IL-6 inhibits IFN-γ induced autophagy in Mycobacterium tuberculosis H37Rv infected macrophages.

Dutta, Rajesh Kumar and Kathania, Mahesh and Raje, Manoj and Majumdar, Sekhar (2012) IL-6 inhibits IFN-γ induced autophagy in Mycobacterium tuberculosis H37Rv infected macrophages. The international journal of biochemistry & cell biology, 44 (6). pp. 942-54. ISSN 1878-5875

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Abstract

The significance of IL-6 production in tuberculosis is yet to be fully elucidated, although it is known for quite some time that IL-6 interferes with IFN-γ induced signal. In order to know which cellular process induced by IFN-γ is actually counteracted by IL-6, we studied the role of IL-6 on IFN-γ induced autophagy formation in virulent Mycobacterium tuberculosis infection in THP-1 cells, since it is well characterized that induction of autophagy by IFN-γ eliminates intracellular mycobacterium by overcoming the phagosome maturation block imposed by bacilli. We report here that IL-6 inhibits both IFN-γ and starvation induced autophagy in M. tuberculosis H37Rv infected cells. M. tuberculosis H37Rv infection results in time dependent production of IL-6 in THP-1 cells and neutralization of this endogenous IL-6 by anti-IL-6 antibody significantly enhances the IFN-γ mediated killing of the intracellular bacteria. IL-6 time dependently lowers Atg12-Atg5 complex and therefore inhibits autophagosome biogenesis rather than autophagolysosome formation. IL-6 also affects IFN-γ mediated stimulation of mTOR, p-38 and JNK pathways. These results clearly indicate that virulent mycobacteria strategically upregulate IL-6 production to combat innate immunity.

Item Type:	Article
Additional Information:	Copyright of this article belongs to Elsevier Science.
Uncontrolled Keywords:	Autophagy; IFN-γ; IL-6; Mycobacteria
Subjects:	Q Science > QR Microbiology
Depositing User:	Dr. K.P.S.Sengar
Date Deposited:	28 Jan 2013 07:00
Last Modified:	28 Jan 2013 07:00
URI:	http://crdd.osdd.net/open/id/eprint/1259

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