IgG binding of mugwort pollen allergens and allergoids exposed to simulated gastrointestinal conditions measured by a self-developed ELISAtest

Abstract

This study considers the influence of exposure to simulated gastrointestinal conditions (saliva, gut, intestine and acidic conditions of the gut) on IgG binding of unmodified allergens and three types of LMW allergoids of Artemisia vulgaris pollen extract obtained by means of potassium cyanate succinic and maleic anhydride. It also concerns the optimization of a self-developed ELISA assay for comparison of the specific IgG binding of mugwort pollen extract and modified mugwort pollen derivatives. The ELISA was conducted with a mugwort pollen extract coupled to the plate, using the sera from 12 mugwort- pollen allergic patients. The exposure to saliva fluid for 2 min did not influence the IgG binding properties of allergens and allergoids. Exposure of mugwort pollen allergens and LMW allergoids to the acidic conditions of the gut did not dramatically change their IgG binding properties. By exposing mugwort pollen extract and LMW derivatives to the SGF conditions for 1 h, the percent of IgG binding epitopes was reduced to a half of its starting value in the extract and to about 30%in all the allergoid samples. After prolonged exposure only the carbamyl derivative showed reduced IgG binding. Changes of the IgG binding potential of all four samples after exposure in SIF followed a similar pattern.

Predmet ovog rada je ispitivanje promena IgG vezivanja nemodifikovanih alergena polena A. vulgaris i tri tipa alergoida malih molekulskih masa dobijenih tretmanom sa kalijum-cijanatom, i anhidridima ćilibarne i meleinske posle izlaganja uslovima gastrointestinalnog trakta (saliva, želudac, tanko crevo i kisela sredina želudačnog soka) i optimizacija domaćeg ELISA testa za određivanje IgG vezivanja alergena i alergoida polena pelina.UELISA testu je za pločicu kuplovan ekstrakt polena pelina i korišćeni su serumi 12 pacijenata alergičnih na pelin. Izlaganje salivi u trajanju od 2 minuta ne utiče na IgG vezujuće osobine alergena i alergoida. Izlaganje kiseloj sredini želudačnog soka značajno ne utiče na IgG vezujuće osobine alergena i alergoida polena pelina. Posle izlaganja simuliranom želudačnom soku alergena i derivata u trajanju od 1 sata, procenat IgG vezujućih epitopa u nemodifikovanom uzorku se smanjuje na polovinu početne vrednosti i na oko 30 % kod sva tri derivata. Jedino se kod karbamil-derivata % IgG vezivanja dodatno smanjuje sa produžavanjem izlaganja SGF-u.Promene u IgG vezujućem potencijalu sva 4 uzorka posle izlaganja simuliranim uslovima tankog creva prate sličan obrazac.