Vaccination by Two DerG LEAPS Conjugates Incorporating Distinct Proteoglycan (PG, Aggrecan) Epitopes Provides Therapy by Different Immune Mechanisms in a Mouse Model of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) can be initiated and driven by immune responses to multiple antigenic epitopes including those in cartilage proteoglycan (PG, aggrecan) and type II collagen. RA is driven by T helper 1 (Th1) or Th17 pro-inflammatory T cell responses. LEAPS (Ligand Epitope Antigen Presentation System) DerG peptide conjugate vaccines were prepared using epitopes from PG that elicit immune responses in RA patients: epitope PG70 (DerG-PG70, also designated CEL-4000) and the citrullinated form of another epitope (PG275Cit). The LEAPS peptides were administered alone or together in Seppic ISA51vg adjuvant to mice with PG G1 domain-induced arthritis (GIA), a mouse model of RA. Each of these LEAPS peptides and the combination modulated the inflammatory response and stopped the progression of arthritis in the GIA mouse model. Despite having a therapeutic effect, the DerG-PG275Cit vaccine did not elicit significant antibody responses, whereas DerG-PG70 (alone or with DerG-PG275Cit) induced both therapy and antibodies. Spleen T cells from GIA mice, vaccinated with the DerG LEAPS peptides, preferentially produced anti-inflammatory (IL-4 and IL-10) rather than pro-inflammatory (IFN-γ or IL-17) cytokines in culture. Similarly, cytokines secreted by CD4+ cells of unvaccinated GIA mice, differentiated in vitro to Th2 cells and treated with either or both DerG vaccine peptides, exhibited an anti-inflammatory (IL-4, IL-10) profile. These results suggest that the two peptides elicit different therapeutic immune responses by the immunomodulation of disease-promoting pro-inflammatory responses and that the combination of the two LEAPS conjugates may provide broader epitope coverage and, in some cases, greater efficacy than either conjugate alone.

Restoring the Balance between Pro-Inflammatory and Anti-Inflammatory Cytokines in the Treatment of Rheumatoid Arthritis: New Insights from Animal Models.

Rheumatoid arthritis (RA) and other autoimmune inflammatory diseases are examples of imbalances within the immune system (disrupted homeostasis) that arise from the effects of an accumulation of environmental and habitual insults over a lifetime, combined with genetic predispositions. This review compares current immunotherapies-(1) disease-modifying anti-rheumatic drugs (DMARDs) and (2) Janus kinase (JAK) inhibitors (jakinibs)-to a newer approach-(3) therapeutic vaccines (using the LEAPS vaccine approach). The Ligand Epitope Antigen Presentation System (LEAPS) therapies are capable of inhibiting ongoing disease progression in animal models. Whereas DMARDs ablate or inhibit specific proinflammatory cytokines or cells and jakinibs inhibit the receptor activation cascade for expression of proinflammatory cytokines, the LEAPS therapeutic vaccines specifically modulate the ongoing antigen-specific, disease-driving, proinflammatory T memory cell responses. This decreases disease presentation and changes the cytokine conversation to decrease the expression of inflammatory cytokines (IL-17, IL-1(α or ß), IL-6, IFN-γ, TNF-α) while increasing the expression of regulatory cytokines (IL-4, IL-10, TGF-ß). This review refocuses the purpose of therapy for RA towards rebalancing the immune system rather than compromising specific components to stop disease. This review is intended to be thought provoking and look forward towards new therapeutic modalities rather than present a final definitive report.

Why Don't We Have a Vaccine Against Autoimmune Diseases? - A Review.

This review examines some of the reasons why we don't have a vaccine against autoimmune diseases and highlights the progress that has been made. Many autoimmune diseases, such as rheumatoid arthritis (RA), multiple sclerosis (MS) and type 1 diabetes (T1D), are driven by autoimmune T cell responses. Unlike vaccines for most infectious diseases, which elicit antibody responses, are intended for immuno-naive individuals and considered preventative, a vaccine for an autoimmune disease must be therapeutic and resolve or control the on-going autoimmune response and condition in the diseased host. Despite these differences, many of the same considerations for infectious disease vaccines must also be addressed to develop a therapeutic vaccine for autoimmune diseases. The disease initiator/triggers, antigens and autoantigens, nature of the immunopathogenic and protective/therapeutic immune response will be compared for infectious and autoimmune diseases as will approaches for developing vaccines including formulations, animal models and indicators of success. The rationale for a therapeutic vaccine for RA will be discussed in greater detail with a relatively limited discussion of T1D, MS and other autoimmune diseases.

Lessons from next generation influenza vaccines for inflammatory disease therapies.

Lessons can be learned for treating inflammatory diseases such as rheumatoid arthritis (RA) from next generation approaches for development of universal influenza vaccines. Immunomodulation of inflammatory diseases, rather than ablation of cytokine or cellular responses, can address the root cause of the disease and provide potential cure. Like influenza, there are different antigenic 'strains' and inflammatory T cell responses, Th1 or Th17, that drive each person's disease. As such, next generation vaccine-like antigen specific therapies for inflammatory diseases can be developed but will need to be customized to the patient depending upon the antigen and T cell response that is driving the disease.

LEAPS Vaccine Incorporating HER-2/neu Epitope Elicits Protection That Prevents and Limits Tumor Growth and Spread of Breast Cancer in a Mouse Model.

The prototype J-LEAPS T cell vaccine for HER-2/neu breast cancer (J-HER) consists of the murine HER-2/neu66-74 H-2d CD8 T cell epitope covalently attached through a triglycine linker to the J-immune cell binding ligand (ICBL) (human ß2 microglobulin38-50 peptide). The J-ICBL was chosen for its potential to promote Th1/Tc1 responses. In this proof-of-concept study, the ability of J-HER to prevent or treat cancer was tested in the TUBO cell-challenged BALB/c mouse model for HER-2/neu-expressing tumors. The J-HER vaccine was administered as an emulsion in Montanide ISA-51 without the need for a more potent adjuvant. When administered as a prophylactic vaccination before tumor challenge, J-HER protected against tumor development for at least 48 days. Despite eliciting protection, antibody production in J-HER-immunized, TUBO-challenged mice was less than that in unimmunized mice. More importantly, therapeutic administration of J-HER one week after challenge with TUBO breast cancer cells limited the spread of the tumors and the morbidity and the mortality in the challenged mice. The ability to elicit responses that prevent spread of the TUBO tumor by J-HER suggests its utility as a neoimmunoadjuvant therapy to surgery. Individual or mixtures of J-LEAPS vaccines can be readily prepared to include different CD8 T cell epitopes to optimize tumor therapy and customize treatment for individuals with different HLA types.

Interactive Journal Club: Teaching an Old Dog New Tricks.

The interactive journal club incorporates basic principles of active and adult learning in a traditional education tool to maximize opportunity to develop critical thinking, communication skills, active reflection, and personal confidence in these skills. Following the choice of an appropriate article, the Designated Leader (DL) directs the discussion by presenting the title and data from the article with instructions for their analysis but without the author's text. The participants, except the DL, are viewing the article for the first time and are prompted in their review of the raw data to provide their own interpretation, discovery, and critique. Participants are challenged to become more adept at study design, data analysis, and presentation and have indicated by informal verbal feedback that they look forward to the interactive journal club as it is enjoyable, relevant, and beneficial. Implementation of the interactive journal club does not require significant training in the approach or extensive revision or preparation of course materials.

Concurrent treatment of chronic psoriasis and asthma with ustekinumab.

A 56-year-old woman with a 40-year history of guttate flares of psoriasis associated with stress and infection as well as chronic asthma was treated with subcutaneous injections of ustekinumab, repeated after 1 month and then every 3 months. Her psoriasis completely resolved, and her capacity for exercise was markedly increased and asthma maintenance medications were no longer needed. Ustekinumab is a human monoclonal antibody that binds the p40 subunit of IL-12 and IL-23 to limit the progression of the Th1 and Th17 inflammatory immune responses that maintain many autoimmune and inflammatory diseases. Th17-related responses drive inflammation during late stages of chronic asthma and can also be blocked by ustekinumab. Blocking the underlying cytokine-mediated inflammatory responses for psoriasis with ustekinumab can also treat other chronic inflammatory diseases.

LEAPS therapeutic vaccines as antigen specific suppressors of inflammation in infectious and autoimmune diseases.

The L.E.A.P.S.(™) (Ligand Epitope Antigen Presentation System) technology platform has been used to develop immunoprotective and immunomodulating small peptide vaccines for infectious and autoimmune diseases. Several products are currently in various stages of development, at the pre-clinical stage (in animal challenge efficacy studies). Vaccine peptides can elicit protection of animals from lethal viral (herpes simplex virus [HSV-1] and influenza A) infection or can block the progression of autoimmune diseases (e.g. rheumatoid arthritis as in the collagen induced arthritis (CIA] or experimental autoimmune myocarditis (EAM) models). L.E.A.P.S. technology is a novel T-cell immunization technology that enables the design and synthesis of non-recombinant, proprietary peptide immunogens. Combination of a small peptide that activates the immune system with another small peptide from a disease-related protein, thus a conjugate containing both an Immune Cell Binding Ligand (ICBL) and a disease specific epitope, which allows the L.E.A.P.S. vaccines to activate precursors to differentiate and become more mature cells that can initiate and direct appropriate T cell responses. As such, readily synthesized, defined immunogens can be prepared to different diseases and are likely to elicit protection or therapy as applicable in humans as they are in mice. L.E.A.P.S. vaccines have promise for the treatment of rheumatoid arthritis and other inflammatory diseases and for infections, such as influenza and HSV1. The protective responses are characterized as Th1 immune and immunomodulatory responses with increased IL-12p70 and IFN-γ (Th1 cytokines) but reduced inflammatory cytokines TNF-α, IL-1 and IL-17 (Th2 and Th17 cytokines) and concomitant changes in antibody subtypes. LEAPS immunogens have been used directly in vivo or as ex vivo activators of DC which are then administered to the host.

J-LEAPS peptide and LEAPS dendritic cell vaccines.

The J-LEAPS vaccines contain a peptide from ß-2-microglobulin covalently attached to disease-related peptides of 8-30 amino acids which contain a T cell epitope. The J-LEAPS vaccines can initiate a protective Th1 immune response or modulate an ongoing Th17 autoimmune response to the peptide. J-LEAPS vaccines activate and direct the nature of the subsequent immune response by promoting the maturation of precursor cells into a unique type of dendritic cell that produces interleukin 12, but not IL-1 or tumour necrosis factor, and presents the antigenic peptide to T cells. Adoptive transfer of JgD-LEAPS dendritic cells, matured with an anti-HSV-1 vaccine, promoted antigen-specific Th1 protection against lethal challenge with the virus. J-LEAPS peptide immunogens and J-LEAPS dendritic cell vaccines have potential applications for antimicrobial prevention and therapy, treatment of autoimmune diseases, and for cancer immunotherapy.

Maturation of dendritic cell precursors into IL12-producing DCs by J-LEAPS immunogens.

LEAPS (ligand epitope antigen presentation system) vaccines consist of a peptide containing a major histocompatibility antigen binding peptide conjugated to an immune cell binding ligand (ICBL) such as the 'J' peptide from beta-2-microglobulin. Treatment of monocytes, monocytes plus GMCSF, or monocytes plus GMCSF and IL4 with JgD (containing a peptide from gD of herpes simplex virus type 1) or JH (with a peptide from HIV p17 gag protein) was sufficient to promote their maturation into Interleukin 12 producing dendritic cells. JgD-dendritic cells supported allotypic activation of T cells to produce Th1-related cytokines.

Immune peptide enhancement of peptide based vaccines.

Vaccines optimize the presentation of an immunogen to the immune system, oftentimes enhancing or replacing the natural activators of antigen presenting cells in order to promote the delivery and the response of T and B lymphocytes to the immunogen. The purpose of this series is to describe new technologies which allow vaccine design, based on our understanding of the immune response, using different approaches to immune peptide enhancement of peptide based vaccines. In this introduction to the series entitled, "Immune Peptide Enhancement of Peptide Based Vaccines", some of the immunological concepts relevant to vaccine design are presented.

The L.E.A.P.S. approach to vaccine development.

The Ligand Epitope Antigen Presentation System (L.E.A.P.S.) approach to vaccine development utilizes immune peptides to promote the immunogenicity and influence the type of immune response generated towards epitopes in peptides which may be too small to elicit an immune response. The covalent attachment of these immune peptides to the antigenic peptide promotes the interaction of the epitope with T cells (T cell binding ligand (TCBL)) or antigen presenting cells (immune cell binding ligand (ICBL)) and ultimately promotes binding with the T cell receptor on CD4 or CD8 T cells. The, J, ICBL/TCBL peptide derived from the beta-2-microglobulin chain of MHC I molecules promotes Th1 type responses to the antigenic peptide while the, G, ICBL/TCBL peptide derived from the beta chain of MHC II molecules promotes Th2 types of responses. The efficacy of this approach has been demonstrated by characterization of the immune responses to L.E.A.P.S. vaccines and by elicitation of protection from infectious challenge with herpes simplex virus and other pathogens. The protection studies show that the L.E.A.P.S. approach allows customization of the immune response appropriate for inducing protection from disease. The theory, background, examples and studies of the mechanism of action of the L.E.A.P.S. vaccines will be discussed.

Strain-dependent structural variants of herpes simplex virus type 1 ICP34.5 determine viral plaque size, efficiency of glycoprotein processing, and viral release and neuroinvasive disease potential.

The ability of certain strains of herpes simplex virus type 1 (HSV-1) to cause encephalitis or neuroinvasive disease in the mouse upon peripheral infection is dependent on a combination of activities of specific forms of viral proteins. The importance of specific variants of ICP34.5 to neuroinvasive disease potential and its correlation with small-plaque production, inefficient glycoprotein processing, and virus release were suggested by comparison of ICP34.5 from the SP7 virus, originally obtained from the brain of a neonate with disseminated disease, and the tissue culture-passaged progeny of SP7 (SLP5 and SLP10) and the KOS321 virus. SLP5, SLP10, and KOS321 are attenuated and exhibit a large-plaque phenotype, including efficient glycoprotein processing and viral release. We show that expression of the KOS321 ICP34.5 protein in cells infected with SP7 or ICP34.5 deletion mutants promotes large plaque formation and efficient viral glycoprotein processing, while expression of the SP7 ICP34.5 protein decreases efficiency of viral glycoprotein processing. In addition, a recombinant virus, 4hS1, with the SP7 ICP34.5 gene replacing the KOS321-like ICP34.5 gene in the SLP10a background, rescues the small-plaque phenotype and neuroinvasive disease. The major difference in the ICP34.5 gene product is the number of Pro-Ala-Thr repeats in the middle region of the protein, with 18 for SP7 and 3 for KOS321. Strain-dependent differences in the ICP34.5 protein can therefore alter the tissue culture behavior and the virulence of HSV-1.