IgE secretion is attenuated by an inhibitor of proteolytic processing of CD23 (Fc epsilonRII).

CD23, the low-affinity IgE receptor, is up-regulated on interleukin (IL)-4-stimulated B cells and monocytes, with a concomitant increase in the release of soluble fragments of CD23 (sCD23) into the medium by proteolytic processing of the surface-bound intact CD23. The effect of inhibition of the processing of CD23 on IgE production in human and mouse cells and in a mouse model in vivo was evaluated. CD23 processing to sCD23 from RPMI 8866 (a human Epstein-Barr virus-transformed B cell line) cell membranes was inhibited by a broad-spectrum matrix-metalloprotease inhibitor, batimastat, with an IC50 of 0.

Stimulatory effects of FK156 in a panel of tests designed to detect changes in immune function.

There is a need to evaluate the utility of experimental models in immune function assessment if these are to be accepted in preclinical safety studies. We have evaluated a panel of tests measuring cellularity and functions of the lymphoid system in the Fischer rat in order to determine whether they would detect immunostimulation, rather than suppression. Injection of the peptide immunostimulant FK156 (D-lactyl-L-alanyl-y-D-glutamyl-(L)-meso-diaminopimelyl- (L)-glycine) increased the numbers of macrophages recovered from the peritoneal cavity, and stimulated their activity, as measured by chemiluminescence, adherence, and secretion of interleukin 1.

Reactivity of mast-cell-bound IgE idiotypes with anti-idiotypic antibody: mediator release or inhibition of antigen-induced mediator release?

When anti-idiotypic antibodies specific for idiotopes on IgE antibodies react with mast-cell-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.

Induction of polyclonal and monoclonal antibodies with a single allergen separated from birch pollen extract by SDS-PAGE and nitrocellulose blots.

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.