IDO catalyzes the first and rate-limiting step in the main pathway of human tryptophan catabolism, the kynurenine pathway. Proinflammatory mediators, such as endotoxin and IFN-gamma induce the expression of IDO in several tissues. IDO-dependent suppression of T-cell responses might function as natural immunoregulatory mechanism. Physiological IDO activity has been implicated in T-cell tolerance to tumors, dysfunctional selftolerance in non-obese diabetic (NOD) mice, and as a protective negative regulator in autoimmune disorders.
ELISA: (direct and indirect: 1:2,000-1:10,000). Flow Cytometry: (1:200-1:500). Immunocytochemistry: (1:500) . Western Blot: (1:2,000-1:5,000 using ECL; suggested blocking and dilution buffer is PBST containing 0.05% Tween 20 and 5% skim milk; suggested incubation time is 1 hour at room temperature). Optimal conditions must be determined individually for each application.