Patent ID: 7517647

Claim:
A method of screening for a protein involved in the extracellular regulation of latent TGF-β activation by: transducing a cell line comprising a TGF-β responsive promoter operatively linked to a gene encoding a green fluorescent protein with a retroviral cDNA library and enriching the reporter cell line for green fluorescent protein (GFP) in response to TGF-β signaling, wherein the reporter cell line secretes endogenous latent TGF-β such that, upon acquisition of a latent TGF-β activator, GFP expression is induced, and wherein the TGF-β promoter is 3TP/PAI-I; growing individual clones created by the reporter cell line; co-culturing each individual clone with a second TGF-β reporter cell line comprising a TGF-β responsive promoter operatively linked to luciferase cDNA that produces luciferase in response to TGF-β, wherein the luciferase production identifies positive clones, and wherein the TGF-β promoter is 3TP/PAI-I; and identifying a protein involved in the extracellular regulation of latent TGF-β that is employed by the positive clones.