[Biochemical and immunological characterization of a suppressor factor specific for the terpolymer GAT]

It has been possible to extract a suppressor factor specific for antigen from non-responder animals that have developed suppressor cells. This factor shows a high affinity for the antigen and cross-reacts with related antigens. It does not carry antigenic determinants of the constant region of immunoglobulin molecules but carries Ia determinants and has an affinity for the GAT comparable to the affinity of the anti-GAT antibodies.