E-selectin is a viable route of infection for polymer-coated adenovirus retargeting in TNF-α-activated human umbilical vein endothelial cells

Background: E-selectin is an attractive endothelial cell surface marker in inflammation and cancer. Purpose: We sought to investigate retargeting of adenovirus via E-selectin as a viable pathway of infection in tumor necrosis factor-a (TNF-alpha)-activated human umbilical vein endothelial cells (HUVECs). Methods: E1, E3-deleted Ad5 expressing cytomegalovirus immediate-early (CMV IE) promoter-driven luciferase (Adluc) was coated with an amino-reactive multivalent hydrophilic polymer based on poly [N-(2-hydroxypropyl) methacrylamide] to generate pHPMA-adenovirus (pcAdluc). This was then retargeted by covalent attachment of a mouse antihuman E-selectin monoclonal antibody (MHES mAb), purified from the H18/7 hybridoma cell line (MHESpcAdluc). Results: MHESpcAdluc was efficiently taken up into HUVECs, generating a high level of transduction in TNF-alpha-treated E-selectin positive cells but not in untreated receptor-negative cells. Specific retargeting of MHESpcAdluc was demonstrated through reduced transduction of stimulated HUVEC when incubated in the presence of free E-selectin antibodies. Discussion and conclusion: Our results suggest that E-selectin could be a valuable target for gene transfer strategies internalizing polymer-coated modified adenovirus particles through a viable receptor-mediated endocytosis pathway, generating adequate levels of transgene expression per virus genome copy without compromising the specific activity of the parental virus.