A NOVEL, SENSITIVE BIOASSAY FOR TRANSFORMING GROWTH-FACTOR-BETA

We have developed a simple, sensitive bioassay for transforming growth factors beta1 and beta2 (TGF-beta1 and TGF-beta2) based on the abilit y of these cytokines to inhibit the interleukin-5 induced proliferatio n of the erythroleukaemia cell line, TF-1. This assay is rapid, reprod ucible and sensitive to less than 500 fg/ml of TGF-beta1, and 5-10 pg/ ml TGF-beta2. The assay is 100-1000-fold less sensitive to other inhib itory molecules such as interferon-beta, interferon-gamma and TNF-alph a. The assay can be made specific for TGF-beta1 or TGF-beta2 by includ ing specific neutralising antibodies for TGF-beta1 or TGF-beta2. The a ssay can recognise all the readily available recombinant molecular spe cies of these molecules as well as the natural proteins produced from human and bovine platelets and detects TGF-beta in serum samples.