Generation of monoclonal antibodies against soluble human T cell receptor polypeptides

Abstract

One approach to the diagnosis and therapy of T cell-mediated diseases is to develop reagents specific for T cell receptor (TcR) variable (V) regions. To date, however, TcR expressed on the surface of antigen-specific T lymphocytes have proven to be poorly immunogenic. As a result, few monoclonal antibodies (mAb) recognizing human variable regions are available. In this report, we have used the “phosphatidylinositol linkage” strategy to generate soluble forms of two human allogeneic TcR derived from human cytotoxic T lymphocytes (CTL) known to be specific for HLA-A2 and HLA-Aw68/HLA-Aw69, respectively. Monomeric TcR α and ß chains from the HLA-A2-specific CTL were purified in large quantities from CHO cells and each was used to immunize mice to generate mAb. In particular, the anti-β chain mAb, denoted anti-V_β13, stain a significant (≈ 5%) fraction of human peripheral blood α/β T lymphocytes, immunoprecipitate native anti-A2 TcR molecules, and activate T cells transfected with the relevant α and β chain cDNA. Anti-α chain mAb were also obtained against a constant region determinant which can immunoprecipitate detergent-solubilized polypeptides. In general, we find that immunizations with soluble protein are far superior to those with cells bearing TcR chimeras or in combination with the purified protein.