Systemic Lectin-Glycan Interaction of Pathogenic Enteric Bacteria in the Gastrointestinal Tract

Seung-Hak Cho,Jun-Young Park,Cheorl-Ho Kim

doi:10.3390/ijms23031451

Abstract

Microorganisms, such as bacteria, viruses, and fungi, and host cells, such as plants and animals, have carbohydrate chains and lectins that reciprocally recognize one another. In hosts, the defense system is activated upon non-self-pattern recognition of microbial pathogen-associated molecular patterns. These are present in Gram-negative and Gram-positive bacteria and fungi. Glycan-based PAMPs are bound to a class of lectins that are widely distributed among eukaryotes. The first step of bacterial infection in humans is the adhesion of the pathogen’s lectin-like proteins to the outer membrane surfaces of host cells, which are composed of glycans. Microbes and hosts binding to each other specifically is of critical importance. The adhesion factors used between pathogens and hosts remain unknown; therefore, research is needed to identify these factors to prevent intestinal infection or treat it in its early stages. This review aims to present a vision for the prevention and treatment of infectious diseases by identifying the role of the host glycans in the immune response against pathogenic intestinal bacteria through studies on the lectin-glycan interaction.

Highlights

Carbohydrates are the most important energy source in the living body, in the form of glucose and glycogen, but are a biomaterial that plays a pivotal role in many biological processes, such as cell fusion, growth, adhesion, migration, death, and immune responses
Studies have shown that sugar chains are involved in most diseases; death may occur if part of the sugar chains are missing or abnormal, and sugar chains are related to bacterial infection and immunosuppression, the pathogenesis and progression of cancer, and metastasis [6,7]
To initiate studies on glycan-based pathogenicity, we previously reported a methodologic and multiomics analytical construction using a lectin-glycan interaction (LGI) concept, applied to enterohemorrhagic Escherichia coli [19]

Summary

Introduction

Carbohydrates are the most important energy source in the living body, in the form of glucose and glycogen, but are a biomaterial that plays a pivotal role in many biological processes, such as cell fusion, growth, adhesion, migration, death, and immune responses These processes are largely performed through interactions between specific lectins, plasma membranes, and cell walls [1,2,3,4]. Lectins are involved in various life phenomena such as protein quality control, host-pathogen interactions, cell-cell communication, inflammation, immune response, cancer progression, and development, through specific binding with sugar chains in living organisms. In intestinal enterohemorrhagic Escherichia coli (EHEC) infection, the carbohydrate structure and the protein surface are altered, resulting in a change in the binding of proteins to glycolipid sugar chains or interactions between proteins, leading to abnormal protein function. Recent research has shown that glycolipid sugar chains directly induce and exacerbate infectious diseases [32]

Immune Responses in the GIT of Hosts in Connection with LGI

Outline and Present Status of LGI Research

Strategies to Search for Lectins of Pathogenic Intestinal Bacteria

Conclusions

Methods