IDO and TTS mRNA expression and effect of CTLA-4-Fc and CD28-Fc in monocytes and DCs. (A) IDO mRNA expression in monocytes and monocyte-derived iDCs and mDCs after 12 hours of culture in the absence or presence of CTLA-4-Fc or CD28-Fc. (B) TTS mRNA expression in monocytes and monocyte-derived iDCs and mDCs after 12 hours of culture in the absence or presence of CTLA-4-Fc or CD28-Fc. □ represents media alone; ▪, CTLA-4-Fc; ▦, CD28-Fc. *P values less than .05 are based on 5 independent experiments. Mean values plus standard errors are shown.