Supportive Effects of Human Embryonic Fibroblast Cell Lines on Growth and Proliferation of EBV-Transformed Lymphoblastoid Cells

Human diploid fibroblast cells produce a spectrum of necessary growth factors and extracellular matrix (ECM) components essential for growth and proliferation of a variety of other cell types. In this study, the effect of five human embryonic fibroblast cell lines, isolated from liver, lung, skin and foreskin tissues, was investigated. A coculture system analyse was employed to cloning efficiency (CE) and DNA synthesis of a human Epstein-Barr virus (EBV)-transformed lymphoblastoid cell line (LCL) in long- and short-term cultures. The fibroblast cells were used as feeder layer after treatment with mitomycin C. Optimal density of the feeder cells induced 10 to 43 times higher CE than cultures supplemented with conditioned media (CM) or cultures without a feeder layer. The stimulatory effect of the feeder cells was partly associated to their tissue origin, with the lung and liver fibroblasts being the most and least effective feeder cells, respectively. Short-term cultures of LCL cells with feeder cells or their CM resulted in a marginal increase in DNA synthesis and proliferation as evidenced by the index of ³H-thymidine incorporation. Our results demonstrated supportive effects of feeder cells on the LCL growth, which can not be replaced by their CM. These supportive effects were partly associated with cell density and tissue origin of the feeder cells