Suppression of experimental allergic encephalomyelitis by the encephalitogenic peptide, in solution or bound to liposomes

An insight into the role of liposomal therapeutics in the reversion of Multiple Sclerosis

INTRODUCTION

Multiple Sclerosis (MS), as an autoimmune disease, has complicated immunopathology, which makes its management relevant to various factors. Novel pharmaceutical vehicles, especially liposomes, can support efficacious handling of this disease both in early detection and prognosis and also in a therapeutic manner. The most well-known trigger of MS onset is the predominance of cellular to humoral immunity and enhancement of inflammatory cytokines level. The installation of liposomes as nanoparticles to control this disease holds great promise up to now.

AREAS COVERED

Various types of liposomes with different properties and purposes have been formulated and targeted immune cells with their surface manipulations. They may be encapsulated with anti-inflammatory, MS-related therapeutics, or immunodominant myelin-specific peptides for attaining a higher therapeutic efficacy of the drugs or tolerance induction. Cationic liposomes are also highly applicable for gene delivery of the anti-inflammatory cytokines or silencing the inflammatory cytokines. Liposomes have also been used as biotools for comprehending MS pathomechanisms or as diagnostic agents.

EXPERT OPINION

The efforts to manage MS through nanomedicine, especially liposomal therapeutics, pave a new avenue to a high-throughput medication of this autoimmune disease and their translation to the clinic in the future for overcoming the challenges that MS patients confront.

Liposome-encapsulated peptides protect against experimental allergic encephalitis

Multiple sclerosis (MS) is a severe inflammatory and neurodegenerative disease with an autoimmune background. Despite the variety of therapeutics available against MS, the development of novel approaches to its treatment is of high importance in modern pharmaceutics. In this study, experimental autoimmune encephalomyelitis (EAE) in Dark Agouti rats has been treated with immunodominant peptides of the myelin basic protein (MBP) encapsulated in mannosylated small unilamellar vesicles. The results show that liposome-encapsulated MBP_46–62 is the most effective in reducing maximal disease score during the first attack, while MBP_124–139 and MBP_147–170 can completely prevent the development of the exacerbation stage. Both mannosylation of liposomes and encapsulation of peptides are critical for the therapeutic effect, since neither naked peptides nor nonmannosylated liposomes, loaded or empty, have proved effective. The liposome-mediated synergistic effect of the mixture of 3 MBP peptides significantly suppresses the progression of protracted EAE, with the median cumulative disease score being reduced from 22 to 14 points, compared to the placebo group; prevents the production of circulating autoantibodies; down-regulates the synthesis of Th1 cytokines; and induces the production of brain-derived neurotrophic factor in the central nervous system. Thus, the proposed formulation ameliorates EAE, providing for a less severe first attack and rapid recovery from exacerbation, and offers a promising therapeutic modality in MS treatment.—Belogurov, A. A., Jr., Stepanov, A. V., Smirnov, I. V., Melamed, D., Bacon, A., Mamedov, A. E., Boitsov, V. M., Sashchenko, L. P., Ponomarenko, N. A., Sharanova, S. N., Boyko, A. N., Dubina, M. V., Friboulet, A., Genkin, D. D., Gabibov, A. G. Liposome-encapsulated peptides protect against experimental allergic encephalitis.

[Therapeutic effect of encapsulated into the nanocontainers MBP immunodominant peptides on EAE development in DA rats]

Multiple Sclerosis (MS) is a serve autoimmune neurodegenerative disease. Development of innovative approaches of MS treatment is of a high priority in the modern immunology and pharmacy. In the present study we showed high therapeutic efficiency of immunodominant peptides of myelin basic protein (MBP) incorporated into the monolayer mannosylated liposomes on the development of experimental autoimmune encephalomyelitis (EAE) in DA rats. MBP is a component ofoligodendrocytes' membrane, which form axonal sheath, and is one of the major autoantigens in MS. We analyzed binding pattern ofanti-MBP autoantibodies from MS patients using previously designed MBP epitope library. Utilizing the same approach we investigated pool of anti-MBP antibodies from SJL/J and C57/BL6 mice and DA rats with induced EAE. The most relevant rodent model to MS was EAE in DA rats according to the autoantibodies' binding pattern. We selected three immunodominant MBP fragments encapsulated in monolayer mannosylated liposomes for the following treatment of verified DA rodent model. MBP fragment 46-62 was the most effective in reducing of the first EAE attack, whereas MBP 124-139 and 147-160 inhibited development of pathology during remission stage. Simultaneous administration of these peptides in liposomes significantly decreased level of anti-MBP antibodies. Synergetic therapeutic effect of MBP fragments reduced integral disease score by inhibiting first EAE wave and subsequent remission, thus, our findings disclosure novel approaches for efficient treatment of Multiple Sclerosis.

Drug targeting systems for inflammatory disease: one for all, all for one

In various systemic disorders, structural changes in the microenvironment of diseased tissues enable both passive and active targeting of therapeutic agents to these tissues. This has led to a number of targeting approaches that enhance the accumulation of drugs in the target tissues, making drug targeting an attractive strategy for the treatment of various diseases. Remarkably, the strategic principles that form the basis of drug targeting are often employed for tumor targeting, while chronic inflammatory diseases appear to draw much less attention. To provide the reader with a general overview of the current status of drug targeting to inflammatory diseases, the passive and active targeting strategies that have been used for the treatment of rheumatoid arthritis (RA) and multiple sclerosis (MS) are discussed. The last part of this review addresses the dualism of platform technology-oriented ("one for all") and disease-oriented drug targeting research ("all for one"), both of which are key elements of effective drug targeting research.

Distribution of albumin nanoparticles in animals induced with the experimental allergic encephalomyelitis

Experimental allergic encephalomyelitis (EAE) is an autoimmune disease characterised by a disruption of the blood-brain barrier (BBB), demyelination and a relevant inflammatory reaction with an intense infiltration of macrophages. These neurological disorders are similar to those observed in the multiple sclerosis (MS) disease. The use of different liposomes and adeno-associated virus has been proposed for improving the treatment of this pathogenesis. The aim of this work was to evaluate the potential and capacity of albumin nanoparticles to reach the central nervous system (CNS) in EAE-induced rats. For this purpose, the distribution of biotinylated nanoparticles within the CNS was studied. Albumin carriers were mainly found in the lumbar portion of the spinal cord, overlying the meningeal and perivascular areas. The optic chiasma, iris and the area of the Purkinje cells of the cerebellum revealed also an intense presence of these carriers. Finally, immunohistochemical studies also revealed that circulating macrophages (ED1), which migrate to damaged sites, and resident activated microglial cells (OX42) were involved in the distribution of albumin nanoparticles. In summary, the use of nanoparticles may be useful for the design of new pharmaceutical dosage forms able to target the lesions associated with alterations of the BBB.

Tolerance induction by acylated peptides: effect on encephalitogenic T cell lines

We reported previously that acylation of an encephalitogenic peptide of myelin basic protein (MBP68-86) by attachment of palmitoyl chloride (PAL68-86) converted this peptide into a powerful tolerogen for EAE in the Lewis rat. In this study we show that T cell lines derived from a PAL68-86-protected rat proliferated poorly to MBP68-86 in vitro, even after repeated passages in this peptide and IL-2. Conversely, T cell lines derived from untreated rats that were challenged with MBP68-86 or PAL68-86 in CFA responded vigorously to MBP68-86 when propagated for many passages in this peptide but became gradually unresponsive after being propagated in the presence of PAL68-86. The modulation of the T cell lines by PAL68-86 in vitro was reflected by a significant reduction in their ability to transfer EAE to recipients. A high percentage of cells stained with an anti-Vbeta8.2 antibody, regardless of whether they were propagated in the presence of unmodified or acylated peptide. The results are consistent with the notion that tolerance induced by PAL68-86 operates by functional inactivation and provide the basis for the use of acylated peptides in the antigen-specific treatment of autoimmune diseases.

Suppression of experimental allergic encephalomyelitis in the Lewis rat, by administration of an acylated synthetic peptide of myelin basic protein

A Myelin Basic Protein (MBP) epitope encephalitogenic for the Lewis rat (amino acid residues 68-86) was synthesized and acylated by the attachment of a palmitoyl residue. Lewis rats treated intravenously (i.v.) with the palmitoylated peptide alone were better protected against clinical manifestations of experimental allergic encephalomyelitis (EAE) than rats treated with the peptide inserted into liposomes or with the native peptide at similar doses. The administration of the acylated peptide (PAL68 86) conferred excellent protection against a challenge with the encephalitogenic peptide (p68-86) or with the intact MBP molecule, both before and after induction of active disease, and also when administered to recipients after the transfer of lymphocytes from MBP-challenged donors. Histological manifestations were also reduced to a statistically significant degree. Treatment with a palmitoylated peptide from a non-encephalitogenic region of the MBP molecule (PAL44-62) or with a palmitoylated unrelated peptide were ineffective. In vitro Ag-specific proliferative responses as well as the ability to transfer disease to syngeneic recipients, by lymph node lymphocytes from PAL68-86-treated donors, were considerably reduced. Addition of IL-2 to these cultures failed to restore either Ag-specific responsiveness or the ability of the cells to transfer disease. The results suggest that the administration of acylated peptides induces a profound state of unresponsiveness, and thus may provide an effective means for treating T cell-mediated autoimmune inflammatory disorders.

Interaction of phospholipids with proteins and peptides. New advances III

1. The review deals with the recent achievements in the study of the various interactions of phospholipids with proteins and peptides. 2. The interactions are classified according to the hydrophobic, hydrophilic or mixed character of the interactive forces. 3. The effect of the interaction on the structure and biological activity of the interacting molecules is also discussed.

The structure and function of central nervous system myelin

Multiple sclerosis (MS) is characterized by the active degradation of central nervous system myelin, a multilamellar membrane system that insulates nerve axons. MS arises from complex interactions between genetic, immunological, infective, and biochemical mechanisms. Although the circumstances of MS etiology remain hypothetical, one persistent theme involves immune system recognition of myelin-specific antigens derived from myelin basic protein, the most abundant extrinsic myelin membrane protein, and/or another equally suitable myelin protein or lipid. Knowledge of the biochemical and physical-chemical properties of myelin proteins, and lipids, particularly their composition, organization, structure, and accessibility with respect to the compacted myelin multilayers, thus becomes central to understanding how and why these antigens become selected during the development of MS. This article focuses on the current understanding of the molecular basis of MS as it may relate to the protein and lipid components of myelin, which dictate myelin morphology on the basis of protein-lipid and lipid-lipid interactions, and the relationship, if any, between the protein/lipid components and the destruction of myelin in pathological situations.