Search

A clear correlation exists between microbiota and the dysregulation of the immune response in Inflammatory Bowel Diseases (IBD), which comprise Crohn’s disease (CD) and ulcerative colitis (UC). These unbalanced reactions also involve humoral responses, with antibodies against Saccharomyces cerevisiae. Thus, here we aimed to quantify IgA and IgG specific to S. cerevisiae (ASCA) in quiescent CD and UC, to correlate the production of these antibodies with patient’s inflammatory response and disease clinical presentation. Twenty-nine subjects (16 CD and 13 UC) and 45 healthy controls were enrolled in this study and had plasma samples tested for ASCA and cytokines (IL-2, IL-4, IL-6, IL-10, IFN-γ, TNF-α), besides clinical evaluation. IBD patients had increase IgA and IgG ASCA, especially those with colonic (L2) and fistulizing (B3) CD. Similarly, patients who dropped out the treatment had augmented ASCA, while IgG was reduced in those receiving sulfasalazine treatment. Furthermore, the quiescent CD patients had elevated IL-6 on plasma, especially in the absence of treatment, together with increased counter regulatory response of IL-10. There was a positive correlation between IgA and IgG on CD but not UC, as well as between IgA and TNF in total IBD patients. In addition, the levels of IgG x TNF, IgA x IL-10 and IgG x IL-10 were also correlated in CD, indicating that ASCA production may be influenced by the inflammatory response. Finally, we concluded that ASCA could be pointed as relevant biomarker of CD presentation and residual inflammation, even in clinical remission patients.

The clinical benefits of short-term therapy with glucocorticoids (GC) in patients with inflammatory bowel disease (IBD) are widely known. However, the effects of this treatment towards the re-establishment of the regulatory network in IBD are not fully explored. We have evaluated the immunological effects of the abbreviated GC therapy in experimental colitis induced by 3% dextran sulphate sodium in C57BL/6 mice. Treatment with GC improved disease outcome, constrained circulating leucocytes and ameliorated intestinal inflammation. The control of the local inflammatory responses involved a reduction in the expression of interferon-γ and interleukin-1β, associated with augmented mRNA levels of peroxisome proliferator-activated receptors (α and γ) in intestine. Furthermore, there was a reduction of CD4+ T cells producing interferon-γ, together with an increased frequency of the putative regulatory population of T cells producing interleukin-10, in spleen. These systemic alterations were accompanied by a decrease in the proliferative potential of splenocytes of mice treated in vivo with GC. Notably, treatment with GC also led to an increase in the frequency of the regulatory markers GITR, CTLA-4, PD-1, CD73 and FoxP3, more prominently in spleen. Taken together, our results pointed to a role of GC in the control of leucocyte responsiveness and re-establishment of a regulatory system, which probably contributed to disease control and the restoration of immune balance. Finally, this is the first time that GC treatment was associated with the modulation of a broad number of regulatory markers in an experimental model of colitis.

Objectives: Toll-like receptors (TLRs) are expressed in several immune cells including blood monocytes and resident macrophages, such as microglia in the central nervous system. TLRs recognize pathogen- or damage-associated molecular patterns, leading to the release of inflammatory and toxic molecules, which can contribute to neuroinflammation associated with Parkinson's disease (PD). The aim of this study was to compare the potential of peripheral blood cells from PD patients or healthy subjects to produce cytokines after exposure to TLR agonists, and to investigate TLR2 and TLR4 expression on monocyte subsets. Methods: Twenty-one patients and 21 healthy controls were recruited. Patients were evaluated according to the Unified Parkinson's Disease Rating Scale, and Hoehn and Yahr stage. Cytokines were measured in supernatants of whole blood cultures after incubation with TLR2, TLR4, or TLR7/8 agonists, by cytometric bead array. Expression of CD14, CD16, TLR2, and TLR4 was analyzed by cytometry. Results: Patient blood cells produced lower levels of cytokines in response to TLR2 and also after TLR7/8/R848 activation than controls. Percentages of CD14+CD16+ or CD14+CD16- monocytes and TLR2 and TLR4 expression were similar between patients and controls. Conclusions: Blood leukocyte TLR2 and TLR7/8 responses are impaired in PD. This was neither associated with imbalance in monocyte subsets nor with TLR2/TLR4 expression on these cells. The association between a decreased TLR response in periphery and damage of brain in PD must be further investigated.

Mutations in NOD2 predisposes to Inflammatory Bowel Diseases. Therefore, we evaluated the role of this innate receptor in the modulation of immunity in face of host microbiota changes. NOD2-/- mice presented higher susceptibility to experimental colitis than WT, with increased CD4 and CD8 T lymphocytes in the spleen. NOD2 deficiency also led to reduced Th17-related cytokines in the colon, with overall augmented IFN-γ in the gut and spleen. Nonetheless, there was increased frequency of CD4+IL-4+ cells in the mesenteric lymph nodes besides elevated CTLA-4 and FoxP3 regulatory markers in the spleen of NOD2-/- mice, although it did not result in more efficient control of gut inflammation. Indeed, these animals also had augmented IL-1β and IL-5 in the peritoneum, indicating that this receptor may be important to control bacteria translocation too. Microbiota exchanging between cohoused WT and NOD2-/- mice led to colitis worsening in the absence of the receptor, while antibiotic therapy in WT mice abrogated this effect. Then, not only the genetic mutation confers increased susceptibility to inflammation, but it is also influenced by the microbiota harbored by the host. Finally, NOD2-/- mice are more prone to intestinal inflammation due to deregulated immune response and increased susceptibility to colitogenic bacteria.

Evidences in the last years have showed the effects of oleic acid (OA) in human health and disease. Olive oil, rich in oleic acid, is supposed to present modulatory effects in a wide physiological functions, while some studies also suggest a beneficial effect on cancer, autoimmune and inflammatory diseases, besides its ability to facilitate wound healing. Although the OA role in immune responses are still controversial, the administration of olive oil containing diets may improve the immune response associated to a more successful elimination of pathogens such as bacteria and fungi, by interfering in many components of this system such as macrophages, lymphocytes and neutrophils. Then, novel putative therapies for inflammatory and infectious diseases could be developed based on the characteristics presented by unsaturated fatty acids like OA. Finally, the purpose of this work was to review some of the modulatory effects of OA on inflammatory diseases and health, aiming at high lightening its potential role on the future establishment of novel therapeutic approaches for infections, inflammatory, immune, cardiovascular diseases or skin repair based on this fatty acid mainly found in the Mediterranean diet.

As doenças inflamatórias intestinais (DII) são causadas por desequilíbrio entre as respostas imunes efetoras e reguladoras na mucosa intestinal e podem ser moduladas pelo eixo hipotálamo-hipófise-adrenal (HPA) por meio de interações neuroimunoendócrinas e secreção de cortisol. Embora os glicocorticóides (GC) sejam utilizados para tratar a DII, o cortisol produzido pelas glândulas supra-renais também está envolvido na resposta ao estresse, que pode levar a doenças inflamatórias descontroladas. Portanto, o objetivo deste trabalho é avaliar a participação do eixo HPA na modulação da resposta imune de mucosa intestinal. Para tal, camundongos C57BL/6 foram submetidos à remoção das glândulas adrenais seguida por indução de colite pela administração de água contendo 3% de dextran sulfato de sódio (DSS). Os resultados demonstraram que a ausência das adrenais levou à maior suscetibilidade à doença e mortalidade precoce, fenômeno que não foi prevenido pela reposição de GC. Os animais adrenalectomizados com colite apresentaram níveis significativamente menores de LPS, concomitantemente ao aumento de IL-6 no soro quando comparados aos camundongos não adrenalectomizados. Além disso, os animais adrenalectomizados apresentaram menor celularidade na lâmina própria (LP), menos áreas de erosão e menor escore histopatológico associado ao aumento de IFN-? e FasL, no intestino, sem produção local compensatória de corticosterona. Houve aumento na atividade das enzimas mieloperoxidase (MPO), N- acetilglicosaminidase (NAG) e eosinófilo-peroxidase (EPO) no intestino dos animais expostos ao DSS quando comparados ao grupo de camundongos controles saudáveis, independentemente da presença do eixo HPA intacto e o tratamento com GC nos animais adrenalectomizados levou à redução significativa da atividade de MPO. Também foi observado na LP dos camundongos adrenalectomizados aumento significativo na frequência de células dendríticas tolerogênicas CD11b+CD11c+CD103+, T auxiliares (CD3+CD4+), T citolíticas (CD3+CD8+) e NKT (CD3+CD49b+), além de redução significativa da população de células dendríticas pró-inflamatórias CD11b+CD11c+CD103-, leucócitos CD11b+ e linfócitos intra-epiteliais, de maneira dependente de GC. A ausência do eixo HPA intacto levou à diminuição de leucócitos totais no baço quando comparados ao grupo com colite, relacionada principalmente à redução significativa na frequência de células NKT (CD3+CD49b+), as quais foram restauradas nos camundongos tratados com GC exógenos. Durante a exposição ao DSS houve aumento de células Th2 e Th1 no baço dos camundongos não adrenalectomizados, enquanto que a remoção das adrenais levou a notável redução na população de células T CD4 produtoras de IL-4, IL-10, IFN-? ou IL-17, com aumento de células Th17 e diminuição significativa de células Th1 no baço dos camundongos adrenalectomizados e tratados com GC. De forma interessante, houve menor acúmulo de células T reguladoras juntamente à redução na intensidade média de fluorescência (MFI) de FOXP3 em células T CD4+CD25+ do baço dos camundongos adrenalectomizados expostos ao DSS, de maneira geral dependente de GC. Por fim, esta diminuição de mecanismos reguladores foi acompanhada de menor índice de proliferação e aumento de IL-10 no sobrenadante de cultura de esplenócitos de camundongos com o eixo HPA não ii funcional, indicando que a ausência de GC endógenos pode alterar significativamente a homeostase do sistema imunológico. Juntos, nossos resultados demonstram que o eixo HPA é importante na modulação da resposta imunológica durante a colite induzida experimentalmente Inflammatory bowel diseases (IBD) are caused by imbalance between regulatory and effector immune responses in the intestinal mucosa and can be modulated by the hypothalamic-pituitary-adrenal (HPA) axis via neuroimmune endocrine interactions and secretion of cortisol. Although glucocorticoids (GC) are used to treat IBD, cortisol produced by the adrenals glands is also involved in the stress response, which can lead to uncontrolled inflammatory diseases. Therefore, the aim of this study was to evaluate the HPA axis in the modulation of the immune response of intestinal mucosa. C57BL/6 mice were subjected to removal of the adrenal glands followed by induction of colitis by administration of water containing 3% dextran sulfate sodium (DSS). The results showed that the absence of adrenals led to increased susceptibility to disease and early mortality, a phenomenon that was not prevented by GC replacement. Adrenalectomized animals exposed to DSS had significantly lower levels of LPS, concomitantly to increased IL-6 in the serum when compared to non-adrenalectomized mice. In addition, adrenalectomized animals had lower cellularity in the lamina propria (LP), less erosion areas and less histopathologic score associated with increased IFN-? and FasL in the intestine, without compensatory local production of corticosterone. There was an increase in the activity of the myeloperoxidase (MPO) enzyme, N- acetilglicosaminidase (NAG) and eosinophil-peroxidase (EPO) in the intestines of DSS-exposed animals when compared to the healthy control group of mice, regardless of the presence of intact HPA axis, while treatment with GC led to significantly reduced MPO activity. It was also observed in the LP of adrenalectomized mice significant increase in the frequency of tolerogenic dendritic cells CD11b+CD11c+CD103+, helper T (CD3+ CD4+), cytolytic T (CD3+ CD8+) and NKT (CD3+ CD49b+) besides significant reduction in the population of pro-inflammatory dendritic cells CD11c+ CD11b+ CD103-, leukocyte CD11b+ and intraepithelial lymphocytes, GC-dependent manner. The absence HPA intact carried decrease in total leukocytes in spleen when compared to the group with colitis, related mainly to significant reduction in the frequency of NKT cells (CD3+CD49b+), which were restored in the GC treated mice. During exposure to DSS there was increased Th2 and Th1 cells in the spleen of non-adrenalectomized mice, while the removal of the adrenals was associated to a marked reduction in the population of CD4 T cells producing IL-4, IL-10, IFN-? or IL-17 with increased Th17 cells and significant decrease in Th1 cells in the spleen of adrenalectomized mice treated with GC. Interestingly there was less accumulation of regulatory T cells together to a reduction in mean fluorescence intensity (MFI) of FOXP3 in CD4+CD25+ T cells in the spleen of mice exposed to DSS after adrenalectomy, most dependent on GC. Finally, the decline of regulatory mechanisms was accompanied by lower rates of proliferation and increased IL-10 in the supernatant culture of splenocytes of mice with disrupted HPA axis, indicating that the absence of endogenous GC altered significantly the homeostasis of the immune system. Together, our results demonstrate that the HPA axis is important in modulating the immune response during experimentally induced colitis

Current therapies for inflammatory bowel disease (IBD) are not totally effective, resulting in persistent and recurrent disease for many patients. Mosquito saliva contains immunomodulatory molecules and therein could represent a novel therapy for IBD. Here, we demonstrated the therapeutic activity of salivary gland extract (SGE) of Aedes aegypti on dextran sulfate sodium (DSS)-induced colitis. For this purpose, C57BL/6 male mice were exposed to 3% DSS in drinking water and treated with SGE at early (days 3-5) or late (days 5-8) time points, followed by euthanasia on days 6 and 9, respectively, for sample collection. The results showed an improvement in clinical disease outcome and postmortem scores after SGE treatment, accompanied by the systemic reduction in peripheral blood lymphocytes, with no impact on bone marrow and mesenteric lymph nodes cellularity or macrophages toxicity. Moreover, a local diminishment of IFN-γ, TNF-α, IL-1β and IL-5 cytokines together with a reduction in the inflammatory area were observed in the colon of SGE-treated mice. Strikingly, early treatment with SGE led to mice protection from a late DSS re-challenging, as observed by decreased clinical and postmortem scores, besides reduced circulating lymphocytes, indicating that the mosquito saliva may present components able to prevent disease relapse. Indeed, high performance liquid chromatography (HPLC) experiments pointed to a major SGE pool fraction (F3) able to ameliorate disease signs. In conclusion, SGE and its components might represent a source of important immunomodulatory molecules with promising therapeutic activity for IBD.