Fernando Pradella

Vitamin D3 induces IDO+ tolerogenic DCs and enhances Treg, reducing the severity of EAE.

A growing body of evidence supports the hypothesis that vitamin D is an important environmental factor in the etiology of T‐cell‐mediated autoimmune diseases such as multiple sclerosis (MS).

Plasmacytoid dendritic cells are increased in cerebrospinal fluid of untreated patients during multiple sclerosis relapse

The plasmacytoid dendritic cells (pDCs) express a high level of Toll-like receptor 9 (TLR-9), which recognizes viral DNA. Activated via TLR-9, pDCs also secrete large amounts of type I interferon which are involved either in stimulation or down regulation of immune response in multiple sclerosis (MS). In the present study, we determinate pDCs levels by flow cytometry in Cerebrospinal Fluid (CSF) and Peripheral Blood from MS patients in relapsing and in remitting phases of the disease, comparing with other non-inflammatory diseases (OND). We provide evidence that MS patients in relapse without any treatment have a significantly (p < 0.01) higher percentage of pDCs in CSF than do patients in remission or those with OND. No change in the percentage of pDCs was observed in the peripheral blood of any of these patients. The increase of pDCs in central nervous system during relapse may be explained either by a virus infection or a down regulatory process.

Regulatory T Cell Induction during Plasmodium chabaudi Infection Modifies the Clinical Course of Experimental Autoimmune Encephalomyelitis

Background Experimental autoimmune encephalomyelitis (EAE) is used as an animal model for human multiple sclerosis (MS), which is an inflammatory demyelinating autoimmune disease of the central nervous system characterized by activation of Th1 and/or Th17 cells. Human autoimmune diseases can be either exacerbated or suppressed by infectious agents. Recent studies have shown that regulatory T cells play a crucial role in the escape mechanism of Plasmodium spp. both in humans and in experimental models. These cells suppress the Th1 response against the parasite and prevent its elimination. Regulatory T cells have been largely associated with protection or amelioration in several autoimmune diseases, mainly by their capacity to suppress proinflammatory response. Methodology/Principal Findings In this study, we verified that CD4+CD25+ regulatory T cells (T regs) generated during malaria infection (6 days after EAE induction) interfere with the evolution of EAE. We observed a positive correlation between the reduction of EAE clinical symptoms and an increase of parasitemia levels. Suppression of the disease was also accompanied by a decrease in the expression of IL-17 and IFN-γ and increases in the expression of IL-10 and TGF-β1 relative to EAE control mice. The adoptive transfer of CD4+CD25+ cells from P. chabaudi-infected mice reduced the clinical evolution of EAE, confirming the role of these T regs. Conclusions/Significance These data corroborate previous findings showing that infections interfere with the prevalence and evolution of autoimmune diseases by inducing regulatory T cells, which regulate EAE in an apparently non-specific manner.

Ten years of proteomics in multiple sclerosis

Multiple sclerosis, which is the most common cause of chronic neurological disability in young adults, is an inflammatory, demyelinating, and neurodegenerative disease of the CNS, which leads to the formation of multiple foci of demyelinated lesions in the white matter. The diagnosis is based currently on magnetic resonance image and evidence of dissemination in time and space. However, this could be facilitated if biomarkers were available to rule out other disorders with similar symptoms as well as to avoid cerebrospinal fluid analysis, which requires an invasive collection. Additionally, the molecular mechanisms of the disease are not completely elucidated, especially those related to the neurodegenerative aspects of the disease. The identification of biomarker candidates and molecular mechanisms of multiple sclerosis may be approached by proteomics. In the last 10 years, proteomic techniques have been applied in different biological samples (CNS tissue, cerebrospinal fluid, and blood) from multiple sclerosis patients and in its experimental model. In this review, we summarize these data, presenting their value to the current knowledge of the disease mechanisms, as well as their importance in identifying biomarkers or treatment targets.

Neuroprotection and immunomodulation by xenografted human mesenchymal stem cells following spinal cord ventral root avulsion

The present study investigates the effects of xenotransplantation of Adipose Tissue Mesenchymal Stem Cells (AT-MSCs) in animals after ventral root avulsion. AT-MSC has similar characteristics to bone marrow mesenchymal stem cells (BM-MSCs), such as immunomodulatory properties and expression of neurotrophic factors. In this study, Lewis rats were submitted to surgery for unilateral avulsion of the lumbar ventral roots and received 5 × 105 AT-MSCs via the lateral funiculus. Two weeks after cell administration, the animals were sacrificed and the moto neurons, T lymphocytes and cell defense nervous system were analyzed. An increased neuronal survival and partial preservation of synaptophysin-positive nerve terminals, related to GDNF and BDNF expression of AT-MSCs, and reduction of pro-inflammatory reaction were observed. In conclusion, AT-MSCs prevent second phase neuronal injury, since they suppressed lymphocyte, astroglia and microglia effects, which finally contributed to rat motor-neuron survival and synaptic stability of the lesioned motor-neuron. Moreover, the survival of the injected AT- MSCs lasted for at least 14 days. These results indicate that neuronal survival after lesion, followed by mesenchymal stem cell (MSC) administration, might occur through cytokine release and immunomodulation, thus suggesting that AT-MSCs are promising cells for the therapy of neuronal lesions.

Up-regulation of T lymphocyte and antibody production by inflammatory cytokines released by macrophage exposure to multi-walled carbon nanotubes

Our data demonstrate that multi-walled carbon nanotubes (MWCNTs) are internalized by macrophages, subsequently activating them to produce interleukin (IL)-12 (IL-12). This cytokine induced the proliferative response of T lymphocytes to a nonspecific mitogen and to ovalbumin (OVA). This increase in the proliferative response was accompanied by an increase in the expression of pro-inflammatory cytokines, such as interferon-gamma (IFNγ), tumor necrosis factor-alpha (TNFα) and IL-6, in mice inoculated with MWCNTs, whether or not they had been immunized with OVA. A decrease in the expression of transforming growth factor-beta (TGFβ) was observed in the mice treated with MWCNTs, whereas the suppression of the expression of both TGFβ and IL-10 was observed in mice that had been both treated and immunized. The activation of the T lymphocyte response by the pro-inflammatory cytokines leads to an increase in antibody production to OVA, suggesting the important immunostimulatory effect of carbon nanotubes.

The Suppressive Effect of IL‐27 on Encephalitogenic Th17 Cells Induced by Multiwalled Carbon Nanotubes Reduces the Severity of Experimental Autoimmune Encephalomyelitis

Both Th1 and Th17 cells specific for neuroantigen are described as encephalitogenic in the experimental autoimmune encephalomyelitis (EAE) model.

Proteome analysis of spinal cord during the clinical course of monophasic experimental autoimmune encephalomyelitis

The induction of autoimmune encephalomyelitis (EAE) in Lewis rats results in a period of exacerbation followed by complete recovery. Therefore, this model is widely used for studying the evolution of multiple sclerosis. In the present investigation, differentially expressed proteins in the spinal cord of Lewis rats during the evolution of EAE were assessed using the combination of 2DE and MALDI‐TOF MS. The majority of the differentially expressed proteins were identified during the acute phase of EAE, in relation to naïve control animals. On the other hand, recovered rats presented a similar protein expression pattern in comparison with the naïve ones. This observation can be explained, at least in part, by the intense catabolism existent in acute phase due to nervous tissue damage. In recovered rats, we have described the upregulation of proteins that are apparently involved in the recovery of damaged tissue, such as light and medium neurofilaments, glial fibrillary acidic protein, tubulins subunits, and quaking protein. These proteins are involved mainly in cell growth, myelination, and remyelination as well as in astrocyte and oligodendrocyte maturation. The present study has demonstrated that the inflammatory response, characterized by an increase of the proliferative response and infiltration of autoreactive T lymphocytes in the central nervous system, occurs simultaneously with neurodegeneration.

Impact of pregabalin treatment on synaptic plasticity and glial reactivity during the course of experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is an autoimmune and neurodegenerative disease that affects young adults. It is characterized by generating a chronic demyelinating autoimmune inflammation in the central nervous system. An experimental model for studying MS is the experimental autoimmune encephalomyelitis (EAE), induced by immunization with antigenic proteins from myelin.

Granulocyte-colony-stimulating factor treatment enhances Foxp3(+) T lymphocytes and modifies the proinflammatory response in experimental autoimmune neuritis.

Despite the evolution of treatments in the past decade, acute inflammatory autoimmune diseases of the peripheral nervous system are still a concern due to their considerable morbidity and mortality [1]. Guillain-Barr e syndrome (GBS) is an acute inflammatory disorder. The study of experimental autoimmune neuritis (EAN), the experimental model of GBS, has provided most of the knowledge regarding GBS disease mechanisms. Inflammatory lesions are primarily located in the sciatic nerves and the cauda equina of EAN-affected Lewis rats [2]. Lesions are characterized by an accumulation of inflammatory cells, primarily T cells, and macrophages. The inflammatory response during EAN is characterized mainly by the migration of neuritogenic cells into the peripheral nerves and by the production and secretion of proinflammatory cytokines, such as IFNc, TNFa, IL-6, and IL-17 [3]. During the last years, hematopoietic factors, such as erythropoietin, granulocyte–macrophage colony-stimulating factor and granulocyte–colony-stimulating factor (G-CSF), have been successfully used to modify experimental autoimmune diseases [4,5]. Moreover, G-CSF has an important and strong tolerogenic function. This cytokine recruits immature dendritic cells (DCs), which induce tolerance through the enhancement of regulatory T cells [5]. In this study, we investigated the effects of short-term G-CSF treatment on the evolution of EAN. EAN was induced using the neuritogenic peptide P253-78 as previously described [6]. The clinical signs of EAN were significantly reduced by the in vivo administration of G-CSF in a short-term treatment regimen (Figure 1A). The development of EAN is characterized by the sensitization and activation of neuritogenic T cells in the peripheral immune organs. These cells migrate into peripheral nerves and release inflammatory mediators, which may contribute directly or indirectly to the destruction of the myelin sheath. We observed a significant reduction in the specific proliferative response of T cells from Lewis rats with EAN treated with G-CSF compared with the cells from the control animals (Figure 1B). Moreover, G-CSF treatment reduced the mononuclear cell infiltration into the sciatic nerve (Figure 1C). The EAN autoaggressive response is characterized by the expression and release of Th1 and/or Th17 cytokines. Therefore, we evaluated the expression, by real-time PCR (Figure S1), of Th1 and Th17 cytokines and transcription factors, in the lymph nodes 10 days after immunization, prior to the migration of the neuritogenic cells from the periphery to the target tissue. We observed a consistent downregulation in the expression of the Th1 (T-bet) and Th17 (RORa and RORct) transcription factors in the G-CSFtreated group compared with control group (Figure 1D). Corroborating the changes in the transcription factors expression profile, the expression of proinflammatory cytokines (IFNc, IL-17A, IL17E, and IL-6) was reduced in the G-CSF-treated group compared with the control group. G-CSF treatment also led to an increase in the expression of anti-inflammatory cytokines, such as IL-10 and