Enhancement of human T-lymphocyte growth by human transferrin in the presence of fetal bovine serum.
All dividing cells require transferrin as a growth factor. During in vitro culture of human lymphocytes, transferrin is usually supplied in the form of serum, either synergic or xenogenic (usually fetal bovine serum (FBS)). In the present work the growth of certain human T-cell lines was examined; these lines were derived from the synovium of rheumatoid arthritis patients and maintained in 10% FBS and 1% synovial fluid. Their growth especially at limiting dilutions was found to be strongly dependent on the presence of synovial fluid at low concentration (0.05-0.1%) in culture medium containing 10% FBS. Further studies indicated that this effect of synovial fluid was duplicated by human serum or plasma, and was due to the presence of human transferrin. A significant effect on T-cell growth was observed using 2 micrograms/ml human transferrin with optimal growth at 10-20 micrograms/ml. This requirement for human transferrin was not a peculiarity of the synovium-derived T-cell lines, but was observed with all T-cell lines tested irrespective of phenotype or function. These observations suggest that bovine transferrin is inadequate for T-cell growth, and that the growth enhancing properties of FBS do not primarily reflect the provision of transferrin. Since some T cells have recently been shown to be capable of secreting transferrin upon activation, endogenous synthesis of transferrin may be an important factor in the in vitro growth of T cells so that such cells would be selected when FBS is the source of serum used to grow human T-cell lines or clones.
D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis; D001769:Blood; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D003470:Culture Media; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D014168:Transferrin / Q000494:pharmacology*
D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D003470:Culture Media; D014168:Transferrin