5). Rat IgG2 and IgG2b, labeled with PE, FITC, or PE-Cy5.5, were used as isotopic controls. The preparations were analyzed using a FACS-Aria flow cytometer (Becton, Dickinson and Company, Franklin Lakes, NJ, USA) located at the UNICAMP’s Hematology Center. The event analyses were performed using FACSDIVA software (Becton, Dickinson and Company). Cytokine concentrations for IFN-γ, interleukin (IL)-4, IL-1β, IL-10 (eBioscience) and tumor necrosis factor α (TNF-α) (OptEIA; BD Biosciences, San Diego,

CA, USA) were measured by ELISA in the culture supernatants using commercial kits, following the manufacturers’ guidelines. Serum concentrations of IgM, IgG, and IgA and fecal concentrations of IgA were measured by a capture ELISA developed in our laboratory, using commercially available BAY 80-6946 clinical trial antibodies (Sigma). Ninety-six-well microtitration plates (NUNC, Roskilde, Denmark) were coated with a solution of goat polyclonal antimouse immunoglobulins, APO866 clinical trial diluted in carbonate/sodium bicarbonate buffer, 0.1 M, pH 9.6. The plates were incubated overnight at 4°C and washed with PBS at 0.2 M, pH 7.4, containing 0.05% Tween 20. The free sites were blocked, and the plates washed as above. The feces extracts were used for fecal IgA detection. The serum and feces

samples were added to the wells at various dilutions, and the plates were incubated for 1 hour at 37°C. After washing, the specific anti-IgG, anti-IgM, or anti-IgA antibodies were tagged with horseradish peroxidase and added at predetermined dilutions. The reaction was developed by adding the chromogenic substrate (0.03% H2O2 and 0.04% orthophenylenediamine in citrate-phosphate buffer, 0.05 M, pH 5.5) followed by incubation in the dark for 15 minutes. The reaction was stopped by adding 4 N H2SO4 to each well. The absorbance was read in a microplate reader (Multiskan MS; Labsystems, Helsinki, Finland) at a wavelength

of 492 nm. The average concentrations of each immunoglobulin tested were calculated with a standard curve prepared with purified IgM, IgG and IgA (Sigma). Nitrite was measured using the specifications of Green et al [20]. Briefly, aliquots of 50 μL Griess reagent (1% sulfanilamide in 5% phosphoric acid and 0.1% naftilethylenediamine dihydrochloride in distilled water, all from Sigma) were added to identical volumes of supernatants from cultures of macrophages, Sodium butyrate distributed previously in 96-well plates. After a 15-minute incubation followed by plate agitation, the readings were performed in a spectrophotometric ELISA reader at 540 nm using sodium nitrite solutions (5 at 320 μM) as standards. The results were expressed in μM nitrite/1 × 106cells/mL. Results are presented as means ± SEM. Statistical analyses were performed using GraphPad Prism software (GraphPad Software, Inc, San Diego, CA, USA). Significance was assessed by analysis of variance followed by Bonferroni test. The significant difference in 2 groups was statistically analyzed using the Student t test.