Cross-Linkage of Ly-6A/E Induces Ca(2+) Translocation in the Absence ofPhosphatidylinositol Turnover and Mediates Proliferation of Normal Murine B Lymphocytes

摘要

Ly-6A/E is a phosphatidylinositol (PI)-linked membrane protein whose expressionis induced or upregulated on normal murine T and B cells by cross-linkage of Ly-6A/E expressed on normal murine T cells which stimulates calcium translocation, and in the presence of a protein kinase C (PKC) activator, lymphokine secretion, and cellular proliferation. Utilizing an anti-Ly-6A/EmAb, we studied the effect of cross-linking Ly-6A/E on treated resting B cells, for Ca2+ translocation, PI turnover, and cellular proliferation. Since these events are known to be stimulated by cross-linkage of B cell membrane (m)Ig, we compared the changes mediated through these respective membrane proteins. We show that cross-linkage of B cell Ly-6A/E stimulates a large, rapid, and sustained increase in the concentration of intracellular free calcium comparable in magnitude, though somewhat delayed, relative to that observed after cross-linking of (m)Ig.