Polyethyleneimine-based immunopolyplex for targeted gene transfer in human lymphoma cell lines.

Background: Specific and efficient delivery of genes into targeted cells is a priority objective in non-viral gene therapy. Polyethyleneimine-based polyplexes have been reported to be good non-viral transfection reagents. However, polyplex-mediated DNA delivery occurs through a non-specific mechanism. This article reports the construction of an immunopolyplex, a targeted non-viral vector based on a polyplex backbone, and its application in gene transfer over human lymphoma cell lines.

Methods: Targeting elements (biotin-labeled antibodies), which should recognize a specific element of the target cell membrane and promote nucleic acid entry into the cell, were attached to the polyplex backbone through a bridge protein (streptavidin). Immunopolyplex transfection activity was studied in several hematological cell lines [Jurkat (CD3+/CD19-), Granta 519 (CD3-/ CD19+), and J.RT3-T3.5 (CD3-/CD19-)] using the EGFP gene as a reporter gene and anti-CD3 and anti-CD19 antibodies as targeting elements. Transfection activity was evaluated via green fluorescence per cell and the percentage of positive cells determined by flow cytometry.

Results: A significant selectivity of gene delivery was observed, since the anti-CD3 immunopolyplex worked only in Jurkat cells while the anti-CD19 immunopolyplex worked only in the Granta cell line. Moreover, transfection of a CD3+/CD3- cell mixture with anti-CD3 immunopolyplexes showed up to 16-fold more transfection in CD3+ than in CD3- cells. Several non-specific transfection reagents showed poor or no transfection activity.

Conclusion: It is concluded that immunopolyplex is a good non-viral vector for specific and selective nucleic acid delivery. Immunopolyplex design allows easy replacement of the targeting element (antibody) - the streptavidin-polyplex backbone remaining intact - thereby conferring high versatility.