Obtención de inmunoglobulinas de yema de huevo contra Helicobacter pylori producidos en gallinas araucanas

Abstract

Helicobacter pylori is responsible for causing various gastroduodenal diseases, with a worldwide prevalence of 50% and a prevalence in Chile of 73-76%. It is necessary to search for more efficient treatment methods for its eradication. In this study, araucana hens were inoculated intramuscularly with H. pylori whole lysates from different H. pylori virulence genotype: strain ATCC 43504 (cagA+, vacAs1m1, dupA-), and strain J99 (ATCC 70824) (cagA+, vacAs1m1, dupA+), associated with the development of gastric cancer and duodenal ulcer, respectively. Egg yolk immunoglobulins (IgY) were isolated, mainly through ultrafiltration and ammonium sulfate precipitation at 40%. IgY against H. pylori, strains J99 and 43504, were purified by thiophilic adsorption chromatography (TAC), obtaining the fractions eluted-peak II and eluted-peak III. The protein concentration for these immunoglobulins ranges between 0.3 and 5.4 mg/mL. The results of polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot (WB) allowed to observe a band of 67 kDa (IgY heavy chain) of immunoglobulins in both strains. By means of indirect immunosorbent assay (I-ELISA), IgY titers against H. pylori strains J99 and 43504 were greater than 1/6,400. In cross-reactivity tests among antibodies from several bacteria, there were significant differences. In the prophylactic and therapeutic in vitro assays using a gastric adenocarcinoma cell line (AGS), the fraction of the eluted-peak III of IgY challenged with H. pylori demonstrated a high protective efficiency against both strains of H. pylori.