Fate of Antigen in Delayed Hypersensitivity and Arthus Reactions

Abstract Hen egg albumin labeled with 125I was followed at the sites of delayed hypersensitivity and Arthus reactions, and in the lymph nodes draining the areas of both reactions. In the delayed hypersensitivity reaction, antigen localized preferentially in the cytoplasmic membrane of mononuclear cells. In the Arthus reaction, antigen localized in the polymorphonuclear leukocyte. The pattern of retention of antigen in the regional lymph nodes was the same in both delayed hypersensitivity and Arthus reactions and resembled that seen in the primed immune state. Antigen was not retained at the site of delayed hypersensitivity reactions. It is suggested that the in vivo observations correlate closely with the in vitro model of macrophage migration.