1 methyl d tryptophan 1 d mt

Peptides used in this investigation (Table 1) were >95% pure. They were generously provided by Drs. Jack Bennink and Jonathan Yewdell (National Institutes of Health). Stock solutions of all peptides were prepared at 1 mM in DMSO and stored at −30°C. Each peptide was used at a final concentration of 500 nM in our assays. 1-Methyl-D-tryptophan (1-D-MT) was purchased from Sigma (Mississauga, ON). The powder was dissolved at 5 mg/mL in 0.1 M NaOH followed by drop-wise addition of 12 M HCl to generate a neutral solution, which was then filter-sterilized and injected as indicated. L-kynurenine (L-Kyn), also from Sigma, was dissolved at 10 mg/mL in PBS shortly before injection.

Recombinant mouse IFNα-2 (eBiosciences, San Diego, CA), recombinant human IFNα-2a (Gemini Bio-Products, Sacramento, CA), recombinant mouse IFNγ (PeproTech, Rocky Hill, NJ) and recombinant human IFNγ (PeproTech) were purchased as described. Methyl-thiohydantoin-DL-tryptophan (MTH-trp) was from Cayman Chemical (Ann Arbor, MI) and dissolved in DMSO. L-tryptophan, kynurenine, 3-HK, kynurenic acid, 3-HAA, quinolinate, 1-methyl-L-tryptophan (1-L-MT) and 1-methyl-D-tryptophan (1-D-MT) were all from Sigma-Aldrich (St Louis, MO).