IgE class-restricted tolerance induced by neonatal administration of soluble or cell-bound IgE.

Abstract

Induction of IgE class-restricted tolerance was studied in high IgE-responder (BALB/c X SJL)F1 mice, of which the parental BALB/c and SJL mice are high and low IgE-responder mice, respectively. 2,4-Dinitrophenyl (DNP)-specific monoclonal IgE was administered to (BALB/c X SJL)F1 mice neonatally in two forms: soluble IgE at 250 micrograms per injection, or 10-100 ng of IgE coupled to 25-50 X 10(6) syngeneic splenocytes by binding to the chemically reactive hapten trinitrobenzene sulfonate (TNBS) or directly conjugated via a heterobifunctional reagent, N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP). Polyclonal induction of IgE class-restricted tolerance was observed in (BALB/c X SJL)F1 mice, neonatally treated with soluble IgE or IgE-conjugated syngeneic splenocytes. Thus these mice failed to mount IgE antibody responses to either keyhole limpet hemocyanin or ovalbumin challenge, assessed by the passive cutaneous anaphylaxis reaction. The IgG antibody responses to these same antigens, however, were not affected by this treatment. The IgE class-restricted tolerance induced by both forms of IgE persisted up to at least 6 mo with repeated antigenic challenges. IgE coupled to syngeneic cells by TNBS or the SPDP method induced prolonged tolerance up to 9 mo. The induction of polyclonal IgE class-restricted tolerance was achieved only by monoclonal IgE, whereas DNP-specific monoclonal IgG1 plus IgG2b coupled to syngeneic splenocytes by the SPDP method failed to modulate either IgE or IgG antibody responses. In contrast, (BALB/c X A/J)F1 mice, of which both parental strains are high IgE responders, developed IgE class-restricted tolerance upon repeated neonatal injection of soluble IgE, but not IgE-conjugated syngeneic splenocytes, indicating that gene products of the low IgE-responder mice contributed to the effective presentation and/or recognition of epsilon heavy chain of the IgE molecules. Taken collectively, these results demonstrated that non-antigen-specific, isotype-restricted tolerance can be induced in the IgE antibody system. The differential induction of IgE class-restricted tolerance by different forms of tolerogen in the strains studied perhaps distinguishes two underlying cellular mechanisms for IgE class-restricted tolerance.

IgE class-restricted tolerance induced by neonatal administration of soluble or cell-bound IgE. Cellular mechanisms.

“…1. First, as shown in A, IgE-restricted tolerance was induced with as little as 2.5 #g of soluble IgE per injection; this dose is 100-fold less than the 250 #g of soluble IgE used in our first report (26).…”

“…The procedure was described in detail previously (26). Briefly, 50 #1 of freshly prepared solution (20 mM) of SPDP was added to 1 mi solution of DNP-specific monoclonal IgE, IgG1, IgG2b, or IgA (1 mg/ml) in phosphate-buffered saline, pH 7.5 (PBS).…”

“…KLH-specific IgG and IgA antibody levels in individual sera, were determined by a solid-phase radioimmunoassay (RIA) system in which serum samples were allowed to react with KLH on solid-phase, and then detected with either RAMG or RAMA, followed by 1~SI-labeled GARG as previously described in detail (26,27). For measuring IgA, DNP-specific MOPC 315 IgA myeioma proteins were used as standards.…”

“…To generate active sulfhydryl groups on the splenocyte surface, 0.5 ml of 0.01 M DTT was added to 10 ml of 2% spleen cell suspension and the mixture was incubated at r.t. for 1 h. The DTT-treated cells were washed thoroughly with PBS, resuspended in 10 ml of PBS, and then reacted with PDP-proteins (1 mg/ml, 10 mi) at r.t. for 1 h. Protein-coupled splenocytes were washed twice in PBS and resuspended at appropriate concentrations in saline for injection. The quantity of IgE molecules coupled to spleen cells was determined by radiolabeling tracer studies using 125I-labeled PDP-IgE (26).…”

“…Recently, we have described a phenomenon in which neonatal treatment of mice with soluble or cell-bound monocional IgE molecules results in the development of profound IgE class-restricted immunodeficiency (26). Such findings indicate that some cellular component(s) associated with the IgE antibody system, possibly capable of reacting specifically with ~ determinants of IgE heavy chains (e.g., FcR~ + cells), are perturbed when confronted by IgE at an early stage of development; this early perturbation manifests itself in adulthood as persistent unresponsiveness in the IgE antibody class.…”