Objectives: Improved bovine tuberculosis (bTB) diagnostics with higher sensitivity and specificity are urgently required. A better understanding of the peripheral blood transcriptional response of Mycobacterium bovis-infected animals after bovine purified protein derivative (PPD-b) stimulation of whole bloodโan important component of current bTB diagnosticsโwill provide new information for development of better diagnostics. Methods: RNA sequencing (RNA-seq) was used to study the peripheral blood transcriptome after stimulation with PPD-b across four time points (โ1~wk pre-infection, and +1~wk, +2~wk, and +10~wk post-infection) from a 14-week M. bovis infection time course experiment with ten age-matched Holstein-Friesian cattle. Results: In vitro PPD-b stimulation of peripheral blood from M. bovis-infected and non-infected cattle elicited a strong transcriptional response. Comparison of PPD-b stimulated, and unstimulated samples revealed higher expression of genes encoding cytokine receptors, transcription factors, and interferon-inducible proteins. Lower expression was seen for genes encoding proteins involved in antimicrobial activity, C-type lectin receptors, inhibition of signal transduction, and genes encoding metal ion transporters. Conclusions: A transcriptional signature associated with the peripheral blood response to PPD-b stimulation consisting of 170 genes was identified exclusively in the post-infection time points. Therefore, this represents a panel of potential biomarkers of M. bovis infection.