For the NO and cytokine assay, approximately 3 × 105 RAW 264·7 or J774·1 macrophages were seeded in a 96-well culture plate (BD, Falcon, San Jose, CA). Cells were stimulated with different concentrations of rRv2626c and incubated at 37° for 48 hr. The positive control group received LPS (1 μg/ml) and IFN-γ (1 ng/ml). As and when required, cells were pretreated PLX-4720 in vitro by adding 10 μm pyrrolidine dithiocarbamate (PDTC; Sigma) and incubating for 1 hr, followed by stimulation with various concentrations of rRv2626c. For NO estimation by the Griess assay, equal aliquots of the culture supernatants were dispensed in duplicate into a 96-well culture plate and

mixed with an equal volume of Griess reagent,35 composed of 1% [weight/volume (w/v)] sulphanilamide, 0·1% (w/v) napthyl-ethylenediamine hydrochloride and 2·5% (v/v) H3PO4. After incubation at room temperature for 5 min, the absorbance was measured at 540 nm in an Ultra Microplate Reader (Bio-Tek, Winooski, VT). The concentration of nitrate was interpolated from the NaNO2 standard curve. TNF-α and IL-12 p40 levels in the culture supernatants were measured by enzyme immunoassay (EIA) (BD Biosciences Pharmingen, San Diego, CA) as described

previously.36 Standard curves for each cytokine were obtained using the recombinant standard protein provided by the manufacturer. RAW 264·7 macrophages (2 × 106 cells/well in a six-well culture plate) were left untreated or treated with 3 μg/ml of rRv2626c in the absence or Lumacaftor order Vitamin B12 presence of LPS and IFN-γ. After 24 hr of incubation, cells were harvested and washed three times with ice-cold FACS buffer [PBS containing 1% bovine serum albumin (BSA) and 0·01%

sodium azide] and then re-suspended in FACS buffer and incubated with anti-mouse B7-1 (clone 1G10; BD Biosciences Pharmingen), anti-mouse B7-2 (clone GL1; BD Biosciences Pharmingen) and anti-mouse CD40 (clone 3/23; BD Biosciences Pharmingen). The control group received isotype control antibody. Cells were washed again with FACS buffer and incubated with anti-mouse FITC (Sigma-Aldrich). Flow cytometric analysis was performed (Becton Dickinson, San Jose, CA) and the FACS data were recorded for 20 000 events for each labelled cell population. Flow cytometry data analyses were carried out using cell quest data analysis software (BD Biosciences, San Jose, CA). The RAW 264·7 macrophages were seeded at a density of 5 × 106 per well in a six-well culture plate and were either left untreated or pretreated with PDTC for 1 hr followed by stimulation with either 5 μg of rRv2626c or a combination of LPS and ΙFN-γ. Cells were harvested and the whole-cell extract was prepared as described previously.