CA2758829C - Method of treating demyelinating disease - Google Patents

Abstract

A method of inhibiting Peptidyl Argininedeiminase (PAD) in a mammal is provided wherein said method comprises the step of administering 2-haloacetamidine to a mammal. The method is useful to treat a demyelinating disease in mammals such as multiple sclerosis, as well as other diseases in which hyper-citrullination is a factor. Pharmaceutical compositions useful to treat said disease are also provided, as well as a method of screening for PAD inhibitors.

Description

METHOD OF TREATING DEMYELINATING DISEASE
Field of the Invention [0001] The present invention relates to a method of treating demyelinating disease, and in particular, to a method of inhibiting a peptidylarginine deiminase (PAD) which ameliorates the symptoms of demyelinating disease.
Background of the Invention

[0002] Multiple Sclerosis (MS) is the most common demyelinating disease of human adults. It is characterized by a patchy degradation of myelin which heals by scar formation. These foci of degradation are called plaques. No explanation for this focal degradation is available at this time. Neither the cause nor the pathogenesis of MS is known. Genetic, environmental and immune factors are considered to play a role. Clinically, it is a heterogeneous disease, and histological heterogeneity has been reported and categorized into four distinct patterns. Two of the patterns were characterized by perivenular demyelination with a predominance of macrophages and T-cells, the second type of which contained IgG deposits and complement. Both these types are suggestive of experimental autoimmune encephalomyelitis (EAE). The other two patterns were characterized by loss of oligodendrocytes, suggesting a primary oligodendrogliopathy. Therefore, these differences in pathogenesis may explain the heterogeneity of the clinical picture.

[0003] The autoimmune theory is based largely on the animal model, experimental autoimmune encephalomyelitis (EAE). It can be induced in susceptible animals by injection of one of several myelin antigens, including myelin basic protein (MBP), proteolipid protein (PLP), myelin oligodendrocyte glycoprotein (MOG) and others. Since the disease can be transmitted by sensitized T-cells, it is autoimmune.
Based on the EAE studies, a number of immune-based therapies, including T-cell receptor antibodies, oral tolerance, etc., have been used but none have been effective.

[0004] The opposing view to the autoimmune theory of the pathogenesis of demyelination alleges that EAE is more akin to acute disseminated encephalomyelitis (ADEM) in humans, in which cellular infiltrates dominate the histological picture.
This is in contrast to MS, in which cellular infiltrates are not a dominant feature. In this case, MS is believed to be primarily a neurodegenerative disease in which demyelination is the primary event rather than sensitization of T-cells.
Subsequent release of myelin antigens sensitizes T-cells, which exacerbate the disease.

[0005] In early observations, myelin basic protein (MBP), the second most abundant protein in myelin, was reported to be critical for the maintenance of the compaction of the normal myelin sheath. These studies involved the fractionation of the MBP into its several components, one of which was demonstrated to contain citrulline, which arose by the action of the enzyme, peptidylarginine deiminase.
Although this citrullinated MBP accounted for 20% of the total MBP in the normal human brain, it accounted for 45% of MBP prepared from chronic MS and accounted for 90% of the MBP in the fulminating form of MS (Marburg's Disease). The conversion of arginine in proteins to citrulline is carried out by the enzyme peptidyl argininedeiminase (PAD) of which five are known, and PAD2 is the most abundant in brain. PAD2 has been found to be elevated in MS and in an animal model of demyelinating disease. These studies suggest that increased citrullination of proteins by increased PAD2 may account for myelin destabilization as part of the pathogenesis of MS.

[0006] These two theories, the autoimmune and the neurodegenerative are not mutually exclusive. Because of the heterogeneity of MS, some cases of MS may have an autoimmune origin, while others maybe primarily neurodegenerative.
Accordingly, given this heterogeneity and lack of effective treatments for MS, the development of an effective treatment for MS is desirable.

Summary of the Invention

[0007] It has now been found that 2-haloacetamidine inhibits PAD
activity and attenuates clinical signs of disease, including demyelinating disease.

[0008] Thus, in one aspect of the present invention, a method of inhibiting PAD in a mammal is provided comprising the step of administering 2-haloacetamidine to the mammal.

[0009] In another aspect of the invention, a method of treating demyelinating disease in a mammal is provided comprising the step of administering an effective amount of 2-haloacetamidine to the mammal.

[0010] A composition for the treatment of demyelinating disease is also provided in another aspect of the invention. The composition comprises 2-haloacetamidine and a pharmaceutically acceptable adjuvant.

[0011] In yet another aspect, an article of manufacture is provided comprising packaging containing a composition. The composition comprises a 2-haloacetamidine and a pharmaceutically acceptable adjuvant, and the packaging is labeled to indicate that the composition is useful to treat demyelinating disease.

[0012] In a further aspect of the invention, the binding site of PAD is provided which comprises the sequence, FLGEVHCGTNVR.

[0013] In a further aspect of the invention, a method of screening for a potential PAD inhibitor is provided comprising the steps of:
i) incubating a candidate inhibitor with a compound incorporating the amino acid sequence FLGEVHCGTNVR; and ii) determining whether or not the candidate binds to the sequence, wherein a determination of binding between the candidate and the sequence indicates that the candidate is a potential PAD
inhibitor.

[0014] These and other aspects of the invention are described in the detailed description that follows, and in the figures as described below.
Brief Description of the Drawings

[0015] Figure 1 graphically illustrates the level of PAD protein (a), citrullinated proteins (b) and total PAD enzyme activity (c) in normal and MS
white matter extracts by immunoslot blots;

[0016] Figure 2 graphically illustrates dose inhibition of PAD2 by 2-CA
(a), while the binding sites of PAD enzymes are identified using mass spectrometric fragmentation analysis (b) as well as the predicted mechanism of PAD/2-CA
binding (c);

[0017] Figure 3 graphically illustrates attenuation of demyelination in transgenic mice treated with 2CA or 2CA with vitamin B12 after disease onset (a) and prior to onset of disease (b), PAD activity in brain extracts from treated mice (c), quantity of PAD2 (d) and PAD4 (e) mRNA brain extracts of treated and untreated transgenic mice, and the relative amount of PAD2 (P2) and PAD4 (P4) protein in brains of treated and untreated mice;

[0018] Figure 4 graphically illustrates the effect on attenuation of demyelination in ND4 transgenic mice treated initially with 2CA and vitamin followed by cessation of 2CA treatment only;

[0019] Figure 5 graphically illustrates attenuation of demyelination in over-expressing transgenic mice treated with 2CA or 2CA with vitamin B12 (a), and PAD2 activity in treated and untreated brain extracts;

[0020] Figure 6 graphically illustrates attenuation of demyelination in CREAE-induced mice treated with 2CA or 2CA + B12 (a), PAD activity in brain extracts during the course of CREAE (b), attenuation of demyelination in chronic relapsing EAE with intermittent 2CA treatment (c)(i) and PAD activity in brain extracts during the course of 2CA treatment (c)(ii), the mean number of relapses standard deviations (s.d.) in 2CA and 2CA+B12 treated mice (d), the ratio of the diameter of lymphocytic infiltrates over blood vessel diameter in the 2CA and 2CA +
B12 treated CREAE mice (e), and IL-17(0/Interferon-gamma (IFNy)(g) secretion in culture media by splenocytes from treated and untreated CREAE induced mice;
and

[0021] Figure 7 illustrates the stimulatory index of splenocytes from 2CA/2CA-B12 treated and untreated CREAE mice.
Detailed Description of the Invention

[0022] A method of treating demyelinating disease in a mammal is provided.
The method includes administering an effective amount of 2-haloacetamidine to the mammal which has been determined to inhibit peptidylarginine deiminase (PAD) activity.

[0023] The present method is useful generally to treat demyelinating disease.
The term "demyelinating disease" is used herein to encompass any pathological condition of the nervous system of a mammal in which there is degradation or damage to the myelin sheath of neurons including, but not limited to, multiple sclerosis;
idiopathic inflammatory demyelinating disease (IIDD) such as Optic-spinal MS
and neuromyelitis optica (NMO or Devic's disease), Acute disseminated encephalomyelitis (ADEM), Balo concentric sclerosis, Schilder disease or diffuse myelinoclastic sclerosis, Marburg multiple sclerosis, Susac's syndrome and peripheral neuropathies such as Guuillain-Barre syndrome; transverse myelitis, progressive multifocal leukoencephalopathy, Charcot-Marie-Tooth disease (CMT), known also as Hereditary Motor and Sensory Neuropathy (HMSN), Hereditary Sensorimotor Neuropathy (HSMN) or Peroneal Muscular Atrophy, neuropathy associated with diabetes and other auto-immune disorders in which demyelination occurs. It is also useful to treat diseases in which hyper-citrullination of proteins occurs including, but not limited to rheumatoid arthritis, Alzheimer's disease, psoriasis and open angle glaucoma.

[0024] The terms "treat", "treatment" and "treating" are used herein to refer to at least the reduction of the symptoms of disease, but may also include the prevention of such symptoms or the amelioration thereof, which result either directly or indirectly from PAD activity.

[0025] The term "PAD" or "peptidylarginine deiminase" or "protein arginine deiminase" refers to an enzyme which converts arginine in peptides and proteins to citrulline, examples of which include PAD1, PAD2, PAD3, PAD4 and PADS.

[0026] The method includes the administration to a mammal of a 2-halo-acetamidine, an inhibitor of PAD. The 2-halo-acetamidine inhibitor is depicted below in formula I:
X

wherein X is selected from the group consisting of F, Cl and I.

[0027] Treatment of demyelinating disease, and other disease (e.g. in which there is hyper-citrullination), is achieved on administration to the mammal of an effective amount of 2-haloacetamidine. The term "mammal" is used herein to include human and non-human mammals such as domestic animals, livestock, and captive and non-captive wild animals. The term "effective amount" as it is used herein with respect to 2-haloacetamidine, refers to an amount that is useful to inhibit or at least reduce the activity of PAD. Reduction of PAD activity in the brain reduces the occurrence of demyelination within the nervous system of the mammal and induces remyelination. Reduction of PAD activity also reduces the occurrence of protein citrullination which is believed to be involved in diseases other than demyelinating disease as indicated. An effective amount of the inhibitor is in the range of about 1 mg/kg to 10 mg / kg.

[0028] The inhibitor may be administered to a mammal in the treatment of disease in a pharmaceutical composition comprising at least one pharmaceutically acceptable adjuvant. The expression "pharmaceutically acceptable" means acceptable for use in the pharmaceutical and veterinary arts, i.e. not being unacceptably toxic, or otherwise unsuitable. Examples of pharmaceutically acceptable adjuvants include, but are not limited to, diluents, excipients and the like. Reference may be made to "Remington's: The Science and Practice of Pharmacy", 21st Ed., Lippincott Williams & Wilkins, 2005, for guidance on drug formulations generally. The selection of adjuvant depends on the intended mode of administration of the composition. In one embodiment of the invention, the compounds are formulated for administration by infusion, or by injection either subcutaneously or intravenously, and are accordingly utilized as aqueous solutions in sterile and pyrogen-free form and optionally buffered or made isotonic. Thus, the compounds may be administered in distilled water or, more desirably, in saline, phosphate-buffered saline or 5% dextrose solution.
Compositions for oral administration via tablet, capsule or suspension are prepared using adjuvants including sugars, such as lactose, glucose and sucrose;
starches such as corn starch and potato starch; cellulose and derivatives thereof, including sodium carboxymethylcellulose, ethylcellulose and cellulose acetates; powdered tragancanth;
malt; gelatin; talc; stearic acids; magnesium stearate; calcium sulfate;
vegetable oils, such as peanut oils, cotton seed oil, sesame oil, olive oil and corn oil;
polyols such as propylene glycol, glycerine, sorbital, mannitol and polyethylene glycol; agar;
alginic acids; water; isotonic saline and phosphate buffer solutions. Wetting agents, lubricants such as sodium lauryl sulfate, stabilizers, tableting agents, anti-oxidants, preservatives, colouring agents and flavouring agents may also be present.
Creams, lotions and ointments may be prepared for topical application using an appropriate base such as a triglyceride base. Such creams, lotions and ointments may also contain a surface active agent. Aerosol formulations, for example, for nasal delivery, may also be prepared in which suitable propellant adjuvants are used. Other adjuvants may also be added to the composition regardless of how it is to be administered, for example, anti-microbial agents may be added to the composition to prevent microbial growth over prolonged storage periods.

[0029] In order to optimize delivery of the inhibitor to the central nervous system, it is desirable to combine the inhibitor with one or more adjuvants that promote transport of the inhibitor across the blood brain barrier. Examples of such adjuvants include, but are not limited to, liposomal formulations, mineral oil, cremophor, EL castor oil, polyethylene glycols (PEGs) of various molecular masses and castor oil.

[0030] The inhibitor may additionally be administered, either simultaneously or separately, to a mammal in the treatment of disease, such as demyelinating disease, with one or more therapeutic agents or agents which enhance the treatment of the disease. Suitable such agents include, but are not limited to, corticosteroids such as methylprednisolone and prednisone, interferon-13, growth factors such as insulin-like growth factor-1 (IGF-1), muscle relaxants, antiplastic agents, anti-oxidants, analgesics such as NSAIDS, acetaminophen, COX-2 inhibitors and narcotics, and other agents useful to treat symptoms associated with demyelinating disease.

[0031] In one embodiment of the invention, the 2-haloacetamidine inhibitor is advantageously administered to a mammal in conjunction with, but not necessarily combined with, a cobalamin, such as cyanocobalamin, methylcobalamin, hydroxocobalamin) in the treatment of demyelinating disease. This combination treatment has been found to be synergistic in that the expected additive effect of treatment with 2-haloacetamidine and a cobalamin is surpassed. In this regard, an amount of each of 2-haloacetamidine inhibitor and cobalamin which provides treatment of disease is, for example, an amount in the range of 0.1 ¨ 10 mg/kg body weight of 2-haloacetamidine and an amount in the range of 1 ¨ 20 mg/kg of cobalamin.

[0032] The simultaneous administration of 2-haloacetamidine with cobalamin may be achieved via a composition comprising an appropriate amount of each of the inhibitor and cobalamin, or via discrete compositions separately comprising 2-haloacetamidine and a cobalamin, as indicated above. As one of skill in the art will appreciate, such a composition(s) may also include additional adjuvants as described herein.

[0033] In a further aspect of the invention, an article of manufacture is provided comprising packaging containing a composition which comprises a 2-haloacetamidine and a pharmaceutically acceptable adjuvant. The packaging is labeled to indicate that the composition is useful to treat demyelinating disease.

[0034] The PAD binding site of 2-haloacetamidine has also been elucidated, and is represented by the amino acid sequence, FLGEVHCGTNVR (SEQ ID No. 1) containing the active site cysteine (C). . Elucidation of this binding site provides an effective means to screen for potential PAD inhibitors. A candidate inhibitor is incubated in the presence of a peptide comprising the sequence, FLGEVHCGTNVR, under conditions suitable to promote binding. It is then determined whether or not the candidate binds to the binding site. A determination of binding between the candidate and the binding site indicates that the candidate is a potential PAD inhibitor that may be useful in the treatment of disease such as demyelinating disease.

[0035] As one of skill in the art will appreciate, a peptide comprising a functionally equivalent binding site to the elucidated PAD binding site, e.g.
an amino acid sequence incorporating amino acid changes that retains 2-haloacetaminidine binding properties, may also be utilized in an inhibitor screening assay as described.
A functionally equivalent binding site may, for example, incorporate one or more amino acid substitutions, for example, conservative amino acid substitutions in which an amino acid in the binding site is replaced with an amino acid of similar size, shape or charge, such as substitution of glutamic acid with aspartic acid, lysine for arginine, glycine for valine, leucine or isoleucine, serine for threonine, or asparagine for glutamine; one or more amino acids is modified or derivatized to provide a binding site with more desirable properties, for example, increased stability; or the binding site is modified by one or more amino acid deletions or additions, such as additions or deletions at a terminal end of the binding site, to yield a sequence that retains the ability to bind to 2-haloacetamidine.

[0036] Embodiments of the invention are described by reference to the following specific examples which are not to be construed as limiting.

Example 1 Materials and Methods

[0037] Alpha-N-benzoyl-L-arginine ethyl ester (BAEE), L-citrulline were purchased from Sigma Chemical Company, St. Louis, MO, USA. Human recombinant PAD2 and PAD4 (EC 3.5-3.15) were provided by Dr Raijmakers from the Department of Biochemistry, Nijmegen Center for Molecular Life Sciences, Radboud University Nijmegen, NL-6500 HB Nijmegen, The Netherlands. The PAD
inhibitor 2-chloroacetamidine (2-CA) was purchased from Alfa Aesar (Ward Hill, MA, USA). Vitamin B12 (B12) was purchased from Sigma Chemical Company (St.
Louis, MO). The primary antibodies used for this study were as follows: mouse monoclonal antibody F95, which recognizes peptidylcitrulline, was a generous gift of Dr. A.P. Nicholas, University of Alabama at Birmingham, AL (as described in Nicholas et al. J Comp Neurol 486, 254-266 (2005)); rabbit anti-panPAD (a gift from Dr. H. Takahara, lbaraki University, lbaralci, Japan) which recognizes all isoforms of PAD (Nishijyo et al.. J Biochem (Tokyo) 121, 868-875 (1997)), and rabbit anti-polyclonal antibody (Abeam, Cambridge, MA) which recognizes only PAD2.

[0038] Heterozygous ND4 mice were obtained as described in Mastronardi, et al. at. (1993). J Neurosci Res 36(3): 315-24.
Briefly, the ND4 transgenic mouse contains 70 copies (ND4) of the transgene encoding DM20, a myelin proteolipid protein. The mouse appears clinically normal up to 3 months of age. By 8-10 months, it shows tremors, unsteady gait, and then dies. Its clinical symptoms correlate with demyelination based on the following criteria: 1) at 10 months of age only 17% of the amount of myelin obtained from normal mice was isolated from the ND4 mice; 2) astrogliosis, a prominent feature of demyelinating disease was minimal at 3 months of age but prominent by 10 months; 3) at the electron microscopic level disrupted myelin was seen at 8 months of age in the ND4 mice and ingested myelin debris was found in astrocytes; 4) lymphocytic infiltration in association with endothelial cells was observed routinely in the ND4 mice; 5) sections through optic nerves showed denuded and thinly myelinated axons in the 8 month old ND4 mice.

[0039] A PAD2-overexpressing mouse line was also used. The PAD2 transgene was constructed by ligating a 2.3 kb rat PAD2 cDNA into the EcoRI
cloning site of the pMG2 plasmid. This plasmid contains 1.8 kb of the mouse MBP
promoter. exon2, intron2, and exon3 of the beta-globin gene. The transgene construct was restriction-digested with Not!, in order to remove bacterial pUC DNA from the MBP-PAD2 minigene. The Not! fragment containing the minigene was purified from a 0.7% agarose gel using the Genecleang kit (Qbiogene, Morgan Irvine, CA) according to the manufacturer's instructions. The isolated DNA was further purified using Elutip-D columns (Schleicher and Schuell, Keene, NH). The minigene was microinjected into donor mouse CD1 eggs and transplanted into pseudo-pregnant surrogate female CD' mice.

[0040] All animals were housed in a closed colony in the animal care facility at The Hospital for Sick Children (HSC, Toronto, Canada). Mouse colonies were established and maintained according to the guidelines and regulations of the HSC
Animal Care Committee.
Therapy protocol

[0041] Heterozygous ND4 mice were treated with either 2-CA or 2-CA + B12 beginning at either 2 months of age (prophylactic effectiveness) or at 3.5 months, after the appearance of clinical signs of demyelinating disease to test disease supression. For the PAD2 transgenic mice, these same treatments were given after the appearance of clinical signs of demyelinating disease at 6 months of age to test disease suppression. For injection 2CA and B12 were dissolved in phosphate buffered saline (PBS), pH 7.4. Both solutions were filter sterilized through 0.2 gm PVDF
syringe filters and used at 5 mg / kg (for 2CA) and 10 mg / kg (for B12) in both ND4 and PAD2 transgenic mice and injected three times per week intraperitoneally.
Animals were clinically scored thrice weekly, and aggregate mean weekly scores standard deviations were plotted relative to age. On each occasion mice were examined and clinical signs assessed by two independent observers using a scale of 0-4, where 0 represented no signs and 4 represented severe signs. The neurological signs measured, included tail droop, tremors, unsteady gait, head shaking, convulsions, physical activity, and righting ability. Controls were non-transgenic littermates. All mice were housed and maintained in the The Hospital for Sick Children's (HSC) Animal Care facility. At the end of each week the scores were summed and the accumulated scores for each cohort were averaged and standard deviations determined. All experiments were conducted following the approval of the HSC Animal Care Committee protocols.
Induction of chronic relapsing EAE and scoring

[0042] CREAE was induced in 6-8 week old female SJL/J mice using PLP
peptide 139-155 by the method previously described (Nicholas et al. J Comp Neurol 486, 254-266 (2005). Clinical scoring of CREAE induced mice was carried out daily during the experiment. The standard disease scale 0-5 was used to measure EAE
symptoms. A score of 0 indicated no signs, a score of I was indicative of a limp /
flaccid tail, a score of 2 was indicative of an inability of righting, a score of 3 was indicative of paralysis of either hind limb or forelimb, a score of 4 indicated full paralysis of both hind or forelimbs and a score of 5 was given to a moribund or dead animal. The animal care protocol for the CREAE experiments were conducted according to the approved protocol by the HSC's Animal Care Committee. For injection 2CA and B12 were dissolved in phosphate buffered saline (PBS), pH
7.4.
Both solutions were filter sterilized through 0.2 p.m PVDF syringe filters and used at 5 mg / kg (for 2CA) and 10 mg / kg (for B12) and injected three times per week intraperitoneally.
T-cell proliferation and measurement of IFN-gamma and IL-17 levels

[0043] Splenocytes were isolated 45 days after EAE induction. Splenocytes (400,000 cells / well) were plated in 96-well flat bottom plates and cultured in HL-1 serum free media supplemented with L-Glutamine (2mM) (BioWhittaker Inc., Walkersville, MD) for 72 hours in the presence of 1 mg of PLP peptide. In T-cell proliferation assays 1 mCi of (311)-Thymidine was added to the cell culture for the final 18 hours and the radioactivity (cpm) was measured by liquid scintillation counting. To quantitate IL-17 and IFN-gamma, supernatants from PLP139-151 stimulated cultures were collected after 72 hours of culture and IL-17 and IFN-gamma levels measured by ELISA according to the manufacturer's protocol (IL-17, R&D
Systems, Minneapolis, MN; IFN-gamma, BD Bioscience, San Jose, CA).
Generation of 1VIAb 4E12

[0044] A synthetic peptide corresponding to the C-terminal portion of the PAD2 enzyme was generated by the Hospital for Sick Children's Advanced Protein Technology Core facility. The peptide 650FLGEVHCGTNVR (SEQ ID No. 1) was synthesized with acetamidine bound at the Cysteine (C) residue. The peptide-adduct was complexed with keyhole-limpet-hemacyanin (KLH). The KLH-peptide adduct was used to generate specific monoclonal antibodies (MAbs) in the Hospital for Sick Children monoclonal core facility. The KLH-peptide-adduct was emulsified in complete Freund's adjuvant and injected into BALB/C mice. Following three weeks a booster of antigen emulsified in incomplete Freund's adjuvant was injected. A
series of four proceeding injections were peptide-adduct alone solubilized in buffered saline.
Antibody production was monitored by tail-tip bleeds. Serum was recovered and assayed by ELISA. When antibody production was maximal, mice were culled and spleens isolated and triturated in culture media. Splenocytes were selected for B-cells and hybridomas generated using the polyethylene glycol method. Cell lines were made clonal by the methyl-cellulose method. Monoclonal antibody production and titer by the clonal cells was monitored by ELISA assay of cell culture media.
Two MAb's (MAb4B11 and MAb4E12) were of sufficiently high titer and were characterized. The lgG fractions were isolated using protein-G sepharose column chromatography. The MAb4B11/E12 IgGs were used in Western blots to determine selective binding to acetamidine-bound and the localization in brain and bioavailabilty of 2CA in 2CA treated mice.
Reverse Transcriptase PCR (RT-PCR)

[0045] Mouse white matter cDNA was prepared from total RNA using an Invitrogen reverse transcriptase kit, according to the manufacturers instructions. For mouse brain white matter, mouse specific primers for GAPDH (glyceraldehyde-3-phosphate dehydrogenase), PAD2, and PAD4 were used. The forward and reverse primers, and PCR programs, were as follows:

GAPDH (947 bp): 5"-GTG AAG GTC GGA GTC AAC GGA T-3' (SEQ ID No. 2); and 5'-CCA AAT TCA TTG TCA TAC CAG-3' (SEQ ID No. 3);
3 min at 94 C, 30 cycles of (1 min, 94 C; 1 min. 50 C; 3 min. 72 C), 10 min at 72 C.
PAD2 (638 bp): 5'-TCC CCA AGC AAC 'FCC TG-3' (SEQ ID No. 4) and 5'-TCA TGT TCA CCA TGT TAG GG-3' (SEQ ID No. 5);
3 min at 94 C, 35 cycles of (1 min, 94 C; 1 min, 60 C; 3 min, 72 C), 5 min at 72 C.
PAD4 (401 bp): 5'-CTC CAT CCA AGA AGA GTA CC-3' (SEQ ID No. 6) and 5'-GAG TCT TCG TGC TTA GGCi TC-3' (SEQ ID No. 7) ;
3 min at 94 C, 40 cycles of (1 min, 94 C; I min, 55 C; 3 min, 72 C), 5 min at 72 C.

[0046] The PCR reaction mixtures were in a total volume of 50 L. The PCR
reaction consisted of 1.0 1, of cDNA prepared from , IX Qiagen buffer, 5.0 L
Q-solution, 2 L of 5 mM dNTP, 0.5 pL HotstarTaq DNA polymerase and 10 }AM each of forward and reverse primers. The reaction mixtures were adjusted with filter sterilized double distilled deionized water. Amplicons were analyzed by agarose gel electrophoresis. Gels were stained with ethidium bromide and bands were visualized with a UV transilluminator. Images were captured with a CCD camera using Image SXM image analysis software. The levels of PAD2 and PAD4 RNA were expressed as ratios to GAPDH RNA.
Protein analysis and immunoslot blot quantification

[0047] Total brain protein extracts were prepared from non-transgenic and transgenic animals using a Teflon tissue homogenizer (Wheaton, Millville, NJ) in phosphate-buffered saline (PBS), pH 7.6, 6 M urea. Both PAD2 and citrullinated proteins were quantified from white matter homogenates by immunoslot blots.
For PAD2 measurements, 5 itg protein extracts were applied onto a nitrocellulose membrane using a Bin-Dot SF Mierofiltration Apparatus (BioRad, Hercules, CA) according to the manufacturer's instructions. Membranes were probed with either anti-PAD2 antibody or anti-peptidylcitrulline (F95) antibody overnight at 4 C.
The membranes were washed 4-times with Tris-buffered saline containing Tween-20 (TBST), and reacted (1 h at 20 C) with secondary antibodies, either goat anti-rabbit antibody conjugated to horseradish peroxidase (HRP), or goat anti-mouse IgM
antibody conjugated to HRP and developed with enhanced chemiluminescence (ECL) reagent after 4 additional washes with TBST, and exposed to X-ray film.
Immunoslot blot images were analyzed using the Image-SXM image analysis software package.
PAD enzyme activity assays 100481 The PAD activities in aqueous white matter extracts from human and whole brains from mice were determined by measuring the conversion of N-benzoyl-L-arginine ethyl ester (BAEE) to its citrulline derivative using a colorimetric assay.
The quantity of citrulline was determined using the linear regression of the absorbance at 464 nm of citrulline standards. The PAD activities were determined as nmol of citrulline/min/mg of total protein.
Transmission electron microscopy of optic nerve [0049] Tissue sectioning, microscopy, and histopathology were performed by the Neuropathology Service Laboratory at The Hospital for Sick Children. Optic nerves from non-transgenic littermates and transgenic mice (ND4), six months of age, were immersion-fixed with either Karnofsky's solution (as described in Feirabend et al. (1994).
JIVeurosci.Methods ,55, 137-153, particularly at pages 145 to 147), or "nerve fix", which is used as the standard procedure for surgical peripheral nerve fixation by the HSC Neuropathology Service Laboratory.
Peripheral nerves were post-fixed, sectioned, and stained with toluidine blue. Images of sciatic nerve cross-sections were captured using a Leica DM bright field microscope. Optic nerves were removed, and stored at 4 C in Karnofsky's fixative for 7 days. The samples were rinsed in 0.1 M cacodylate buffer and post-fixed in osmium tetroxide. They were dehydrated in an ascending dilution series of acetone, and infiltrated and embedded in plastic Embed 812. Ultrathin cross-sections of the optic nerves from each animal were prepared and mounted on copper grids, stained with uranyl acetate and lead citrate, and viewed in a EDC_LA\M 1467863\1 15

48 JEM-1230 transmission electron microscope (TEM) operated at 80 kV (JEOL U.S.A.

Inc., Peabody, MA). Images were captured using a charge-coupled device (CCD) digital camera. Five hundred measurements of myelin thickness from each group were done using the CCD camera software (AMT Advantage HR Camera System, AMT
Corp., Danvers, MA), and expressed as a mean standard error of the mean. The Student t-test was used to compare the results from the treated, non-treated and the non-transgenic control mice.
Immunogold Electron Microscopy [0050] Optic nerves from non-treated and 2CA treated transgenic mice were fixed in 4% paraformaldehyde containing 0.1% glutaraldehyde in 0.1 M phosphate buffer pH 7.4 for a minimum of 4 hours. Following a thorough rinse in phosphate buffer, samples were infused with 2-3 M sucrose for several hours prior to freezing in liquid nitrogen. The sucrose-infused material was plunged frozen in liquid nitrogen on aluminum ultramicrotomy pins and ultrathin cryosections prepared with a cryo-ultramicrotome at -95 C with a diamond knife. Sections were transferred to formvar nickel grids with a loop of molten sucrose and immunogold labeled. Following blocking in PBS containing 0.15% glycine and 0.5% BSA, the grids were rinsed with PBS/BSA prior to incubation with MAb4E12 against C-terminal PAD-acetamidine adduct for 1 hour. The grids were then washed several times with PBS/BSA prior to incubation with 10 nm gold goat anti-murine complexes (Amersham Life Sciences, Illinois USA). After a thorough rinsing in PBS and distilled water, sections were stabilized in a thin film of methylcellulose containing 0.2% uranyl acetate.
Controls included the omission of either primary antibody or antibody gold complexes.
All of the grids were then examined in JEOL JEM 1230 transmission electron microscope (JEOL USA, Peabody, MA) and images were acquired with a digital camera (AMT
Corp, Danvers, MA).
Histology and morphometric measurement of blood vessel infiltrates [0051] Histology of formalin-fixed, paraffin embedded brain sections using eosin and hematoxylin was done on CREAE induced mice and CREAE mice treated with 2CA and 2CA-EB12. The brains were sagitally bisected and 10 i_tm thick sections were collected onto glass slides. Every third section was stained with eosin-hematoxylin. A total of 5 sections from each mouse was used. The sections were viewed and photographed with an Olympus BX60 light microscope equipped with a CCD camera. TIF images of blood vessel infiltrates were analyzed using Image SXM
software on an Apple Power Macintosh computer running OSX 10.4x software (Apple Inc., Cupertino, Ca). To account for the differences in blood vessel diameter, the ratio of infiltrate diameter (pixels) / blood vessel diameter (pixels) was calculated.
Mass spectrometry [0052] Recombinant PAD2 protein (5 lig) was reacted with 2CA in the presence of Ca2+ in Hepes buffer, pH 7.6 at 52 C for one hour. The PAD-2CA
reaction mixture was placed in dialysis membrane (Spectra/Port Membrane, molecular weight cut off 6-8,000: Spectrum Laboratories, Inc, Rancho Dominguez, CA) and dialyzed against double distilled deionized water to remove any non-bound 2CA and salts, which could adversely affect mass spectrometric analysis. 2CA-bound and non-bound recombinant PAD2 enzyme was digested in-solution using 0.05 g of trypsin (sequencing grade, Roche diagnostics) in 25 mM ammonium bicarbonate pH

8.6 with a total volume of 50 L. After overnight incubation at 37 C, the peptide solution was lyophilized by Speed Vac centrifugation and re-suspended in 20 1_, 0.1%
Trifluoroacetic acid (TFA)(Fluka BioChemika). 10 I, of sample were used for LCMS/MS experiment.
[0053] Reverse phase chromatography was performed on an Agilent 1100 NanoLC system (Santa Clara, CA). Samples (10 L) were first loaded onto a pre-column (100 mm i.d. x 5 cm), and then eluted to an analytical column (75 mm i.d. x cm) for further separation. A 5 cm of regular fused silica capillary with a Kasil fit at one end was used for the pre-column barrel. The analytical column is a fused silica emitter with a tip diameter of 6 mm (Proxeon Biosystems). Both columns were packed in our lab with Pursuit C18 ( 5 um particle size, 200 A pore size, by Varian Inc., Palo Alto, CA). The mobile phase was composed of solutions A and B, where A
was 2% acetonitrile in water, and B was 90% acetonitrile in water, each containing 0.1% formic acid and 0.02% TFA. The gradient started at 0% B and ramped to 100%
B in 65 min. Flow rate was set at 0.3 L/min. The total LC run time was 125 min.

[0054] Mass spectrometry experiment was done on a QSTAR XL electrospray ionization QTOF mass spectrometer (Applied Biosystems/MDS Sciex, Concord, ON, Canada) which was coupled with the above-mentioned Agilent LC system. The mass spectrometer was operated in Information Dependent Acquisition mode automatically cycling through acquisition of an MS survey scan and three MS/MS scans. MS/MS
spectra were recorded sequentially on the three most abundant ions detected in the initial MS scan. Each cycle time was set at 10 sec. (1 sec. MS scan followed by three 3 sec. MS/MS scans).
Peptide sequencing and modification determination [0055] The acquired data set was converted into a peak list file called Mascot Generic File (MGF) using the Mascot script, which comes with the Analyst QS
1.1 software. The MGF file was then used to search against a PAD2 FASTA sequence database using our in-house MASCOT search engine. A custom modification on cysteine called acetamidination was built into the modification database with composition C(2)H(4)N(2), which has a delta mass of 56.0374(monoisotopic).
Protein N-terminal acetylation, methionine oxidation and acetamidination were set as variable modifications in the search. Peptide mass tolerance and MS/MS tolerance were both set to 0.2 Da.
Statistics [0056] Clinical disease course in different animal groups were compared by log-rank statistics and final outcomes by parametric Welch tests, the latter providing a more conservative measure insensitive to the distribution of cohort values.
Trends were the same with either approach. All tests were 2-tailed. Significance was set at 5%.

RESULTS
Inhibition of PAD enzymes by 2CA
[0057] In order to determine if increased citrullinated MBP was associated with increased amounts of PAD enzyme white matter extracts from normal and NAWM from MS brain were used to measure PAD protein with anti-PAD antibody and citrullinated proteins with the F95 monoclonal antibody by slot blots. PAD

protein was elevated in NAWM from MS brain (Figure la) by about 3 fold with a corresponding increase in citrullinated proteins (Figure lb). These levels for both measurements were statistically significant with a parametric p value < 0.05.
The PAD activities in normal (non-neurological patients) and MS white matter extracts from MS victims (Table 1) differed in total activity by about 2 fold (Figure lc, p<
0.01).
Table 1 Patient Sample and PAD activity (nmol cit/
Pathology+ min/mg protein) s.d.
1 Normal, MI 8.9 0.7 2 Normal, CHD, Hy, AF 11.5 0.75 3 Normal, AA, Pcy, Ob 13.7 0.02 4 Normal, Pcy, DM, Fly 12.8 0.84 Normal, CHD, PVD, 15.1 1.3 CRD
6 NA MS 18.5 0.9 7 20 MS 24.2 0.58 8 2 MS 15.1 + 1.6 9 1 MS 17.5 1.1 1 MS 8.24 2.1 11 1 MS 14.6 0.7 12 20 MS 26.2 3.6 13 2 MS 25.4 1.6 14 CP MS 11.6 1.1 1 MS 9 0.3 16 RR MS 17.1+2.5 + 1 - Primary progressive MS; 2 - Secondary progressive MS; CP ¨ Chronic progressive MS; RR ¨ Relapsing Remitting; MI ¨ Myocardial infarction; CHD ¨ Coronary heart disease; Hy ¨
Hypothyroidism; AF ¨ Atrial fibrillation; AA - Aplastic anemia; Pcy ¨ Pancytopenia; Ob ¨ Obesity; DM ¨
Diabetes Mellitus; Cl-IF ¨
Congestive heart disease; PVD ¨ Peripheral vascular disease; CRD ¨ Coronary renal disease [0058] To compare the specific activities of the PAD enzyme in normal and MS white matter, more accurately a standard curve was prepared in which pixel density was correlated with amount (0 ng - 80 ng) of recombinant PAD. The specific activities of the PAD2 from normal brain was 7.98 nmoles citrulline / min / ng and that from the MS NAWM was 8.37 nmoles citrulline / min / ng PAD2. These data show that the elevation of PAD in MS represented an increase in the normal PAD

enzyme (Figure 4).
[0059] To determine the site of interaction of 2CA with PAD2, recombinant PAD2 was reacted with 2CA in the presence of Ca2+ in vitro. The inhibition curve of recombinant PAD2 enzyme shown in Figure 2a) revealed 50% inhibition of PAD2 activity with 100 lag of 2CA. By mass spectrometric fragmentation analysis of the unmodified protein, a cysteine peptide was obtained with a y = 649.3086 and for the modified peptide the y value was 705.3461 (Figure 2b). The mass change between unbound and bound peptide was 56.0375 mass units corresponding to one molecule of acetamidine. The peptide containing the bound acetamidine was isolated from a tryptic digest and sequenced by ES1 mass spectrometry. The mass of the unmodified peptide was 1330.4452 and the modified peptide was 1386.6827 giving a mass difference of 56.0398 corresponding to one molecule of inhibitor which is consistent with the formation of an adduct. The sequence of this peptide was determined to be, 650FLGEVHCGTNVR, located at the C-terminus of the protein. Alignment of the corresponding active site peptides from PAD's 1, 2, 3 and 4 revealed a high degree of sequence identity indicating that acetamidine would bind to all PAD family members at their cysteines (*C) ) in the catalytic site. The proposed mechanism of the reaction between cysteine (*C) and 2CA is shown in Figure 2c which results in a covalent acetamidine adduct at the Cys656 position.
[0060] To determine whether acetamidine was bound to PAD enzyme and was able to get into brain the PAD2 c-terminal peptide was synthesized containing the active site cysteine. The peptide 650FLGEVHCGTNVR was reacted with 2-CA to form a peptide acetamidine covalently bound adduct. Monoclonal antibodies to this adduct were generated by the Hospital for Sick Children's antibody core facility. A
monoclonal antibody MAb 4E12 was isolated and tested on Western blots to determine whether it could bind specifically to recombinant PAD2-acetamidine versus PAD2 without acetamidine. The results revealed that MAb 4E12 bound PAD2-acetamidine exclusively but did not bind unmodified PAD2 and PAD4 (data not shown). MAb4E12 was next used on optic nerve eryosections from mice that were treated with 2CA and control non-treated mice in immuno-electron microscopic localization. The results revealed that secondary anti-mouse-conjugated gold particles bound to clusters in both the nucleus of the oligodendrocyte and myelin of 2CA

treated mice. These results confirm that 2CA is able to get into brain compartments including myelin and the nuclei of oligodendrocytes and binds to PAD.
Attenuation of disease by inhibition of PAD activity in demyelinating mice [0061] Since 2CA was found to inhibit PAD activity in vitro (Figure 2a), it was next determined whether inhibition of PAD activity in vivo could attenuate demyelinating disease. For these studies three models of CNS demyelinating disease were used. One model, the ND4 mouse had extra copies of the myelin proteolipid protein DM20. A second transgenic mouse possessed extra copies of the PAD2 cDNA
expressed in oligodendrocytes. Both these models developed non-inflammatory primary progressive demyelinating disease following normal periods of adult development. The third model was the autoimmune model represented by chronic relapsing encephalomyelitis (CREAE).
I The DM20 over-expressing transgenic mouse (ND4) (a) 2CA treatment after disease onset [0062] To determine whether 2CA could modify the clinical signs during disease progression, mice were treated after disease onset at 3.5 months of age (Treatment start arrow Figure 3a). The treated mice had few signs, which did not worsen during two months of continuous treatment. Their clinical signs remained within the upper limit of the normal mouse range of 10 (shaded region under the curve). The mean clinical scores were significantly below those of non-treated mice at 6.5 months of age (p< 0.01). The inclusion of B12 in the treatment extended the effects of 2CA possibly by methylation of the PAD promoter. These mice remained well within the normal range of symptoms (shaded area). After 6.5 months of age (3 months of treatment) this cohort continued with few signs indistinguishable from their non-transgenic littermates. The mean clinical scores in the combination treated group were significantly different from the non-treated cohort (p< 0.001) indicating that B12 has complex (pleiotropic) effects as an adjunct to the 2CA therapy.
(b) Removal of 2CA treatment results in disease rebound [0063] To determine if the improved clinical signs were the direct result of the treatments, the treatments were stopped with 2CA and 2CA + B12 after 6.5 months of age. The 2CA treated cohort quickly rebounded with worsening clinical signs after only 1 to 2 weeks post treatment (Figure 3a). The signs continued to worsen up to 8 months of age at which time the mice were moribund. The combination treated cohort (p <0.001), worsened more slowly, than the 2CA group. The mean clinical scores remained well below those of the non-treated group at 6.5 months of age (Figure 3a).
(c) 2CA treatment before disease onset [0064] Since disease was attenuated in the model, the efficacy of 2CA
was tested one month prior to disease development to determine if disease could be prevented by starting treatments at two months of age (Figure 3b). Those that received 2CA alone had attenuated symptoms that persisted throughout the treatment period of 4.5 months. The group that received combination treatment (2-CA and B12) had even fewer clinical signs than the 2CA group, although the reduction was not significant.
The mean clinical signs at six months of age for 2CA treated mice were 10 1.5, and 3 1, after three months (p<0.001) for the 2CA and combination treated groups respectively. Therefore PAD inhibition by 2CA alone or in combination with B12 given before disease onset prevented demyelination.
[0065] The effect of removing 2CA from therapy after combination treatment but continuing with B12 treatment was also determined. In this case, the delay in disease rebound was much more pronounced (Figure 4). This combination treatment appears to have at least a dual role which includes inhibition of PAD enzyme activity.
While not wishing to be bound to particular modes of action, it may also reduce PAD
gene expression associated with methylation of the PAD2 gene promoter. Due to the pleiotropic effects of B12 as a universal methylating agent in biological reactions, which include protein, lipid, DNA and RNA methylation, other actions may be involved.
(d) PAD enzyme activity and PAD2 and PAD4 mRNA expression [0066] To determine if improvement in clinical signs was accompanied by decreased PAD activity, 6 months old mice from each of the three groups (Figure 3a) were used to measure PAD activity with BAEE (Figure 3c). Treatment of the mice with 2CA alone resulted in decreased PAD activity and treatment with the combination 2CA +B12 resulted in lower PAD activity to 50% of the untreated group.
After treatment was stopped (post treatment) the PAD activity increased above that of the non-treated group (p<0.05) demonstrating that rebound in disease was accompanied by increased PAD activity.
[0067] To measure PAD2 transcription, RNA was isolated from white matter of ND4 mice, reverse transcribed and amplified with specific primers for PAD2.
The results were expressed as a ratio of PAD2 / GAPDH (Figure 3d). The 2CA alone did not affect PAD2 mRNA levels compared to the non-treated ND4. A large decrease in the mRNA levels was found in the combination treated group suggesting that methylation of the PAD2 promoter by B12 decreased transcription. PAD4 mRNA /
GAPDH mRNA ratios using PAD4 specific primers shown in Figure 3e revealed that the PAD4 mRNA level in the 2CA ND4 treatment group was not different from untreated ND4 mice. The level in the combination group was reduced slightly.
The relative amount of PAD2 and PAD4 protein in brain extracts of ND4 mice treated with 2-CA and 2-CA with B12 is shown in Figure 3f. A differential effect was observed on PAD2 as compared with PAD4. Whereas PAD4 was unchanged, PAD2 was decreased in all mice.
(e) Reversal of myelinolysis after 2CA treatment [0068] Morphological changes in myelin structure following treatment were studied by transmission electron microscopy of cross-sections of optic nerves.
A cross section of the optic nerve from a non-transgenic littermate is shown in Figure 4b.

Axons were well myelinated and the myelin was of uniform thickness. The non-treated ND4 transgenic mouse showed areas of myelin loss and degradation. Nude axons were common. Following 2CA treatment, the morphological picture was improved revealing overall better myelination. Combination treatment with 2CA
+
B12 resulted in a morphological picture indistinguishable from normal indicating a role for B12 in remyelination. Lower resolution histology after luxol fast blue staining showed that the improved remyelination was a general feature in the treated mice.
[0069] Transmission electron micrographs of optic nerves from mice from which treatment was removed show that, at two months post-treatment of the 2CA

treated mice, nude axons were abundant. In the combination treated mice thinly myelinated sheaths were observed along with nude axons. Therefore removal of treatment resulted in renewed demyelination.
[0070] To quantitate the changes of myelination, the G-ratio (axon diameter /
fiber diameter) of myelinated fibers was calculated to determine whether myelin thickness was affected by the treatments. The mean G-ratio was 0.96 0.3 in the transgenic compared with 0.74 0.13 in the non-transgenic littermate represented a significant reduction in thickness of optic nerve myelin (p< 0.001). In the 2CA treated ND4 mouse, myelin thickness was slightly increased as evidenced by a G-ratio of 0.9 0.15 but with less variation in myelin thickness as compared with the untreated group. In the 2CA+B12 treated mice the optic nerve G-ratio decreased further to 0.81 0.18 (p<0.001). These results showed that the treatments improved myelination.
II PAD2 overexpressing mice Attenuation of disease [0071] To provide additional support of the causal role of PAD enzymes in pathogenesis of demyelination, the PAD2 overexpressing mouse carrying 30 copies of the cDNA for PAD2 (padi2) directed to the oligodendrocyte by the MBP promoter was used. Clinical signs of disease were observed at 6 months of age at which time they were treated with 2CA and a second group with the 2CA + B12 combination (Figure 5a). Attenuation of clinical signs was observed in both groups with no difference between the 2CA and the combination groups. PAD activity from the treated groups was reduced to the same level as the non-treated group (Figure 5b) consistent with the attenuation of clinical signs.
III Attenuation of chronic relapsing EAE (CREAE) by 2CA
[0072] CREAE was induced in SJL/J mice with proteolipid protein peptide 139-155 by the method described (Mastronardi, F.G., et al. J Immunol 172, 6418-6426 (2004)). Treatments with 2CA and 2CA+B12 started at day 11 when clinical signs of disease were obvious (the vertical arrow in Figure 6a). To determine whether PAD activity was affected during the course of CREAE, CREAE was induced in SJL/J mice (n=20) and at various stages of disease development measured PAD
activity. The results shown in Figure 6b, reveal that the PAD activity in brains from day 9 had no increase relative to day 0 with a range from 4 to 4.2 nmol citrulline /
minute / mg of brain homogenate. The PAD activity in brains of mice at the peak of the acute phase of disease had the highest PAD activity with an activity at day 16 ranging from 8.9 to 9.5 nmol citrulline / minute / mg of brain homogenate (p<
0.0001). During the chronic relapsing disease phase PAD activities were lower but remained significantly higher than those at day 0 and day 9 (p< 0.001). These results are indicative that PAD activity correlates with the progression and severity of CREAE. To test if PAD activity was associated with CREAE, CREAE was induced in mice and various groups of mice were treated with 2CA when PAD activity was maximal. Treatments of 2CA were started based on the PAD activities determined during the course of CREAE (Figure 6b). Mice were separated into four groups.
Treatment with 2CA began at either day 14 (the peak of the acute phase as determined by clinical scoring), day 20 (end of the acute phase), day 25 (the start of the chronic phase of disease) and day 30. The treatments continued until day 40 at which point brains were excised and prepared for enzyme activity assays. The clinical score data shown in Figure 6c, revealed that 2CA treatments resulted in reduced mean clinical scores at all stages of disease suggestive that PAD activity was a contributing factor in disease development of CREAE.
EDC_LAIM 1467863\1 25 [0073] The non-treated group had relapses and remissions following the acute phase of disease. Both treated groups showed attenuated signs and reduced numbers of relapses over the course of the experiment (Figure 6d) with the combination treated group showing greater reduction in relapses (Figure 6c). After 45 days, the brain of each animal was removed and the extent of disease was determined by the extent of cellular infiltration in eosin, hematoxylin stained sections by morphometric analysis of brain sections. A significant reduction of lymphocytic infiltration around blood vessels (Figure 6e) was observed.
The effect of 2CA and 2CA+B12 on the autoimmune response.
(a) Sensitization of lymphocytes [0074] In order to determine whether the treated and non-treated mice possessed lymphocytes responsive to various myelin and neuronal antigens proliferation assays were conducted. The results shown in Figure 7 revealed that treated and non-treated groups responded equally to PLP139-155, but did not respond to human MBP (C-1 or C-8 the most un-modified C-1 and the citrullinated component C-8). This result showed that the immune system from non-treated and treated mice was equally exposed to the stimulatory effects of PLPI39-155 peptide antigen used in the disease induction.
(b) Proinflammatory cytokines [0075] The secretion of the pro-inflammatory cytokines IL-17 and interferon-gamma (IFNy) was then examined in the media recovered from splenocytes cultured from CREAE mice without and with treatment to determine if this secretion was affected by 2CA or 2CA + B12. The results for IL-17 shown in Figure 6e revealed a 2-fold reduction (p<0.05) in IL-17 secretion in media from mice treated with either 2CA and 2CA+B12. IFNy secretion (Figure 6f) showed a 4-fold decrease (p<0.05) in both treated groups.

[0076] These results revealed that 2CA and 2CA+B12 decreased the secretion and/or production of inflammatory cytokines associated with inflammatory demyelination.

Claims (12)

28We Claim:

1. Use of 2-chloroacetamidine and cobalamin to treat demyelinating disease in a mammal.

2. Use as defined in claim 1, wherein the dernyelinating disease is multiple sclerosis.

3. Use as defined in claim 1, wherein the cobalamin is selected from the group consisting of cyanocobalamin, methylcobalamin and hydroxocobalamin.

4. Use as defined in claim 1, wherein the amount of 2-chloroacetamidine is in the range of 0.1 ¨
mg/kg body weight and the amount of cobalamin is in the range of 1 ¨ 20 mg/kg.

5, Use of 2-haloacetamidine and cobalamin to inhibit peptidylarginine deiminase 2 in a mammal.

6. Use as defined in claim 5, for treating a deinyelinating disease.

7. Use as defined in claim 6, wherein the disease is multiple sclerosis.

8. Use as defined in claim 5, for treating a disease selected from the group consisting of rheumatoid arthritis, Alzheimer's disease, psoriasis and open angle glaucoma.

9. A composition for the treatment of demyelinating disease comprising 2-chloroacetamidine and a cobalamin.

10. The composition as defined in claim 9, additionally comprising a pharmaceutically acceptable adjuvant.

11. The composition as defined in claim 9, comprising an additional therapeutic agent.

12. An article of manufacture comprising packaging containing a cornposition, the composition comprising a 2-ehloroacetamidine, cobalamin and a pharmaceutically acceptable adjuvant, and the packaging being labeled to indicate that the composition is useful to treat dernyelinating disease.