Chemical modification of timothy grass pollen antigen B—I.: Loss of antibody binding properties

Abstract

Selective modification of the antigenic determinant of the major allergen of timothy grass pollen, antigen B,was achieved by a photooxidation reaction. The modified antigen B, OX-AgB, does not react with either rabbit or human (reaginic) antibodies directed against the native antigen B (AgB). LAP 1 mice immunized with either 10 or 100 μg protein of OX-AgB adsorbed to 1 mg alum and given two additional boosts with the same dose of OX-AgB over a 63-day period did not produce IgE or IgG 1 antibodies that react with either native or OX-AgB. In contrast, LAF 1 mice similarly immunized with 10 μg AgB produced significant levels of IgE and IgG 1 antibodies. Antigen-induced lymphocyte transformation was used to determine the effect of the chemical modification upon the carrier determinants of AgB. These studies indicate that OX-AgB retains a significant portion of the T-cell activating properties of AgB.