The C‐type lectin superfamily in the immune system

Abstract

Protein-carbohydrate interactions serve multiple functions in the immune system. Many animal lectins (sugar-binding proteins) mediate both pathogen recognition and cell-cell interactions using structurally related Ca(2+)-dependent carbohydrate-recognition domains (C-type CRDs). Pathogen recognition by soluble collections such as serum mannose-binding protein and pulmonary surfactant proteins, and also the macrophage cell-surface mannose receptor, is effected by binding of terminal monosaccharide residues characteristic of bacterial and fungal cell surfaces. The broad selectivity of the monosaccharide-binding site and the geometrical arrangement of multiple CRDs in the intact lectins explains the ability of the proteins to mediate discrimination between self and non-self. In contrast, the much narrower binding specificity of selectin cell adhesion molecules results from an extended binding site within a single CRD. Other proteins, particularly receptors on the surface of natural killer cells, contain C-type lectin-like domains (CTLDs) that are evolutionarily divergent from the C-type lectins and which would be predicted to function through different mechanisms.

Recombinant human lactoferrin expressed in glycoengineered Pichia pastoris: effect of terminal N-acetylneuraminic acid on in vitro secondary humoral immune response

“…Also, the two forms of human LF are identical in their amino acid sequence, but different in sugar moiety. The granulocytic LF is not fucosylated and this seemingly predisposes this form to transduce certain signals that do not require fucose-specific receptors such as mannose receptor exhibiting equal affinity to fucose and mannose [38]. Here, it was demonstrated that the activity of rhLF depends on the terminal N-acetylneuraminic acid.…”

The rat antigen-presenting lectin-like receptor complex influences innate immunity and development of infectious diseases

“…[5][6][7] The ligands and functions of the receptors remain unknown, but the receptor type has been implicated in diverse functions, such as microbial pattern recognition, cellular adhesion and migration, antigen uptake and presentation, T cell co-stimulation, and signal transduction through immunoreceptor tyrosine-based inhibitory or activating motifs (ITIMs and ITAMs, respectively). [8][9][10][11] Interestingly, we observed earlier that APLEC regulates clinical phenotypes in RA models induced by nonimmunogenic structures that activate the innate immune system, for example, incomplete Freund's adjuvant oil and yeast b-glucan. 5 Herein, we tested the hypothesis that APLEC might also regulate infectious diseases and innate macrophage reactivity.…”

Differential proteome profile of skin mucus of gilthead seabream (Sparus aurata) after probiotic intake and/or overcrowding stress

“…Lectins are a group of sugar binding proteins which are involved in both innate and adaptive immunity [53], including pathogen recognition and neutralization [54]. Furthermore, a diversity of lectins was reported in fish skin mucus [55].…”