Feedback control of the secondary antibody response. I. A suppressor, suppressor-inducer mechanism from the interaction of B-memory cells with Lyt 2- T cells.

The cellular elements of an antigen-specific suppressor system for secondary antibody responses have been identified, using positive cell-selection techniques in the fluorescence-activated cell sorter. In a double-adoptive transfer of memory cells for a thymus-dependent antigen, from one irradiated recipient to another, antigen-specific suppressor T cells are recruited after a critical time in the primary recipient. It is also a source of B cells that are able to induce further suppressors in carrier-primed, but otherwise naive donors. There are two distinct routes, therefore, for the generation of suppressor T cells: primary induction by adoptive transfer with antigen, or secondary induction by B cells recruited in the primary irradiated host. We have shown that both primary and secondary suppressors are recruited from a Lyt 2- memory population, although the Lyt 2 alloantigen is expressed at the effector stage.