Active immunization against murine TNFalpha peptides in mice: generation of endogenous antibodies cross-reacting with the native cytokine and in vivo protection

Molecular Peptide Grafting as a Tool to Create Novel Protein Therapeutics

The study of peptides (synthetic or corresponding to discrete regions of proteins) has facilitated the understanding of protein structure-activity relationships. Short peptides can also be used as powerful therapeutic agents. However, the functional activity of many short peptides is usually substantially lower than that of their parental proteins. This is (as a rule) due to their diminished structural organization, stability, and solubility often leading to an enhanced propensity for aggregation. Several approaches have emerged to overcome these limitations, which are aimed at imposing structural constraints into the backbone and/or sidechains of the therapeutic peptides (such as molecular stapling, peptide backbone circularization and molecular grafting), therefore enforcing their biologically active conformation and thus improving their solubility, stability, and functional activity. This review provides a short summary of approaches aimed at enhancing the biological activity of short functional peptides with a particular focus on the peptide grafting approach, whereby a functional peptide is inserted into a scaffold molecule. Intra-backbone insertions of short therapeutic peptides into scaffold proteins have been shown to enhance their activity and render them a more stable and biologically active conformation.

Vaccine targeting TNF epitope 1-14 do not suppress host defense against Mycobacterium bovis Bacillus Calmette-Guérin infection

Anti-TNF inhibitors are efficacious in the treatment of chronic inflammatory diseases such as rheumatoid arthritis (RA), Crohn's disease (CD), juvenile idiopathic arthritis (JIA), and ankylosing spondylitis (AS). However, more and more clinical case reports revealed that anti-TNF inhibitors could increase the risk of viral, fungal, and bacterial (especially intracellular) infection. In this study, based on Immune Epitope Database (IEDB) online B cell epitope prediction and the knowledge of TNF three dimensional (3D) structure we developed a novel vaccine (DTNF114-TNF114) that targeting TNF epitope 1-14, which produced antibodies only partially binding to trans-membrane TNF (tmTNF), therefore partially sparing tmTNF-TNFR1/2 interaction. Immunization with DTNF114-TNF114 significantly protected and prolonged the survival rate of mice challenged with lipopolysaccharide (LPS); and in the mCherry expressing Mycobacterium bovis Bacillus Calmette-Guérin (mCherry-BCG) infection model, DTNF114-TNF114 immunization significantly decreased soluble TNF (solTNF) level in serum, meanwhile did not suppress host immunity against infection. Thus, this novel and infection concern-free vaccine provides a potential alternative or supplement to currently clinically used anti-TNF inhibitors.

Peptide-Based Vaccination Therapy for Rheumatic Diseases

Rheumatic diseases are extremely heterogeneous diseases with substantial risks of morbidity and mortality, and there is a pressing need in developing more safe and cost-effective treatment strategies. Peptide-based vaccination is a highly desirable strategy in treating noninfection diseases, such as cancer and autoimmune diseases, and has gained increasing attentions. This review is aimed at providing a brief overview of the recent advances in peptide-based vaccination therapy for rheumatic diseases. Tremendous efforts have been made to develop effective peptide-based vaccinations against rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), while studies in other rheumatic diseases are still limited. Peptide-based active vaccination against pathogenic cytokines such as TNF-α and interferon-α (IFN-α) is shown to be promising in treating RA or SLE. Moreover, peptide-based tolerogenic vaccinations also have encouraging results in treating RA or SLE. However, most studies available now have been mainly based on animal models, while evidence from clinical studies is still lacking. The translation of these advances from experimental studies into clinical therapy remains impeded by some obstacles such as species difference in immunity, disease heterogeneity, and lack of safe delivery carriers or adjuvants. Nevertheless, advances in high-throughput technology, bioinformatics, and nanotechnology may help overcome these impediments and facilitate the successful development of peptide-based vaccination therapy for rheumatic diseases.

Active immunotherapy for TNF-mediated inflammation using self-assembled peptide nanofibers

Active immunotherapies raising antibody responses against autologous targets are receiving increasing interest as alternatives to the administration of manufactured antibodies. The challenge in such an approach is generating protective and adjustable levels of therapeutic antibodies while at the same time avoiding strong T cell responses that could lead to autoimmune reactions. Here we demonstrate the design of an active immunotherapy against TNF-mediated inflammation using short synthetic peptides that assemble into supramolecular peptide nanofibers. Immunization with these materials, without additional adjuvants, was able to break B cell tolerance and raise protective antibody responses against autologous TNF in mice. The strength of the anti-TNF antibody response could be tuned by adjusting the epitope content in the nanofibers, and the T-cell response was focused on exogenous and non-autoreactive T-cell epitopes. Immunization with unadjuvanted peptide nanofibers was therapeutic in a lethal model of acute inflammation induced by intraperitoneally delivered lipopolysaccharide, whereas formulations adjuvanted with CpG showed comparatively poorer protection that correlated with a more Th1-polarized response. Additionally, immunization with peptide nanofibers did not diminish the ability of mice to clear infections of Listeria monocytogenes. Collectively this work suggests that synthetic self-assembled peptides can be attractive platforms for active immunotherapies against autologous targets.

A Rationally Designed TNF-α Epitope-Scaffold Immunogen Induces Sustained Antibody Response and Alleviates Collagen-Induced Arthritis in Mice

The TNF-α biological inhibitors have significantly improved the clinical outcomes of many autoimmune diseases, in particular rheumatoid arthritis. However, the practical uses are limited due to high costs and the risk of anti-drug antibody responses. Attempts to develop anti-TNF-α vaccines have generated encouraging data in animal models, however, data from clinical trials have not met expectations. In present study, we designed a TNF-α epitope-scaffold immunogen DTNF7 using the transmembrane domain of diphtheria toxin, named DTT as a scaffold. Molecular dynamics simulation shows that the grafted TNF-α epitope is entirely surface-exposed and presented in a native-like conformation while the rigid helical structure of DTT is minimally perturbed, thereby rendering the immunogen highly stable. Immunization of mice with alum formulated DTNF7 induced humoral responses against native TNF-α, and the antibody titer was sustained for more than 6 months, which supports a role of the universal CD4 T cell epitopes of DTT in breaking self-immune tolerance. In a mouse model of rheumatoid arthritis, DTNF7-alum vaccination markedly delayed the onset of collagen-induced arthritis, and reduced incidence as well as clinical score. DTT is presumed safe as an epitope carrier because a catalytic inactive mutant of diphtheria toxin, CRM197 has good clinical safety records as an active vaccine component. Taken all together, we show that DTT-based epitope vaccine is a promising strategy for prevention and treatment of autoimmune diseases.

Immunization against an IL-6 peptide induces anti-IL-6 antibodies and modulates the Delayed-Type Hypersensitivity reaction in cynomolgus monkeys

Interleukin-6 (IL-6) overproduction has been involved in the pathogenesis of several chronic inflammatory diseases and the administration of an anti-IL-6 receptor monoclonal antibody has been proven clinically efficient to treat them. However, the drawbacks of monoclonal antibodies have led our group to develop an innovative anti-IL-6 strategy using a peptide-based active immunization. This approach has previously shown its efficacy in a mouse model of systemic sclerosis. Here the safety, immunogenicity, and efficacy of this strategy was assessed in non human primates. No unscheduled death and clinical signs of toxicity was observed during the study. Furthermore, the cynomolgus monkeys immunized against the IL-6 peptide produced high levels of anti-IL-6 antibodies as well as neutralizing antibodies compared to control groups. They also showed an important decrease of the cumulative inflammatory score following a delayed-type hypersensitivity reaction induced by the Tetanus vaccine compared to control groups (minus 57,9%, P = 0.014). These findings are highly significant because the immunizing IL-6 peptide used in this study is identical in humans and in monkeys and this novel anti-IL-6 strategy could thus represent a promising alternative to monoclonal antibodies.

Targeting VEGF-A with a vaccine decreases inflammation and joint destruction in experimental arthritis

OBJECTIVES

Inflammation and angiogenesis are two tightly linked processes in arthritis, and therapeutic targeting of pro-angiogenic factors may contribute to control joint inflammation and synovitis progression. In this work, we explored whether vaccination against vascular endothelial growth factor (VEGF) ameliorates collagen-induced arthritis (CIA).

METHODS

Anti-VEGF vaccines were heterocomplexes consisting of the entire VEGF cytokine (or a VEGF-derived peptide) linked to the carrier protein keyhole limpet hemocyanin (KLH). Two kinds of vaccines were separately tested in two independent experiments of CIA. In the first, we tested a kinoid of the murine cytokine VEGF (VEGF-K), obtained by conjugating VEGF-A to KLH. For the second, we selected two VEGF-A-derived peptide sequences to produce heterocomplexes (Vpep1-K and Vpep2-K). DBA/1 mice were immunized with either VEGF-K, Vpep1-K, or Vpep2-K, before CIA induction. Clinical and histological scores of arthritis, anti-VEGF, anti-Vpep Ab titers, and anti-VEGF Abs neutralizing capacity were determined.

RESULTS

Both VEGF-K and Vpep1-K significantly ameliorated clinical arthritis scores and reduced synovial inflammation and joint destruction at histology. VEGF-K significantly reduced synovial vascularization. None of the vaccines reduced anti-collagen Ab response in mice. Both VEGF-K and Vpep1-K induced persistently high titers of anti-VEGF Abs capable of inhibiting VEGF-A bioactivity.

CONCLUSION

Vaccination against the pro-angiogenic factor VEGF-A leads to the production of anti-VEGF polyclonal Abs and has a significant anti-inflammatory effect in CIA. Restraining Ab response to a single peptide sequence (Vpep1) with a peptide vaccine effectively protects immunized mice from joint inflammation and destruction.

Targeting IL-6 by both passive or active immunization strategies prevents bleomycin-induced skin fibrosis

Introduction

Interleukin-6 (IL-6) is a pleiotropic cytokine for which preliminary data have suggested that it might contribute to systemic sclerosis (SSc). Our aims were to investigate, firstly, IL-6 expression in patients with SSc and, secondly, the efficacy of both passive and active immunization against IL-6 to reduce skin fibrosis in complementary mouse models of SSc.

Methods

Human serum levels and skin expression of IL-6 were determined by enzyme-linked immunosorbent assay and immunohistochemistry, respectively. We first evaluated the antifibrotic properties of the monoclonal anti-IL-6R antibody, MR16-1, in the bleomycin-induced dermal fibrosis mouse model, reflecting early and inflammatory stages of SSc. Then, we assessed the efficacy of MR16-1 in tight skin-1 (Tsk-1) mice, an inflammation-independent model of skin fibrosis. Additionally, we have developed an innovative strategy using an anti-IL-6 peptide-based active immunization. Infiltrating leukocytes, T cells, and B cells were quantified, and IL-6 levels were measured in the serum and lesional skin of mice after passive or active immunization.

Results

Serum and skin levels of IL-6 were significantly increased in patients with early SSc. Treatment with MR16-1 led in the bleomycin mouse model to a 25% (P = 0.02) and 30% (P = 0.007) reduction of dermal thickness and hydroxyproline content, respectively. MR16-1 demonstrated no efficacy in Tsk-1 mice. Thereafter, mice were immunized against a small peptide derived from murine IL-6 and this strategy led in the bleomycin model to a 20% (P = 0.02) and 25% (P = 0.005) decrease of dermal thickness and hydroxyproline content, respectively. Passive and active immunization led to decreased T-cell infiltration in the lesional skin of mice challenged with bleomycin. Upon bleomycin injections, serum and skin IL-6 levels were increased after treatment with MR16-1 and were significantly reduced after anti-IL-6 active immunization.

Conclusions

Our results support the relevance of targeting IL-6 in patients with early SSc since IL-6 is overexpressed in early stages of the disease. Targeting IL-6 by both passive and active immunization strategies prevented the development of bleomycin-induced dermal fibrosis in mice. Our results highlight the therapeutic potential of active immunization against IL-6, which is a seductive alternative to passive immunization.

Strategies for active TNF-α vaccination in rheumatoid arthritis treatment

Local overexpression of tumor necrosis factors alpha (TNF-α) is critically involved in the inflammatory response and tissue destruction of rheumatoid arthritis (RA). Currently, the blockade of TNF-α by passive immunotherapy is indeed efficacious in the treatment of RA, but it still present some disadvantages. Induction of high level of anti-TNF-α neutralizing autoantibodies by TNF-α autovaccine has been developed to avoid these shortcomings. This review is to briefly introduce several vaccination approaches that have been used to induce a B cell response, including coupled TNF-α (entire/peptide) with a carrier protein, modified TNF-α with foreign Th cell epitopes, and engineered DNA vaccine. These methods showed remarkable therapeutic efficiency in experimental animals which indicated that active TNF-α immunization would be a promising and cost-effective new treatment option for RA.

An IL-17 peptide-based and virus-like particle vaccine enhances the bioactivity of IL-17 in vitro and in vivo

AIMS

To develop an IL-17 peptide-based virus-like particle vaccine that elicits autoantibodies to IL-17 and to evaluate the effects of the vaccine in mice with experimental colitis.

MATERIALS & METHODS

Recombinant IL-17 vaccines were constructed by inserting selected peptides derived from mouse IL-17 into the carrier protein, hepatitis B core antigen, using molecular engineering methods. To evaluate the in vivo effects of the vaccine, mice with 2,4,6-trinitrobenzene sulfonic acid-induced chronic colitis were injected three times with the vaccine, carrier or saline after the second delivery of 2,4,6-trinitrobenzene sulfonic acid. Colon inflammation and fibrosis were evaluated by histological examination. Serum IL-17-specific IgG and colon-tissue cytokine levels were measured by ELISA. In vitro inhibition tests of sera from vaccine-immunized mice were performed using IL-17-induced IL-6 production by NIH 3T3 cells and IL-17-induced TNF production by macrophages.

RESULTS

Immunization with the vaccine without the use of adjuvants induced high-titered and long-lasting antibodies to IL-17. Unexpectedly, vaccinated mice exhibited increases in colon inflammation, collagen deposition, levels of TNF and IL-17 cytokines compared with carrier and saline groups. Furthermore, in vitro study revealed that serum IL-17-specific IgG from vaccine-immunized mice significantly enhanced IL-17-induced IL-6 production and IL-17-induced TNF production dose-dependently.

CONCLUSION

The IL-17 peptide-based vaccine enhances the bioactivity of IL-17 in vitro and in vivo, providing a potential immunotherapy for treatment of diseases associated with insufficient IL-17 production, such as hyper-IgE syndrome.

Active and passive anticytokine immune therapies: current status and development

Anticytokine (AC) immune therapies derived from vaccine procedures aim at enhancing natural immune defense mechanisms ineffective to contain abnormally produced cytokines and counteract their pathogenic effects. Given their short half-life, cytokines, the production of which by effector immune cells (T and B lymphocytes, antigen-presenting cells (APCs), natural killer (NK) and endothelial cells) is inducible and controlled by negative feedback regulation, (1) exert locally their signaling to paracrine/autocrine target responder cells carrying high-affinity membrane receptors and (2) are commonly present at minimal concentration in the body fluid (lymph, serum). Aberrant signaling triggered by cytokines, uncontrolly released by effector immune cells or produced by cancer and other pathologic cells, contribute to the pathogenesis of chronic diseases including cancer, viral infections, allergy, and autoimmunity. To block these ectopic cytokine signaling and prevent their pathogenic effects, AC Abs supplied either by injections (passive AC immune therapy) or elicited by immunization with cytokine-derived immunogenes called Kinoids (active AC immune therapy) proved to be experimentally effective and safe. In this review, we detailed the rationale and the requirements for the use of AC immunotherapies in humans, the proof of efficacy of these medications in animal disease models, and their current clinical development and outcome, including adverse side effects they may generate. We particularly show that, to date, the benefit:risk ratio of AC immune therapies is highly positive.

Targeting IL-12/IL-23 by employing a p40 peptide-based vaccine ameliorates TNBS-induced acute and chronic murine colitis

Interleukin (IL)-12 and IL-23 both share the p40 subunit and are key cytokines in the pathogenesis of Crohn's disease. Previously, we have developed and identified three mouse p40 peptide-based and virus-like particle vaccines. Here, we evaluated the effects and immune mechanisms of the optimal vaccine in downregulating intestinal inflammation in murine acute and chronic colitis, induced by intrarectal administrations of trinitrobenzene sulfonic acid (TNBS). Mice were injected subcutaneously with vaccine, vaccine carrier or saline three times, and then intrarectally administered TNBS weekly for 2 wks (acute colitis) or 7 wks (chronic colitis). The severity of colitis was evaluated by body weight, histology and collagen and cytokine levels in colon tissue. Th1 and Th17 cells in mesenteric lymph nodes (MLN) were determined. Our results showed the vaccine induced high level and long-lasting specific IgG antibodies to p40, IL-12 and IL-23. After administrations of TNBS, vaccinated mice had significantly less body weight loss and a significant decrease of inflammatory scores, collagen deposition and expression of p40, IL-12, IL-23, IL-17, TNF, iNOS and Bcl-2 in colon tissues, compared with carrier and saline groups. Moreover, vaccinated mice exhibited a trend to lower percentages of Th1 cells in acute colitis and of Th17 cells in chronic colitis in MLN than in controls. In summary, administration of the vaccine induced specific antibodies to IL-12 and IL-23, which was associated with improvement of intestinal inflammation and fibrosis. This suggests that the vaccine may provide a potential approach for the long-term treatment of Crohn's disease.

Immunodrugs: breaking B- but not T-cell tolerance with therapeutic anticytokine vaccines

Pathology in most chronic inflammatory diseases is characterized by an imbalance in cytokine expression. Targeting cytokines with monoclonal antibodies has proven to be a highly effective treatment. However, monoclonal antibody therapy has disadvantages such as high production costs, generation of antimonoclonal antibodies and the inconvenience of frequent injections. Therapeutic vaccines have the potential to overcome these limitations. The aim of active vaccination is to induce B-cell responses and obtain autoantibodies capable of neutralizing the interaction of the targeted cytokine with its receptor. In order to achieve this, therapeutic vaccines need to circumvent the potent tolerance mechanisms that exist to prevent immune responses against self-molecules. This article focuses on the tolerance mechanisms of the B- and T-cell compartments and how these may be manipulated to obtain high-affinity autoantibodies without inducing potentially dangerous autoreactive T-cell responses.

Targeting TGF-beta1 by employing a vaccine ameliorates fibrosis in a mouse model of chronic colitis

BACKGROUND

Intestinal fibrosis and stricture formation are major complications of inflammatory bowel disease (IBD), for which there are currently few effective treatments. We sought to investigate whether targeting transforming growth factor-beta1 (TGF-beta1), a key profibrotic mediator, with a peptide-based virus-like particle vaccine would be effective in suppressing intestinal fibrosis by using a mouse model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced chronic colitis.

METHODS

The vaccine was prepared by inserting a peptide derived from mouse TGF-beta1 into a carrier hepatitis B core antigen using gene recombination methods. Chronic colitis was induced in BALB/c mice by 8 weekly TNBS administrations. Mice were subcutaneously injected with vaccine, carrier, or phosphate-buffered saline (PBS) in 2 separate studies: either before or after acute inflammatory responses commenced.

RESULTS

Sera from vaccinated mice exhibited significantly elevated levels of TGF-beta1-specific immunoglobulin G (IgG), which inhibited TGF-beta1-induced luciferase production in mink lung epithelial cells. In the chronic colitis model, mice receiving vaccine showed improved body weight gain and significantly reduced colonic collagen deposition. Hematoxylin and eosin staining and semiquantitative scoring indicated that vaccination even ameliorated colonic inflammation. Cytokine profile analysis revealed that levels of TGF-beta1, interleukin (IL)-17, and IL-23 in vaccinated mouse colon tissues were decreased, and that percentages of IL-17-expressing CD4(+) lymphocytes in mesenteric lymph node cells were reduced. Furthermore, Smad3 phosphorylation, a key event in TGF-beta signaling, was decreased in colonic tissue in vaccinated mice.

CONCLUSIONS

This TGF-beta1 peptide-based vaccine, which suppressed excessive TGF-beta1 bioactivity, may prevent the development of intestinal fibrosis and associated complications, presenting a novel approach in the treatment of IBD.

Enhancement of IL-10 bioactivity using an IL-10 peptide-based vaccine exacerbates Leishmania major infection and improves airway inflammation in mice

IL-10 is a regulatory cytokine that plays important roles in promoting disease progression in cutaneous leishmaniasis and suppressing allergic responses in asthma. We sought to develop an IL-10 peptide-based vaccine for the control of IL-10-related diseases. To break self-tolerance, hepatitis B core antigen (HBcAg) was used as a carrier. The vaccine was prepared by inserting a peptide derived from mouse IL-10 into the carrier using gene recombination methods. This vaccine presented as virus-like particles, bound to polyclonal anti-IL-10 antibodies, and induced high titers of IL-10-specific IgG. The in vivo effects of the vaccine were investigated in a murine model of cutaneous leishmaniasis. Unexpectedly, vaccinated mice developed larger cutaneous lesions, harbored significantly more parasites, and cells from lymph nodes produced higher amounts of parasite-specific IL-4, IL-10 and IFN-gamma in cultures. Further in vitro studies showed that serum IL-10-specific IgG from vaccinated mice significantly enhanced IL-10 bioactivity dose-dependently. This enhancing effect was confirmed in OVA-induced asthmatic mice. Vaccinated mice exhibited a significant decrease in airway eosinophils, lung inflammation, goblet hyperplasia, and levels of serum OVA-specific IgE, compared to control mice. We concluded that the IL-10 vaccine enhances the bioactivity of IL-10 in vitro and in vivo, providing a potential therapeutic approach in diseases associated with insufficient IL-10 production.

A measles-derived peptide treats and vaccinates against adjuvant arthritis

Measles vaccine and porcine myelin basic protein were both found to ameliorate or abolish the symptoms of adjuvant arthritis (AA) in Lewis rats whether inoculated at the time of adjuvant administration or after the onset of arthritis. These results are consistent with clinical observations that measles infection can sometimes cause remission of juvenile rheumatoid arthritis. The fact that measles virus proteins and myelin basic protein have significant regions of homology allowed peptides based on these regions to be synthesized. A twenty-amino acid sequence exhibits significant anti-arthritic activity when inoculated into rats with pre-existing AA and it also prevented onset of AA when a single dose was preinoculated three weeks prior to AA induction. These data suggest the possibility of developing novel therapeutic vaccines against some forms of arthritis.

Emerging applications of anticytokine vaccines

Most chronic inflammatory diseases have an unknown etiology but all involve cytokine cascade in their development. Several cytokines have been identified as major targets in various autoimmune diseases, resulting in the development of monoclonal antibodies against those cytokines. Even if monoclonal antibodies are indeed efficient, passive immunotherapies present some disadvantages and are expensive. To counter this, several strategies have been developed, including active immunotherapy, based on vaccination principles. The aim of such a strategy is to induce a B-cell response and to obtain autoantibodies able to neutralize the interaction of the self-cytokine to its receptor. Efficient vaccines have to induce a short-term response to avoid permanent inhibition of a given cytokine. This review focuses on the different therapeutic vaccination strategies with cytokines in preclinical studies; the benefit-risk ratio of such a strategy and the present development of clinical trials in some autoimmune diseases are also discussed.

Vaccination with cytokines in autoimmune diseases

Most autoimmune diseases have an unknown etiology, but all involve cytokines cascade in their development. At the present time, several cytokines have been identified as major targets in various autoimmune diseases, involving the development of monoclonal antibodies (MAbs) against those cytokines. Even if MAbs are indeed efficient, the passive immunotherapies also present some disadvantages and are expensive. To counter this, several strategies have been developed, including active immunotherapy, based on the vaccination principle. The aim of such a strategy is to induce a B cell response and to obtain autoantibodies able to neutralize the interaction of the self-cytokine with its receptor. To that purpose, cytokines (entire or peptide) are either coupled with a protein-carrier or virus-like particle, or modified with foreign Th cell epitopes. DNA vaccination can also be used with cytokine sequences. This review focuses on the different vaccination strategies with cytokines (including Tumor Necrosis Factor (TNF)alpha, Interleukin-1beta (IL-1beta), IL-17) in different autoimmune diseases in preclinical studies; the benefit/risk ratio of such a strategy and the present development of clinical trials in some autoimmune diseases are also discussed.

Vaccination with IL-6 analogues induces autoantibodies to IL-6 and influences experimentally induced inflammation

IL-6 is involved in inflammation and a therapeutic target. 0.1% of Danish blood donors have nanomolar plasma concentrations of polyclonal, picomolar affinity and in vitro as well as in vivo neutralizing IgG autoantibodies to IL-6 (aAb-IL-6). Such donors are assumed to be severely IL-6 deficient; yet they appear healthy and do not exhibit overt clinical or laboratory abnormalities. We induced comparable levels of aAb-IL-6 in different mouse strains by vaccination with immunogenic IL-6 analogues. We observed that the induced aAb-IL-6 protected against collagen-induced arthritis and experimental allergic encephalitis. Furthermore, aAb-IL-6 carrying mice displayed increased plasma TNFalpha concentrations upon challenge with LPS. Taken together, induction of IL-6 autoantibodies was possible in different mouse strains. The autoantibodies influenced experimental inflammation. This immunotherapeutic principle might be a viable alternative in immune competent humans suffering from disorders driven by IL-6.

TNFalpha kinoid vaccination-induced neutralizing antibodies to TNFalpha protect mice from autologous TNFalpha-driven chronic and acute inflammation

The proinflammatory cytokine TNFalpha is a potent mediator of septic shock and a therapeutic target for chronic inflammatory pathologies including rheumatoid arthritis and Crohn's disease. As an alternative to anti-human TNFalpha (hTNFalpha) mAbs and other hTNFalpha blocker approved drugs, we developed an active anti-hTNFalpha immunotherapy, based on a vaccine comprised of a keyhole limpet hemocyanin-hTNFalpha heterocomplex immunogen (hTNFalpha kinoid) adjuvanted in incomplete Freund's adjuvant. In mice transgenic for hTNFalpha (TTg mice), hTNFalpha kinoid vaccination elicited high titers of Abs that neutralized hTNFalpha bioactivities but did not result in a cellular response to hTNFalpha. The vaccine was safe and effective in two experimental models. Kinoid-immunized but not control TTg mice resisted hTNFalpha-driven shock in one model and were prevented from spontaneous arthritis, inflammatory synovitis, and articular destruction in a second model. These data demonstrate an anti-cytokine induction of autoimmune protection against both acute and chronic hTNFalpha exposure. They show that active vaccination against a human cytokine can be achieved, and that the immune response can be effective and safe.