Specific Immunologic Unresponsiveness to Delayed Hypersensitivity Elicited in Adult Mice.

Abstract

Immunologic unresponsiveness directed against delayed but not immediate hypersensitivity to protein antigen can be elicited in adult mice by exposing them to a buffer solution of antigen within a certain short, critical time after they have been vaccinated with the same antigen in water-in-oil emulsion. Further study of this phenomenon may improve understanding of and control over the mechanisms of induction of delayed and immediate hypersensitlvities. In the experiment reported, unresponsiveness was induced by skin-testing mice with 0.2 ml of 1% chicken ovalbumin in buffer solution 4 days after they had been vaccinated subcutaneously with 0.1 ml of water-in-oil emulsion containing 0.25 mg of ovalbumin and 0.25 mg of mycobacterial adjuvant. As a consequence of this treatment emergence of delayed hypersensitivity ot the albumin was prevented, while immediate hypersensitivity to this antigen developed normally. Mice skin-tested at progressively longer intervals after sim -ilar vaccination showed correspondingly less supression of the delayed allergic response, until at 18 days none was evident.