GENE EXPRESSION OF BOVINE PERIPHERAL BLOOD MONONUCLEAR CELLS IN VITRO CHALLENGED WITH MYCOBACTERIUM BO VIS

摘要

Mycobacterium bovis (M. bovis) is causative agent of tuberculosis in cattle and humans populations. To understand its effects on gene expression profiles, we conducted an in vitro time-course study to identify transcriptional changes in infected bovine peripheral blood mononuclear cells (PBMCs), using quantitative RT-PCR. We discovered a likely involvement of C-type lectin domain family 4, member E (CLEC4E) in triggering a series of negative intracellular signaling via Syk/CARD9 pathway for cytokines, as early as 24 h post-infection (hpi). This is the first report confirming induction of CLEC4E and the Syk/CARD9 pathway in PBMCs in response to M. bovis infection, and these findings support the view that M. bovis inhibits signaling pathways of antimycobacterial host defense in bovine cells. In addition, M. bovis infection in PBMCs may suppress apoptosis by interfering with TNF-a signaling. This study, contributes to a better understanding of M. frows-reduced signal transduction and microbial changesin PBMCs earlier than 24 hpi.