Figure 2.

P2X₇-stimulated shedding of CD62L by lymphocytes. To enable the direct comparison of responses of cells from New Zealand Black (NZB) mice, New Zealand White (NZW) mice and (NZB × NZW)F₁ (NZB/W) mice in a single tube, lymphocytes from these strains were stained with anti-CD4^PE, anti-CD4^CYCHROME and anti-CD4^APC, respectively, mixed and stained with anti-CD62L^FITC. Thus labelled, cells could subsequently be distinguished by flow cytometric gating. Cells were stimulated with the P2X₇ agonist 2'-3'-O-(4-benzoylbenzoyl)-adenosine 5'-triphosphate (BzATP) at the time indicated by the arrow in (a). (a) Density plots of the rate of CD62L shedding in each cell population, as indicated by decreased binding of anti-CD62L^FITC. (b) Corresponding levels of cell surface CD62L in each population (NZB, red line; NZW, green line; NZB/W, black line) immediately preceding P2X₇ stimulation (indicated by left-hand gates in (a)) or 7 min after P2X₇ stimulation (indicated by right-hand gates in (a)). (c) Effect of a broad inhibitor of metalloproteinases on loss of CD62L. Lymphocytes from NZW mice were stained with anti-CD4^CYCHROME and anti-CD62L^PE, and the rate of loss of CD62L was assessed by flow cytometry. Cells were stimulated with BzATP in the presence or absence of 10 μM metalloproteinase inhibitor at the time indicated by an arrow. Shedding of CD62L is indicated by decreased binding of anti-CD62L^PE. MMP, matrix metallopoteinase.