Effect of idiotype-specific suppressor T cells on primary and secondary responses

Previous reports have shown that suppression of idiotype can be adoptively transferred by T cells, or by rosettes containing T cells with anti-idiotypic receptors, from an idiotypically suppressed, syngeneic mouse. The present data indicate that secondary B cells are highly resistant to such suppression. Priming recipients to the relevant hapten, p-azophenylarsonate, 6 days or 4 mo before the adoptive transfer prevented suppression. This was independent of the carrier used for the hapten group during priming or subsequent immunization, suggesting that resistance to suppression is attributable to secondary cells with specificity for the hapten. The effect of suppressor T cells could also be overcome by mixing them with specifically purified B cells having receptors for the hapten group before the adoptive transfer. Adoptive transfer of the suppressed state by specifically purified B cells from suppressed, hyperimmunized animals confirmed our previous finding that the suppression of idiotype can also be caused by B cells lacking idiotypic receptors, evidently through a mechanism involving clonal dominance. Possible mechanisms of idiotypic suppression by T cells are discussed.