PROLONGED INHIBITION OF IGE PRODUCTION IN MICE FOLLOWING TREATMENT WITH AN IGE-SPECIFIC IMMUNOTOXIN

The synthesis of IgE antibodies by B cells is the first in a series of steps resulting in an allergic response. To eliminate IgE-bearing B c ells and thereby prevent IgE production, we have developed an immunoto xin OTA) composed of the non-anaphylactic 84.1c anti-mouse IgE mAb and the A chain of ricin (ricin A). This ITA specifically inhibited the i nduction of IgE synthesis by lipopolysaccharide plus interleukin-4 (LP S+IL-4) in vitro, and antigen-specific IgE production in vivo in adult mice. A single dose of anti-IgE ITA, given within a week (either befo re or after) of antigen challenge completely abolished antigen-specifi c primary IgE responses. No IgE production was seen for 2 months after ITA treatment. Following antigenic re-challenge, a suppressed seconda ry response (over 50% reduction) was still seen in the ITA-treated mic e, 100 days after immunization. The results of this study demonstrate the potential use of anti-IgE toxin conjugates for the suppression of periodic (seasonal) allergic outbreaks. Copyright (C) 1996 Elsevier Sc ience Ltd.