Immunization with purine salvation pathway recombinant enzymes induces the production of anti- Schistosoma mansoni immunoglobulines

Schistosomiasis, a disease caused by the trematodes of the Schistosoma genus, affects about 240 million people worldwide. The Praziquantel (PZQ) is the drug used to treat this disease. However, reports of resistant strains reinforce the need to develop a new schistosomicidal drug. The study of new drugs and vaccines that can contribute to the control of this pathology becomes urgent. A new approach can be held by the study of the following Schistosoma mansoni enzymes: purine nucleoside phosphorilase 1 (PNP), hypoxanthine guanine phosphoribosyltransferase (HGPRT) and adenylate kinase 1 (ADK). The parasite, incapable of synthetizing purine nucleotides through the de novo pathway, has multiple mechanisms to incorporate purine bases through the purine salvage pathway. Our goal was to assess, through immunoenzimatic assay (ELISA-indirect), the production of total IgG, IgE and IgG2a in the plasma after immunization with the PNP, HGPRT and ADK enzymes, using the S. mansoni cercariae - infected murine model. Our results showed that the immunization in Balb/c mice with the enzymes mentioned above induced production of the immunoglobulines at the 48th and 85th days, post-infection. Thereby, new assays must be made for a better assessment on how these enzymes modulate an immune response.CNPqFAPES

Evaluation of immunization with purine salvation pathway recombinant enzymes in Schistosoma mansoni worms and eggs in murine schistosomiasis

According to the World Health Organization (WHO), on tropical and subtropical areas, schistosomiasis is the second parasitic disease of greater prevalence, in terms of morbidity and mortality, surpassed only by malaria. The Praziquantel (PZQ) is used for the treatment of this disease. However, reports of resistant strains reinforce the need to develop a new schistosomicidal drug. The infection by the parasite induces an inflammatory reaction of long duration due to the presence of adult worms living in the mesenteric venous system. The parasite lays eggs in small vessels of the submucosa of the intestines. These eggs are transported by the blood flow to the liver and they cause a granulomatous inflammatory reaction. A new approach can be held by the study of the following Schistosoma mansoni enzymes: purine nucleoside phosphorilase 1 (PNP), hypoxanthine guanine phosphoribosyltransferase (HGPRT) and adenylate kinase (ADK). The parasite, incapable of synthetizing purine nucleotides through the de novo pathway, has multiple mechanisms to incorporate purine bases through the purine salvage pathway. In our results, we suggest that the immunization in Balb/c mice with the mentioned recombinant enzymes was capable of inducing a specific immune response, favoring the reduction of both the parasite load and number of eggs per gram of feces. The acquired data show that these enzymes can be considered as new targets to immunotherapy against schistosomiasis mansoni.CNPqFAPES

Prostaglandin E2 via EP4/IL-1R inhibits Th17 cell differentiation during the efferocytosis of infected cells

A fagocitose de células apoptóticas promove a síntese de mediadores como o fator de transformação de crescimento (TGF-β), a prostaglandina E2 (PGE2) e a interleucina-10 (IL- 10), importantes para a diferenciação de células T reguladoras (Treg). No entanto, a fagocitose de células apoptóticas infectadas, por células dendríticas, resulta na síntese de citocinas, tais como TGF-β, IL-6 e IL-23, que sabidamente favorecem a diferenciação de linfócitos T heper 17 (Th17). Resultados preliminares obtidos por nosso grupo demonstram que, além destas citocinas, a PGE2 também é produzida durante a eferocitose de células infectadas, no entanto, nada se sabia até o momento quanto ao envolvimento deste prostanóide no processo de diferenciação de linfócitos Th17. Desta forma, a hipótese deste trabalho fundamentou-se no estudo do mecanismo de sinalização intracelular pelo qual a PGE2, via receptor E prostanóide (EP), estaria envolvida na diferenciação de linfócitos Th17, no contexto da eferocitose. Os resultados apresentados demonstram que além da produção de TGF-β e IL-6, a fagocitose de células apoptóticas infectadas com Escherichia coli, por células dendríticas, induz a síntese de altos níveis de PGE2 e IL-1β, previamente descritos como indutores de Th17. Entretanto, diferente da nossa hipótese original, a presença da PGE2 inibiu a diferenciação de linfócitos Th17, uma vez que a ausência deste prostanóide resultou no aumento da porcentagem e número de linfócitos Th17. O tratamento de linfócitos T CD4+ naive com antagonistas e agonistas de EP2/EP4 demonstrou que o efeito supressor da PGE2 é mediado primordialmente pelo receptor EP4, via ativação de cAMP e PKA. Além disso, o eixo PGE2-EP4 modulou negativamente a expressão do receptor de IL-1β (IL-1R), comprometendo, desta forma, a diferenciação de Th17. Ainda, in vivo, no modelo de colite infeciosa por Citrobacter rodentium, a inibição da síntese da PGE2 ou o bloqueio do receptor EP4 resultou no aumentou da população de linfócitos Th17 e da expressão de peptídeos antimicrobianos no cólon, além de uma drástica redução na carga bacteriana. Por fim, o conjunto destes resultados demonstram que a PGE2, via EP4-PKA-IL-1R, suprime a diferenciação de linfócitos Th17, in vitro e in vivo, e desvenda um mecanismo inédito na modulação da resposta imune adaptativa de linfócitos Th17 promovido pela PGE2, no contexto da eferocitose.Phagocytosis of apoptotic cells promotes the synthesis of mediators such as transforming growth factor (TGF-β), prostaglandin E2 (PGE2) and interleukin-10 (IL-10), which are important for the differentiation of regulatory T cells (Treg). However, phagocytosis of infected apoptotic cells by dendritic cells results in the synthesis of cytokines such as TGF-Beta;, IL-6 and IL-23 known to promote T helper 17 cell (Th17) differentiation. Preliminary results obtained by our group showed that, along with these cytokines, PGE2 is also produced during efferocytosis of infected cells. However, nothing was known regarding the involvement of this prostanoid on Th17 differentiation process. Thus, our hypothesis was based on the study of intracellular signaling mechanism by which PGE2, via E prostanoid receptor (EP), could be involved in the differentiation of Th17 cells in the context of efferocytosis. Our results show that, besides TGF-β and IL-6 production, phagocytosis of Escherichia coli-infected apoptotic cells by dendritic cells induces the synthesis of high levels of PGE2 and IL-1β, as previously described as Th17 inducers. However, unlike our original hypothesis, the presence of PGE2 inhibited the differentiation of Th17 cells, while the absence of this prostanoid resulted in increased percentage and number of this phenotype. Naive CD4+ T cells treated with EP2/EP4 agonists and antagonists demonstrated that the suppressive effect of PGE2 is primarily mediated by the EP4 receptor, via activation of cAMP and PKA. Furthermore, PGE2-EP4 negatively modulates the expression of IL-1β receptor (IL-1R), impairing Th17 differentiation. Also, in vivo, during Citrobacter rodentium infection, inhibition of PGE2 synthesis or EP4 receptor blockade resulted in increased population of Th17 cells and greater expression of antimicrobial peptides in colon, as well as a drastic reduction in bacterial load. Finally, all these data demonstrate that PGE2, via EP4-PKA-IL-1R, suppresses Th17 differentiation in vitro and in vivo, and reveals a novel mechanism in the modulation of adaptive immune response of Th17 cells promoted by PGE2 in the context of efferocytosis

Anticoronavirus and Immunomodulatory Phenolic Compounds: Opportunities and Pharmacotherapeutic Perspectives

In 2019, COVID-19 emerged as a severe respiratory disease that is caused by the novel coronavirus, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). The disease has been associated with high mortality rate, especially in patients with comorbidities such as diabetes, cardiovascular and kidney diseases. This could be attributed to dysregulated immune responses and severe systemic inflammation in COVID-19 patients. The use of effective antiviral drugs against SARS-CoV-2 and modulation of the immune responses could be a potential therapeutic strategy for COVID-19. Studies have shown that natural phenolic compounds have several pharmacological properties, including anticoronavirus and immunomodulatory activities. Therefore, this review discusses the dual action of these natural products from the perspective of applicability at COVID-19

Effect of a probiotic beverage consumption (Enterococcus faecium CRL 183 and Bifidobacterium longum ATCC 15707) in rats with chemically induced colitis.

BACKGROUND:Some probiotic strains have the potential to assist in relieving the symptoms of inflammatory bowel disease. The impact of daily ingestion of a soy-based product fermented by Enterococcus faecium CRL 183 and Lactobacillus helveticus 416 with the addition of Bifidobacterium longum ATCC 15707 on chemically induced colitis has been investigated thereof within a period of 30 days. METHODS:Colitis was induced by dextran sulfate sodium. The animals were randomly assigned into five groups: Group C: negative control; Group CL: positive control; Group CLF: DSS with the fermented product; Group CLP: DSS with the non-fermented product (placebo); Group CLS: DSS with sulfasalazine. The following parameters were monitored: disease activity index, fecal microbial analyses, gastrointestinal survival of probiotic microorganisms and short-chain fatty acids concentration in the feces. At the end of the protocol the animals' colons were removed so as to conduct a macroscopical and histopathological analysis, cytokines and nitrite quantification. RESULTS:Animals belonging to the CLF group showed fewer symptoms of colitis during the induction period and a lower degree of inflammation and ulceration in their colon compared to the CL, CLS and CLP groups (p<0.05). The colon of the animals in groups CL and CLS presented severe crypt damage, which was absent in CLF and CLP groups. A significant increase in the population of Lactobacillus spp. and Bifidobacterium spp. at the end of the protocol was verified only in the CLF animals (p<0.05). This group also showed an increase in short-chain fatty acids (propionate and acetate). Furthermore, the intestinal survival of E. faecium CRL 183 and B. longum ATCC 15707 in the CLF group has been confirmed by biochemical and molecular analyzes. CONCLUSIONS:The obtained results suggest that a regular intake of the probiotic product, and placebo to a lesser extent, can reduce the severity of DSS-induced colitis on rats

Table_1_The relationship between obesity-related H19DMR methylation and H19 and IGF2 gene expression on offspring growth and body composition.DOCX

Background and objectiveImprinted genes are important for the offspring development. To assess the relationship between obesity-related H19DMR methylation and H19 and IGF2 gene expression and offspring growth and body composition.MethodsThirty-nine overweight/obese and 25 normal weight pregnant women were selected from the “Araraquara Cohort Study” according to their pre-pregnancy BMI. Fetal growth and body composition and newborn growth were assessed, respectively, by ultrasound and anthropometry. The methylation of H19DMR in maternal blood, cord blood, maternal decidua and placental villi tissues was evaluated by methylation-sensitive restriction endonuclease qPCR, and H19 and IGF2 expression by relative real-time PCR quantification. Multiple linear regression models explored the associations of DNA methylation and gene expression with maternal, fetal, and newborn parameters.ResultsH19DMR was less methylated in maternal blood of the overweight/obese group. There were associations of H19DMR methylation in cord blood with centiles of fetal biparietal diameter (BPD) and abdominal subcutaneous fat thickness and newborn head circumference (HC); H19DMR methylation in maternal decidua with fetal occipitofrontal diameter (OFD), HC, and length; H19DMR methylation in placental villi with fetal OFD, HC and abdominal subcutaneous fat thickness and with newborn HC. H19 expression in maternal decidua was associated with fetal BPD and femur length centiles and in placental villi with fetal OFD and subcutaneous arm fat. IGF2 expression in maternal decidua was associated with fetal BPD and in placental villi with fetal OFD.ConclusionTo our knowledge, this is the first study to demonstrate associations of imprinted genes variations at the maternal-fetal interface of the placenta and in cord blood with fetal body composition, supporting the involvement of epigenetic mechanisms in offspring growth and body composition.</p

Data_Sheet_1_The relationship between obesity-related H19DMR methylation and H19 and IGF2 gene expression on offspring growth and body composition.PDF

Background and objectiveImprinted genes are important for the offspring development. To assess the relationship between obesity-related H19DMR methylation and H19 and IGF2 gene expression and offspring growth and body composition.MethodsThirty-nine overweight/obese and 25 normal weight pregnant women were selected from the “Araraquara Cohort Study” according to their pre-pregnancy BMI. Fetal growth and body composition and newborn growth were assessed, respectively, by ultrasound and anthropometry. The methylation of H19DMR in maternal blood, cord blood, maternal decidua and placental villi tissues was evaluated by methylation-sensitive restriction endonuclease qPCR, and H19 and IGF2 expression by relative real-time PCR quantification. Multiple linear regression models explored the associations of DNA methylation and gene expression with maternal, fetal, and newborn parameters.ResultsH19DMR was less methylated in maternal blood of the overweight/obese group. There were associations of H19DMR methylation in cord blood with centiles of fetal biparietal diameter (BPD) and abdominal subcutaneous fat thickness and newborn head circumference (HC); H19DMR methylation in maternal decidua with fetal occipitofrontal diameter (OFD), HC, and length; H19DMR methylation in placental villi with fetal OFD, HC and abdominal subcutaneous fat thickness and with newborn HC. H19 expression in maternal decidua was associated with fetal BPD and femur length centiles and in placental villi with fetal OFD and subcutaneous arm fat. IGF2 expression in maternal decidua was associated with fetal BPD and in placental villi with fetal OFD.ConclusionTo our knowledge, this is the first study to demonstrate associations of imprinted genes variations at the maternal-fetal interface of the placenta and in cord blood with fetal body composition, supporting the involvement of epigenetic mechanisms in offspring growth and body composition.</p

Table_2_The relationship between obesity-related H19DMR methylation and H19 and IGF2 gene expression on offspring growth and body composition.docx

Background and objectiveImprinted genes are important for the offspring development. To assess the relationship between obesity-related H19DMR methylation and H19 and IGF2 gene expression and offspring growth and body composition.MethodsThirty-nine overweight/obese and 25 normal weight pregnant women were selected from the “Araraquara Cohort Study” according to their pre-pregnancy BMI. Fetal growth and body composition and newborn growth were assessed, respectively, by ultrasound and anthropometry. The methylation of H19DMR in maternal blood, cord blood, maternal decidua and placental villi tissues was evaluated by methylation-sensitive restriction endonuclease qPCR, and H19 and IGF2 expression by relative real-time PCR quantification. Multiple linear regression models explored the associations of DNA methylation and gene expression with maternal, fetal, and newborn parameters.ResultsH19DMR was less methylated in maternal blood of the overweight/obese group. There were associations of H19DMR methylation in cord blood with centiles of fetal biparietal diameter (BPD) and abdominal subcutaneous fat thickness and newborn head circumference (HC); H19DMR methylation in maternal decidua with fetal occipitofrontal diameter (OFD), HC, and length; H19DMR methylation in placental villi with fetal OFD, HC and abdominal subcutaneous fat thickness and with newborn HC. H19 expression in maternal decidua was associated with fetal BPD and femur length centiles and in placental villi with fetal OFD and subcutaneous arm fat. IGF2 expression in maternal decidua was associated with fetal BPD and in placental villi with fetal OFD.ConclusionTo our knowledge, this is the first study to demonstrate associations of imprinted genes variations at the maternal-fetal interface of the placenta and in cord blood with fetal body composition, supporting the involvement of epigenetic mechanisms in offspring growth and body composition.</p