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.
|Number of pages||6|
|State||Published - Aug 3 1999|
Bibliographical noteFunding Information:
We thank Dr Ralph Chelvarajan for critical review of the manuscript and Mr Darrell Robertson for his technical assistance. This work was supported by Grants AI 21490 and AI 05731 to S.B. from the National Institutes of Health.
- B lymphocytes
- PI 3-kinase
ASJC Scopus subject areas
- Immunology and Allergy