Felix Borek

Immunogenicity and Role of Size: Response of Guinea Pigs to Oligotyrosine and Tyrosine Derivatives

Guinea pigs injected with 100 micrograms of p-azobenzenearsonate derivatives of hexa-L-tyrosine, tri-L-tyrosine, or N-acetyl-L-tyrosine amide, in complete Freunds adjuvant, developed, after 10 to 19 days, delayed-type hypersensitivity to these substances. This was shown by skin reactions, followed by the formation of circulating antibodies that were detectable by passive cutaneous anaphylaxis. Experiments with p-azobenzenearsonate-hexa-L-tyrosine labeledwith iodine-131 showed that this substance was bound in vitro to proteins of normal guinea pig serum. Binding was similar with the nonantigenic hexa-L-tyrosine and its p-azobenzoate derivative.

Immunological properties of a collagen-like synthetic polypeptide

A synthetic polypeptide (l-Pro-Gly-l-Pro)n with an ordered sequence, previously shown to have physical properties similar to those of collagen2,7, was found to be immunogenic in guinea pig and rabbits. Guinea pigs, immunized with (l-Pro-Gly-l-Pro)n, produced antibodies which cross-reacted by passive cutaneous anaphylaxis with a random copolymer of similar composition (l-Pro66Gly34)n. However, no delayed-type skin cross-reactions between the two synthetic antigens were observed. Antibodies produced early in the course of immunization likewise failed to give cross-reactions. These results are interpreted as showing that the antigen must complement the reactive moiety mediating delayed reactions or the early antibody to a higher degree than the late antibody. In a passive cutaneous anaphylaxis test cross-reactions were also observed between (l-Pro-Gly-l-Pro)n and fish, rat and guinea pig collagens. No cross-reactions between (l-Pro66Gly34)n and collagens or between gelatin and the synthetic polypeptides were observed. The results suggest that the polymer of ordered sequence cross-reacts immunologically with collagen by virtue of the triple helix conformation common to both substances.

Specificity of delayed reactions to hapten-polypeptide conjugates.

Abstract Guinea pigs sensitized with p -azobenzenearsonate conjugates of polytyrosine, poly Lys 51 Tyr 49 , poly Glu 52 Tyr 48 and poly Ala 34 Glu 36 Tyr 30 , showed delayed cross-reactions with p -azobenzenearsonate conjugate of bovine serum albumin. When conjugates of poly-peptides containing other haptens such as p -azobenzoate, p -azobenzenesulfonate and p -nitrophenylazo were used as sensitizing antigens, no delayed cross-reactions were observed with the corresponding hapten-bovine serum albumin conjugates, in conformity with the “carrier-specificity” known to exist in most delayed hypersensitivity reactions.