Functions of galectins as ‘self/non-self’-recognition and effector factors

Abstract

Carbohydrate structures on the cell surface encode complex information that through specific recognition by carbohydrate-binding proteins (lectins) modulates interactions between cells, cells and the extracellular matrix, or mediates recognition of potential microbial pathogens. Galectins are a family of ß-galactoside-binding lectins, which are evolutionary conserved and have been identified in most organisms, from fungi to invertebrates and vertebrates, including mammals. Since their discovery in the 1970s, their biological roles, initially understood as limited to recognition of endogenous carbohydrate ligands in embryogenesis and development, have expanded in recent years by the discovery of their roles in tissue repair and regulation of immune homeostasis. More recently, evidence has accumulated to support the notion that galectins can also bind glycans on the surface of potentially pathogenic microbes, and function as recognition and effector factors in innate immunity, thus establishing a new paradigm. Furthermore, some parasites 'subvert' the recognition roles of the vector/host galectins for successful attachment or invasion. These recent findings have revealed a striking functional diversification in this structurally conserved lectin family.

Galectin-1: A Jack-of-All-Trades in the Resolution of Acute and Chronic Inflammation

“…However, as mentioned above, administration of Gal-1 ameliorated corneal immunopathology induced by Pseudomonas aeruginosa by suppressing Th17 responses (36). Finally, Gal-1, as well as other galectins, have been proposed to serve as pathogen-recognition receptors that could positively or negatively regulate inflammatory responses by sensing glycans on the surface of pathogenic microbes (141). Thus, Gal-1 may play multifaceted roles during infection by subverting antimicrobial responses, orchestrating host immunity, or curbing pathogen-driven immunopathology.…”

Human-like NSG mouse glycoproteins sialylation pattern changes the phenotype of human lymphocytes and sensitivity to HIV-1 infection

“…Glycosylation of stromal mouse counter-receptors is important for pre-B cells signaling and proliferation [35] and retention in bone marrow for B cells [36]. Maturation and activation of human B and T cells in mouse primary (bone marrow and thymus) and secondary lymphoid organs (spleen, lymph nodes) will likely affect B and T cell receptors repertoire and development [37]. Using the same donor of HSPC, we compared the B and T cell receptors repertoires in the new and existing NSG strain at 8 months of age.…”

Carbohydrate Recognition Mechanism of the Mushroom Galectin ACG

“…Recent insights have led to the suggestion that galectins originally functioned as recognition and effector factors in innate immunity, through binding to surface glycans of pathogenic microbes, while parasites attempted subvert the recognition roles of host galectins (57). It will be interesting to investigate whether proteins with a galectin scaffold consisting of β-sandwich/jerry roll structures really have greater binding potential for β-galactosides than others.…”