Effect of the Sialyl Lewis X (SLe^x) Moiety on Splenic Accumulation of SLe^x-Carboxymethylpullulan Conjugate

Abstract

Sialyl Lewis X (SLe^x), an E-selectin ligand, was conjugated with carboxymethylpullulan (CMPul) and the disposition characteristics of this conjugate after intravenous administration were investigated using. mice with ear edema. The concentration of ³H-labeled SLe^x-CMPul in the spleen was significantly high. When CMPul was modified with a saccharide unable to bind to E-selectin, this splenic accumulation was not observed. The uptake of radiolabeled SLe^x-CMPul by the spleen was completely inhibited by a 100-fold molar of cold SLe^x-CMPul but not by a sialyl N-acetyllactosamine-CMPul conjugate (SLN-CMPul). Microautoradiography analyses revealed that SLe^x-CMPul accumulated in the marginal zone of the spleen.