Improvement of K562 Cell Line Transduction by FBS Mediated Attachment to the Cell Culture Plate

Lentiviral vectors have been used for gene therapy in the clinical phase in recent years. These vectors provide a tool for gene insertion, deletion, or modification in organisms. The K562 human cell line has been used extensively in hematopoietic research. Despite its broad application, it is hard-to-transfection and transduction. So, this study presents a simple method to increase the transduction efficiency of K562 cells with a low multiplicity of infection (MOI) of the virus particle. For this purpose, 24-well plate was coated by 300 μl fetal bovine serum (FBS) before seeding. Then 2×10(4) K562 cells were seeded in each FBS coated plate. After 24h, K562 cells were attached and doubled. Different amount of lentivirus-based GFP vector according to MOI (5, 10, 15, and 20) along with 8 μg polybrene was added to the attached K562 cells and after 6h cells and viral particle complex were spinfected. Then cells were returned to the plate and incubated in 37°C overnight. After 48h transduction efficiency was established by measuring the GFP-expressing cells by flow cytometry. Flow cytometry analysis showed that, after plate treatment by FBS, 64.5% transduction rate in K562 cells was achieved at MOI=20. Therefore, this method can be an effective and simple way to increase the lentiviral transduction rate for suspended cells such as K562.