Specific Inhibition of Contact Dermatitis to Dinitrochlorobenzene in Guinea Pigs by Injection of Haptens and Protein Conjugates

Abstract
Guinea-pigs sensitized to dinitrochlorobenzene (DNCB) by epicutaneous application or intradermal injection were injected intravenously with DNCB, dinitrobenzene sulfonate (DNBSO3), dinitrophenyl (DNP)-amino acid haptens and DNP-protein conjugates. Specific but only partial and termporary inhibition of the contact reaction to DNCB was obtained with DNCB, DNP-S-cysteine, DNP-S-glutathione, DNP-guinea-pig serum and DNP-bovine gamma-globulin. Complete inhibition was achieved with DNBSO3, whereas [epsilon]-DNP-lysine did not have any inhibitory effect. According to the dose injected or the hypersensitivity level of the animals, a flare-up of older test sites and/or a specific generalized dermatitis could be elicited by intravenous injection of DNBSO3. These findings provide some basis for speculations about the nature of the antigen (s) responsible for contact hypersensitivity, the inhomo-geneous specificities of the hypersensitive cells (or antibodies) involved and the mechanism of the contact reaction itself.