Patent Application
20170007684
A Sequence Listing is included pursuant to 37 C.F.R. 1.821. The Sequence Listing was submitted via EFS-Web on Mar. 17, 2016. The Sequence Listing includes the text file SequenceListing.txt, which is 13 KB in size and was created on Apr. 15, 2013, and which is incorporated by reference herein in its entirety. The Sequence Listing does not include any new matter which goes beyond the disclosure of the application as filed. The attached sequence descriptions and Sequence Listing comply with the rules governing nucleotide and/or amino acid sequence disclosures in patent applications as set forth in 37 C.F.R. §§1.821-1.825. The Sequence Listing contains the one letter code for nucleotide sequence characters and the three letter codes for amino acids as defined in conformity with the IUPAC-IUBMB standards described in Nucleic Acids Res. 13:3021-3030 (1985) and in the Biochemical J. 219 (No. 2):345-373 (1984). The symbols and format used for nucleotide and amino acid sequence data comply with the rules set forth in 37 C.F.R. §1.822.
Autoimmune diseases are characterized by the proliferation of auto-reactive T cells that recognize endogenous antigens. Disease progression is generally typified by T cell activation mediated through two primary signal pathways designated Signal-1 and Signal-2. Signal-1 occurs when the T-cell antigen receptor recognizes the peptide:Major Histocompatibility Complex-II on the surface of an antigen presenting cell (APC). Thus, Signal-1 may be delivered upon the formation of a T-Cell Receptor:Major Histocompatibility Complex-peptide complex. Signal-2 may be delivered upon the binding of a Signal-2 receptor on the T cell to its protein ligand on the surface of an APC. The assembly of both the Signal-1 and Signal-2 receptors at the T cell/APC interface leads to the formation of the “immunological synapse.”
Antigen recognition and the response propagated by immune cells are key events in disease progression for autoimmune and other diseases. Many of the current therapeutic approaches attempt to interfere with these events either directly or through the manipulation of secondary pathways such as cytokine production. Traditionally, these therapeutic pathways have been targeted independently; for example, monoclonal Abs targeting specific receptors (e.g. cell-adhesion or co-stimulation), altered peptide ligands or interfering with antigen presentation. Unfortunately, these treatments often lack long term efficacy or result in deleterious side effects, requiring a new therapeutic strategy. Current therapeutic strategies, such as Copaxone® (a polymeric antigen) or allergy injections, effect Signal-1 by repeated low dose antigen exposure, thereby attempting to induce tolerance. Conversely, therapeutics targeting Signal-2 (e.g. anti-ICAM-1 or anti-LFA-1 or co-stimulatory molecules) give non-specific immunosupression and have been shown to temporarily suppresses the progression of autoimmune diseases. However, these therapies suffer from side-effects, unexpected immune responses, and a lack of specificity.
A therapeutic that combines a Signal-2 inhibitor with a disease specific antigen (Signal-1) generally may provide the ability to suppress certain autoimmune diseases or otherwise tailor immune responses; however, this type of technology currently requires a highly complex synthesis process and purification scheme. Similarly, current compositions combining antigens and Signal-2 inhibitors generally may not be available in the desired region as they tend to persist at the site of injection or go into systemic circulation.
The present disclosure relates generally to bifunctional conjugate compositions and associated methods. More particularly, the present disclosure relates to bifunctional conjugate compositions that comprise a Signal-1 moiety and a Signal-2 moiety, methods of making bifunctional conjugate compositions and their use as a therapeutic for the treatment of auto-immune diseases, infectious diseases, allergies, cancers, etc.
In one embodiment, the present disclosure provides a composition comprising a Signal-1 moiety bound to a first polymer carrier, wherein the combined size of the Signal-1 moiety and the first polymer carrier is about 1 nanometer to about 500 nanometers; and a Signal-2 moiety bound to a second polymer carrier, wherein the combined size of the Signal-2 moiety and the second polymer carrier is about 1 nanometer to about 500 nanometers. In some embodiments, the Signal-1 moiety and the Signal-2 moiety are bound to the same polymer carrier.
In another embodiment, the present disclosure provides a method comprising administering to a subject in need thereof a therapeutically effective amount of composition comprising: a Signal-1 moiety bound to a first polymer carrier, wherein the combined size of the Signal-1 moiety and the first polymer carrier is about 1 nanometer to about 500 nanometers; and a Signal-2 moiety bound to a second polymer carrier, wherein the combined size of the Signal-2 moiety and the second polymer carrier is about 1 nanometer to about 500 nanometers.
In yet another embodiment, the present disclosure provides a method comprising: providing a polymer carrier comprising at least one reactive amide or aminooxy group; providing a Signal-1 moiety comprising at least one reactive amide or aminooxy group, a Signal-2 moiety comprising at least one reactive amide or aminooxy group, or both; and reacting the polymer carrier with the Signal-1 moiety, the Signal-2 moiety, or both to form a conjugate via a N-oxime bond.
The features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the description of the embodiments that follows.
Some specific example embodiments of the disclosure may be understood by referring, in part, to the following description and the accompanying drawings.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
While the present disclosure is susceptible to various modifications and alternative forms, specific example embodiments have been shown in the figures and are herein described in more detail. It should be understood, however, that the description of specific example embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, this disclosure is to cover all modifications and equivalents as illustrated, in part, by the appended claims.
The present disclosure relates generally to bifunctional conjugate compositions and associated methods. More particularly, the present disclosure relates to bifunctional conjugate compositions that comprise a Signal-1 moiety and a Signal-2 moiety, methods of making bifunctional conjugate compositions, and their use as a therapeutic for the treatment of auto-immune diseases, infectious diseases, allergies, cancers, etc.
As previously mentioned above, a two-signal event must generally occur to fully activate a T cell. First, responding T cells must detect a foreign antigen on an antigen presenting cell (APC) (Signal-1). Second, the same T cell must also detect a “danger” or co-stimulatory signal, which leads to the formation of the “immunological synapse” (Signal-2). Firm, sustained adhesion between APC and T cells is necessary to form a mature immunological synapse between the cells and induce stimulation of T cells. Within the immunological synapse, antigen recognition can occur alongside a variety of co-stimulatory signals with firm adhesion mediated predominantly by LFA-1/ICAM-1. The potency of T cell activation is directly related to the number (valency), pattern, and duration of these signals.
In the past, researchers have mainly focused on discretely altering antigen exposure, blocking cell adhesion molecules, or inhibiting co-stimulation as a means to treat autoimmune diseases. For example, it is known that delivering low doses of antigen alone, either sublingually or subcutaneously, can lead to immune tolerance, however this requires delivery over a long duration and outcomes are sporadic at best. Similarly, it is also known that inhibiting cell adhesion or co-stimulatory signals temporarily suppress certain auto-immune diseases, such as type-1 diabetes, rheumatoid arthritis, and multiple sclerosis, but can also result in systemic immunosuppression. Multiple sclerosis is a relapse-remitting disease; an individual with the disease experiences attacks (also called relapses or exacerbations) of worsening neurologic functioning followed by periods of remission in which partial or complete recovery occurs.
The present disclosure is based, at least in part, on the observation that simultaneous exposure of T cells to a bifunctional conjugate composition comprising both a Signal-1 moiety and a Signal-2 moiety is believed to mitigate disease progression significantly better than either repeated low-dose antigen exposure or inhibition of immune cell adhesion or co-stimulation alone, for example. In addition, the present disclosure is also based on the observation that the physical size of the bifunctional conjugate composition is important to promote drainage from the site of injection to the lymphatic region. Accordingly, based at least in part on size, the bifunctional conjugate compositions of the present disclosure advantageously drain to the lymph nodes adjacent to the locus of the autoimmune disease, as opposed to persisting at the injection site or passing to systemic circulation.
Accordingly, in some embodiments, the present disclosure provides bifunctional conjugate compositions that can be used, inter alia, as a therapeutic for the treatment of multiple immune disease targets (e.g. vaccines for immune protection or therapeutics for treating autoimmune diseases), including, but not limited to, multiple sclerosis, rheumatoid arthritis, insulin dependent diabetes, lupus, or some asthmas, or diseases benefitting from vaccination (e.g. infectious diseases or cancer). In general, bifunctional conjugate compositions of the present disclosure may also be used as a therapeutic for the treatment of any disease state or therapeutic target (viruses, cancers) that utilizes the Signal-1 and Signal-2 proliferation pathways.
In one embodiment, the present disclosure provides bifunctional conjugate compositions that comprise at least one polymer carrier, a Signal-1 moiety, and a Signal-2 moiety. As used herein, the term “Signal-1 moiety” includes any antigen or antigen epitope (i.e., the peptide or other portion of any antigen and/or mimetics thereof to which a T cell receptor binds). As used herein, the term “Signal-2 moiety” includes a peptide and/or mimetics including small molecules known to bind to Signal-2 receptors and/or affect binding of a Signal-2 receptor to its complimentary ligand. Such Signal-2 receptors may be stimulatory or inhibitory. In some embodiments, a Signal-1 moiety and a Signal-2 moiety may be bound to the same polymer carrier or to separate polymer carriers. However, as would be recognized by one of skill in the art with the benefit of this disclosure, when a bifunctional conjugate composition comprises a Signal-1 moiety and a Signal-2 moiety bound to separate polymer carriers, the composition should be administered to a subject so as to result in the co-delivery of both a Signal-1 moiety and a Signal-2 moiety to the desired region. For example, separate Single-1 and Single-2 polymer carriers may be co-administered or administered sequentially so as to affect substantially contemporaneous delivery.
As mentioned above, the bifunctional conjugate compositions of the present disclosure are sized so as to drain to the lymph nodes adjacent to the locus of the autoimmune disease, as opposed to persisting at the injection site or entering systemic circulation. Accordingly, in those embodiments where both a Signal-1 moiety and a Signal-2 moiety are bound to one polymer carrier, the combined size of the polymer carrier, Signal-1 moiety and Signal-2 moiety is about 1 nanometers to about 500 nanometers, more preferably about 5 nanometers to about 100 nanometers, and most preferably about 10 nanometers to about 50 nanometers. In those embodiments where only a Signal-1 or Signal-2 moiety is bound to a polymer carrier, the combined size of the polymer carrier and a Signal-1 or Signal-2 moiety is about 1 nanometers to about 500 nanometers, more preferably about 5 nanometers to about 100 nanometers, and most preferably about 10 nanometers to about 50 nanometers. Furthermore, in those embodiments where only a Signal-1 or Signal-2 moiety are bound to a polymer carrier, the size of the polymer carrier for the Signal-1 moiety and the size of the polymer carrier for the Signal-2 moiety ‘carriers’ may be substantially similar so as to affect substantially contemporaneous delivery to the lymphatic area. In some embodiments, where a bifunctional conjugate composition comprises more than one polymer carrier, the plurality of polymer carriers may be associated via an interpenetrating network or semi-interpenetrating network.
The bifunctional conjugate compositions of the present disclosure comprise at least one polymer carrier. Polymer carriers suitable for use in the present invention include those polymers that are capable of binding a Signal-1 moiety and/or a Signal-2 moiety. Examples of suitable polymer carriers include, but are not limited to, polysaccharides, such as glycosaminoglycans (e.g., hyaluronic acid, chondroitin sulfate, dermatan sulfate, keratan sulfate, heparin, heparin sulfate, etc.) and chitosan, poly-N-vinyl formamide (PNVF), poly(ethylene glycol), poly(ethylene glycol) derivatives, polyethers and other degradable polymers such as polypeptides or polyesters. One of ordinary skill in the art with the benefit of this disclosure would be able to select an appropriate polymer carrier to be used in the bifunctional conjugate compositions of the present disclosure based on, inter alia, the type of Signal-1 moiety and/or a Signal-2 moiety which would be bound thereto.
In addition to at least one polymer carrier, the bifunctional conjugate compositions of the present disclosure comprise at least one Signal-1 moiety. In certain embodiments, the bifunctional conjugate compositions of the present disclosure comprise two or more Signal-1 moieties. Signal-1 moieties suitable for use in the compositions of the present disclosure may include a vast array of antigens or antigen epitopes. There are already many known Signal-1 moieties of interest that are defined in the literature. A partial list of some representative Signal-1 moieties include those listed in U.S. Pat. No. 7,786,257, which is hereby incorporated by reference. This list is by no means exhaustive as there are potentially thousands of Signal-1 moieties. One of ordinary skill in the art with the benefit of this disclosure would be able to select an appropriate Signal-1 moiety to be used in the bifunctional conjugate compositions of the present disclosure based on, inter alia, the type of health condition that is to be treated using the composition and/or the type of Signal-2 moiety to be used.
Examples of suitable Signal-1 moieties may include those shown in Tables 1 below:
Homo sapiens
Mus musculus
Homo sapiens
Yersinia HSP
Yersinia
enterocolitica
Homo sapiens
Homo sapiens
Homo sapiens
Felis
domesticus
Felis
domesticus
Ambrosia
artenisiifdia
Ambrosia
trifida
Cryptomeria
japonica
Cryptomeria
japonica
Apis mellifera
Hevia
brasiliensis
Dermatophagoides
pteronyssinus
Mus musculus
Mus musculus
Mus musculus
Mus musculus
Mus musculus
The bifunctional conjugate compositions of the present disclosure additionally comprise at least one Signal-2 moiety. In certain embodiments, the bifunctional conjugate compositions of the present disclosure comprise two or more Signal-2 moieties. Signal-2 moieties suitable for use in the compositions of the present disclosure may include a vast array of peptides known to bind to Signal-2 receptors and/or affect binding of a Signal-2 receptor to its complimentary ligand on an APC. There are already many known Signal-2 moieties of interest that are defined in the literature. A partial list of some representative Signal-2 moieties include those listed in U.S. Pat. No. 7,786,257, which is hereby incorporated by reference. This list is by no means exhaustive. One of ordinary skill in the art with the benefit of this disclosure would be able to select an appropriate Signal-2 moiety to be used in the bifunctional conjugate compositions of the present disclosure based on, inter alia, the type of health condition that is to be treated using the composition and/or the type of Signal-1 moiety to be used.
Examples of suitable Signal-2 moieties include those shown in Tables 2, 3 and 4 below:
Homo
sapiens
Homo
sapiens
Homo
sapiens
Mus
musculus
Homo
sapiens
Mus
musculus
Mus
musculus
Homo
sapiens
Mus
musculus
Homo
sapiens
Mus
musculus
Mus
musculus
Mus
musculus
Mus
musculus
Mus
musculus
Mus
musculus
Mus
musculus
Mus
musculus
Mus
musculus
Mus
musculus
Mus
musculus
Mus
musculus
Mus
musculus
In some embodiments, the Single-2 moiety may comprise an immune suppressor that is capable of inhibiting or preventing activity of the immune system. In general, the immune suppressor is provided with the Signal-1 moiety. For example, the immune suppressor may be provided together with the Signal-1 moiety on a polymer carrier or provided on a separate polymer carrier independent from a Signal-1 moiety. Any immune suppressor may be suitable, including, but not limited to glucocorticoids, cytostatics, small molecules acting on immunophilins (e.g., rapamycin, ciclosporin, tacrolimus), interferons, TNF binding proteins, mycophenolate, and fingolimod. Furthermore, in some embodiments, suitable Signal-1 moieties and/or Signal-2 moieties may be glycosylated.
Signal-1 moieties and/or Signal-2 moieties suitable for use in the present disclosure may be synthesized or prepared by a number of techniques which are well known in the art. Examples include, but are not limited to, automated peptide synthesis by a robotic multiple peptide synthesizer employing Fmoc amino acid chemistry by standard methods. In these embodiments, wang resin (p-benzyloxybenzyl alcohol polystyrene) may be used as the solid support. Peptides can be characterized by reversed-phase HPLC and electrospraymass-spectrometry. This synthesis, referred to as Merrifield peptide synthesis, utilizes traditional organic chemical reactions carried out on a solid material so that the peptide chain is lengthened while attached to the support structure. The peptides will be cleaved from the resin using TFA, and purified by reverse-phase HPLC and analyzed by mass spectroscopy. Alternatively, these reactions can be carried out in solution when larger amounts of the peptides are desired. Examples of other suitable preparation methods are well known in the art. See, for example, Creighton, 1983, Proteins: Structures and Molecular Principles, W. H. Freeman and Co., New York, which is incorporated herein by reference in its entirety. Short peptides, for example, can be synthesized on a solid support or in solution. Longer peptides maybe made using recombinant DNA techniques. Nucleotide sequences encoding peptides suitable for use in the present disclosure may be synthesized, and/or cloned, and expressed according to techniques well known to those of ordinary skill in the art. See, for example, Sambrook, et al., 1989, Molecular Cloning, A is Laboratory Manual, Vols. 1-3, Cold Spring Harbor Press, New York.
Alternatively, the peptides suitable for use in the present disclosure may be synthesized such that one or more of the bonds which link the amino acid residues of the peptides are non-peptide bonds. These alternative non-peptide bonds may be formed by utilizing reactions well known to those in the art, and may include, but are not limited to amino, ester, hydrazide, semicarbazide, and azo bonds, to name but a few. In yet another embodiment, peptides comprising the sequences described above may be synthesized with additional chemical groups present at their amino and/or carboxy termini, such that, for example, the stability, bioavailability, and/or inhibitory activity of the peptides is enhanced. For example, hydrophobic groups such as carbobenzoxyl, dansyl, or t-butyloxycarbonyl groups, may be added to the peptides' amino termini. Likewise, an acetyl group or a 9-fluorenylmethoxy-carbonyl group may be placed at the peptides' amino termini. Additionally, the hydrophobic group, t-butyloxycarbonyl, or an amido group may be added to the peptides' carboxy termini.
Purchasing preformed peptides provides another alternative source of peptides having 25 amino acids or less as these are easily purchased from commercial peptide synthesis laboratories. In later synthesis schemes, peptide mimetic compounds may be synthesized in place of the peptide moieties and linked by the same chemistry. The design of peptidomimetics is an established technique and known correlates of key amino acids of the peptide can be synthesized by previously published methods. Furthermore, as it is well known in the art, peptidomimetics may be developed which have the same modulation properties as the preferred peptides detailed herein. As these peptidomimetics require no more than routine skill in the art to produce, such peptidomimetics are embraced within the present application. Notably, the side chains of these peptidomimetics will be very similar in structure to the side chains of the preferred peptides herein, however, their peptide backbone may be very different or even entirely dissimilar. If resistance to degradation in vivo or greater conformational stability were desired, the peptides could be cyclized by any well known method. One such method adds Penicillamine (Pen) and cysteine (Cys) residues to the N- and C-termini to form cyclic peptides via a disulfide bond between the Pen and Cys residues. The formation of this cyclic peptide restricts the peptide conformation to produce a conformational stability, thereby providing better selectivity for cell surface receptors than its linear counterpart.
In some embodiments, the bifunctional conjugate compositions of the present disclosure may have defined hapten densities and/or valences, as well as concentration ratios, so as to target a range of therapeutic needs. Accordingly, in certain embodiments, a bifunctional conjugate composition of the present disclosure may have one or more of the characteristics shown in Table 5 below (Dintzis, H. M.; Dintzis, R. Z.; Vogelstein, B. Molecular determinants of immunogenicity: the immunon model of immune response. Proc Natl Acad Sci USA 1976, 73, (10), 3671-5). Similarly, in certain embodiments, the polymeric carrier, Signal-1 moieties and/or Signal-2 moieties of the bifunctional conjugate compositions of the present disclosure may have one or more of the characteristics discussed in U.S. Pat. Nos. 7,083,959, 6,375,951, 6,340,460, 6,022,544, 5,370,871, and 5,126,131 issued to Dintzis et al., the relevant portions of which are hereby incorporated by reference. In certain embodiments, a bifunctional conjugate composition of the present disclosure may have one or more of the immunogenic or tolerogenic characteristics shown in Table 5 below.
Similarly, in certain embodiments, the combined molecular weight of the polymer carrier, Signal-1 moiety and Signal-2 moiety may be less than about 500 kDa, or alternatively from about 5-100 kDa, or alternatively from about 10-50 kDa. In those embodiments where only a Signal-1 or Signal-2 moiety is bound to a polymer carrier, the combined molecular weight of the polymer carrier and a Signal-1 or Signal-2 moiety may be less than about 500 kDa, or alternatively from about 5-100 kDa, or alternatively from about 10-50 kDa. Furthermore, in those embodiments where only a Signal-1 or Signal-2 moiety are bound to a polymer carrier, the molecular weight of the polymer carrier for the Signal-1 moiety and the molecular weight of the polymer carrier for the Signal-2 moiety ‘carriers’ may be substantially similar so as to affect substantially contemporaneous delivery to the lymphatic area.
Furthermore, in some embodiments, the bifunctional conjugate compositions of the present disclosure may also be modified with an imaging agent or a label capable of providing a detectable signal, either directly or indirectly. Exemplary labels may include, but are not limited to, radioisotopes, fluorescent molecules, biotin and the like.
The present disclosure also provides methods of making a bifunctional conjugate composition. In one embodiment, a bifunctional conjugate composition may be prepared by conjugating a polymer carrier with a Signal-1 moiety and/or a Signal-2 moiety using conventional chemical methods such as conjugations between carboxylic acids and amines, aldehydes or ketones and amines, di-sulfide bonds, or other reactions that would be known to one skilled in the art.
In another embodiment, a bifunctional conjugate composition may be prepared using N-oxime chemistry. N-oxime chemistry provides an opportunity to conjugate a compound comprising a reactive amide group with a compound comprising a reactive aminooxy group in a specific manner due to the increased reactivity of the amino ester bond for an amide group. While not being bound by any theory, it is currently believed that the presence of the reactive aminooxy group on a compound may allow for complete de-protection of the compound prior to synthesis of a conjugate. Additional details regarding oxime chemistry may also be found in U.S. Patent Publication 2010/0047225, which is herein incorporated by reference.
Previously, it was believed that mainly aldehyde and ketone groups were reactive with aminooxy groups. However, the presence of aldehydes or ketones generally results in highly hydrophobic polymers which is undesirable. (Gajewiak 2006, Heredia 2007, Hwang 2007). A particular advantage of N-oxime chemistry is that it can be carried out in aqueous solvents and avoids many of the harsh catalysts or reaction conditions currently used to create conjugated compounds, such as multivalent polymer-peptide conjugates. Additionally, the reaction can be conducted at lowered temperatures and the reaction efficiency becomes dependent on reactant solubility providing a highly scalable process to manufacture conjugates with a high degree of haptenation (different ligands). In some embodiments, the reaction may be carried out in buffered aqueous media, at pH conditions of 4-8, and decreased temperatures, such as about 20-30° C., although a broader range of temperatures may be also be suitable. In those embodiments where a bifunctional conjugate composition is prepared using N-oxime chemistry, the methods may allow for an increased product yield, reduced purification steps, and greater product stability.
Accordingly, in some embodiments of the present disclosure, a bifunctional conjugate composition may be prepared by reacting a polymer carrier comprising at least one reactive amide or aminooxy group with a Signal-1 moiety comprising at least one reactive amide or aminooxy group, a Signal-2 moiety comprising at least one reactive amide or aminooxy group, or both to form a conjugate via a N-oxime bond. In some embodiments, the resulting conjugate may be represented by the following Formula (I):
wherein R′ or R″ may be independently selected to be any of a number of compounds including a peptide, a protein, a polymer, a saccharide, a small molecule, a Signal-1 moiety, a Signal-2 moiety, etc. and wherein X may be H, CnH(n+2) or other atoms. In some embodiments, the resulting conjugate may be represented by the following Formula (II):
wherein R′ or R″ may be independently selected to be any of a number of compounds including a peptide, a protein, a polymer, a saccharide, a small molecule, a Signal-1 moiety, a Signal-2 moiety, etc. and wherein X may be H, CnH(n+2) or other atoms.
In one embodiment, a polymer carrier, a Signal-1 moiety and/or a Signal-2 moiety may comprise a reactive amide group. As used herein, the term “reactive amide group” refers to an amide group that is capable of reacting with a reactive aminooxy group to form a N-oxime bond. The reactive amide group may be located anywhere on the compound provided it is still capable of reacting with a reactive aminooxy group. For example, the reactive amide group may be present in a side-chain, an end-group, or connected to the compound through one or more linkers. As will be recognized by one of ordinary skill in the art with the benefit of this disclosure, synthesis of a compound comprising a reactive amide group may be accomplished by functionalizing a desired compound (e.g., a polymer carrier, a Signal-1 moiety, a Signal-2 moiety) with an amide group through procedures well known to those of skill in the art.
Similarly, in some embodiments, a polymer carrier, a Signal-1 moiety and/or a Signal-2 moiety may comprise a reactive aminooxy group. As used herein, the term “reactive aminooxy group” refers to an aminooxy group that is capable of reacting with a reactive amide group to form a N-oxime bond. The reactive aminooxy group may be located anywhere on the compound provided it is still capable of reacting with a reactive amide group. For example, the reactive aminooxy group may be present in a side-chain, an end-group, or connected to the compound through one or more linkers. As will be recognized by one of ordinary skill in the art with the benefit of this disclosure, synthesis of a compound comprising a reactive aminooxy group may be accomplished by functionalizing a desired compound (e.g., a polymer carrier, a Signal-1 moiety, a Signal-2 moiety) with an aminooxy group through procedures well known to those of skill in the art.
In some embodiments, the present disclosure also provides pharmaceutical compositions comprising bifunctional conjugates and the use of conjugates in the manufacture of a medicament for treating a disease. Pharmaceutical compositions of the present disclosure may comprise one or more suitable pharmaceutical excipients. Standard pharmaceutical formulation techniques and excipients are well known to persons skilled in the art (see, e.g., 2005 Physicians' Desk Reference, Thomson Healthcare: Montvale, N.J., 2004; Remington: The Science and Practice of Pharmacy, 20th ed., Gennado et al., Eds. Lippincott Williams & Wilkins: Philadelphia, Pa., 2000). The compositions may or may not contain preservatives. Additionally, the pharmaceutical composition may comprise any of the conjugates described herein either as the sole active compound or in combination with another compound, composition, or biological material.
The formulation of pharmaceutical compositions may vary depending on the intended route of administrations and other parameters (see, e.g., Rowe et al. Handbook of Pharmaceutical Excipients, 4th ed., APhA Publications, 2003.) Administration of a pharmaceutical composition of the present disclosure is not limited to any particular delivery system and may include, without limitation, parenteral (including subcutaneous, intravenous, intracranial, intramedullary, intraarticular, intramuscular, intrathecal, or intraperitoneal injection), transdermal, or oral (for example, in capsules, suspensions, or tablets). Administration to an individual may occur in a single dose or in repeat administrations, and in any of a variety of physiologically acceptable salt forms, and/or with an acceptable pharmaceutical carrier and/or additive as part of a pharmaceutical composition.
The bifunctional conjugate compositions described herein are administered in therapeutically effective amounts. Generally, a therapeutically effective amount may vary with the subject's age, condition, and sex, as well as the severity of the medical condition in the subject. The dosage may be determined by a physician and adjusted, as necessary, to suit observed effects of the treatment. Toxicity and therapeutic efficacy of such compounds can be determined by standard pharmaceutical procedures in vitro (i.e., cell cultures) or in vivo (i.e., experimental animal models), e.g., for determining the LD50 (the dose lethal to 50% of the population) and the ED50 (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index (or therapeutic ratio), and can be expressed as the ratio LD50/ED50. Conjugates that exhibit therapeutic indices of at least 1, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 20 are described herein.
To facilitate a better understanding of the present disclosure, the following examples of certain aspects of some embodiments are given. In no way should the following examples be read to limit, or define, the entire scope of the invention.
Materials.
Hyaluronic acid (HA), with an average molecular weight of 31 kD was purchased from Lifecore. Analytical grade acetonitrile and synthesis grade trifluoro acetic acid (TFA) were purchased from Fisher Scientific. Research grade sodium acetate, acetic acid, and D2O were purchased from Sigma. Water was provided by a Labconco Water PRO PS ultrapure water purification unit. Poly (DL-lactic-co-glycolic acid) (50:50) (PLGA; inherent viscosity of 1.05 dL/g, Mw ˜101 kDa) was purchased from LACTEL Absorbable Polymers International (Pelham, Ala., USA). Pluronic® F68 (Mw ˜8.4 kD) and Pluronic® F108 (Mw ˜14.6 kD) were obtained from BASF Corporation. Acetone, diethyl ether and 1×Tris/EDTA buffer solution (pH 8) were obtained from Fisher Scientific. D-mannitol, Dess-Martin periodianine, tert-butyl carbazate (TBC), trinitrobenzenesulfonic acid (TNBS), dichloromethane anhydrous (DCM) and Triton X-100 were purchased from Sigma-Aldrich.
Peptide Synthesis.
Aminooxy peptides were synthesized using 9-fluorenylmethyloxycarbonyl-protected amino acid chemistry on polyethylene glycol-polystyrene resins. The peptides synthesized were aminooxy-LABL (aminooxy-ITDGEATDSG, Ao-LABL), a ligand of ICAM-1 (SEQ ID NO: 54) and aminooxy-PLP (aminooxy-HSLGKWLGHPDKF, Ao-PLP), an antigen derived from proteolipid protein amino acids 139-151 (PLP137-151) (SEQ ID NO: 55). Peptides were deprotected, cleaved from resin, and isolated by precipitation in ether. Purification was completed using preparatory High Performance Liquid Chromatography (HPLC) followed by lyophilization. Peptide identity was verified and purity/content was assessed using Mass Spectroscopy and analytical HPLC. BPI, which is a fusion of PLP and LABL, was synthesized and purified as previously reported (HSLGKWLGHPDKF-AcGAcGAc-ITDGEATDSG) (SEQ ID NO: 56).
Reaction of Aminooxy Peptides to Polymers.
HA was dissolved in 20 mM Acetate buffer (pH 5.5±0.1 pH units) and aminooxy reactive peptide(s) added. When both LABL and PLP peptides were used, each was weighed separately, and then added simultaneously. After addition of the peptide(s), the reaction solution pH was adjusted back to pH 5.5±0.1 pH units. Reaction solutions were stirred at 500 RPM using magnetic stir bars for ˜16 hr. After the reaction, the soluble antigen array (SAgA) product was purified by extensive dialysis to remove any unreacted peptide, and then lyophilized.
Gel Permeation Chromatography.
The relative molecular weight of the HA and of the SAgAs was estimated using a Viscotek GPC max VE 2001 GPC solvent/sample module, VE 3580 refractive index detector, and 270 Dual Detector with right angle light scattering. A tandem column setup of two Viscogel GMPWx1 columns (Viscotek) was used at a flow rate of 1 mL/min with isocratic elution in water for 30 min.
Conversion of Terminal Hydroxyl Groups to Terminal Aldehyde Groups on Pluronic® F108.
To conjugate peptides to Pluronic® on PLGA nanoparticles an oxidizing reagent was used to convert hydroxyl groups on Pluronic®F108 (Pluronic®F108-OH) to aldehyde groups (Pluronic®F108-CHO). One gram Pluronic®F108-OH was dissolved in 30 mL DCM. Subsequently, 58.1 mg Dess-Martin periodianine was added and reacted for 24 h at room temperature. The product was purified by precipitation in cold diethyl ether, followed by filtration. The obtained Pluronic®F108-CHO was verified by nuclear magnetic resonance spectroscopy (1H-NMR). Deuterated chloroform (CDCl3) was used to dissolve the samples. The conversion percentage was also determined. An excess amount of TBC was added to the Pluronic®F108-CHO solution as previously described and the amount of unreacted TBC was measured using TNBS solution. A UV/VIS Spectrophotometer (SpectraMax) operating at 334 nm was employed to quantify the colored mixture of TBC and TNBS.
Preparation of PLGA Nanoparticles.
A solvent displacement method was employed to prepare PLGA nanoparticles (NPs). Briefly, PLGA (inherent viscosity 1.05 dL/g) was dissolved in acetone (15 mg/mL). A mixture of 1425 μL of PLGA solution and 75 μL 1×Tris/EDTA buffer solution was injected into 15 mL water containing 0.1% w/v Pluronic® using a syringe pump (10 mL/hr) while stirring (1000 rpm). Stirring was continued for 1.5 hours and then excess surfactant was removed by centrifugation (15,000 rpm, 15 min, 4° C.) for 3 cycles, resuspending in water between cycles. Using a sonication bath (Branson 2510 ultrasonic cleaner). A 25:75 Pluronic® (CHO:OH) ratio was used for fabrication of NPs with conjugated PLP (NP-ArrayPLP), LABL (NP-ArrayLABL), or both (NP-ArrayLABL-PLP). The 0:100 Pluronic® (CHO:OH) ratio was used as the control (NP-Blank) without any peptide conjugation.
Conjugation of Peptides to PLGA Nanoparticles.
Stock solutions of 2 mg/mL of PLP and LABL peptides were separately prepared. To prepare the NP-ArrayPLP, 4.0 mL of PLP stock was added to 102.3 mg NPs in 3.52 mL of water. For NP-ArrayLABL preparation, 2.6 mL of LABL stock was added to 112.5 mg NPs in 3.2 mL of water. Finally, to prepare the NP-ArrayLABL-PLP, 3.6 mL of PLP stock and 2.34 mL of LABL stock were added to 227.84 mg NPs in 2.844 mL water. The volume of each nanoparticle sample was increased to 50 mL using ddH2O. The volume of NP-Blank sample was also increased up to 50 mL as well (227.84 mg NPs). The samples reacted overnight and were purified by centrifugation (15,000 rpm, 15 min, 4° C.) for 3 cycles, resuspending in water between cycles.
Dynamic Light Scattering.
Particle size was measured using a ZetaPALS dynamic light scattering instrument (Brookhaven Instrument Corporation).
High Performance Liquid Chromatography.
Quantification of free peptide post reaction was accomplished by gradient reversed phase HPLC (SHIMADZU) using a Vydac HPLC protein and peptide C18 column. HPLC system was composed of an SCL-20A SHIMADZU system controller, LC-10AT VP SHIMADZU liquid chromatograph, SIL-10A XL SHIMADZU auto-injector set at 75 μL injection volume, DGU-14A SHIMADZU degasser, sample cooler, and SPD-10A SHIMADZU UV-vis detector (220 nm). A personal computer equipped with SHIMADZU class VP software controlled the HPLC-UV system. Gradient elution was conducted at constant flow of 1 mL/min, from 100% A to 35% A (corresponding to 0% B to 65% B) over 50 min, followed by an isocratic elution at 75% B for 3 min. Mobile phase compositions were (A) acetonitrile-water (5:95) with 0.1% TFA and (B) acetonitrile-water (90:10, v/v) with 0.1% TFA. At the completion of each analysis, the cartridge was equilibrated at initial conditions at 1 mL/min flow rate for 5 min with A.
Calculation of Peptide Density on the Surface of NPs.
Peptide surface density was calculated by subtracting the amount of peptide recovered after conjugation from the amount of peptide added to the NP suspension. This value was then divided by the total surface area assuming a normal Gaussian particle size distribution and using a particle density of 1.34 g/cm3. NP-Blank suspension was used as a negative control. PLP and LABL at molar ratios of 100:0, 50:50, and 0:100 were added to the NP-Blank and peptide adsorption was quantified as an additional control. Peptide adsorption to blank particles or plastic was negligible.
Induction of EAE and Therapeutic Study.
SJL/J (H-2s) female mice, 4-6 weeks old, were purchased from The Jackson Laboratory and housed under specified, pathogen-free conditions at The University of Kansas. All protocols involving live mice were approved by the Institutional Animal Care and Use Committee. Mice were immunized subcutaneously (s.c) with 200 mg of PLP139-151 in a 0.2 mL emulsion composed of equal volumes of phosphate-buffered saline (PBS) and complete Freund's adjuvant (CFA) containing killed Mycobacterium tuberculosis strain H37RA (final concentration of 4 mg/mL; Difco). The PLP139-151/CFA was administered to regions above the shoulders and the flanks (total of four sites; 50 μL at each injection site). In addition, 200 ng/100 μL of pertussis toxin (List Biological Laboratories Inc.) was injected intraperitoneally (i.p.) on the day of immunization (day 0) and 2 days post-immunization. The mice received s.c. injections of each sample, equivalent to 100 nMol PLP/100 μL, on days 4, 7, 10. All NP samples were sonicated to disperse NPs before injection. For HA samples and controls, 100 μL of each vehicle was injected. For NP vehicles, 400 μL solution was used to assure suspension stability. Disease progression was evaluated blindly by the same observer using clinical scoring as follows: 0, no clinical signs of the disease; 1, tail weakness or limp tail; 2, paraparesis (weakness or incomplete paralysis of one or two hind limbs); 3, paraplegia (complete paralysis of two hind limbs); 4, paraplegia with forelimb weakness or paralysis; and 5, moribund (mice were euthanized if they were found to be moribund). Body weight was also measured daily.
Statistical Analysis
Statistical differences were determined by comparing treated groups to the negative control (PBS) for clinical disease score and body weight. A one-way analysis of variance (ANOVA) followed by Fisher's least significant difference was applied to these data. All analyses were performed using GraphPad Software (GraphPad Software Inc.).
Results
Characterization of Polymeric Soluble Antigen Arrays.
Gel permeation chromatography (GPC) and HPLC were employed to observe any change in retention time resulting from the presence of peptides grafted to the HA. When analyzed by GPC, the product showed a decrease in retention time suggesting an increase in molecular weight relative to the HA (
Conversion of Terminal Hydroxyl Groups to Terminal Aldehyde Groups on Pluronic® F108.
The hydroxyl groups of Pluronic® were converted to aldehyde groups in order to utilize Pluronic® for conjugation to the terminal aminooxy of the PLP and LABL peptides. Pluronic® F108-CHO with aldehyde groups were prepared by the Dess-Martin oxidation reaction. To confirm conversion, 1H NMR spectra from before and after the reaction were compared. After conversion, the signal corresponding to the aldehyde group (δ=9.75) appeared which confirmed the conversion of hydroxyl groups to aldehyde groups. The yield of the conversion was also determined to be 74.0% via a colormetric TBC/TNBS assay.
Characterization of NP-Arrays. Reversed phase HPLC was used to indirectly determine the amount of peptide conjugated to NPs. NPs were centrifuged from solution and the amount of unreacted peptide was quantified from the supernatant. Blank NPs and empty vials were used as controls to ensure that peptide was not being adsorbed to surfaces non-specifically. The peptide density on the surface of NPs was calculated based on the total NP surface area, assuming a normal Gaussian particle size distribution (Table 7). The NP-ArrayLABL-PLP had a 1.1:1 ratio of LABL:PLP peptide on the surface. Light scattering data showed that all NP-Arrays showed similar size both before and after peptides were conjugated to the surface (Table 7). For the nanoparticles displaying only one peptide, the NP-ArrayPLP had a similar surface density as the NP-ArrayLABL (Table 6). The difference was nest significant.
Suppression of EAE by Arrays.
The SAgAs and NP-Arrays were evaluated in an EAE model induced in SJL/J mice. The in vivo study designs are outlined in Table 8.
The disease onset usually occurs around day 8 and progresses to remission around day 20. Eight-12 days after immunization, the mice showed disease signs, such as weakness, paralysis of their tail and limbs, and loss of body weight. Subcutaneous injections of each sample were given on days 4, 7, 10. SAgALABL-PLP inhibited the progression of EAE more effectively (p<0.05, day 17) than the 28 kDa HA which was used as the SAgA backbone (
Once the efficacy of the SAgALABL-PLP was confirmed, the effect of SAgALABL-PLP dose was evaluated and compared to the positive control PLP-BPI. The BPI molecule was composed of three portions: the EAE antigen peptide (PLP) and the ICAM-1 inhibitor (LABL) separated by a spacer (see methods). Clinical results for BPI were consistent with previously published data. The effect of SAgALABL-PLP dose was evaluated by increasing the concentration to 200 nM and 400 nM as defined by the molar quantity of PLP antigen administered. Clinical scores suggested that increasing the SAgALABL-PLP dose to 200 nM PLP reduced disease score (p<0.05, day 15,
The role of scaffold was investigating by replacing the hyaluronic acid polymer backbone with a PLGA-Pluronic® nanoparticle. The LABL and PLP peptides were grafted to the nanoparticles by reacting the aminooxy peptides to the particle surface. These particles were then delivered as a suspension with the dose of PLP at 100 nMol. The clinical scoring results showed both the soluble polymer SAgALABL-PLP and colloidal NP-ArrayLABL-PLP provided disease suppression (
The effect of multivalent display of only antigen or only the cell-adhesion inhibitor was also investigated by conjugating either PLP peptide or LABL targeting peptide to the HA polymer or to the NPs. As an additional control a mix of free LABL and PLP peptides was tested. Clinical scores suggested that the multivalent LABL treatments (SAgALABL and NP-ArrayLABL) exacerbated disease with data trending higher than that of the PBS control. Conversely, the multivalent PLP treatments (SAgAPLP and NP-ArrayPLP) showed trending similar to or slightly lower than the PBS control (
Materials.
Hyaluronic acid (HA), with an average molecular weight of 17 and 31 kDa were purchased from Lifecore. Analytical grade acetonitrile, synthesis grade trifluoro acetic acid (TFA), and PBS buffer were purchased from Fisher Scientific. Research grade sodium acetate, acetic acid, and D2O and heparin were purchased from Sigma. Water was provided by a Labconco Water PRO PS ultrapure water purification unit.
Mice.
Four-6 weeks old SJL/J (H-2s) female mice were purchased from The Jackson Laboratory. Animals were housed under specified pathogen-free conditions at The University of Kansas Animal Care Facility. The University of Kansas Institutional Animal Care and Use Committee approved all protocols involving live mice.
Peptide Synthesis.
9-fluorenylmethyloxycarbonyl-protected amino acid chemistry on polyethylene glycol-polystyrene resins was used to synthesize the aminooxy peptides. Peptides synthesized for this study were aminooxy-LABL (aminooxy-ITDGEATDSG, Ao-LABL), a ligand of ICAM-1 (SEQ ID NO: 54), aminooxy-IBR (aminooxy-GGGPRGGVS, Ao-IBR), a ligand of LFA-1 (SEQ ID NO: 57), and aminooxy-PLP (aminooxy-HSLGKWLGHPDKF, Ao-PLP) (SEQ ID NO: 55), an antigen derived from proteolipid protein amino acids 139-151 (PLP137-151). Each peptide was deprotected, cleaved from resin, and isolated by precipitation in ether. Preparatory High Performance Liquid Chromatography (HPLC) was employed to purify the peptides, followed by lyophilization. Purity/content and peptide identity were verified using analytical HPLC and Mass Spectroscopy. PLP-BPI, a fusion of PLP and LABL (HSLGKWLGHPDKF-AcGAcGAc-ITDGEATDSG) (SEQ ID NO: 56), was synthesized and purified as previously reported.
Reaction of Aminooxy Peptides to Polymers.
The HA scaffolds were dissolved into 20 mM Acetate buffer (pH 5.5±0.1 pH units) and aminooxy reactive peptide(s) added. When multiple peptide species were used, each was weighed separately, and then both peptides were added simultaneously. Reaction solution pH was adjusted back to pH 5.5±0.1 pH units after addition of the peptide(s). Reaction solutions were stirred at for ˜16 hr. After the reaction, the soluble antigen array (SAgA) product was purified by extensive dialysis to remove any unreacted peptide, and then lyophilized.
High Performance Liquid Chromatography.
Reversed phase HPLC (SHIMADZU) using a Vydac HPLC protein and peptide C18 column was used to quantified conjugated peptide. The HPLC system was made up of an SCL-20A SHIMADZU system controller, LC-10AT VP SHIMADZU liquid chromatograph, SIL-10A XL SHIMADZU auto-injector set at 75 μL injection volume, DGU-14A SHIMADZU degasser, sample cooler, and SPD-10A SHIMADZU UV-vis detector (220 nm). The HPLC-UV system was controlled by a personal computer equipped with SHIMADZU class VP software. A gradient elution was conducted at constant flow of 1 mL/min, from 100% A to 35% A (corresponding to 0% B to 65% B) over 50 min, followed by an isocratic elution at 75% B for 3 min. The mobile phases were (A) acetonitrile-water (5:95) with 0.1% TFA and (B) acetonitrile-water (90:10, v/v) with 0.1% TFA. After each analysis, the cartridge was equilibrated at initial conditions at 1 mL/min flow rate for 5 min with A.
Preparation of Near Infrared Dye IR-820.
To prepare the dye, 125 mg 6-aminocaproic acid was dissolved in dry DMF (20 mL). TEA (130 μL) was added and the mixture was allowed to stir under argon for ˜5 min. Then, 500 mg IR-820 was added. A reflux condenser was attached and the mixture was heated to 85° C. for 3 hr in the dark. After the reaction the solvent was removed using a rotovap and placed under vacuum over night to dry.
Conjugation of IR-820 to Hyaluronic Acid.
IR-820-5 aminohexanoic acid dye was dissolved into water. EDC was added and the solution pH was adjusted to 4.5. Then, DMAP was added and the solution was stirred, in the dark, for 5 min. After activation of IR-820 (5 min), hyaluronic acid was added to the flask and the solution was stirred in the dark, for 48 hours. The product was purified by dialyzing against 95% EtOH for 8 hours, then against water twice (8 Hours a time) in the dark. The retentate was lyophilized and the dye content of the product was confirmed using NMR.
Nuclear Magnetic Resonance Spectroscopy.
For dye content analysis, samples were dissolved in D2O to a concentration of 10 mg/mL. H1 spectra were acquired on a Bruker 400 MHz spectrometer at 25° C.
Induction of EAE and Therapeutic Study.
Four-6 week-old SJL/J female mice were immunized subcutaneously (s.c) with 200 mg of PLP139-151 in a 0.2 mL emulsion composed of equal volumes of complete Freund's adjuvant (CFA) containing killed Mycobacterium tuberculosis strain H37RA (final concentration of 4 mg/mL; Difco) and phosphate-buffered saline (PBS) containing PLP. The PLP139-151/CFA emulsion was administered to regions above the shoulders and the flanks (total of four sites; 50 μL at each injection site). Additionally, 200 ng/100 μL of pertussis toxin (List Biological Laboratories Inc.) was injected intraperitoneally (i.p.) on the day of immunization (day 0) and 2 days post-immunization. Mice received s.c. injections of each sample, equivalent to 200 nMol PLP/100 μL, on days 4, 7, 10. One hundred μL of each vehicle was injected for all samples and controls. Disease progression was evaluated blindly by the same observer using clinical scoring as follows: 0, no clinical signs of the disease; 1, tail weakness or limp tail; 2, paraparesis (weakness or incomplete paralysis of one or two hind limbs); 3, paraplegia (complete paralysis of two hind limbs); 4, paraplegia with forelimb weakness or paralysis; and 5, moribund (mice were euthanized if they were found to be moribund). Body weight was also measured daily.
Cytokine Analysis.
Blood samples were taken from each mouse via mandibular bleeds (˜100 uL) on days 0, 6, 12, 18, 25. To ensure there was enough sample to perform ELISA cytokine testing blood from, two mice within the same group was pooled at each time point for a total of four samples per group. Samples were collected in heparin-containing tubes and centrifuged to separate red blood cells. Plasma was collected and sent for cytokine analysis to the Cytokine Core Laboratory at the University of Maryland. The cytokines analyzed were IL-2, IL-4, IL-10, IL-17, TNF-α, and TGF-β.
In Vivo Imaging.
In vivo imaging was completed using the Maestro Imaging Suite. Animals were anesthetized using an isoflurane vaporizer and IR-820 labeled SAgA was injected s.c. at the base of the neck. After injection images were taken of the animal's top, left, bottom, and right side by rotating the animal in the exposure pane. The animal was imaged at defined time points over a 24 hour period to track the drainage and clearance of the SAgA from the injection site.
Statistical Analysis.
Statistical differences were determined by comparing treated groups to the negative control (PBS) for clinical disease score and body weight. A one-way analysis of variance (ANOVA) followed by Fisher's least significant difference was applied to these data. For individual clinical day scores and cytokine measurements T test was employed. All analyses were performed using GraphPad Software (GraphPad Software Inc.).
Results
Characterization of Polymeric Soluble Antigen Arrays.
The concentration of peptide grafted to the HA backbone was quantified by HPLC. (Table 10) Peptide was released from scaffold by incubating the SAgA product in pH 2 mobile phase buffer at room temperature. Chromatograph results demonstrated the presence of the Ao-LABL or Ao-IBR peptide, and the Ao-PLP peptide at approximately the desired 1:1 ratio for all products. All SAgA results showed a high level of conjugation efficiency, >90%.
Efficacy of SAgAs was evaluated in the EAE model induced in SJL/J mice. The study design is outlined in Table 11 below. Typically disease onset occurs at approximately day 8 and progresses to remission around day 20. Disease is manifested by physical signs, such as weakness, paralysis of their tail and limbs, and loss of body weight. Injections of each sample were given subcutaneously on days 4, 7, 10.
Effect of Cell Adhesion Target on Suppression.
SAgAs targeting either ICAM-1 (SAgALABL-PLP) or LFA-1 (SAgAIBR-PLP) performed significantly better than the negative PBS control in clinical score (p<0.01, for days 14 & 17-19 for both) (
Effect of SAgA Size on Suppression.
Both the 50 kDa and 80 kDa SAgALABL-PLP and the 50 kDa and 80 kDa SAgAIBR-PLP inhibited the disease progression of EAE as evidenced by very low clinical scores. This treatment was more effectively than the negative PBS control (
In Vivo Imaging of SAgAs.
Both the 50 and 80 kDa SAgALABL-PLP were imaged and compared to a 30 kDa HA (the 80 kDa backbone) and a 70 kDa HA that was similar in Mw to the final products. After injection of the IR820-labeled HA or SAgALABL-PLP, the drainage from the injection site was tracked and images were acquired over 24 hours (
Effect of SAgA on Cytokine Profile.
The plasma samples were analyzed for 6 cytokines; IL-2, IL-4, IL-10, IL-17, TNF-α, and IFN-γ. Baseline levels of each cytokines were measured at Day 0 before disease induction. IL-2 and IL-10 were below the limit of detection in all samples. Examination of IL-4, IL-17, TNF-α, and IFN-γ all showed that treatment with SAgAs led to differences in the cytokine production profiles when compared to both the PBS and PLP-BPI controls. The largest differences were seen with the levels of IFN-γ, TNF-α, and IL-17 data, while smaller differences were seen with IL-4 levels (
For both TNF-α and IL-17, treatment with all groups led to an increase in the circulating cytokine concentrations compared to the PBS control. Similar to the IFN-γ data, peak concentrations of TNF-α occurred on day 6 for the PBS samples; however, these levels were very low at 1.8 pg/mL. The PLP-BPI reached 3.1 pg/mL of TNF-α on day 6. The 50 kDa SAgALABL-PLP (3.7 pg/mL), 80 kDa SAgALABL-PLP (3.4 pg/mL), and 80 kDa SAgAIBR-PLP (2.6 pg/mL) reached peak levels on day six. The 50 kDa SAgAIBR-PLP showed peak concentrations at days 6 and 18 (3.7 & 4.2 pg/mL).
The IL-17 data for the PBS control showed a peak concentration at day 6 (23 pg/mL). The 80 kDa SAgAIBR-PLP (45 pg/mL) and the PLP-BPI (40 pg/mL) control gave slightly elevated levels of IL-17; however, the PLP-BPI maintained these levels through day 12 (31 pg/mL), then returned toward baseline. Interestingly, peak concentrations at both days 6 and 18 were seen for the 50 kDa SAgAIBR-PLP (45 & 82 pg/mL), and both the 50 kDa SAgALABL-PLP (66 & 21 pg/mL) and 80 kDa SAgALABL-PLP (45 & 41 pg/mL).
Finally, IL-4 concentrations, though low, showed similar results for all samples (0.25-0.35 pg/mL), except for the 50 kDa SAgALABL-PLP and 80 kDa SAgAIBR-PLP, which had increased baseline levels. The 50 kDa SAgALABL-PLP IL-4 levels decreased to day 6 levels similar to all other samples (0.25 pg/mL), however, increased at day 12 (1.1 pg/mL). The 80 kDa SAgAIBR-PLP level decreased to day 6 concentrations of 0.73 pg/mL. After day 6, the 80 kDa SAgAIBR-PLP IL-4 level continued to decrease, however, became elevated at the study end (0.2 pg/mL).
Materials.
Hyaluronic acid (HA), with an average molecular weight of 17 and 31 kDa were purchased from Lifecore. Analytical grade acetonitrile, synthesis grade trifluoro acetic acid (TFA), and PBS buffer were purchased from Fisher Scientific. Research grade sodium acetate, acetic acid, and D2O and heparin were purchased from Sigma. Water was provided by a Labconco Water PRO PS ultrapure water purification unit.
Mice.
Four-6 weeks old SJL/J (H-2s) female mice were purchased from The Jackson Laboratory. Animals were housed under specified pathogen-free conditions at The University of Kansas Animal Care Facility. The University of Kansas Institutional Animal Care and Use Committee approved all protocols involving live mice.
Peptide Synthesis.
9-fluorenylmethyloxycarbonyl-protected amino acid chemistry on polyethylene glycol-polystyrene resins was used to synthesize the aminooxy peptides. Peptides synthesized for this study were aminooxy-LABL (aminooxy-ITDGEATDSG, Ao-LABL), a ligand of ICAM-1 (SEQ ID NO: 54), aminooxy-B7AP (aminooxy-EFMYPPPYLD, Ao-B7AP), a ligand of B7 (SEQ ID NO: 58), aminooxy-CAP1 (aminooxy MQPPGC, Ao-CAP1), a ligand of CD80 (SEQ ID NO. 59), aminooxy-SF2 (aminooxy-TEAGAAGCRGVGVAFIGSCVFG-OH, a CTLA-4 ligand) (SEQ ID NO: 60), aminooxy-IBR (aminooxy-GGGPRGGVS, Ao-IBR) (SEQ ID NO: 57), aminooxy-MOG (aminooxy-GWYRSPFSRVVHL-OH), an antigen (SEQ ID NO: 61), and aminooxy-PLP (aminooxy-HSLGKWLGHPDKF, Ao-PLP), an antigen derived from proteolipid protein amino acids 139-151 (PLP137-151) (SEQ ID NO: 55). Each peptide was deprotected, cleaved from resin, and isolated by precipitation in ether. Preparatory High Performance Liquid Chromatography (HPLC) was employed to purify the peptides, followed by lyophilization. Purity/content and peptide identity were verified using analytical HPLC and Mass Spectroscopy. PLP-BPI, a fusion of PLP and LABL (HSLGKWLGHPDKF-AcGAcGAc-ITDGEATDSG) (SEQ ID NO: 56), was synthesized and purified as previously reported.
Reaction of Aminooxy Peptides to Polymers.
The HA scaffolds were dissolved into 20 mM Acetate buffer (pH 5.5±0.1 pH units) and aminooxy reactive peptide(s) added. A 2 mg/mL solution of HA was used. When multiple peptide species were used, each was weighed separately, and then both peptides were added simultaneously. Reaction solution pH was adjusted back to pH 5.5±0.1 pH units after addition of the peptide(s). Reaction solutions were stirred at for ˜24 hr at about 400 rpm. After the reaction, the soluble antigen array (SAgA) product was purified by extensive dialysis to remove any unreacted peptide. Dialysis was performed using 6000-8000 MWCO dialysis tubing. The dialysis wash should be 100× the reaction volume. Dialysis was performed for 24 hours changing dialysis solution at least three times. Following dialysis, the soluble antigen array (SAgA) product was then lyophilized.
High Performance Liquid Chromatography.
Reversed phase HPLC (SHIMADZU) using a Vydac HPLC protein and peptide C18 column was used to quantified conjugated peptide. The HPLC system was made up of an SCL-20A SHIMADZU system controller, LC-10AT VP SHIMADZU liquid chromatograph, SIL-10A XL SHIMADZU auto-injector set at 75 μL injection volume, DGU-14A SHIMADZU degasser, sample cooler, and SPD-10A SHIMADZU UV-vis detector (220 nm). The HPLC-UV system was controlled by a personal computer equipped with SHIMADZU class VP software. A gradient elution was conducted at constant flow of 1 mL/min, from 100% A to 35% A (corresponding to 0% B to 65% B) over 50 min, followed by an isocratic elution at 75% B for 3 min. The mobile phases were (A) acetonitrile-water (5:95) with 0.1% TFA and (B) acetonitrile-water (90:10, v/v) with 0.1% TFA. After each analysis, the cartridge was equilibrated at initial conditions at 1 mL/min flow rate for 5 min with A.
Induction of EAE and Therapeutic Study.
Four-6 week-old SJL/J female mice were immunized subcutaneously (s.c) with 200 mg of PLP139-151 in a 0.2 mL emulsion composed of equal volumes of complete Freund's adjuvant (CFA) containing killed Mycobacterium tuberculosis strain H37RA (final concentration of 4 mg/mL; Difco) and phosphate-buffered saline (PBS) containing PLP. The PLP139-151/CFA emulsion was administered to regions above the shoulders and the flanks (total of four sites; 50 μL at each injection site). Additionally, 200 ng/100 μL of pertussis toxin (List Biological Laboratories Inc.) was injected intraperitoneally (i.p.) on the day of immunization (day 0) and 2 days post-immunization. Mice received s.c. injections of each sample, equivalent to 200 nMol PLP/100 μL, on days 4, 7, 10. One hundred μL of each vehicle was injected for all samples and controls. Disease progression was evaluated blindly by the same observer using clinical scoring as follows: 0, no clinical signs of the disease; 1, tail weakness or limp tail; 2, paraparesis (weakness or incomplete paralysis of one or two hind limbs); 3, paraplegia (complete paralysis of two hind limbs); 4, paraplegia with forelimb weakness or paralysis; and 5, moribund (mice were euthanized if they were found to be moribund). Body weight was also measured daily.
Statistical Analysis.
Statistical differences were determined by comparing treated groups to the negative control (PBS) for clinical disease score and body weight. A one-way analysis of variance (ANOVA) followed by Fisher's least significant difference was applied to these data. For individual clinical day scores and cytokine measurements T test was employed. All analyses were performed using GraphPad Software (GraphPad Software Inc.).
Results
The results of the study indicate that 5 different signal-2 peptides give significant suppression of EAE as compared to PBS control. LABL-PLP, B7AP-PLP, and SF2-PLP SagAs showed significant suppression (p<0.05) as compared to control on days 11-15. CAP1-PLP showed significant suppression as compared to control on days 11-16. (
Mixtures of peptides combined, but not present on the same polymer, had a similar suppressive effect to peptides present on the same polymer were also considered.
The suppressive effect of mixtures of HA, PLP, and LABL and HA along were also compared to LABL-PLP SAgAs. Significant suppression of EAE with LABL-PLP SAgAs vs. polymer only (HA) occurred on days 11-14. Significant suppression of EAE with a physical mixture of polymer and peptide (HA, PLP, LABL mixed) on days 13-14 as compared to polymer only. (
Rapamycin, an immunosuppressant, was conjugated to HA and its suppressive effect was assessed. Rapamycin was reacted with succinic anhydride in toluene at 45° C. for 36h in the presence of novozyme 435 to get a first product. After purification, the first product was reacted with HA for 20 h, followed by dialysis. Conjugation percentage of rapamycin to HA was approximately 10 wt %. Similar animal studies were performed as described above in the previous examples.
Significant suppression (P<0.05) of EAE occurred with LABL-PLP SAgAs (days 12-18, and 20) and with Rapa-SAgA+PLP SAgA mixture (days 12-21, and 23) vs. PBS control. (
Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.
This application is a continuation of U.S. patent application Ser. No. 13/725,524 filed Dec. 21, 2012 which is a continuation-in-part of International Application No. PCT/US2011/41792, filed Jun. 24, 2011, which claims the benefit of U.S. Provisional Application No. 61/358,166, filed Jun. 24, 2010, the entire disclosures of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61358166 | Jun 2010 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13725524 | Dec 2012 | US |
| Child | 15072559 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US11/41792 | Jun 2011 | US |
| Child | 13725524 | US |
