T lymphocyte-mediated suppression of myeloma function in vitro. IV. Generation of effector suppressor cells specific for myeloma idiotypes.

BALB/c mice immunized intravenously with syngeneic splenocytes, to which affinity-purified IgA produced by the MOPC 315 myeloma is covalently coupled, develop suppressor T cells (Ts1) that inhibit IgA secretion by MOPC 315 cells after 3-4 d of co-culture. Immunization with M315-coupled splenocytes subcutaneously, followed by administration of a soluble extract of Ts1 cells, leads to the generation of effector Ts that are also idiotype specific and inhibit myeloma function within 1 d. Moreover, effector Ts are Lyt-1-2+, whereas Ts1 are either Lyt-1+2+ or require Lyt-1+ and Lyt-2+ cells to mature into effector Ts in vitro. Such a protocol should be useful for analyzing the interactions that result in the maturation of Ts and in defining the mechanisms of action of Ts, whose effect can be measured on a homogeneous target population and that are specific for a well-characterized myeloma idiotype.