Figure 6.
Development of a NAEK-containing lentiviral vector as a vehicle for the selective delivery of nucleic acid macromolecules into cells with high expression of integrins. (A) Expression of integrin αvβ3 in MDA-MB-435S vs. MCF-7 cells as detected by flow cytometry. The trypsinized cells, after sequential blocking by 10% BSA and washing, were incubated with monoclonal integrin αvβ3 antibody (red line) and an isotype control IgG antibody (green line) overnight in parallel and then incubated with Alexa 488 labeled secondary antibody for 1 h. After washing three times with PBST, the treated cells were analyzed by Guava EasyCyte Plus. The level of integrin αvβ3 expression on the cell surface of MDA-MB-435S cells is almost 3-fold higher than that on MCF-7 cells according to flow cytometry. (B) Characterization of the enhanced infectivity of NAEK-containing lentiviral vectors (Vector) and vectors upon conjugation with RGD (Vector-RGD) or RAD (Vector-RAD) at different sites towards MDA-MB-435S cells. The significance was confirmed by one-way ANOVA test (*P < 0.05, **P < 0.01, ***P < 0.001). (C) Characterization of the infectivity of the NAEK-containing vector and the RGD- or RAD-conjugated lentiviral vectors in MCF-7 cells. All quantitative data shown are average values with standard deviations from triplicate experiments.