Mitogen-Activated Protein Kinases Mediate the Production of B-Cell Lymphoma 2 Protein by Mycobacterium tuberculosis in Monocytes

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P. L. Natarajan^# and Sujatha Narayanan^#*

Department of Immunology, Tuberculosis Research Centre, Chennai, India; fax: +91-044-2836-2528; E-mail: sujatha.sujatha36@gmail.com

^# The authors contributed equally to this work.

^* To whom correspondence should be addressed.

Received November 12, 2010; Revision received January 28, 2011

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Changes in the levels of antiapoptotic protein B-cell lymphoma 2 (Bcl-2) protein has been reported in murine and human tuberculosis. We investigated the role of mitogen-activated protein kinase pathways in the production of Bcl-2 protein in THP-1 human monocytes infected with Mycobacterium tuberculosis H37Rv and H37Ra. Analysis of phosphorylation profiles of mitogen-activated protein kinase kinase-1, extracellular-signal regulated kinase 1/2, mitogen-activated protein kinase kinase 3/6, and p38 mitogen-activated protein kinase; B-cell lymphoma 2 kinetics; and tumor necrosis factor-α (TNF-α) secretion levels showed variation between the two strains. Mycobacterium tuberculosis H37Rv induced higher Bcl-2 and lower TNF-α levels, whereas H37Ra the reverse. The strains also differed in their usage of CD14 and human leukocyte antigen-DR receptors in mediating extracellular-signal regulated kinase 1/2 and p38 mitogen-activated protein kinase activation. Mycobacterium tuberculosis H37Rv- and H37Ra-induced Bcl-2 production was reduced by specific inhibitors of mitogen-activated protein kinase kinase-1 (PD98059) and p38 (SB203580), but increased by nuclear factor κB (NF-κB) inhibitor (BAY 11-7082). TNF-α production by both strains was reduced in the presence of specific inhibitors of mitogen-activated protein kinase kinase-1 (PD98059), p38 (SB203580), and NF-κB (BAY 11-7082). Furthermore, inhibition of NF-κB was accompanied by an increase in strain-induced extracellular-signal regulated kinase 1/2 phosphorylation. Collectively, these results indicate for the first time that the production of Bcl-2 and TNF-α by M. tuberculosis H37Rv/H37Ra-infected THP-1 human monocytes is mediated through mitogen-activated protein kinases and NF­­-κB.

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KEY WORDS: M. tuberculosis, ERK, p38 MAPK, Bcl-2 production, NF-κB

DOI: 10.1134/S0006297911080104

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