Establishment of cell lines from adult T-cell leukemia cells dependent on negatively charged polymers

Growing adult T-cell leukemia/lymphoma (ATLL) cells in vitro is difficult. Here, we examined the effects of static electricity in the culture medium on the proliferation of ATLL cells. Six out of 10 ATLL cells did not proliferate in vitro and thus had to be cultured in a medium containing negatively charged polymers. In the presence of poly-γ-glutamic acid (PGA) or chondroitin sulfate (CDR), cell lines (HKOX3-PGA, HKOX3-CDR) were established from the same single ATLL case using interleukin (IL)-2, IL-4, and feeder cells expressing OX40L (OX40L⁺HK). Dextran sulfate inhibited growth in both HKOX3 cell lines. Both PGA and OX40L⁺HK were indispensable for HKOX3-PGA growth, but HKOX3-CDR could proliferate in the presence of CDR or OX40L⁺HK alone. Thus, the specific action of each negatively charged polymer promoted the growth of specific ATLL cells in vitro.