting the binding of a T cell receptor to its TCR binding partner in order to prevent the proliferation of T cells associated with psoriasis.

16. The method of claim 15 wherein the T cell receptor β-chain comprises Vβ3, Vβl3.1 or Vβl7.

17. A method of preventing or reducing the severity of psoriasis in an individual comprising contacting T cells specifically associated with psoriasis with an effective amount of a cytotoxic or cytostatic agent specifically reactive with such T cells to inhibit their activity.

18. The method of claim 17 wherein the T cells bear T cell receptors having Vβ3, Vβl3.1 or Vβl7.

19. The method of claim 17 wherein the agent is an antibody attached to a moiety selected from the group consisting of radioactive moieties, chemotherapeutic moieties and chemotoxic moieties.

20. A method of diagnosing or predicting susceptibility to psoriasis in an individual comprising detecting T cells having a T cell receptor associated with psoriasis in a sample from the individual, the presence of abnormal expression of T cells containing the T cell receptor indicating the pathology or susceptibility to psoriasis.

21. The method of claim 20 wherein the T cell receptor has Vβ3, Vβl3.1 or Vβl7.

22. A method of preventing or reducing the severity of psoriasis in an individual comprising preventing the attachment of a psoriasis-associated T- cell receptor to its binding partner.

23. The method of claim 22 wherein the T cell receptor has Vβ3, Vβl3.1 or Vβl7.

24. A method of preventing or reducing the severity of psoriasis in an individual, comprising administering to the individual a vector comprising an expression control sequence operatively linked to a nucleic acid encoding substantially a peptide having substantially the sequence of a non-conserved region of a T cell receptor present on the surface of T cells mediating psoriasis, or a fragment thereof, wherein the peptide or fragment is capable of causing an effect on the immune system to regulate the T cells.

25. The method of claim 24 wherein the peptide comprises substantially the variable region of a β-chain of a T cell receptor.

26. The method of claim 25 wherein the peptide comprises substantially Vβ3, Vβl3.1 or Vβl7.

27. The method of claim 24 wherein the peptide comprises substantially the amino acid sequence of the CDRl, CDR2 or CDR4 region of β-chain variable region of the T cell receptor.

28. The method of claim 27 wherein the β-chain variable region is Vβ3, Vβl3.1 or Vβl7.

29. The method of claim 28 wherein the peptide comprises substantially the Vβ3 sequence DPGLGLRLIY FSYDVK KEK G (fragment of SEQ ID NO: 1) or a fragment thereof.

30. The method of claim 28 wherein the peptide comprises substantially the Vβl3.1 sequence DPGMGLRLIH YSVGAGITDQ G (fragment of SEQ ID NO: 2) , or a fragment thereof.

31. The method of claim 28 wherein the peptide comprises substantially the Vβl7 sequence DPGQGLRLI

YYSQIVNKFQ KG (fragment of SEQ ID NO: 3) or a fragment thereof.

32. The method of claim 24 wherein the peptide comprises substantially the CD3 region of a β-chain.

33. The method of claim 32 wherein the β-chain comprises Vβ3, Vβl3.1 or Vβl7.

34. A vector comprising an expression control sequence operatively linked to a nucleic acid encoding a peptide comprising substantially the sequence of a non- conserved region sequence of a T cell receptor present on the surface of T cells mediating psoriasis or a fragment thereof, wherein the peptide or fragment is capable of causing an effect on the immune system to regulate the T cells.