Mycobacterium bovis BCG induces high mobility group box 1 protein release from monocytic cells. 
High mobility group box 1 protein (HMGB-1), a nuclear protein is a critical cytokine that mediates the response to infection, injury and inflammation.  The aim of our study was to elaborate a reliable in vitro model to investigate whether Mycobacterium bovis BCG is able to induce HMGB-1 secretion from the monocytic U-937 cells.  Western blot technique was applied for the detection of HMGB-1 from supernatants of cells, following induction with LPS, Staphylococcus aureus, and Mycobacterium bovis BCG.  HMGB-1 was subjected to MALDI-TOF mass and PSD analysis.  Quantitation of the secreted HMGB-1 was performed by ELISA.  The BCG strain induced higher amounts of secreted HMGB-1 than LPS or Staphylococcus aureus.  The translocation of the HMGB-1 to the cytoplasm following infection of cells with BCG was demonstrated by immunofluorescence examinations.  Our pilot experiments draw attention the to HMGB-1-inducing ability of Mycobacterium bovis.  Assessment of the pathophysiological role of this late cytokine in mycobacterial infections demands further in vitro and in vivo examinations.