High-fat diet-induced obesity worsens TH2 immune response and immunopathologic characteristics in murine model of eosinophilic oesophagitis.

BACKGROUND: Eosinophilic oesophagitis (EoE) is an emergent chronic immune-mediated disease of the oesophagus, which affects both children and adults. It is clinically characterized by dysphagia, food impaction and oesophageal eosinophilia. Epidemiological studies indicate that obesity can worsen allergic symptoms; however, its effect on EoE immunopathological response has not been evaluated yet. This study aimed to assess the effect of obesity on allergic inflammation and T helper-2 profile in an EoE experimental model. METHODS: Obesity was induced by high-fat feeding. After 7 weeks of diet, male BALB/c mice were subcutaneously sensitized and orally challenged with OVA. RESULTS: Obesity itself induced a significant mast cell and eosinophil accumulation in the oesophagus, trachea, gut and lung. After allergy induction, this number was higher, when compared to lean-allergic mice. Moreover, obese-allergic mice showed higher remodelling area, in the oesophagus, associated with higher IL-5 and TSLP mRNA expression. In contrast, FoxP3 and IL-10 were less expressed in comparison with lean-allergic mice. In addition, the amount of CD11c+ MHCII+ PDL1+ dendritic cells was reduced, while the number of CD11c+ MHCII+ CD80+ DCs and CD3+ CD4+ GATA3+ IL-4+ cells was increased in obese-allergic mice in the spleen and lymph nodes when compared to lean-allergic mice. CONCLUSION: Obesity aggravated the immune histopathological characteristics in the EoE experimental model, which was associated with the reduction in the regulatory profile, and the increased inflammatory cells influx, related to the TH 2 profile. Altogether, the data provide new knowledge about obesity as a risk factor, worsening EoE symptoms, and contribute for future treatment strategies for this specific profile.

Genistein modulates the expression of Toll-like receptors in experimental autoimmune encephalomyelitis.

OBJECTIVE AND DESIGN: The present work investigates the modulation of experimental autoimmune encephalomyelitis (EAE) using genistein before the EAE induction. MATERIAL: Female C57BL/6 mice (n = 96 mice/experiment), 4-6 weeks old, were used to induce the EAE. The mice were divided into three experimental groups: non-immunized group, immunized group (EAE), and immunized and treated with genistein group (Genistein). TREATMENT: Genistein was used at a dose of 200 mg/kg s.c. and were initiated 2 days before the immunization and continued daily until day 6 postimmunization. METHODS: Animals were monitored daily for clinical signs of EAE up to day 21. Inflammatory infiltration, demyelination, Toll-like receptor (TLR) expression, cytokines and transcription factors were analyzed in spinal cords. RESULTS: The present study demonstrates, for the first time, the genistein ability to modulate the factors involved in the innate immune response in the early stages of EAE. The genistein therapy delayed the onset of the disease, with reduced inflammatory infiltration and demyelination. In addition, the expression of TLR3, TLR9 and IFN-ß were increased in genistein group, with reduction in the factors of TH1 and Th17 cells. CONCLUSION: These findings shed light on the potential of genistein as a prophylactic strategy for multiple sclerosis (MS) prevention.

Presence of mecA-positive multidrug-resistant Staphylococcus epidermidis in bovine milk samples in Brazil.

Bacteria of the genus Staphylococcus are one of the major pathogens causing bovine mastitis. In recent decades, resistance of this genus to oxacillin (methicillin) has been a matter of concern due to the possibility of reducing the effectiveness of mastitis treatments and the transfer of resistance determinants to other bacteria. Oxacillin resistance was studied in 170 staphylococci from bovine milk samples, including 79 Staphylococcus aureus and 91 coagulase-negative staphylococci (CNS). The susceptibility profile of 10 antimicrobial agents used in veterinary practice was determined by the Etest method. In addition to the Etest, the phenotypic characterization of oxacillin resistance was tested using the cefoxitin disk diffusion test. All isolates were screened by PCR to detect the mecA gene in 2 different regions of the gene. The isolates with an oxacillin minimum inhibitory concentration ≥0.5 µg/mL or resistant to cefoxitin were identified by sequencing a 536-bp fragment of the 16S rRNA gene. This group of isolates was also evaluated for the presence of blaZ and mecC genes. Molecular analysis of the mecA gene was carried out by typing of the staphylococcal cassette chromosome mec (SCCmec). The relatedness of the mecA-positive isolates was evaluated by macrorestriction of chromosomal DNA followed by pulsed-field gel electrophoresis. With the exception of penicillin and oxacillin, 86% of the isolates showed susceptibility to cephalothin, gentamicin, erythromycin, sulfonamide, trimethoprim-sulfamethoxazole, and tetracycline. All S. aureus isolates were susceptible to oxacillin, whereas 47% (n=43) of the CNS isolates were resistant. The CNS isolates showed a higher resistance to cephalothin, erythromycin, tetracycline, and gentamicin in comparison with S. aureus. The mecA gene was only detected in 10 CNS isolates, identified as Staphylococcus epidermidis, and classified into 3 pulsotypes (A, B, and C) and 4 subtypes (A1, B1, B2, and B3). Among the isolates with an oxacillin resistance phenotype, 12 were positive for the blaZ gene, and 9 of them were mecA-positive. Two of the oxacillin-resistant isolates amplified the mecA homolog gene of Staphylococcus sciuri and none amplified mecC. Three SCCmec types, I, IV, and V, were found. Our results suggest that Staphylococcus epidermidis can be a reservoir for mecA for other Staphylococcus species. Studies investigating the molecular and phenotypic profile of antimicrobial resistance in staphylococcal species should be performed for controlling the spread of resistance and the selection of appropriate therapeutic measures.

Disodium cromoglycate treatment reduces TH2 immune response and immunohistopathological features in a murine model of Eosinophilic Esophagitis.

Eosinophilic esophagitis (EoE) is an emergent chronic disease of the esophagus. The immunopathological process in EoE is characterized by Th2 immune response and prominent eosinophilic influx, in response to common food allergens. The classical treatment consists of allergen elimination diet and systemic/topical corticosteroid therapy. Nevertheless, patients do not always comply to treatment, and the prolonged corticosteroid therapy can cause side effects, therefore, there is an immediate need for new therapeutic approach for EoE. Disodium cromoglicate (DSCG) is a substance broadly used in allergic asthma treatment, and a well-known mast cell activation stabilizer. However, its effect in EoE have not been evaluated yet. This study aimed to assess the effects of DSCG treatment in an EoE experimental model. Male Balb/C mice were subcutaneously sensitized for five days with OVA, and subsequently orally OVA-challenged, DSCG administration was performed between the OVA-challenges. DSCG treatment not only reduced eosinophilic and mast cell influx, as well as reduced fibrosis. In addition, tslp, GATA3, IL-5, FoxP3 and IL-10 mRNA expression were reduced in esophageal mucosa, associated with lower Th2 (CD3+CD4+GATA3+IL4+) and B cells (CD19+CD40+) number in peripheral lymphoid organs. In conclusion, the data demonstrate DSCG treatment was effective in reducing mast cell activation and Th2 immune response, important immunopathological EoE features. Therefore, the use of DSCG as an EoE treatment can be considered a promising therapeutic approach to treat this disease.