Figure 1.

Shedding mechanism of Pecam-1 and its status in adaptive immunity. (A) The immunologically reactive molecule Pecam-1 is shed from the T-cell surface upon activation of immune cells. (B) Availability of Pecam-1 is restricted to early phases of T-cell development. Upon antigen presentation by an antigen presenting cell (APC), sPecam-1 is shed from the T-cell’s surface. The molecule’s decreasing quantity on the cell surface is illustrated by the yellow curve progression. Concomitantly but inversely, the expression of pro-inflammatory cytokines by the T-cells in various differentiation stages are rising as illustrated by the pale red curve progression. P: potential phosphorylation site, APC: antigen presenting cell, TN: naïve T-cell, TREG: regulatory T-cell, TSCN: stem central memory T-cell, TCM: central memory T-cell, TEM: effector memory T-cell, TEFF: effector T-cell, TEMRA: terminally differentiated effector memory RA T-cell.