Antigen-binding T and B lymphocytes in sensitization and unresponsiveness to dinitrochlorobenzene (DNCB) contact sensitivity.

The frequency of DNP-binding T and B lymphocytes was studied in various states of sensitization and unresponsiveness to DNCB contact sensitivity. In guinea-pigs, where unresponsiveness to DNCB had been established with DNBSO by pretreatment or during the primary response, no increase in antigen-binding cell frequency was found after antigenic stimulation. On the contrary, DNCB-sensitive guinea-pigs, later desensitized with DNBSO, showed the same frequency of antigen-binding cells as sensitized animals, although they were unable to react to DNCB. These results confirm and extend the idea of a different mechanism for tolerance' and desensitization' to contact sensitivity.