Related Experiment Video

Updated: Aug 26, 2025

Author Spotlight: Dendritic Cells Maturation Using Sialidases-Based Enzymatic Treatment of the Cell Surface
13:36

Author Spotlight: Dendritic Cells Maturation Using Sialidases-Based Enzymatic Treatment of the Cell Surface

Published on: October 20, 2023

3.6K

α2,6-Sialylation Is Upregulated in Severe COVID-19, Implicating the Complement Cascade

Rui Qin1, Emma Kurz2, Shuhui Chen3

  • 1Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.

ACS Infectious Diseases
|October 11, 2022
PubMed

Insights

Severe COVID-19 involves increased alpha-2,6-sialylation, a sugar modification, particularly on complement proteins in plasma and lung tissue. This finding may guide new COVID-19 therapies.

Area of Science:

  • Immunology
  • Glycobiology
  • Pathology

Background:

  • Hyper-inflammation is a hallmark of severe COVID-19.
  • The precise molecular triggers and the role of glycosylation in this process remain unclear.

Purpose of the Study:

  • To investigate the role of glycosylation, specifically sialylation, in the molecular mechanisms of severe COVID-19.
  • To analyze glycomic alterations in patient plasma and autopsy lung tissues.

Main Methods:

  • High-throughput glycomic analysis of plasma samples from COVID-19 patients.
  • Analysis of autopsy lung tissues for glycosylation patterns and complement deposition.
  • Correlation of sialylation levels with clinical markers and prognosis.

Main Results:

  • Upregulation of alpha-2,6-sialylation was observed in the plasma of severe COVID-19 patients and in autopsied lung tissue.
  • Elevated alpha-2,6-sialylation was found on complement cascade proteins (C5, C9) in severe cases.
  • Increased complement deposition in lung tissue correlated with higher alpha-2,6-sialylation, IL-6, and fibrotic markers.
  • The sialylation enzyme ST6GAL1 was upregulated in patients who died from COVID-19.

Conclusions:

  • A novel link between alpha-2,6-sialylation and complement activation in severe COVID-19 is identified.
  • These findings suggest sialylation as a potential therapeutic target for severe COVID-19.
  • The study provides new insights into the molecular pathology of severe COVID-19.

Keywords:
SARS-CoV-2complementglycosylationlectin arraylectin microarraysialic acid

More Related Videos

Visualization of SARS-CoV-2 using Immuno RNA-Fluorescence In Situ Hybridization05:23

Visualization of SARS-CoV-2 using Immuno RNA-Fluorescence In Situ Hybridization

Published on: December 23, 2020

6.2K
Author Spotlight: Exploring the Role of Inflammation in the Co-occurrence of Primary Sjogren's Syndrome and Lung Adenocarcinoma10:21

Author Spotlight: Exploring the Role of Inflammation in the Co-occurrence of Primary Sjogren's Syndrome and Lung Adenocarcinoma

Published on: September 20, 2024

528

Related Concept Videos

Complement System01:27

Complement System

The complement system is a group of approximately 20 plasma proteins that strengthen the body's defenses against infections through opsonization, inflammation, and cell lysis. Opsonization involves coating pathogens with complement proteins, making them more recognizable and facilitating phagocyte engulfment. Certain complement proteins induce inflammation that attracts immune cells to the site of infection. Cell lysis involves the destruction of pathogens through the formation of a...
2.6K
Proteoglycans01:05

Proteoglycans

Glycans, a class of complex heterogeneous molecules, can be covalently attached to proteins to form glycosylated proteins that regulate various physiological and pathological processes. Glycosylated proteins or glycoproteins comprise N-linked and O-linked oligosaccharides. O-glycosylation is the most common type of protein glycosylation. Here, glycans attach to the oxygen atom of the hydroxyl groups of Serine or Threonine residues. O-linked glycosylation occurs later in protein processing,...
4.0K
Conjugated Proteins02:50

Conjugated Proteins

Simple proteins and protein complexes contain only amino acids. In contrast, many other proteins, called conjugated proteins, covalently bond with non-protein moieties.
Nucleoproteins are protein complexes that contain nucleic acids, categorized as deoxyribonucleoproteins (DNPs) or ribonucleoproteins (RNPs) respectively. The nucleosome is a typical example of a DNP where nuclear DNA is associated with histone proteins. The major antigen for the Covid-19 virus SARS-CoV is an RNP that is critical...
18.5K
Oligosaccharide Assembly01:24

Oligosaccharide Assembly

Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...
3.0K