Synthetic peptide-generated monoclonal antibodies to transforming growth factor-beta 1

Using a synthetic peptide with the amino acid sequence corresponding to residues 78-109 of human TGF-beta 1 (A78/109 peptide) as an immunogen, we generated and characterized monoclonal antibodies (Mabs) against transforming growth factor-beta 1 (TGF-beta 1). Spleen cells from a mouse immunized with carrier-free A78/109 peptide were fused with a myeloma cell line, P3U1. Two hybridoma cell lines were selected with A78/109 peptide used as the antigen, and the Mabs were designated as 3H10 and 4C10. Mab 4C10 recognized TGF-beta 1 only in immunoblotting analysis, but not in ELISA. In contrast, Mab 3H10 recognized it in not only ELISA but also immunoblotting analysis. Neither Mab was capable of recognizing both porcine TGF-beta 2 and chicken TGF-beta 3, and, therefore, both Mabs were TGF-beta 1 specific. From the results of epitope-mapping analysis, both Mab 3H10 and Mab 4C10 recognized the 78-87 portion of TGF-beta 1. The epitope recognized by Mab 4C10 was mapped specifically to amino acids 85-87. These results suggest that the region within 78-87 is exposed in the dimeric TGF-beta 1 and is one of the antigenic determinants in this molecule.