Anti-idiotypic antibodies that inhibit immediate-type skin reactions in unsensitized monkeys on challenge with staphylococcal enterotoxin.

Abstract

The staphylococcal enterotoxin B (SEB)-induced immediate-type skin reaction in unsensitized monkeys was used as a nonimmunological mast cell stimulus to examine whether the toxin exerts its effect via specific receptors on the target cell membrane. Anti-idiotypic antibodies (anti-Id) were raised in BALB/c mice against monoclonal anti-SEB antibodies (anti-SEB) and purified by idiotype affinity chromatography. The anti-Id nature of the antibody was demonstrated by its ability to inhibit the binding of 125I-labeled anti-SEB to the ligand in a concentration-dependent manner. Moreover, binding of anti-SEB to anti-Id was antagonized by the SEB ligand in a competitive way. These antibodies completely abolished skin reactions in unsensitized monkeys on challenge with SEB and impeded those provoked by staphylococcal enterotoxins A and C1 but did not have the biological activity of the toxin. These data are compatible with the view that receptors for staphylococcal enterotoxins may exist on the membrane of mast cells in the skin of unsensitized monkeys. The data suggest an experimental approach for producing anti-cell receptor antibodies that are of potential value to influence the course of staphylococcal enterotoxin-mediated effects.Staphylococcal enterotoxin has been implicated in one of the most prevalent types of food-borne debilitating enteric intoxication in humans. Next to man, monkeys are found to be the most susceptible to oral administration ofthe enterotoxin, which produces emesis and diarrhea, the classic symptoms of such food poisoning, whereas the toxin appears to have little clinical effect in other laboratory animals (1).Although considerable effort has been expended on attempts to clarify the pathogenesis, very little, if any, information was available on the mode and cellular site of staphylococcal enterotoxin action in the gastrointestinal tract (2).Recently, however, detailed evidence was provided that staphylococcal enterotoxin B (SEB) causes, in addition to emesis, immediate-type skin reactions in unsensitized monkeys by affecting cutaneous mast cells. That mast cell mediators are involved is reflected by the fact that both the skin reactions and the emetic responses to SEB are completely abolished by histamine H2 receptor antagonists and calcium channel blockers (3). Another feature of this study was the loss of toxicity associated with the complete abrogation of skin-sensitizing activity without changing the immunological specificity of SEB after carboxymethylation of the toxin. Furthermore it has been established that carboxymethylated SEB can in fact specifically inhibit the response to native SEB in unsensitized skin sites. Thus, it is reasonable to assume that carboxymethylated SEB competitively antagonizes the action of native SEB on binding sites of mast cells but is incapable of promoting activation signals by itself. It has to be delineated, however, whether SEB exerts its effect on mast cells by binding to specific cellsurface receptors or whether some less-specific type of ligand...

Protection against the staphylococcal enterotoxin-induced intestinal disorder in the monkey by anti-idiotypic antibodies.

“…per kg of body weight) by use of a pediatric gastroscope (GIF-P10, Olympus, Munich). In a few cases, the animals were challenged with 0.1 ml of either 5 ,M SEB or 25 ,uM CM-SEB, respectively, or with a mixture of both (0.1 ml total) at a molar ratio of 1:5 by injection into the duodenal mucosa with a sclerotherapy needle (diameter 0.18 mm) as shown in Fig. 1.…”

“…The IgG-enriched fraction of anti-Id was obtained from ascitic fluid by precipitation with 2 M ammonium sulfate and subsequently absorbed with preimmune BALB/c IgG cross-linked to Eupergit C following approved techniques (5). Finally, anti-Id was purified by elution from a monoclonal anti-SEB-Eupergit C column (5). Isotyping of purified anti-Id by ELISA using subclass-specific antisera yielded antibodies of the IgG1K isotype.…”

“…of dinitrophenylsubstituted anti-SEB. Splenic lymphocytes (1 x 108) from one immunized mouse were fused with 2 x 107 P3X63-Ag8.653 mouse myeloma cells by standard techniques (10) as described in detail (5). Supernatants of hybridoma were screened for anti-Id in inhibition enzyme immunoassay.…”

“…SEB was highly purified by the method described previously (7). To prepare CM-SEB, the procedure of Harris and Hill (8) (10) and were purified by affinity chromatography as described by Bamberger et al (5). Polyclonal anti-Id, with specificity against the binding sites of anti-SEB, were prepared and purified by published methods (5).…”

“…To prepare CM-SEB, the procedure of Harris and Hill (8) (10) and were purified by affinity chromatography as described by Bamberger et al (5). Polyclonal anti-Id, with specificity against the binding sites of anti-SEB, were prepared and purified by published methods (5). For production of monoclonal anti-Id, BALB/c mice primed with dinitrophenyl-substituted ovalbumin were immunized with monoclonal anti-SEB lightly substituted with dinitrophenyl by the method of Schuler et al (11) with slight modifications (12).…”