Inhibition of TNF-alpha-induced Cyclooxygenase-2 Expression by Mycobacterium bovis BCG in Human Alveolar Epithelial A549 Cells

Bansal, K and Narayana, Y and Balaji, KN (2008) Inhibition of TNF-alpha-induced Cyclooxygenase-2 Expression by Mycobacterium bovis BCG in Human Alveolar Epithelial A549 Cells. In: Scandinavian Journal of Immunology, 69 (1). pp. 11-19.

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Abstract

Cyclooxygenase-2 (COX-2) is implicated in pathophysiological processes associated with the initiation or maintenance of host inflammatory responses to infection. Our results demonstrates that Mycobacterium bovis BCG (M. bovis BCG) downregulates tumour necrosis factor-alpha (TNF-alpha)-induced COX-2 gene expression in alveolar epithelial cells by inhibiting the phosphorylations of Raf-1 and p38 kinases. Further, M. bovis BCG-mediated inhibition of COX-2 or p38 mitogen-activated protein kinase could be reversed by Calyculin A, a selective inhibitor of Ser/Thr phosphatases. Moreover, M. bovis BCG inhibited the TNF-alpha-triggered NF-kappaB activation following IkappaB degradation. Taken together, these results suggest that the attenuation of COX-2 expression by vaccine strain, M. bovis BCG, represents a novel strategy to maintain robust host proinflammatory responses to subsequent challenges with virulent tuberculosis bacilli.

Item Type:	Journal Article
Publication:	Scandinavian Journal of Immunology
Publisher:	Blackwell Publishing
Additional Information:	Copyright of this article belongs to Blackwell Publishing.
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	14 Sep 2009 11:28
Last Modified:	19 Sep 2010 05:00
URI:	http://eprints.iisc.ac.in/id/eprint/18164

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