No abstract

An acid-insoluble, methacrylic acid, methyl methacrylate copolymer (Eudragit L-100) was used to give an enteric coating to a grass pollen extract in order to protect it against gastric degradation. Substantial protection against the degradative effects of simulated gastric secretion was demonstrated using this preparation which was well tolerated by grass pollen-allergic volunteers. The enteric-coated allergen induced a greater secondary antibody response than did an aqueous presentation when administered orally to guinea pigs which had been primed previously by subcutaneous injection. This result indicates that an effective hyposensitisation regimen could consist of a short series of initial parenteral injections, followed by an oral course of the protected allergen.

When anti-idiotypic antibodies specific for idiotopes on IgE antibodies react with mast-dell-bound IgE antibody, the reaction may be expected to lead either to mediator release or to inhibition of allergen-induced release. This study was carried out to determine which would occur. Anti-idiotype antiserum (anti-Ids) was raised in syngeneic mice by immunisation with affinity-purified DNP-specific mouse monoclonal IgE. Sera from these immunised mice and from a similarly immunised rabbit inhibited the binding of the monoclonal IgE to radio-iodinated dinitrophenylated (DNP) ovalbumin, whereas a high concentration of affinity-purified rabbit antimouse ε-chain-specific antibody was unable to inhibit even though it was shown to bind to the monoclonal IgE. The mouse anti-Ids did not give a positive passive cutaneous anaphylactic reaction in rats sensitised with high-titre grass-pollen-specific IgE-containing antiserum, whereas it gave a positive result in rats sensitised with the DNP-specific monoclonal IgE. Rabbit antimonoclonal antiserum and rabbit anti-ε-chain antibody both gave positive results in these two assays. The results indicated that anti-idiotypic antibodies specific for idiotopes on IgE antibody can react and release mediators from IgE-sensitised mast cells. The significance of this in view of the increased levels of anti-idiotypes that can occur during immunotherapy is discussed.

A Gold staining allergenic band, Bet v 1, was excised from a nitrocellulose blot following SDS-PAGE of birch pollen extract. This was used to raise a polyclonal rabbit antiserum and monoclonal mouse antibodies specific only for the Bet v 1. The method offers practical advantages for the production of antibodies to individual allergens in complex extract mixtures, without laborious purification methods.