Serum IL-12p40 was measured by ELISA as recommended by the manufacturer (BD Bioscience). Cells from

uninfected mice had no detectable IL-10, IL-4, or IFN-γ production with antigen stimulation in these experiments. Serum from uninfected mice had no detectible IL-12p40. Nitric oxide production was assayed by measuring nitrite in 3-day recall supernatants A769662 with the Griess reaction (16). Serial dilutions of sera from infected mice were assayed for Leishmania-specific IgG1 and IgG2a/c by ELISA using L. mexicana FTAg for capture, and biotin-conjugated anti-mouse IgG1 and IgG2a/c (BD Biosciences) with peroxidase-conjugated streptavidin (Jackson ImmunoResearch; West Grove, PA, USA) for detection, using 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) as substrate. IgG quantitation shows mean and SEM for ≥5 mice per group. Significant differences were determined by t-test from optical density

(OD) values for the top two dilutions only. Relative amounts of IgG were calculated for the mean WT value by first creating a standard curve from the mean OD values of the KO serum dilution series, plotting OD vs. (1/dilution factor) and fitting the curve using a 6th degree polynomial (KaleidaGraph Mac v.3.6.4). Values of r2 were always very close to 1·0 for this fit (0·9999 for each). The KO dilution, as read from the calculated function, that gave the same OD as the 60-fold dilution of WT serum was designated as the relative amount after the 60-fold dilution Roscovitine research buy was taken into account. LN cells from infected mice were incubated with or without L. mexicana FTAg for 3 days and

then were stimulated Orotidine 5′-phosphate decarboxylase with phorbol myristate acetate (50 ng/mL), ionomycin (0·5 μg/mL), and Brefeldin A (10 μg/mL) for 4 h followed by staining for CD3ε (FITC-145–2C11), CD8α (PerCP-53–6·7), and CD25 (PE-PC61 5·3), fixed with 1% formaldehyde, and stained for intracellular IL-10 (APC-JES5-16E3) after permeabilization with 1% saponin. We used CD3+CD8− staining to determine CD4+ cells because of the relative downregulation of CD4 with antigen stimulation. Antibodies were from BD Biosciences, eBiosciences, or Caltag (CD25) and flow cytometry was acquired and analysed using a FACSCaliber flow cytometer with CellQuest Pro software (BD Biosciences). Isotype controls were used to identify positive vs. negative cell populations. Parasite quantification was performed for three randomly chosen mice per group, by limiting dilution as described previously (17). The limit of detection was 1·4 log = 25 parasites/lesion. Experiments were performed two to four times and representative data are shown. A two-tailed, unequal variance Student’s t-test was used to compare means of lesion sizes, log parasite burdens, cytokine production, IgG levels, mean fluorescence intensity, and FACS distributions from different groups of mice.