Intranasal vaccination with proinsulin DNA induces regulatory CD4+ T cells that prevent experimental autoimmune diabetes

Insulin, an autoantigen in type 1 diabetes, when administered mucosally to diabetes-prone NOD mice induces regulatory T cells (T_reg) that protect against diabetes. Compared with protein, Ag encoded as DNA has potential advantages as a therapeutic agent. We found that intranasal vaccination of NOD mice with plasmid DNA encoding mouse proinsulin II-induced CD4⁺ T_reg that suppressed diabetes development, both after adoptive cotransfer with "diabetogenic" spleen cells and after transfer into NOD mice given cyclophosphamide to accelerate diabetes onset. In contrast to prototypic CD4⁺CD25⁺ T_reg, CD4⁺ T_reg induced by proinsulin DNA were both CD25⁺ and CD25^– and not defined by markers such as glucocorticoid-induced TNFR-related protein (GITR), CD103, or Foxp3. Intriguingly, despite induction of T_reg and reduced islet inflammation, diabetes incidence in proinsulin DNA-treated mice was unchanged. However, diabetes was prevented when DNA vaccination was performed under the cover of CD40 ligand blockade, known to prevent priming of CTL by mucosal Ag. Thus, intranasal vaccination with proinsulin DNA has therapeutic potential to prevent diabetes, as demonstrated by induction of protective T_reg, but further modifications are required to improve its efficacy, which could be compromised by concomitant induction of pathogenic immunity.

Simultaneous neuroprotection and blockade of inflammation reverses autoimmune encephalomyelitis

In multiple sclerosis, the immune system attacks the white matter of the brain and spinal cord, leading to disability and/or paralysis. Myelin, oligodendrocytes and neurons are lost due to the release by immune cells of cytotoxic cytokines, autoantibodies and toxic amounts of the excitatory neurotransmitter glutamate. Experimental autoimmune encephalomyelitis (EAE) is an animal model that exhibits the clinical and pathological features of multiple sclerosis. Current therapies that suppress either the inflammation or glutamate excitotoxicity are partially effective when administered at an early stage of EAE, but cannot block advanced disease. In a multi-faceted approach to combat EAE, we blocked inflammation with an anti-MAdCAM-1 (mucosal addressin cell adhesion molecule-1) monoclonal antibody and simultaneously protected oligodendrocytes and neurons against glutamate-mediated damage with the -amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)/kainate antagonist 2,3-dihydroxy-6-nitro-7- sulfamoylbenzo(f)quinoxaline (NBQX) and the neuroprotector glycine–proline–glutamic acid (GPE; N-terminal tripeptide of insulin-like growth factor). Remarkably, administration at an advanced stage of unremitting EAE of either a combination of NBQX and GPE, or preferably all three latter reagents, resulted in amelioration of disease and repair of the CNS, as assessed by increased oligodendrocyte survival and remyelination, and corresponding decreased paralysis, inflammation, CNS apoptosis and axonal damage. Each treatment reduced the expression of nitric oxide and a large panel of proinflammatory and immunoregulatory cytokines, in particular IL-6 which plays a critical role in mediating EAE. Mice displayed discernible improvements in all physical features examined. Disease was suppressed for 5 weeks, but relapsed when treatment was suspended, suggesting treatment must be maintained to be effective. The above approaches, which allow CNS repair by inhibiting inflammation and/or simultaneously protect neurons and oligodendrocytes from damage, could thus be effective therapies for multiple sclerosis.

Prevention of a chronic progressive form of experimental autoimmune encephalomyelitis by an antibody against mucosal addressin cell adhesion molecule-1, given early in the course of disease progression.

A role for α4 and β7 integrins in mediating leucocyte entry into the central nervous system in the multiple sclerosis (MS)-like disease experimental autoimmune encephalomyelitis (EAE) has been demonstrated. However, the individual contributions of their respective ligands mucosal addressin cell adhesion molecule-1 (MAdCAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-cadherin expressed on the blood-brain barrier has not been determined. In the present paper, it is shown that an antibody directed against MAdCAM-1, the preferential ligand for α4β7, effectively prevented the development of a progressive, non-remitting, form of EAE, actively induced by injection of myelin oligodendrocyte glycoprotein peptide (MOG(_35-55)) autoantigen. Combinational treatment with both anti-MAdCAM-1, VCAM-1, and intercellular adhesion molecule-1 (ICAM-1) (ligand for integrin lymphocyte function-associated antigen (LFA)-1) mAbs led to more rapid remission than that obtained with anti-MAdCAM-1 antibody alone. However, neither MAdCAM-1 monotherapy, nor combinational antibody blockade was preventative when administered late in the course of disease progression. In conclusion, MAdCAM-1 plays a major contributory role in the progression of chronic EAE and is a potential therapeutic target for the treatment of MS. Critically, antivascular addressin therapy must be given eaA role for alpha4 and beta7 integrins in mediating leucocyte entry into the central nervous system in the multiple sclerosis (MS)-like disease experimental autoimmune encephalomyelitis (EAE) has been demonstrated. However, the individual contributions of their respective ligands mucosal addressin cell adhesion molecule-1 (MAdCAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-cadherin expressed on the blood-brain barrier has not been determined. In the present paper, it is shown that an antibody directed against MAdCAM-1, the preferential ligand for alpha4beta7, effectively prevented the development of a progressive, non-remitting, form of EAE, actively induced by injection of myelin oligodendrocyte glycoprotein peptide (MOG(35-55)) autoantigen. Combinational treatment with both anti-MAdCAM-1, VCAM-1, and intercellular adhesion molecule-1 (ICAM-1) (ligand for integrin lymphocyte function-associated antigen (LFA)-1) mAbs led to more rapid remission than that obtained with anti-MAdCAM-1 antibody alone. However, neither MAdCAM-1 monotherapy, nor combinational antibody blockade was preventative when administered late in the course of disease progression. In conclusion, MAdCAM-1 plays a major contributory role in the progression of chronic EAE and is a potential therapeutic target for the treatment of MS. Critically, antivascular addressin therapy must be given early in the course of disease prior to the establishment of irreversible damage if it is to be effective, as a single treatment modality.

Anti-inflammatory immunotherapy for multiple sclerosis/experimental autoimmune encephalomyelitis (EAE) disease

Multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), are inflammatory diseases of the central nervous system (CNS) characterized by localized areas with demyelination. Disease is believed to be an autoimmune disorder mediated by activated immune cells such as T- and B-lymphocytes and macrophages/microglia. Lymphocytes are primed in the peripheral tissues by antigens, and clonally expanded cells infiltrate the CNS. They produce large amounts of inflammatory cytokines, nitric oxide (NO) that lead to demyelination and axonal degeneration. Although several studies have shown that oligodendrocytes (OLGs), the myelin-forming glial cells in the CNS, are sensitive to cell death stimuli, such as cytotoxic cytokines, anti-myelin antibodies, NO, and oxidative stress, in vitro, the mechanisms underlying injury to the OLGs in MS/EAE remain unclear. The central role of glutamate receptors in mediating excitotoxic neuronal death in stroke, epilepsy, trauma and MS has been well established. Glutamate is the major excitatory amino acid transmitter within the CNS and it's signaling is mediated by a number of postsynaptic ionotropic and metabotropic receptors. Inflammation can be blocked with anti-cell adhesion molecules MAb, simultaneously protected oligodendrocytes and neurons against glutamate-mediated damage with the AMPA/kainate antagonist NBQX, and the NMDA receptor antagonist GPE, could thus be effective therapies for multiple sclerosis.

IgM-mediated autoimmune responses directed against anchorage epitopes are greater in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) than in major depression

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and depression are considered to be neuro-immune disorders (Maes and Twisk, BMC Medicine 8:35, 2010). There is also evidence that depression and ME/CFS are accompanied by oxidative and nitrosative stress (O&NS) and by increased autoantibodies to a number of self-epitopes some of which have become immunogenic due to damage by O&NS. The aim of this study is to examine IgM-mediated autoimmune responses to different self-epitopes in ME/CFS versus depression. We examined serum IgM antibodies to three anchorage molecules (palmitic and myristic acid and S-farnesyl-L-cysteine); acetylcholine; and conjugated NO-modified adducts in 26 patients with major depression; 16 patients with ME/CFS, 15 with chronic fatigue; and 17 normal controls. Severity of fatigue and physio-somatic (F&S) symptoms was measured with the Fibromyalgia and Chronic Fatigue Syndrome Rating Scale. Serum IgM antibodies to the three anchorage molecules and NO-phenylalanine were significantly higher in ME/CFS than in depression. The autoimmune responses to oxidatively, but not nitrosatively, modified self-epitopes were significantly higher in ME/CFS than in depression and were associated with F&S symptoms. The autoimmune activity directed against conjugated acetylcholine did not differ significantly between ME/CFS and depression, but was greater in the patients than controls. Partially overlapping pathways, i.e. increased IgM antibodies to a multitude of neo-epitopes, underpin both ME/CFS and depression, while greater autoimmune responses directed against anchorage molecules and oxidatively modified neo-epitopes discriminate patients with ME/CFS from those with depression. These autoimmune responses directed against neoantigenic determinants may play a role in the dysregulation of key cellular functions in both disorders, e.g. intracellular signal transduction, cellular differentiation and apoptosis, but their impact may be more important in ME/CFS than in depression.

In depression, bacterial translocation may drive inflammatory responses, oxidative and nitrosative stress (O&NS) and autoimmune responses directed against O&NS- damaged neoepitopes

Objective: Depression is accompanied by activation of immuno-inflammatory and oxidative and nitrosative stress (IO&NS) pathways, and increased IgM/IgA responses to lipopolysaccharide (LPS) of gram-negative commensal bacteria. The latter suggests that bacterial translocation has caused IgM/IgA responses directed against LPS. Bacterial translocation may drive IO&NS responses.

Method: To examine the associations between IgM/IgA responses to LPS and IO&NS measurements, including plasma/serum interleukin-1 (IL-1), tumor necrosis factor (TNF)α, neopterin, lysozyme, oxidized LDL (oxLDL) antibodies, peroxides, and IgM (auto)immune responses against malondialdehyde (MDA), azelaic acid, phophatidyl inositol (Pi), NO-tryptophan and NO-tyrosine in depressed patients and controls.

Results: We found significant positive associations between IgM/IgA responses to LPS and oxLDL antibodies, IgM responses against MDA, azelaic acid, Pi, NO-tryptophan, and NO-tyrosine. The IgA responses to LPS were correlated with lysozyme. There were no significant positive correlations between the IgM/IgA responses to LPS and IL-1 and neopterin.

Conclusion: The findings show that in depression there is an association between increased bacterial translocation and lysozyme production, an antibacterial compound, O&NS processes, and autoimmune responses directed against O&NS generated neoantigenic determinants. It is suggested that bacterial translocation may drive IO&NS pathways in depression and thus play a role in its pathophysiology.

Central pathways causing fatigue in neuro-inflammatory and autoimmune illnesses

The genesis of severe fatigue and disability in people following acute pathogen invasion involves the activation of Toll-like receptors followed by the upregulation of proinflammatory cytokines and the activation of microglia and astrocytes. Many patients suffering from neuroinflammatory and autoimmune diseases, such as multiple sclerosis, Parkinson's disease and systemic lupus erythematosus, also commonly suffer from severe disabling fatigue. Such patients also present with chronic peripheral immune activation and systemic inflammation in the guise of elevated proinflammtory cytokines, oxidative stress and activated Toll-like receptors. This is also true of many patients presenting with severe, apparently idiopathic, fatigue accompanied by profound levels of physical and cognitive disability often afforded the non-specific diagnosis of chronic fatigue syndrome.

Nitrosative stress, hypernitrosylation, and autoimmune responses to nitrosylated proteins: new pathways in neuroprogressive disorders Including depression and chronic fatigue syndrome.

Nitric oxide plays an indispensable role in modulating cellular signaling and redox pathways. This role is mainly effected by the readily reversible nitrosylation of selective protein cysteine thiols. The reversibility and sophistication of this signaling system is enabled and regulated by a number of enzymes which form part of the thioredoxin, glutathione, and pyridoxine antioxidant systems. Increases in nitric oxide levels initially lead to a defensive increase in the number of nitrosylated proteins in an effort to preserve their function. However, in an environment of chronic oxidative and nitrosative stress (O&NS), nitrosylation of crucial cysteine groups within key enzymes of the thioredoxin, glutathione, and pyridoxine systems leads to their inactivation thereby disabling denitrosylation and transnitrosylation and subsequently a state described as "hypernitrosylation." This state leads to the development of pathology in multiple domains such as the inhibition of enzymes of the electron transport chain, decreased mitochondrial function, and altered conformation of proteins and amino acids leading to loss of immune tolerance and development of autoimmunity. Hypernitrosylation also leads to altered function or inactivation of proteins involved in the regulation of apoptosis, autophagy, proteomic degradation, transcription factor activity, immune-inflammatory pathways, energy production, and neural function and survival. Hypernitrosylation, as a consequence of chronically elevated O&NS and activated immune-inflammatory pathways, can explain many characteristic abnormalities observed in neuroprogressive disease including major depression and chronic fatigue syndrome/myalgic encephalomyelitis. In those disorders, increased bacterial translocation may drive hypernitrosylation and autoimmune responses against nitrosylated proteins.

Early recognition of ipilimumab-related autoimmune hypophysitis in patients with metastatic melanoma: case studies and recommendations for management

Ipilimumab is a human anti-CTLA-4 monoclonal antibody recently approved for the treatment of advanced melanoma. Stimulation of T-cell activity unmasks antitumor activity, but can cause immune-related adverse events. Autoimmune hypophysitis is of particular importance because its presentation can be subtle but life threatening. We present two cases where early recognition of ipilimumab-related autoimmune hypophysitis led to timely intervention and low subsequent morbidity, without compromise of antitumor effects. We provide recommendations for detection and management of this potentially life-threatening complication of ipilimumab.

Disease fingerprinting with cDNA microarrays reveals distinct gene expression profiles in lethal type 1 and type 2 cytokine-mediated inflammatory reactions

Development of polarized immune responses controls resistance and susceptibility to many microorganisms. However, studies of several infectious, allergic, and autoimmune diseases have shown that chronic type-1 and type-2 cytokine responses can also cause significant morbidity and mortality if left unchecked. We used mouse cDNA microarrays to molecularly phenotype the gene expression patterns that characterize two disparate but equally lethal forms of liver pathology that develop in Schistosoma mansoni infected mice polarized for type-1 and type-2 cytokine responses. Hierarchical clustering analysis identified at least three groups of genes associated with a polarized type-2 response and two linked with an extreme type-1 cytokine phenotype. Predictions about liver fibrosis,  apoptosis, and granulocyte recruitment and activation generated by the microarray studies were confirmed later by traditional biological assays. The data show that cDNA microarrays are useful not only for determining  coordinated gene expression profiles but are also highly effective for molecularly “fingerprinting” diseased tissues. Moreover, they illustrate the potential of genome-wide approaches for generating comprehensive views on the molecular and biochemical mechanisms regulating infectious  disease pathogenesis.

Vitamin D: status, supplementation and immuno-modulation

Numerous studies have shown suboptimal vitamin D status in populations at high geographical latitudes, owing to a reduced capacity to synthesise vitamin D, especially during wintertime. Vitamin D supplementation has been shown to be effective at maintaining adequate vitamin D status throughout the year in these countries. Classically reported to play a central role in bone health, vitamin D has more recently been shown to modulate immune function by promoting an anti-inflammatory response, which may be related to onset or progression of autoimmune inflammatory disorders. One such condition is multiple sclerosis (MS). There is an increasing incidence of MS with increasing latitude, with higher prevalence reported in countries further away from the equator, where vitamin D synthesis is inadequate. Vitamin D has been shown to have positive effects on the animal model of MS, experimental autoimmune encephalomyelitis. However, there have been few human intervention studies to investigate the effect of vitamin D supplementation on symptoms of MS or indeed of other autoimmune disorders. Further research is required to examine the potential beneficial role of vitamin D in MS to ultimately determine the optimal vitamin D status required to alleviate symptoms and possibly prevent this and other chronic diseases.