[Genetic control of contact hypersensitivity in guinea pigs]

Guinea pigs sensitized intradermally with haptenized macrophages exhibit a positive skin reaction to an epicutaneous challenge with the specific hapten only when syngenic macrophages were used. Skin reactions to the hapten were in guinea pigs treated with haptenized allogenic macrophages always negative. There are two possible explanations: (1) T-lymphocytes are unable to recognize the hapten on allogenic macrophages, and consequently the animal is not hypersensitive. (2) The antigenic complex used for sensitization (haptenized allogenic macrophages) is not identical with the complex formed during the epicutaneous challenge with the hapten in respect of the carrier. Therefore, the skin reaction to the hapten remains negative.