Suppressor cells in tolerance to contact sensitivity active against hapten-syngeneic and hapten-allogeneic determinants*

Genetic restrictions in generation and expression of hapten-specific suppressor cells for contact sensitivity were found. Dinitrophenol-(DNP) or trinitrophenol-modified mouse spleen cells (SC) induced suppressors in donors able to transfer suppression to normal recipients. When allogeneic DNP-SC were injected into BALB/c mice, cells were generated which were suppressive only in the allogeneic strain providing the DNP-SC. In contrast, when DNP-BALB/c-SC were injected into BALB/c mice, suppressors were generated which were active both in BALB/c and in allogeneic mice (e.g., CBA). This apparent absence of syngeneic major histocompatibility complex restriction may be explained by cross reactive T-cell receptors which are V_H gene products.