Adriel S. Moraes

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.

Chloroquine Treatment Enhances Regulatory T Cells and Reduces the Severity of Experimental Autoimmune Encephalomyelitis

Background The modulation of inflammatory processes is a necessary step, mostly orchestrated by regulatory T (Treg) cells and suppressive Dendritic Cells (DCs), to prevent the development of deleterious responses and autoimmune diseases. Therapies that focused on adoptive transfer of Treg cells or their expansion in vivo achieved great success in controlling inflammation in several experimental models. Chloroquine (CQ), an anti-malarial drug, was shown to reduce inflammation, although the mechanisms are still obscure. In this context, we aimed to access whether chloroquine treatment alters the frequency of Treg cells and DCs in normal mice. In addition, the effects of the prophylactic and therapeutic treatment with CQ on Experimental Autoimmune Encephalomyelitis (EAE), an experimental model for human Multiple Sclerosis, was investigated as well. Methodology/Principal Findings EAE was induced in C57BL/6 mice by immunization with myelin oligodendrocyte glycoprotein (MOG35–55) peptide. C57BL/6 mice were intraperitoneally treated with chloroquine. Results show that the CQ treatment provoked an increase in Treg cells frequency as well as a decrease in DCs. We next evaluated whether prophylactic CQ administration is capable of reducing the clinical and histopathological signs of EAE. Our results demonstrated that CQ-treated mice developed mild EAE compared to controls that was associated with lower infiltration of inflammatory cells in the central nervous system CNS) and increased frequency of Treg cells. Also, proliferation of MOG35–55-reactive T cells was significantly inhibited by chloroquine treatment. Similar results were observed when chloroquine was administrated after disease onset. Conclusion We show for the first time that CQ treatment promotes the expansion of Treg cells, corroborating previous reports indicating that chloroquine has immunomodulatory properties. Our results also show that CQ treatment suppress the inflammation in the CNS of EAE-inflicted mice, both in prophylactic and therapeutic approaches. We hypothesized that the increased number of regulatory T cells induced by the CQ treatment is involved in the reduction of the clinical signs of EAE.

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.

Disruption of melatonin circadian rhythm production is related to multiple sclerosis severity: A preliminary study.

Sunlight can influence the immune system independently of vitamin D, such as through melatonin production in the pineal gland. Inflammatory disorders can suppress nocturnal melatonin production, but only a few studies have investigated melatonin status in multiple sclerosis (MS). We aimed to study melatonin production in association with clinical and immunological data in MS patients. Eleven treated relapsing-remitting MS (RRMS) patients and eight controls underwent neurological examination and were assessed for fatigue severity and depressive symptoms. Inflammatory cytokines were analyzed in blood samples and concentration of 6-sulfatoxymelatonin (6-SMT) was determined in 24h urine. Patients with an abnormal proportion of overnight 6-SMT (n=8, 72.7%) had higher disability and fatigue severity (p<0.05). Overnight 6-SMT was inversely related with fatigue severity (p=0.016), number of relapses in the previous 12 months (p=0.010) and EDSS scores (p=0.049). In conclusion, disruption of melatonin circadian rhythm production is frequent among RRMS patients and seemingly related to higher disability and fatigue scores. Future studies with larger sample size are necessary to establish melatonin status as a biomarker of disease severity in MS.

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.

Aquaporin-4 Antibodies Are Not Related to HTLV-1 Associated Myelopathy

Introduction The seroprevalence of human T-cell leukemia virus type 1 (HTLV-1) is very high among Brazilians (∼1∶200). HTLV-1 associated myelopathy or tropical spastic paraparesis (HAM/TSP) is the most common neurological complication of HTLV-1 infection. HAM/TSP can present with an acute/subacute form of longitudinally extensive myelitis, which can be confused with lesions seen in aquaporin-4 antibody (AQP4-Ab) positive neuromyelitis optica spectrum disorders (NMOSD) on MRI. Moreover, clinical attacks in patients with NMOSD have been shown to be preceded by viral infections in around 30% of cases. Objective To evaluate the frequency of AQP4-Ab in patients with HAM/TSP. To evaluate the frequency of HTLV-1 infection in patients with NMOSD. Patients and Methods 23 Brazilian patients with HAM/TSP, 20 asymptomatic HTLV-1+ serostatus patients, and 34 with NMOSD were tested for AQP4-Ab using a standardized recombinant cell based assay. In addition, all patients were tested for HTLV-1 by ELISA and Western blotting. Results 20/34 NMOSD patients were positive for AQP4-Ab but none of the HAM/TSP patients and none of the asymptomatic HTLV-1 infected individuals. Conversely, all AQP4-Ab-positive NMOSD patients were negative for HTLV-1 antibodies. One patient with HAM/TSP developed optic neuritis in addition to subacute LETM; this patient was AQP4-Ab negative as well. Patients were found to be predominantly female and of African descent both in the NMOSD and in the HAM/TSP group; Osame scale and expanded disability status scale scores did not differ significantly between the two groups. Conclusions Our results argue both against a role of antibodies to AQP4 in the pathogenesis of HAM/TSP and against an association between HTLV-1 infection and the development of AQP4-Ab. Moreover, the absence of HTLV-1 in all patients with NMOSD suggests that HTLV-1 is not a common trigger of acute attacks in patients with AQP4-Ab positive NMOSD in populations with high HTLV-1 seroprevalence.

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