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

Sialyl Lewis X (SLex), 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 SLex-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 SLex-CMPul by the spleen was completely inhibited by a 100-fold molar of cold SLex-CMPul but not by a sialyl N-acetyllactosamine-CMPul conjugate (SLN-CMPul). Microautoradiography analyses revealed that SLex-CMPul accumulated in the marginal zone of the spleen.