A VLP-based vaccine against interleukin-1α protects mice from atherosclerosis

IL-1 signaling pathway, an important target for inflammation surrounding in myocardial infarction

Acute myocardial infarction is an important cardiovascular disease worldwide. Although the mortality rate of myocardial infarction (MI) has improved dramatically in recent years due to timely treatment, adverse remodeling of the left ventricle continues to affect cardiac function. Various immune cells are involved in this process to induce inflammation and amplification. The infiltration of inflammatory cells in the infarcted myocardium is induced by various cytokines and chemokines, and the recruitment of leukocytes further amplifies the inflammatory response. As an increasing number of clinical anti-inflammatory therapies have achieved significant success in recent years, treating myocardial infarction by targeting inflammation may become a novel therapeutic option. In particular, successful clinical trials of canakinumab have demonstrated the important role of the inflammatory factor interleukin-1 (IL-1) in atherosclerosis. Targeted IL-1 therapy may decrease inflammation levels and improve cardiac function in patients after myocardial infarction. This article reviews the complex series of responses after myocardial infarction, including the involvement of inflammatory cells and the role of cytokines and chemokines, focusing on the progression of the IL-1 family in myocardial infarction as well as the performance of current targeted therapy drugs in experiments.

Two decades of vaccine development against atherosclerosis

Atherosclerosis is an immune-mediated chronic inflammatory disease that leads to the development of fatty plaques in the arterial walls, ultimately increasing the risk of thrombosis, stroke, and myocardial infarction. The immune response in this complex disease is both atheroprotective and pro-atherogenic, involving both innate and adaptive immunity. Current treatments include the adjustment of lifestyle factors, cholesterol-lowering drugs such as statins, and immunotherapy, whereas vaccine development has received comparatively little attention. In this review, we discuss the potential of antigen-specific vaccination as a preventative approach based on more than 20 years of research and innovation. Vaccination targets include proteins that are more abundant in atherosclerotic patients, such as oxidized low-density lipoprotein (LDL), apolipoprotein B-100, proprotein convertase subtilisin/kexin type-9 serine protease (PCSK9), cholesteryl ester transfer protein (CETP), and heat shock proteins HSP60 and HSP65. Immunization with such proteins or their peptide epitopes has been shown to induce T-cell activation, produce antigen-specific antibodies, reduce the size of atherosclerotic lesions, and/or reduce serum cholesterol levels. Vaccination against atherosclerosis therefore offers a new strategy to address the burden on healthcare systems caused by cardiovascular disease, the leading cause of death worldwide.

NLRP3 Inflammasome in Atherosclerosis: Putting Out the Fire of Inflammation

Atherosclerosis (AS) is a chronic inflammatory disease with thickening or hardening of the arteries, which led to the built-up of plaques in the inner lining of an artery. Among all the clarified pathogenesis, the over-activation of inflammatory reaction is one of the most acknowledged one. The nucleotide-binding domain leucine-rich repeat (NLR) and pyrin domain containing receptor 3 (NLRP3) inflammasome, as a vital and special form of inflammation and innate immunity, has been widely revealed to participate in the onset and development of AS. This review will introduce the process of the pathogenesis and progression of AS, and will describe the biological features of the NLRP3 inflammasome. Furthermore, the role of the NLRP3 inflammasome in AS and the possible mechanisms will be discussed. In addition, several kinds of agents with the effect of anti-atherosclerotic taking advantage of the NLRP3 inflammasome intervention will be described and discussed in detail, including natural compounds (baicalin, dihydromyricetin, luteolin, 5-deoxy-rutaecarpine (R3) and Salvianolic acid A, etc.), microRNAs (microRNA-30c-5p, microRNA-9, microRNA-146a-5p, microRNA-16-5p and microRNA-181a, etc.), and autophagy regulators (melatonin, dietary PUFA and arglabin, etc.). We aim to provide novel insights in the exploration of the specific mechanisms of AS and the development of new treatments of AS.

Preclinical Efficacy of a Capsid Virus-like Particle-Based Vaccine Targeting IL-1β for Treatment of Allergic Contact Dermatitis

Hypersensitivity to a contact allergen is one of the most abundant forms of inflammatory skin disease. Today, more than 20% of the general population are sensitized to one or more contact allergens, making this disease an important healthcare issue, as re-exposure to the allergen can initiate the clinical disease termed allergic contact dermatitis (ACD). The current standard treatment using corticosteroids is effective, but it has side effects when used for longer periods. Therefore, there is a need for new alternative therapies for severe ACD. In this study, we used the versatile Tag/Catcher AP205 capsid virus-like particle (cVLP) vaccine platform to develop an IL-1β-targeted vaccine and to assess the immunogenicity and in vivo efficacy of the vaccine in a translational mouse model of ACD. We show that vaccination with cVLPs displaying full-length murine IL-1β elicits high titers of neutralizing antibodies, leading to a significant reduction in local IL-1β levels as well as clinical symptoms induced by treatment with 1-Fluoro-2,4-dinitrobenzene (DNFB). Moreover, we show that a single amino acid mutation in muIL-1β reduces the biological activity while maintaining the ability to induce neutralizing antibodies. Collectively, the data suggest that a cVLP-based vaccine displaying full-length IL-1β represents a promising vaccine candidate for use as an alternative treatment modality against severe ACD.

A single-dose, implant-based, trivalent virus-like particle vaccine against "cholesterol checkpoint" proteins

Cardiovascular disease is the number one cause of death globally. Lowering cholesterol levels in plasma is the mainstay therapy; however lifelong treatment and adverse effects call for improved therapeutic interventions. We developed a trivalent vaccine candidate targeting proprotein convertase subtilisin/kexin-9 (PCSK9), apolipoprotein B (ApoB), and cholesteryl ester transfer protein (CETP). Vaccine candidates were developed using bacteriophage Qβ-based virus-like particles (VLPs) displaying antigens of PCKS9, ApoB, and CETP, respectively. Vaccine candidate mixtures were formulated as slow-release PLGA:VLP implants using hot-melt extrusion. The delivery of the trivalent vaccine candidate via the implant produced antibodies against the cholesterol checkpoint proteins at levels comparable to a three-dose injection schedule with soluble mixtures. The reduction in PCSK9 and ApoB levels in plasma, inhibition of CETP (in vitro), and total plasma cholesterol decrease was achieved. All-together, we present a platform technology for a single-dose multi-target vaccination platform targeting cholesterol checkpoint proteins.

Interleukin-1 in obesity-related low-grade inflammation: From molecular mechanisms to therapeutic strategies

Since adipose tissue (AT) can upregulate pro-inflammatory interleukins (ILs) via storing extra lipids in obesity, obesity is considered the leading cause of chronic low-grade inflammation. These ILs can pave the way for the infiltration of immune cells into the AT, ultimately resulting in low-grade inflammation and dysregulation of adipocytes. IL-1, which is divided into two subclasses, i.e., IL-1α and IL-1β, is a critical pro-inflammatory factor. In obesity, IL-1α and IL-1β can promote insulin resistance via impairing the function of adipocytes and promoting inflammation. The current study aims to review the detailed molecular mechanisms and the roles of IL-1α and IL-1β and their antagonist, interleukin-1 receptor antagonist(IL-1Ra), in developing obesity-related inflammatory complications, i.e., type II diabetes (T2D), non-alcoholic steatohepatitis (NASH), atherosclerosis, and cognitive disorders. Besides, the current study discusses the recent advances in natural drugs, synthetic agents, and gene therapy approaches to treat obesity-related inflammatory complications via suppressing IL-1.

Gene Expression Analysis Suggests Immunological Changes of Peripheral Blood Monocytes in the Progression of Patients With Coronary Artery Disease

Objectives

To analyze the gene expression profile of peripheral blood monocytes in different stages of coronary artery disease (CAD) by transcriptome sequencing, and to explore potential genes and pathway involved in CAD pathogenesis.

Methods

According to the screening of coronary angiography and quality control of blood samples, eight intermediate coronary lesion patients were selected, then eight patients with acute myocardial infarction, and eight patients with normal coronary angiography were matched by age and gender. Transcriptomics sequencing was conducted for the peripheral blood monocytes of these 24 samples by using the Illumina HiSeq high-throughput platform. Then, differentially expressed genes (DEGs) were analyzed. Gene Ontology (GO) functional annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation, and protein-protein interaction (PPI) network were applied to annotate the potential functions of DEGs.

Results

Compared with the normal coronary angiography group, we identified a total of 169 DEGs in the intermediate coronary lesion group, which were significantly enriched in 59 GO terms and 17 KEGG pathways. Compared with the normal coronary angiography group, we found a total of 2,028 DEGs, which were significantly enriched in 311 GO terms and 20 KEGG pathways in the acute myocardial infarction group. The cross-comparison between normal versus intermediate coronary lesion group, and normal versus acute myocardial infarction group included 98 differential genes with 65 up regulated and 33 down regulated genes, which were significantly enriched in 46 GO terms and 10 KEGG pathways. During the progression of CAD, there was a significant up-regulated expression of CSF3, IL-1A, CCR7, and IL-18, and down-regulated expression of MAPK14. Besides GO items such as inflammatory response was significantly enriched, KEGG analysis showed the most remarkable enrichments in IL-17 signaling pathway and cytokine-cytokine receptor interactions.

Conclusions

Transcriptomics profiles vary in patients with different severity of CAD. CSF3, IL-1A, CCR7, IL-18, and MAPK14, as well as IL-17 signaling pathway and cytokine and cytokine receptor interaction signaling pathway related with inflammatory response might be the potential biomarker and targets for the treatment of coronary artery disease.

Targeting IL-1β in the Treatment of Atherosclerosis

The role of inflammation in atherosclerosis has been recognized several decades ago and existing treatments provide benefits in part through non-specific anti-inflammatory actions. Compared with other cytokines, interleukin-1β (IL-1β) is associated with acute and chronic inflammation. Anti-inflammatory therapy with canakinumab targeting the IL-1β innate immunity pathway could significantly reduce the rate of recurrent cardiovascular events than placebo. The results of CANTOS suggested an important role of IL-1β in atherosclerosis. However, there are numerous mechanisms that are to be clarified. We herein discussed the important immunomodulatory effect IL-1β exerts on atherosclerosis and the potential mechanisms underlying it. We also reviewed bench-to-bedside clinical translation of IL-1β neutralizing strategies associated with the use of IL-1β blockade in patients with atherosclerosis.

Novel ssRNA phage VLP platform for displaying foreign epitopes by genetic fusion

Virus-like particles (VLPs) can be used as efficient carriers of various antigens and therefore serve as attractive tools in vaccine development. Although VLPs of different viruses can be used, VLPs of ssRNA phages have convincing advantages due to their unique properties, including efficient protein production in bacterial and yeast expression systems, low production cost and easy and fast purification. Currently, the range of ssRNA phage VLPs is limited. In particular, this is true for VLPs that tolerate insertions at the N- and C-termini of the coat protein. It is therefore necessary to find new alternatives within the known ssRNA phage VLP range. From previous studies, we found approximately 80 new VLPs forming ssRNA phage coat proteins. In the current study, we attached a model peptide to the N- and C-termini of coat proteins. As a model peptide, we used a triple repeat of 23 N-terminal residues of the ectodomain of the influenza M2 protein, used previously in the development of the flu vaccine. Examining 43 novel phage coat proteins for the ability to form chimeric VLPs, we found ten new promising candidates for further vaccine design, five of which were tolerant to insertions at both the N- and C-termini. Furthermore, we demonstrate that most of the chimeric VLPs have good antigenic properties as judged from their reactivity with anti-M2 antibodies.

Multifactorial Design of a Supramolecular Peptide Anti-IL-17 Vaccine Toward the Treatment of Psoriasis

Current treatments for chronic immune-mediated diseases such as psoriasis, rheumatoid arthritis, or Crohn's disease commonly rely on cytokine neutralization using monoclonal antibodies; however, such approaches have drawbacks. Frequent repeated dosing can lead to the formation of anti-drug antibodies and patient compliance issues, and it is difficult to identify a single antibody that is broadly efficacious across diverse patient populations. As an alternative to monoclonal antibody therapy, anti-cytokine immunization is a potential means for long-term therapeutic control of chronic inflammatory diseases. Here we report a supramolecular peptide-based approach for raising antibodies against IL-17 and demonstrate its efficacy in a murine model of psoriasis. B-cell epitopes from IL-17 were co-assembled with the universal T-cell epitope PADRE using the Q11 self-assembling peptide nanofiber system. These materials, with or without adjuvants, raised antibody responses against IL-17. Exploiting the modularity of the system, multifactorial experimental designs were used to select formulations maximizing titer and avidity. In a mouse model of psoriasis induced by imiquimod, unadjuvanted nanofibers had therapeutic efficacy, which could be enhanced with alum adjuvant but reversed with CpG adjuvant. Measurements of antibody subclass induced by adjuvanted and unadjuvanted formulations revealed strong correlations between therapeutic efficacy and titers of IgG1 (improved efficacy) or IgG2b (worsened efficacy). These findings have important implications for the development of anti-cytokine active immunotherapies and suggest that immune phenotype is an important metric for eliciting therapeutic anti-cytokine antibody responses.

Viral nanoparticles for drug delivery, imaging, immunotherapy, and theranostic applications

Viral nanoparticles (VNPs) encompass a diverse array of naturally occurring nanomaterials derived from plant viruses, bacteriophages, and mammalian viruses. The application and development of VNPs and their genome-free versions, the virus-like particles (VLPs), for nanomedicine is a rapidly growing. VLPs can encapsulate a wide range of active ingredients as well as be genetically or chemically conjugated to targeting ligands to achieve tissue specificity. VLPs are manufactured through scalable fermentation or molecular farming, and the materials are biocompatible and biodegradable. These properties have led to a wide range of applications, including cancer therapies, immunotherapies, vaccines, antimicrobial therapies, cardiovascular therapies, gene therapies, as well as imaging and theranostics. The use of VLPs as drug delivery agents is evolving, and sufficient research must continuously be undertaken to translate these therapies to the clinic. This review highlights some of the novel research efforts currently underway in the VNP drug delivery field in achieving this greater goal.

Vaccination against Allergy: A Paradigm Shift?

Since the discovery that IgE antibodies mediate allergy, decades of research have unraveled complex mechanisms associated with conventional immunotherapy and the vital protagonists that shape 'immune tolerance' to allergens. Debate exists on what should constitute the dominant effector mechanism in driving rational drug designs for next-generation immunotherapies. As vaccine technology continues to advance, the development of novel vaccines in this area of continued medical need might stand on a threshold of breakthrough inspired by experiments by Dunbar on the passive vaccination of allergic animals more than 100 years ago. In this opinion article, we discuss both novel insights into IgG antibodies as the principle effector modality induced by specific immunotherapy and advances in antigen-carrier design that may catapult allergy treatment into our modern world.

Macrophage Foam Cell-Targeting Immunization Attenuates Atherosclerosis

Background: Macrophage foam cells (FCs) play a crucial role in the initiation and progression of atherosclerosis. Reducing the formation or inducing the removal of FCs could ameliorate atherosclerosis. The present study examined whether the whole-cell vaccination using FCs could be used as novel prevention and treatment strategies to battle atherosclerosis.

Methods: ApoE^−/− mice with initial or established atherosclerosis were subcutaneously immunized three times with FCs in Freund's adjuvant.

Results: Immunization with FCs resulted in an overt reduction of atherosclerotic lesion in the whole aorta and the aortic root with enhanced lesion stability. Subsequent study in mechanism showed that FCs vaccination dramatically increased CD4⁺ T cell and CD8⁺ T cell populations. Immunization with FCs significantly raised the plasma FCs-specific IgG antibodies. Of note, the FCs immune plasma could selectively recognize and bind to FC. FCs immune plasma significantly blocked the process of FCs formation, finally reduced the accumulation of FCs in plaque. Additionally, it was observed that FCs immunization down-regulated the expression level of atherosclerosis related pro-inflammatory cytokines, including IFN-γ, MCP-1, and IL-6 and enhanced the lesion stability with a significant increase in TGF-β1 level and collagen content.

Conclusions: These findings demonstrate that the whole-cell vaccination using FCs significantly decreased lesion development and positively modulated lesion progression and stability by targeting FCs. The whole-cell FCs vaccine might represent a potential novel strategy for development of new antibodies and vaccines to the prevention or treatment of atherosclerosis.

Virus-like particle vaccines: immunology and formulation for clinical translation

INTRODUCTION

Virus-like particle (VLP) vaccines face significant challenges in their translation from laboratory models, to routine clinical administration. While some VLP vaccines thrive and are readily adopted into the vaccination schedule, others are restrained by regulatory obstacles, proprietary limitations, or finding their niche amongst the crowded vaccine market. Often the necessity to supplant an existing vaccination regimen possesses an immediate obstacle for the development of a VLP vaccine, despite any preclinical advantages identified over the competition. Novelty, adaptability and formulation compatibility may prove invaluable in helping place VLP vaccines at the forefront of vaccination technology.

AREAS COVERED

The purpose of this review is to outline the diversity of VLP vaccines, VLP-specific immune responses, and to explore how modern formulation and delivery techniques can enhance the clinical relevance and overall success of VLP vaccines.

EXPERT COMMENTARY

The role of formation science, with an emphasis on the diversity of immune responses induced by VLP, is underrepresented amongst clinical trials for VLP vaccines. Harnessing such diversity, particularly through the use of combinations of select excipients and adjuvants, will be paramount in the development of VLP vaccines.

Biomaterial strategies for generating therapeutic immune responses

Biomaterials employed to raise therapeutic immune responses have become a complex and active field. Historically, vaccines have been developed primarily to fight infectious diseases, but recent years have seen the development of immunologically active biomaterials towards an expanding list of non-infectious diseases and conditions including inflammation, autoimmunity, wounds, cancer, and others. This review structures its discussion of these approaches around a progression from single-target strategies to those that engage increasingly complex and multifactorial immune responses. First, the targeting of specific individual cytokines is discussed, both in terms of delivering the cytokines or blocking agents, and in terms of active immunotherapies that raise neutralizing immune responses against such single cytokine targets. Next, non-biological complex drugs such as randomized polyamino acid copolymers are discussed in terms of their ability to raise multiple different therapeutic immune responses, particularly in the context of autoimmunity. Last, biologically derived matrices and materials are discussed in terms of their ability to raise complex immune responses in the context of tissue repair. Collectively, these examples reflect the tremendous diversity of existing approaches and the breadth of opportunities that remain for generating therapeutic immune responses using biomaterials.

Development of Autologous C5 Vaccine Nanoparticles to Reduce Intravascular Hemolysis in Vivo

The complement system is emerging as a new target for treating many diseases. For example, Eculizumab, a humanized monoclonal antibody against complement component 5 (C5), has been approved for paroxysmal nocturnal hemoglobinuria (PNH) in which patient erythrocytes are lysed by complement. In this study, we developed vaccines to elicit autologous anti-C5 antibody production in mice for complement inhibition. Immunization of mice with a conservative C5 xenoprotein raised high titers of IgG's against the xenogenous C5, but these antibodies did not reduce C5 activity in the blood. In contrast, an autologous mouse C5 vaccine containing multiple predicted epitopes together with a tolerance-breaking peptide was found to induce anti-C5 autoantibody production in vivo, resulting in decreased hemolytic activity in the blood. We further validated a peptide epitope within this C5 vaccine and created recombinant virus-like particles (VLPs) displaying this epitope fused with the tolerance breaking peptide. Immunizing mice with these novel nanoparticles elicited strong humoral responses against recombinant mouse C5, reduced hemolytic activity, and protected the mice from complement-mediated intravascular hemolysis in a model of PNH. This proof-of-concept study demonstrated that autologous C5-based vaccines could be an effective alternative or supplement for treating complement-mediated diseases such as PNH.

Vaccine against arteriosclerosis: an update

Substantial data from experimental and clinical investigation support the role of immune-mediated mechanisms in atherogenesis, with immune systems responding to many endogenous and exogenous antigens that play either proatherogenic or atheroprotective roles. An active immunization strategy against many of these antigens could potentially alter the natural history of atherosclerosis. This review mainly focuses on the important studies on the search for antigens that have been tested in vaccine formulations to reduce atherosclerosis in preclinical models. It will also address the opportunities and challenges associated with potential clinical application of this novel therapeutic paradigm.

Beyond passive immunization: toward a nanoparticle-based IL-17 vaccine as first in class of future immune treatments

Nanoparticles occur naturally as part of repetitive molecular structures forming virus-like particles (VLPs). VLPs are powerful immune activators. Specifically, VLP can elicit a direct activation of B lymphocytes to trigger production of antibodies targeted at molecules chemically linked to the VLP. We here review recent data from genetics research, large-scale genomic sequencing, as well as clinical trials which suggest that a VLP-based vaccine against the signaling molecule IL-17 will be safe and effective in the common skin disease psoriasis, as well as other conditions. Active vaccination against IL-17 is capable of replacing the costly manufacture of antibodies currently in clinical use with huge implications for treatment availability and health economics.

Enhancing immunogenicity and transmission-blocking activity of malaria vaccines by fusing Pfs25 to IMX313 multimerization technology

Transmission-blocking vaccines (TBV) target the sexual-stages of the malaria parasite in the mosquito midgut and are widely considered to be an essential tool for malaria elimination. High-titer functional antibodies are required against target antigens to achieve effective transmission-blocking activity. We have fused Pfs25, the leading malaria TBV candidate antigen to IMX313, a molecular adjuvant and expressed it both in ChAd63 and MVA viral vectors and as a secreted protein-nanoparticle. Pfs25-IMX313 expressed from viral vectors or as a protein-nanoparticle is significantly more immunogenic and gives significantly better transmission-reducing activity than monomeric Pfs25. In addition, we demonstrate that the Pfs25-IMX313 protein-nanoparticle leads to a qualitatively improved antibody response in comparison to soluble Pfs25, as well as to significantly higher germinal centre (GC) responses. These results demonstrate that antigen multimerization using IMX313 is a very promising strategy to enhance antibody responses against Pfs25, and that Pfs25-IMX313 is a highly promising TBV candidate vaccine.

Cytokines in atherosclerosis: Key players in all stages of disease and promising therapeutic targets

Atherosclerosis, a chronic inflammatory disorder of the arteries, is responsible for most deaths in westernized societies with numbers increasing at a marked rate in developing countries. The disease is initiated by the activation of the endothelium by various risk factors leading to chemokine-mediated recruitment of immune cells. The uptake of modified lipoproteins by macrophages along with defective cholesterol efflux gives rise to foam cells associated with the fatty streak in the early phase of the disease. As the disease progresses, complex fibrotic plaques are produced as a result of lysis of foam cells, migration and proliferation of vascular smooth muscle cells and continued inflammatory response. Such plaques are stabilized by the extracellular matrix produced by smooth muscle cells and destabilized by matrix metalloproteinase from macrophages. Rupture of unstable plaques and subsequent thrombosis leads to clinical complications such as myocardial infarction. Cytokines are involved in all stages of atherosclerosis and have a profound influence on the pathogenesis of this disease. This review will describe our current understanding of the roles of different cytokines in atherosclerosis together with therapeutic approaches aimed at manipulating their actions.

Antisense oligonucleotides, microRNAs, and antibodies

The specificity of Watson-Crick base pairing and the development of several chemical modifications to oligonucleotides have enabled the development of novel drug classes for the treatment of different human diseases. This review focuses on promising results of recent preclinical or clinical studies on targeting HDL metabolism and function by antisense oligonucleotides and miRNA-based therapies. Although many hurdles regarding basic mechanism of action, delivery, specificity, and toxicity need to be overcome, promising results from recent clinical trials and recent approval of these types of therapy to treat dyslipidemia suggest that the treatment of HDL dysfunction will benefit from these unique clinical opportunities. Moreover, an overview of monoclonal antibodies (mAbs) developed for the treatment of dyslipidemia and cardiovascular disease and currently being tested in clinical studies is provided. Initial studies have shown that these compounds are generally safe and well tolerated, but ongoing large clinical studies will assess their long-term safety and efficacy.

Cytokines and Immune Responses in Murine Atherosclerosis

Atherosclerosis is an inflammatory disease of the vessel wall characterized by activation of the innate immune system, with macrophages as the main players, as well as the adaptive immune system, characterized by a Th1-dominant immune response. Cytokines play a major role in the initiation and regulation of inflammation. In recent years, many studies have investigated the role of these molecules in experimental models of atherosclerosis. While some cytokines such as TNF or IFNγ clearly had atherogenic effects, others such as IL-10 were found to be atheroprotective. However, studies investigating the different cytokines in experimental atherosclerosis revealed that the cytokine system is complex with both disease stage-dependent and site-specific effects. In this review, we strive to provide an overview of the main cytokines involved in atherosclerosis and to shed light on their individual role during atherogenesis.

Immunization with advanced glycation end products modified low density lipoprotein inhibits atherosclerosis progression in diabetic apoE and LDLR null mice

Background

Diabetes accelerates atherosclerosis through undefined molecular mechanisms. Hyperglycemia induces formation of advanced glycation end product (AGE)-modified low-density lipoprotein (LDL). Anti-AGE-LDL autoantibodies favor atherosclerosis (AS) progression in humans, while anti oxidized LDL immunization inhibits AS in hypercholesterolemic, non-diabetic mice. We here investigated if AGE-LDL immunization protects against AS in diabetic mice.

Methods

After diabetes induction with streptozotocin and high fat diet, both low density lipoprotein receptor (LDLR)−/− and apoE female mice were randomized to: AGE-LDL immunization with aluminum hydroxide (Alum) adjuvant; Alum alone; or PBS.

Results

AGE-LDL immunization: significantly reduced AS; induced specific plasma IgM and IgG antibodies; upregulated splenic Th2, Treg and IL-10 levels, without altering Th1 or Th17 cells; and increased serum high density lipoprotein(HDL) while numerically lowering HbA1c levels.

Conclusions

Subcutaneous immunization with AGE-LDL significantly inhibits atherosclerosis progression in hyperlipidemic diabetic mice possibly through activation of specific humoral and cell mediated immune responses and metabolic control improvement.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-014-0151-6) contains supplementary material, which is available to authorized users.

Multi-therapeutic potential of autoantibodies induced by immune complexes trapped on follicular dendritic cells

Induction of autoantibodies (autoAbs) targeting disease drivers / mediators is emerging as a potential immunotherapeutic strategy. Auto-immune complex (IC)-retaining follicular dendritic cells (FDCs) critically regulate pathogenic autoAb production in autoreactive germinal centers (GCs); however, their ability to induce potentially therapeutic autoAbs has not been explored. We hypothesized that deliberate display of clinically targeted antigens (Ags) in the form of ICs on FDC membranes induces target-specific autoreactive GCs and autoAbs that may be exploited therapeutically. To test our hypothesis, three therapeutically relevant Ags: TNF-α, HER2/neu and IgE, were investigated. Our results indicated that TNF-α-, HER2/neu- and IgE-specific autoAbs associated with strong GC reactions were induced by TNF-α-, HER2/neu- and IgE-IC retention on FDCs. Moreover, the induced anti-TNF-α autoAbs neutralized mouse and human TNF-α with half maximal Inhibitory Concentration (IC₅₀) of 7.1 and 1.6 nM respectively. In addition, we demonstrated that FDC-induced Ab production could be non-specifically inhibited by the IgG-specific Endo-S that accessed the light zones of GCs and interfered with FDC-IC retention. In conclusion, the ability of FDCs to productively present autoAgs raises the potential for a novel immunotherapeutic platform targeting mediators of autoimmune disorders, allergic diseases, and Ab responsive cancers.