Glycans

European Federation of Animal Science (EAAP) organized their 71st annual meeting as a virtual meeting, because the previously scheduled live event in Portugal had to be cancelled due to Covid-19 restrictions. The virtual meeting took place in December 1-4, 2020. One of Hankkija FFI’s four posters in the event was titled “N-glycan profiling of chicken intestine as a tool for designing improved feed supplements”. This poster presented an innovative technique, N-glycan profiling, which can be used for developing feed supplements for improved intestinal wellbeing.

Cells of all vertebrates communicate through interactions between short carbohydrate chains referred to as glycans. Host-microbiota interplay in the intestine is also based on these sugar structures. Study of the carbohydrate language of the body is called glycomics. This yet rather uncommon technology will likely increase in importance with the emerging understanding of host-microbiota interactions to human and animal health.

The intestinal mucosa of all vertebrates is covered with complex carbohydrate structures, including N-glycans. N-glycans are oligosaccharides which commonly contain galactose, mannose and/or fucose, and are attached to asparagine side chains of glycoproteins via N-acetylglucosamine. They can be divided into neutral and acidic, and further into several types, the abundance of which differ between intestinal segments of vertebrates.

Pathogenic bacteria recognize and bind to their target N-glycans on the surface of intestinal epithelium. This opens a possibility to affect the capacity of pathogens to bind to gut epithelium by affecting the N-glycans of their target cells. The aim of the study was to characterize the intestinal N-glycans of different compartments of broiler chicken.
Here we used N-glycan profiling for analyzing various parts of the intestinal mucosa of broiler chicken with the aim of identifying target structures for pathogens. To our knowledge, this was the first time the N-glycan profile of chicken intestine was characterized.

RESEARCH DESIGN
Three broiler chickens were sampled for tissue from proximal jejunum, distal jejunum, distal ileum and caecum. The samples were thoroughly rinsed with phosphate buffered saline and scraped for mucus and epithelial cells. The protein-bound N-glycans in mucosal lysates were liberated with glycosidase F from Chryseobacterium meningosepticum. The detached glycans were purified and analysed by MALDI-TOF mass spectrometry. The intensity of all N-glycan signals in the mass spectra was measured.

In all samples, the most common neutral N-glycans corresponded to high-mannose type N-glycans, many of which can be seen as housekeeping glycans produced by all tissues. Jejunal and ileal profiles differed especially in the abundance of the high- and low-mannose glycans, while the cecal samples were rich in complex-type glycans. Compared with neutral N-glycans, the acidic N-glycans showed more variation and presence of sialylated structures which may act as pathogen receptors.

The mapping of the N-glycan profile of chicken intestine will serve as a foundation for rational design of novel, functional feed supplements from the brewer’s yeast Saccharomyces cerevisiae or other sustainable raw materials.

Reference: Hannele Kettunen1, Annamari Heiskanen2, Anne Olonen2, Tero Satomaa2, Juhani Saarinen2, Juhani Vuorenmaa1 (2020) N-glycan profiling of chicken intestine as a tool for designing improved feed supplements. Abstract no. 35.14 in: 71st European Federation of Animal Science (EAAP) meeting, Virtual meeting 1-4 December 2020. 1Hankkija Ltd, Peltokuumolantie 4, FI-05801 Hyvinkää, Finland, 2Glykos Finland Ltd, Viikinkaari 6, FIN-00790 Helsinki, Finland