I-J restriction of T cells that suppress in vivo antibody responses to Thy-1.

The contact-sensitizing haptens dinitrophenyl (DNP) and oxazalone (Ox) act as helper determinants for antibody responses to Thy-1 when conjugated to donor thymus cells. The helper effect is transferrable from primed to naive mice with spleen cells, producing specific augmentation of in vivo PFC responses to Thy-1. The helper cells are hapten-specific and require associative recognition of hapten and Thy-1, excluding a role for nonspecific B cell activation. The phenotype of the helper cells is Thy-1+ and Lyt-1+2-. Antigen-specific suppression could be readily generated by using an inoculum of DNP-modified syngeneic RBC. T cells from these suppressed donors (Ts) were shown to abolish the helper effects of TH in adoptive transfer experiments in vivo. These Ts were characterized as Thy-1+ and Lyt-1-2+. A requirement for MHC compatibility at the I-J subregion was necessary between the Ts and the recipient to obtain a transfer of suppression.