BAC or PBMC (106 each) were stimulated with 10μg PPD, or 2.5μg PHA (per mL final concentration) or with M.tb (MOI 10) for 24 hrs. Expression of IL-12Rβ1 and IL-12Rβ2 was assessed by qRT-PCR. IL-12Rβ1 mRNA expression (copy numbers/60ng cDNA): panel (A) BAC and (C) PBMC [(A, C): CC n=5 (TST+ n=3, TST − n=2), TB n= 6]. IL-12Rβ2 mRNA expression (copy numbers/60ng cDNA): panel (B) BAC and (D) PBMC [(B, D): CC n=5 (TST+ n=3, TST− n=2); (B) TB n= 6, (D) TB n=5]. IL-12Rβ1 and IL-12Rβ2 mRNA expression data are normalized to account for differences in alveolar T cell proportions in BAC from TB patients and CC.