SPECIFIC BINDING OF A SOLUBLE RECOMBINANT BETA-CHAIN T-CELL ANTIGEN RECEPTOR TO TOXIC SHOCK SYNDROME TOXIN-1, A SUPERANTIGEN

Toxic shock syndrome toxin-1 (TSST-1) is a bacterial superantigen that causes toxic shock in humans, probably by polyclonal activation of T- cells resulting from the cross linking of class II major histocompatab ility complex (MHC) molecules of antigen-presenting cells to the antig en receptors of T-cells (TCRs). The X-ray crystal structures of the co mplexes between superantigens and the human class II MHC molecule HLA- DR1 have revealed the molecular basis of the interaction between two p roteins. However, structural studies of the TCR:superantigen complex h ave been hampered primarily by the lack of sufficient amounts of homog eneous TCR protein. Here we report the preparation of large amounts of a soluble beta-chain TCR and its interaction with TSST-1. The beta-ch ain TCR was expressed in E. coli as inclusion bodies. The inclusion bo dy protein was refolded with an efficiency of 10-15% by a dialysis met hod in the presence of a reduced/oxidized glutathione redox buffer. Th e refolded beta-chain TCR binds specifically to TSST-1 with a binding interaction strong enough to be detected by native gel shift assay and to make it possible to purify the complex by gel-filtration chromatog raphy.