MECHANISM OF INDUCTION OF IMMUNOLOGICAL TOLERANCE

Publisher Website
Google Scholar
Abstract
Summary: Rats were rendered tolerant to the Salmonella flagellar antigen fg by multiple injections of monomeric flagellin, starting at birth. When such rats were challenged in adult life, they responded normally to a variety of unrelated antigens such as sheep and chicken red blood cells, C16 phage, and bovine serum albumin.Two H antigens, i and d, were then chosen on the basis of exhaustive serological study which showed them to be unrelated to fg. It was shown that rats tolerant to fg also exhibited a substantial degree of tolerance to the other Salmonella antigens. However, they were not tolerant when challenged with Proteus vulgaris flagellin or a variety of other antigens.When normal adult rats were given an injection of fg flagella and, 6 weeks later, an injection of i flagella, the primary response to the antigen i was significantly depressed.Thus, there seems to be an immunological relationship of a unique kind between Salmonella flagellar antigens, particularly exemplified by i and fg. While there is no trace of antigenic overlap in their in vitro behaviour, prior injection of one alters the immunogenicity of the other. The significance of these findings for theories of antibody production and tolerance is discussed.