Simultaneous Generation of Tuberculin-Type and Cutaneous Basophilic Hypersensitivity at Separate Sites in the Guinea Pig

Abstract

Strain-2 guinea pigs received two separate intradermal immunizations. The first was a mixture of living BCG (Phipps strain of bacille Calmette-Guerin) and syngeneic line-10 hepatoma cells. The second, administered after 6 weeks or more, was keyhole limpet hemocyanin (KLH) in saline. One week after the second injection, the animals were skin tested at separate sites with tumor cells, purified protein derivative of tuberculin (PPD) and KLH. Delayed cutaneous hypersensitivity (DCH) reactions were evident by 24 h. At this time the reaction sites were processed by histological methods that preserved basophil morphology and staining qualities. Three distinctive infiltrates were elicited by the different antigens. In addition to the mononuclear cell infiltrate common to all three reactions, the KLH site had a high concentration of basophils and few neutrophils, characteristic of cutaneous basophilic hypersensitivity (CBH); the PPD site had practically no basophils but many neutrophils; and the tumor cell reaction was predominantly mononuclear, with small numbers of basophils and virtually no neutrophils. Simultaneous generation of different DCH reactions in the same animal and quantitative description of the cellular infiltrate provided a basis for DCH classifications, with KLH CBH and tuberculin reactions as standards for comparison. Since challenge with three antigens at separate sites in the same animal generated DCH reactions with widely differing patterns of cellular infiltration, the reason for the differences must occur at the local sites or, if circulating, must be antigen-specific.