Mucin O-glycosylation and pathogen binding ability differ between rainbow trout epithelial sites

• Mucins are highly glycosylated proteins that make up the mucus covering internal and external surfaces of fish. Mucin O-glycans regulate pathogen quorum sensing, growth, virulence and attachment to the host. Knowledge on this mucosal defense system can enable alternative treatments to diseases posing a threat to productivity and welfare in aquaculture. Here, we characterize the rainbow trout (Oncorhynchus mykiss) gill, skin, pyloric ceca and distal intestinal mucin O-glycosylation and compare it to known teleost O-glycomes. We identified 54 O-glycans, consisting of up to nine monosaccharide residues. Skin glycans were most acidic, shortest on average and con-sisted mainly of NeuAc alpha 2-6GalNAc. Glycans from the gills were less acidic with predominantly core 1 and 2 glycans, whereas glycans from pyloric ceca and distal intestine expressed an increased number of core 5 glycans, distinctly decorated with NeuAc alpha 2-8NeuAc-like epitopes. When compared to Atlantic salmon and Arctic charr, trends on the core distribution, average size and overall acidity remained similar, although the epitopes varied. Rainbow trout mucins from gill and intestine bound A. salmonicida and A. hydrophila more efficiently than skin mucins. This is in line with a model where skin mucins with small glycans limit bacterial adhesion to the fish surface whereas the complex intestinal mucin glycans aid in trapping and removing pathogens from the epithelial surface.

Subject headings

NATURVETENSKAP  -- Biologi -- Zoologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Zoology (hsv//eng)

Keyword

Teleost

Epithelial surface

Mucosal defense

Mucus barrier

Glycan

structure

Glycomics

Mass spectrometry

outer-membrane protein

aeromonas-hydrophila

atlantic salmon

helicobacter-pylori

skin mucus

common carp

glycoprotein

expression

virulence

exposure

Fisheries

Immunology

Marine & Freshwater Biology

Veterinary Sciences

Publication and Content Type

ref (subject category)

art (subject category)