Efeito prolilático da associaçao de MOG com vitamina D na encefalomielite autoimune experimental

Multiple sclerosis is a chronic, inflammatory and demyelinating disease of the central nervous system (CNS). As there is no cure for this disease, new prophylactic or therapeutic strategies are necessary. The main objective of this work was to evaluate the prophylactic potential of the association of myelin oligodendrocyte glycoprotein (MOG) with vitamin D3 in experimental autoimmune encephalomyelitis (EAE). C57BL/6 mice were immunized with MOG associated with vitamin D3 and then submitted to EAE induction. Animals were euthanized 7 and 19 days after, during the preclinical and acute disease phases, respectively. The following parameters were evaluated: body weight, clinical score, inflammatory process in the CNS, amount of dendritic and regulatory T cells in the spleen and cytokine production by spleen and CNS cell cultures. Immunization with MOG associated with vitamin D3 blocked clinical EAE development. This prophylactic effect was associated with a drastic reduction in clinical score, body weight loss, CNS inflammation, dendritic cells maturation and also in the production of cytokines by CNS and spleen cell cultures. This association was therefore highly tolerogenic, being able to avoid EAE development. A similar effect from vitamin D3 association with other specific self-antigens is expected in other autoimmune conditions and deserves future evaluationA esclerose múltipla (EM) é uma doença inflamatória, crônica e desmielinizante do Sistema Nervoso Central (SNC). A caracterização de estratégias profiláticas ou terapêuticas na EM é necessária já que não há cura para a doença. Neste contexto, o objetivo deste trabalho foi avaliar o potencial profilático da associação de MOG (glicoproteína da mielina do oligodendrócito) com vitamina D3 (VitD) na encefalomielite autoimune experimental (EAE). Para isto, camundongos C57BL/6 foram imunizados com MOG na presença de VitD e posteriormente submetidos à indução da EAE. Os animais foram então eutanasiados nos dias 7 e 19 após indução da EAE os quais correspondem às fases pré-clinica e clínica da doença, respectivamente. Os seguintes parâmetros foram avaliados: peso corporal, escore clínico, processo inflamatório no SNC, quantidade de células dendríticas (DCs) e de T reguladoras (Tregs) no baço e produção de citocinas por células esplênicas e células mononucleares eluídas do SNC. A imunização com MOG associada com VitD impediu o desenvolvimento da EAE. O efeito profilático observado reduziu a maturação das DCs e a produção de citocinas encefalitogênicas, mas não aumentou a quantidade de Tregs no baço. Já no SNC a imunização determinou redução acentuada no processo inflamatório e na produção de citocinas encefalitogênicas. Os dados obtidos indicam que a associação do antígeno específico (MOG) com VitD foi suficientemente tolerogênica para evitar o desenvolvimento da EAE. Efeito similar em outras patologias autoimunes é esperado e merece investigaçãoCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Efeito prolilático da associaçao de MOG com vitamina D na encefalomielite autoimune experimental

Multiple sclerosis is a chronic, inflammatory and demyelinating disease of the central nervous system (CNS). As there is no cure for this disease, new prophylactic or therapeutic strategies are necessary. The main objective of this work was to evaluate the prophylactic potential of the association of myelin oligodendrocyte glycoprotein (MOG) with vitamin D3 in experimental autoimmune encephalomyelitis (EAE). C57BL/6 mice were immunized with MOG associated with vitamin D3 and then submitted to EAE induction. Animals were euthanized 7 and 19 days after, during the preclinical and acute disease phases, respectively. The following parameters were evaluated: body weight, clinical score, inflammatory process in the CNS, amount of dendritic and regulatory T cells in the spleen and cytokine production by spleen and CNS cell cultures. Immunization with MOG associated with vitamin D3 blocked clinical EAE development. This prophylactic effect was associated with a drastic reduction in clinical score, body weight loss, CNS inflammation, dendritic cells maturation and also in the production of cytokines by CNS and spleen cell cultures. This association was therefore highly tolerogenic, being able to avoid EAE development. A similar effect from vitamin D3 association with other specific self-antigens is expected in other autoimmune conditions and deserves future evaluationA esclerose múltipla (EM) é uma doença inflamatória, crônica e desmielinizante do Sistema Nervoso Central (SNC). A caracterização de estratégias profiláticas ou terapêuticas na EM é necessária já que não há cura para a doença. Neste contexto, o objetivo deste trabalho foi avaliar o potencial profilático da associação de MOG (glicoproteína da mielina do oligodendrócito) com vitamina D3 (VitD) na encefalomielite autoimune experimental (EAE). Para isto, camundongos C57BL/6 foram imunizados com MOG na presença de VitD e posteriormente submetidos à indução da EAE. Os animais foram então eutanasiados nos dias 7 e 19 após indução da EAE os quais correspondem às fases pré-clinica e clínica da doença, respectivamente. Os seguintes parâmetros foram avaliados: peso corporal, escore clínico, processo inflamatório no SNC, quantidade de células dendríticas (DCs) e de T reguladoras (Tregs) no baço e produção de citocinas por células esplênicas e células mononucleares eluídas do SNC. A imunização com MOG associada com VitD impediu o desenvolvimento da EAE. O efeito profilático observado reduziu a maturação das DCs e a produção de citocinas encefalitogênicas, mas não aumentou a quantidade de Tregs no baço. Já no SNC a imunização determinou redução acentuada no processo inflamatório e na produção de citocinas encefalitogênicas. Os dados obtidos indicam que a associação do antígeno específico (MOG) com VitD foi suficientemente tolerogênica para evitar o desenvolvimento da EAE. Efeito similar em outras patologias autoimunes é esperado e merece investigaçãoCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Candida tropicalis Systemic Infection Redirects Leukocyte Infiltration to the Kidneys Attenuating Encephalomyelitis

Environmental factors, including infections, are strongly associated with the pathogenesis of multiple sclerosis (MS), which is an autoimmune and demyelinating disease of the central nervous system (CNS). Although classically associated with bacterial and viral agents, fungal species have also been suspected to affect the course of the disease. Candida tropicalis is an opportunistic fungus that affects immunocompromised individuals and is also able to spread to vital organs. As C. tropicalis has been increasingly isolated from systemic infections, we aimed to evaluate the effect of this fungus on experimental autoimmune encephalomyelitis (EAE), a murine model to study MS. For this, EAE was induced in female C57BL/6 mice 3 days after infection with 106 viable C. tropicalis yeasts. The infection decreased EAE prevalence and severity, confirmed by the less inflammatory infiltrate and less demyelization in the lumbar spinal cord. Despite this, C. tropicalis infection associated with EAE results in the death of some animals and increased urea and creatinine serum levels. The kidneys of EAE-infected mice showed higher fungal load associated with increased leukocyte infiltration (CD45+ cells) and higher expression of T-box transcription factor (Tbx21) and forkhead box P3 (Foxp3). Altogether, our results demonstrate that although C. tropicalis infection reduces the prevalence and severity of EAE, partially due to the sequestration of leukocytes by the inflamed renal tissue, this effect is associated with a poor disease outcome

Experimental Autoimmune Encephalomyelitis Is Successfully Controlled by Epicutaneous Administration of MOG Plus Vitamin D Analog

Multiple sclerosis (MS) is an inflammatory and demyelinating disorder of the central nervous system (CNS). Experimental autoimmune encephalomyelitis (EAE) has been widely employed to evaluate new strategies to control MS, including procedures to induce immunological tolerance. Considering that skin exposure to protein antigens can induce tolerance and that vitamin D analogs conserve immunomodulatory potential and are less toxic, we investigated the efficacy of epicutaneous application of a myelin oligodendrocyte glycoprotein peptide (MOG35–55) associated with paricalcitol (PARI) on EAE development. Three and 11 days after EAE induction, C57BL/6 mice were treated with an occlusive patch containing MOG plus PARI. Clinical parameters were daily assessed, whereas immunological and histological evaluations were performed during the acute EAE phase. MOG and MOG + PARI significantly controlled disease development reducing weight loss and clinical score. Moreover, MOG and MOG + PARI reduced the inflammatory process and preserved the myelin sheath in the CNS. High percentages of Foxp3+ regulatory T cells (Tregs) and lower MHCII fluorescence intensity in dendritic cells in draining lymph nodes were concomitantly observed. MOG + PARI association was, however, more efficient being able to reduce disease incidence and clinical scores more significantly than MOG or PARI alone. This experimental group also displayed a higher ratio between mRNA expression for Foxp3 and RORc and a higher percentage of Foxp3+ cells in the CNS. Modulation of activation markers observed in microglial cells eluted from EAE treated mice were confirmed by in vitro studies with the BV-2 microglial cell line. The results show that MOG + PARI association applied by an epicutaneous route controlled EAE development. Protective involved mechanisms include mainly a higher proportion of Tregs and also a direct immunomodulatory effect of PARI on microglial cells

Systemic Administration of Proteoglycan Protects BALB/c Retired Breeder Mice from Experimental Arthritis

This study was undertaken to evaluate the prophylactic potential of proteoglycan (PG) administration in experimental arthritis. Female BALB/c retired breeder mice received two (2xPG50 and 2xPG100 groups) or three (3xPG50 group) intraperitoneal doses of bovine PG (50 μg or 100 μg) every three days. A week later the animals were submitted to arthritis induction by immunization with three i.p. doses of bovine PG associated with dimethyldioctadecylammonium bromide adjuvant at intervals of 21 days. Disease severity was daily assessed after the third dose by score evaluation. The 3xPG50 group showed significant reduction in prevalence and clinical scores. This protective effect was associated with lower production of IFN-γ and IL-17 and increased production of IL-5 and IL-10 by spleen cells restimulated in vitro with PG. Even though previous PG administration restrained dendritic cells maturation this procedure did not alter the frequency of regulatory Foxp3+ T cells. Lower TNF-α and IL-6 levels and higher expression of ROR-γ and GATA-3 were detected in the paws of protected animals. A delayed-type hypersensitivity reaction confirmed specific tolerance induction. Taken together, these results indicate that previous PG inoculation determines a specific tolerogenic effect that is able to decrease severity of subsequently induced arthritis

Systemic Infection by Non-albicans Candida Species Affects the Development of a Murine Model of Multiple Sclerosis

Candidiasis may affect the central nervous system (CNS), and although Candida albicans is predominant, non-albicans Candida species can also be associated with CNS infections. Some studies have suggested that Candida infections could increase the odds of multiple sclerosis (MS) development. In this context, we investigated whether systemic infection by non-albicans Candida species would affect, clinically or immunologically, the severity of experimental autoimmune encephalomyelitis (EAE), which is an animal model used to study MS. For this, a strain of C. glabrata, C. krusei, and C. parapsilosis was selected and characterized using different in vitro and in vivo models. In these analysis, all the strains exhibited the ability to form biofilms, produce proteolytic enzymes, and cause systemic infections in Galleria mellonella, with C. glabrata being the most virulent species. Next, C57BL/6 mice were infected with strains of C. glabrata, C. krusei, or C. parapsilosis, and 3 days later were immunized with myelin oligodendrocyte glycoprotein to develop EAE. Mice from EAE groups previously infected with C. glabrata and C. krusei developed more severe and more prevalent paralysis, while mice from the EAE group infected with C. parapsilosis developed a disease comparable to non-infected EAE mice. Disease aggravation by C. glabrata and C. krusei strains was concomitant to increased IL-17 and IFN-γ production by splenic cells stimulated with fungi-derived antigens and with increased percentage of T lymphocytes and myeloid cells in the CNS. Analysis of interaction with BV-2 microglial cell line also revealed differences among these strains, in which C. krusei was the strongest activator of microglia concerning the expression of MHC II and CD40 and pro-inflammatory cytokine production. Altogether, these results indicated that the three non-albicans Candida strains were similarly able to reach the CNS but distinct in terms of their effect over EAE development. Whereas C. glabrata and C. Krusei aggravated the development of EAE, C. parapsilosis did not affect its severity. Disease worsening was partially associated to virulence factors in C. glabrata and to a strong activation of microglia in C. krusei infection. In conclusion, systemic infections by non-albicans Candida strains exerted influence on the experimental autoimmune encephalomyelitis in both immunological and clinical aspects, emphasizing their possible relevance in MS development

Preclinical Therapy with Vitamin D3 in Experimental Encephalomyelitis: Efficacy and Comparison with Paricalcitol

Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system (CNS). MS and its animal model called experimental autoimmune encephalomyelitis (EAE) immunopathogenesis involve a plethora of immune cells whose activation releases a variety of proinflammatory mediators and free radicals. Vitamin D3 (VitD) is endowed with immunomodulatory and antioxidant properties that we demonstrated to control EAE development. However, this protective effect triggered hypercalcemia. As such, we compared the therapeutic potential of VitD and paricalcitol (Pari), which is a non-hypercalcemic vitamin D analog, to control EAE. From the seventh day on after EAE induction, mice were injected with VitD or Pari every other day. VitD, but not Pari, displayed downmodulatory ability being able to reduce the recruitment of inflammatory cells, the mRNA expression of inflammatory parameters, and demyelination at the CNS. Lower production of proinflammatory cytokines by lymph node-derived cells and IL-17 by gut explants, and reduced intestinal inflammation were detected in the EAE/VitD group compared to the EAE untreated or Pari groups. Dendritic cells (DCs) differentiated in the presence of VitD developed a more tolerogenic phenotype than in the presence of Pari. These findings suggest that VitD, but not Pari, has the potential to be used as a preventive therapy to control MS severity

Preclinical Therapy with Vitamin D3 in Experimental Encephalomyelitis: Efficacy and Comparison with Paricalcitol

Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system (CNS). MS and its animal model called experimental autoimmune encephalomyelitis (EAE) immunopathogenesis involve a plethora of immune cells whose activation releases a variety of proinflammatory mediators and free radicals. Vitamin D3 (VitD) is endowed with immunomodulatory and antioxidant properties that we demonstrated to control EAE development. However, this protective effect triggered hypercalcemia. As such, we compared the therapeutic potential of VitD and paricalcitol (Pari), which is a non-hypercalcemic vitamin D analog, to control EAE. From the seventh day on after EAE induction, mice were injected with VitD or Pari every other day. VitD, but not Pari, displayed downmodulatory ability being able to reduce the recruitment of inflammatory cells, the mRNA expression of inflammatory parameters, and demyelination at the CNS. Lower production of proinflammatory cytokines by lymph node-derived cells and IL-17 by gut explants, and reduced intestinal inflammation were detected in the EAE/VitD group compared to the EAE untreated or Pari groups. Dendritic cells (DCs) differentiated in the presence of VitD developed a more tolerogenic phenotype than in the presence of Pari. These findings suggest that VitD, but not Pari, has the potential to be used as a preventive therapy to control MS severity