Abstract

Cell-based
assays are a
valuable tool to predict in vivo effects of drug candidates during early
steps of development.Cell-based assays are performed using either cell
lines or primary cells.Most cell lines are easy to handle and
offer the advantage of infinite proliferation, allowing the generation
of large cell banks and a facilitated use in screenings or long-term
experiments. However, due to their transformed phenotype, many cell lines
often exhibit a reduced physiological relevance. In contrast, primary
cells are more representative of the in vivo state when
compared to cell lines. However, their use in vitro is hampered by limited
tissue availability, scarce cell yields and a restriction or even lack
of proliferation. Taken together, these factors may significantly
compromise the scope, length and reproducibility of experiments and often
circumvent their use for extended cell-based screenings.

Here, we
describe the controlled expansion of human primary cells by lentiviral
transduction with proliferation-inducing genes, enabling production
volumes of up to 2500 vials containing 5∙10⁶ cells each. As a
proof of principle, primary cells from several relevant target tissues (liver,
skin, muscle) were transduced, subsequently demonstrating successful expansion
to large cell banks including tissue specific characterization.