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Isolation and Chemical Characterization of Lipid A from Gram-negative Bacteria
12:57

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Published on: September 17, 2013

Bacterial lipopolysaccharide induced B cell activation is mediated via a phosphatidylinositol 3-kinase dependent

C Venkataraman1, G Shankar, G Sen

  • 1Department of Microbiology and Immunology, Sanders-Brown Research Center on Aging, University of Kentucky, Lexington 40536, USA.

Immunology Letters
|September 11, 1999
PubMed

Bacterial lipopolysaccharide (LPS) is a potent stimulant of B cells and macrophages. LPS induces B cell proliferation and differentiation into antibody secreting cells. In addition, LPS also stimulates IL-6 secretion in mature B cells and in immature B cell lines such as WEHI-231. Although sufficient literature is available on LPS induced signaling events in monocytes and macrophages, the mechanisms involved in LPS induced B cell activation are not well understood. In this report, it is shown that both LPS mediated B cell proliferation and IL-6 secretion are dependent on phosphatidylinositol 3-kinase (PI 3-kinase) signaling pathways. The B cell specific co-receptor, CD19 is not tyrosine phosphorylated in LPS stimulated B cells. Thus, in contrast to B cell antigen receptor (BCR) signaling, the activation of PI 3-kinase appears not to be related to the recruitment of PI 3-kinase to tyrosine phosphorylated CD19. This is the first demonstration of the importance of PI 3-kinase signaling pathway in LPS mediated B lymphocyte activation.

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