T cell response to myelin basic protein before and after treatment with interferon beta in multiple sclerosis

Bridging the gap between vaccination with Bacille Calmette-Guérin (BCG) and immunological tolerance: the cases of type 1 diabetes and multiple sclerosis

At the end of past century, when the prevailing view was that treatment of autoimmunity required immune suppression, experimental evidence suggested an approach of immune-stimulation such as with the BCG vaccine in type 1 diabetes (T1D) and multiple sclerosis (MS). Translating these basic studies into clinical trials, we showed the following: BCG harnessed the immune system to 'permanently' lower blood sugar, even in advanced T1D; BCG appeared to delay the disease progression in early MS; the effects were long-lasting (years after vaccination) in both diseases. The recently demonstrated capacity of BCG to boost glycolysis may explain both the improvement of metabolic indexes in T1D, and the more efficient generation of inducible regulatory T cells, which counteract the autoimmune attack and foster repair mechanisms.

Current multiple sclerosis treatments have improved our understanding of MS autoimmune pathogenesis

Multiple sclerosis (MS) is the most common inflammatory disorder of the central nervous system (CNS) in young adults. When MS is not treated, it leads to irreversible and severe disability. The etiology of MS and its pathogenesis are not fully understood. The recent discovery that MS-associated genetic variants code for molecules related to the function of specific immune cell subsets is consistent with the concept of MS as a prototypic, T-cell-mediated autoimmune disease targeting the CNS. While the therapeutic efficacy of the currently available immunomodulatory therapies further strengthen this concept, differences observed in responses to MS treatment as well as additional clinical and imaging observations have also shown that the autoimmune pathogenesis underlying MS is much more complex than previously thought. There is therefore an unmet need for continued detailed phenotypic and functional analysis of disease-relevant adaptive immune cells and tissues directly derived from MS patients to unravel the immune etiology of MS in its entire complexity. In this review, we will discuss the currently available MS treatment options and approved drugs, including how they have contributed to the understanding of the immune pathology of this autoimmune disease.

A role for interferon-beta in Guillain-Barré Syndrome?

Guillain-Barré syndrome (GBS) is an acute inflammatory demyelinating neuropathy that is associated with long-lasting morbidity and a substantial risk of mortality. The 2 reference treatments, plasma exchange and intravenous immunoglobulins (IVIg), do not change the functional prognosis for the most severely ill patients. The pathogenesis of GBS involves humoral and cellular immune dysfunctions that have only recently been characterised. Antibodies to nerve antigens may participate in complement activation, antibody-dependent macrophage cytotoxicity and reversible conduction failure. The cellular immune reaction is associated with increases in pro-inflammatory cytokines [such as tumour necrosis factor-alpha (TNFalpha)] and matrix metalloproteinases (MMPs; e.g. MMP-9), and a decrease in anti-inflammatory cytokines [such as transforming growth factor-beta1 (TGFbeta1)]. All the changes favour adhesion to and transmigration across the endothelium of immune cells, a key phenomenon associated with GBS. Recovery from GBS is characterised by the normalisation of these changes. Experimental allergic neuritis (EAN), the experimental model of GBS, has strikingly similar immunological characteristics. The usual treatment options for patients with GBS (plasma exchange and IVIg) mainly target the humoral component of the immune response. Interferon-beta (IFNbeta) is a cellular immunomodulator that inhibits antigen presentation and TNFalpha production and binding, and modulates macrophage properties. IFNbeta increases anti-inflammatory T cell functions and the production of anti-inflammatory cytokines, such as TGFbeta1. IFNbeta has important effects on leukodiapedesis, caused by modulating the expression of cell adhesion molecules and the MMP-9 proteinases. It has been used with success in EAN, in some patients with acute exacerbation of chronic inflammatory demyelinating polyneuropathy, and in 1 patient with GBS. The pathophysiology of patients with GBS, an understanding of IFNbeta properties and results of experimental studies support the investigation of IFNbeta in trials of patients with GBS.

Multiple sclerosis in childhood and adolescence: clinical features and management

The presentation of multiple sclerosis (MS) in childhood has traditionally been thought to be rare. However, more paediatric cases are now being reported, as a result of progress in diagnostic techniques with the use of sensitive imaging modalities of the brain and spinal cord. Management from an early age and the availability of new treatment options have changed the outcome of paediatric MS. Drugs currently available for treatment, such as beta-interferons, copolymer-1 and intravenous immunoglobulin G, have been found to reduce relapse rate, disease severity and progression to disability in adults, but have not been investigated in children and adolescents. The overall outcome of MS in children is apparently no worse than in adults and the disease may even be less aggressive in children. In juvenile MS, disease progression does not appear to be related to age of onset, severity of neurological involvement or mono/polysymptomatic involvement at presentation. The potential to treat MS has significantly changed the prognosis. Early diagnosis is important, as early treatment can prevent or delay the development of disability.

Modulation of the IL-10/IL-12 cytokine circuit by interferon-beta inhibits the development of epitope spreading and disease progression in murine autoimmune encephalomyelitis

IFN-beta has been shown to be effective in the treatment of multiple sclerosis (MS). However, the primary mechanism by which IFN-beta mediates its therapeutic effect remains unclear. Recent studies indicate that under defined conditions, IFN-beta may downregulate DC expression of IL-12. We and others have shown that IFN-beta may also downregulate IL-10. In light of the recently proposed paradigm that an IL-10/IL-12 immunoregulatory circuit controls susceptibility to autoimmune disease, we examined the effect of IFN-beta on the development and behavior of the autoreactive T cell repertoire during experimental autoimmune encephalomyelitis (EAE), an animal model sharing many features with MS. SWXJ mice were immunized with the immunodominant p139-151 determinant of myelin proteolipid protein (PLP), and at onset of EAE were treated every other day with IFN-beta. After eight weeks of treatment, we assessed autoreactivity and observed no significant IFN-beta effect on splenocyte proliferation or splenocyte production of IFN-gamma, IL-2, IL-4, or IL-5 in response to the priming determinant used to initiate disease. However, in IFN-beta treated mice, the cytokine profile in response to the priming immunogen was significantly skewed toward an increased production of IL-10 and a concurrent decreased production of IL-12. Moreover, the in vivo modulation of the IL-10/IL-12 immunoregulatory circuit in response to the priming immunogen was accompanied by an aborted development of epitope spreading. Our results indicate that IFN-beta induces a reciprocal modulation of the IL-10/IL-12 cytokine circuit in vivo. This skewed autoreactivity establishes an inflammatory microenvironment that effectively prevents endogenous self-priming thereby inhibiting the progression of disease associated with epitope spreading.