Effect of the sialyl Lewis X (SLe(x)) moiety on splenic accumulation of SLe(x)-carboxymethylpullulan conjugate

Sialyl Lewis X (SLe(x)), an E-selectin ligand, was conjugated with carboxym ethylpullulan (CMPul) and the disposition characteristics of this conjugate after intravenous administration were investigated using mice with ear ede ma. The concentration of H-3-labeled SLe(x)-CMPul in the spleen was signifi cantly high. When CMPul was modified with a saccharide unable to bind to E- selectin, this splenic accumulation was not observed. The uptake of radiola beled SLe(x)-CMPul by the spleen was completely inhibited by a 100-fold mol ar of cold SLe(x)-CMPul but not by a sialyl N-acetyllactosamine-CMPul conju gate (SLN-CMPul). Microautoradiography analyses revealed that SLe(x)-CMPul accumulated in the marginal zone of the spleen.