ANALYSIS OF ORAL UPTAKE OF A SYNTHETIC ADJUVANT BY AN IMMUNOASSAY WITH MONOCLONAL-ANTIBODIES

A blocking ELISA with specific antibodies against a synthetic sulpholi po-polysucrose (SL-Ficoll400) was developed to quantify this vaccine a djuvant component in faeces with the purpose of estimating the uptake thereof by the gastrointestinal tract after oral administration. Speci fic monoclonal antibodies (MABs) prepared against SL-Ficoll400 did not cross-react with components in murine faeces. SL-Ficoll400 inhibited the reactivity of the MABs in a dose-dependent fashion in the blocking ELISA and the concentration causing 50% inhibition (IC50) was about 1 mu g SL-Ficoll400 per milliliter. Derivatives of Ficoll400 lacking su lphate or lipid groups or both were unable to block the MABs (IC50 > 1 000 mu g/ml) which confirmed the specificity of the test system. Quant ification of SL-Ficoll400 in extracts of faeces of untreated mice spik ed with SL-Ficoll400 revealed that more than 90% could be recovered. T he blocking ELISA was used to quantify SL-Ficoll400 in the faeces of m ice given this compound orally. One, two and three days after oral adm inistration, the cumulative recovery of SL-Ficoll400 in faeces was 30, 40 and 92%, respectively. From these data, we concluded that the MABs obtained were specific for SL-Ficoll400, that SL-Ficoll400 in murine faeces could be quantified by a blocking ELISA with MABs and that SL-F icoll400 was poorly absorbed by the gastrointestinal tract. (C) 1998 E lsevier Science B.V. All rights reserved.