Specific antigen binding by proteins secreted by an antigen-specific T cell hybrid

Antigen-specific molecules secreted by a murine T cell hybrid specific for azobenzene arsonate (ABA) were purified from ascites fluid by ion exchange chromatography and affinity for antigen. The antigen-specific proteins were purified 250 fold and were resolved predominantly as Mr 110,000 polypeptides by reduction and SDS-polyacrylamide gel electrophoresis. The ability of these molecules to bind antigen was analyzed by an ELISA using antigen-coated microtiter trays. Binding of the T cell proteins to antigen was detected with antisera specific for the proteins. Antigen binding to ABA-ovalbumin but not ovalbumin was optimal at 37 degrees C and protein derived from another T cell hybrid did not bind ABA-ovalbumin. Solid phase antigen binding was inhibited specifically by soluble ABA-ovalbumin, indicating that these T cell-derived proteins bind nominal antigen in the solid or liquid phase. It is suggested that these proteins represent a soluble, antigen specific manifestation of some T cell function.