Altered signal transduction secondary to surface IgM cross-linking on B-chronic lymphocytic leukemia cells. Differential activation of the phosphatidylinositol-specific phospholipase C.

摘要: To further study the mechanisms by which surface Ig triggering activates inositol phospholipid signaling pathway, we have used B cells from chronic lymphocytic leukemia patients which, as previously described, display two patterns of response upon sIg cross-linking: in one group this cross-linking induces an phosphate release, intracellular free Ca2+ concentration elevation and a subsequent cell proliferation; second none these events occur although there is increased class II Ag expression following anti-mu stimulation first group. We been able to demonstrate that phosphatidyl specific phospholipase C (PI-PLC) can be activated permeabilized direct stimulation, with GPT gamma S, guanine nucleotide binding (G) protein. In addition, since + GTP S stimulate production cells, suggests PI-PLC via G However, no released after directly high concentrations. This reflects interruption cascade sIg/G protein/PI-PLC at level protein or coupling. both groups PMA treatment, known alter metabolism completely inhibits activation even These studies show inositol-dependent altered different levels cells.