Safe way to manipulate immune cells developed

A team led by scientists at the A*STAR Bioprocessing Technology Institute and the A*STAR Institute of High Performance Computing has now developed a non-viral strategy to deliver DNA into this intractable cell type. By optimizing a technique termed sonoporation, the researchers managed to introduce genes into B cells with high rates of success1.

"Our work is the first to demonstrate the use of sonoporation as an alternative, non-viral method for stable and highly efficient transfection of recalcitrant B cell lines," says biomedical engineer and study leader Andre Boon-Hwa Choo.

Sonoporation combines ultrasonic sound frequencies and tiny gas-filled bubbles to generate transient pores in the cell membrane through which DNA can travel. Choo and his colleagues tweaked the acoustic energy levels and microbubble concentrations to deliver a circular piece of DNA that they could track visually in a trio of human B cell lines.

In one cell line, for example, the researchers achieved around 43 per cent transfection efficiency through sonoporation, compared to just 3 per cent with a conventional transfection method called lipofection (see image). Through further selection techniques, the researchers enriched the population of transfected B cells to more than 70 per cent. They achieved similarly impressive results with the two other B cell lines.

According to Charlene Li Ling Yong, co-first-author of the study along with Dave Siak-Wei Ow, the sonoporation-based transfection technique can now be used in the laboratory to better understand how B cells regulate immune responses against pathogens. "It allows scientists to elucidate the biological pathways of immune responses," says Yong.

Numerous clinical research teams are also pursuing B-cell-based gene therapies to induce tolerance against autoimmune diseases. The method described in the current study could come in particularly handy for treatments in the human body -- without any of the adverse effects of viral-mediated gene therapy. "Sonoporation has the potential to be applied in vivo," Ow says. "It offers a safer and noninvasive alternative to existing gene therapies."