, 2001; Werling & Jungi, 2003; Doherty & Arditi, 2004). In our study, the expressions of TLR2 and TLR4 were increased in both tuberculosis and healthy control groups 3-h poststimulation; however, only TLR2 expression showed a significant difference (P≤0.05) between the two see more groups. The increase in the expression of the TLR2 gene is more significant in healthy cattle (6.54-fold)

response to stimulation than the tuberculosis group (2.64-fold). This demonstrates that the TLR2 signal pathway may play a larger role in healthy control cattle than the tuberculosis group, possibly resulting in a more efficient proinflammatory gene activation. An important anti-inflammatory cytokine, IL10, was also examined in our study. IL10 downregulates the Th1 type immune response and upregulates the Th2 type in pathogen–host interaction (Jacobs et al., 2000). It has been shown in previous studies, in both humans and mice, that increased

expression of IL10 is associated with the decreased ability of macrophages to restrict the growth of intracellular Mycobacterium (Jamil et al., 2007; Bilenki et al., 2010). Our results show that IL10 expression is more increased in tuberculosis cattle (8.74-fold) than the healthy group (2.90-fold) relative to 3-h poststimulation compared with nonstimulated cells. The differential regulation of IL10 in tuberculosis cattle may reflect vulnerability in the defense of macrophages against M. bovis. The development trend of gene expressions in this study is consistent with that seen by Meade NU7441 and colleagues, while the different levels of gene expression seen could be attributed to cell populations (PBMCs vs. MDMs), stimulator (bovine tuberculin vs. M. bovis) or comparison of different clinical phenotypes [active BTB infection vs. Latent TB (LTB)]. Our study provides evidence of differences in gene expression between tuberculosis and healthy cattle, which confirms that the innate immune response, TLRs signal pathway

and Th1/Th2 bias are important in BTB infection. The current techniques cannot predict the risk of an individual LTB animal developing into the active disease, and genes implicated in susceptibility and BCKDHA resistance of tuberculosis in cattle cannot point to clear solutions. Building on the differences in gene expression regulation demonstrated in this study, it may provide insights into the diagnosis and treatment of tuberculosis cattle and lead to diagnostics that may characterize the immune response prognostic information in BTB infection. This work was supported by the key project of Ministry of Agriculture, China (Project no. 2009ZX08009-183B), the Beijing Science Foundation of China (Project no. 6101002) and the Natural Science Foundation of China (Project no. 30972164). Y.W. and X.Z. contributed equally to this work. Table S1. Data of IFN-γ ELISA assays (shown as values of optical density at 450 nm, OD 450 nm). Table S2.