Figure 4. TNF-α production of A) human THP-1 cells and of B) human monocyte-derived macrophages (MDM) in response to the M. tuberculosis strain of the index case (9729/07) and the laboratory strain H37Rv.

PMA-differentiated human THP-1 cells and MDM were incubated with indicated multiplicities of infection (MOI) of viable M. tuberculosis. Supernatants were harvested 24 h after infection and TNF levels were determined by ELISA. Data from one representative experiment of three are shown (LPS: lipopolysacharide; ctrl.: medium control, n.d.: not detectable).