Abstract:Objective To elucidate if IL-8-induced L-selectin shedding is associated with the changes in microtopology and stiffness of cell membrane, which in turn regulates the kinetics of L-selectin binding to its ligands. Method Intact Jurkat cells constitutively expressing L-selectin (Case I) were incubated by IL-8 (Case II), pre-incubated by TAPI-0 following by incubating with IL-8 (Case III), or treated by TAPI-0 alone (Case IV). The microtopology and stiffness of cell membrane were measured using electron scanning microscopy and micropipette aspiration assay, respectively. Results The presentation of microvilli on the surface was reduced and cell membrane became smooth in Cases II and III but not in Case IV, as compared to that in Case I. No significant difference in membrane stiffness was found for all four cases. Conclusion Surface microtopology of a Jurkat cell was modified by IL-8 treatment, which would affect the binding kinetics of L-selectin to its ligands, whereas membrane stiffness retained the same as that for an intact cell, which would not contribute to the kinetics.