Inactivated M. tuberculosis and M.tuberculosis Infection remodels the macrophage response

Background: Tuberculosis (TB) remains a major public health problem, especially in developing countries, with 1.5 million deaths annually worldwide. Macrophages (Mfs) are central to TB pathogenesis. Mfs play a key role in the outcome of the infection. More importantly, Mfs are the primary cell target of MTB, which has developed different strategies to multiply inside the Mf phagosome. Here we aim to compare the transcriptome of Mycobacterium tuberculosis (MTB)-infected Mfs with that of cells stimulated with heat-killed MTB. Results: Here, we used live and heat-inactivated MTB to examine the impact of infection on the human macrophage response. Gene expression profiling has revealed about 3,259 genes differentially expressed in macrophages incubated with heat-inactivated MTB and 4,179 genes differentially expressed with live MTB. We found that the response to live and heat-inactivated MTB was strongly correlated (r>0.78). Conclusions: Our results show that macrophages respond in a similar manner to live and heat-inactivated MTB. We also identified some genes differentially expressed only in one condition. Overall design: Evaluation of host response to live MTB and heat-inactivated MTB in human macrophages.