A solubilized T-cell receptor from a human leukemia cell line binds to a ligand in the absence of MHC products

A human T cell antigen receptor from the acute lymphoblastoid leukemia line HPB-ALL (also called HPB-MLT) binds and is precipitated in detergent solubilized form by an antigen present on the surface and secreted by several strains of the gram-positive bacterium Staphylococcus aureus. This binding is completely independent of major histocompatibility complex (MHC) antigens. Receptor/ligand binding is unique to this one cell line (i. e., clonotypic) and furthermore completely blocked by an idiotype-specific monoclonal antibody (mAb) to this receptor, but not by three different nonidiotype-specific mAbs. The nature of this interaction appears more similar to immunoglobulin/antigen binding than to T-cell receptor/antigen/MHC/accessory molecule interactions and would suggest that some T-cell receptors may not require MHC products to interact with antigen.