Biological Roles of Lectins in Innate Immunity: Molecular and Structural Basis for Diversity in Self/Non-Self Recognition

Vasta, Gerardo R.; Ahmed, Hafiz; Tasumi, Satoshi; Odom, Eric W.; Saito, Keiko

doi:10.1007/978-0-387-71767-8_27

Cited by 62 publications

(53 citation statements)

References 73 publications

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“…As previously mentioned, host lectins are thought to act as pathogen recognition receptors (Glinski and Jarosz, 1997; Janeway and Medzhitov, 2002; Vasta et al, 2007) and, therefore, one of the objectives of the present study was to profile the glycan repertoire presented to the snail host by early infecting larval schistosomes to begin assessing the role of specific glycotopes in promoting or suppressing snail immune activity. Previous studies suggest that shared glycan elements, particularly those featuring a terminal Fucα1-3GalNAc linkage, i.e., F-LDN and F-LDN-F, possibly mediate CHO-based molecular mimicry between larval schistosomes and B. glabrata (Lehr et al, 2007, 2008), which is thought to be a parasite strategy for immune evasion (Yoshino and Bayne, 1983; Bayne et al, 1987; Damian, 1989).…”

Section: Discussionmentioning

confidence: 99%

Glycotope analysis in miracidia and primary sporocysts of Schistosoma mansoni: Differential expression during the miracidium-to-sporocyst transformation

Peterson

Hokke

Deelder

et al. 2009

International Journal for Parasitology

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Fucosylated carbohydrate epitopes (glycotopes) expressed by larval and adult schistosomes are thought to modulate the host immune response and possibly mediate parasite evasion in intermediate and definitive hosts. While previous studies showed glycotope expression is developmentally and stage-specifically regulated, relatively little is known regarding their occurrence in miracidia and primary sporocysts. In this study, previously defined monoclonal antibodies were used in confocal laser scanning microscopy, standard epifluorescence microscopy and Western blot analyses to investigate the developmental expression of the following glycotopes in miracidia and primary sporocysts of Schistosoma mansoni: GalNAcβ1-4GlcNAc (LDN), GalNAcβ1-4(Fucα1-3)GlcNAc (LDN-F), Fucα1-3GalNAcβ1-4GlcNAc (F-LDN), Fucα1-3GalNAcβ1-4(Fucα1-3)GlcNAc (F-LDN-F), GalNAcβ1-4(Fucα1-2Fucα1-3)GlcNAc (LDNDF), Fucα1-2Fucα1-3GalNAcβ1-4(Fucα1-2Fucα1-3)GlcNAc (DF-LDN-DF), Galβ1-4(Fucα1-3)GlcNAc (Lewis X) and the truncated trimannosyl N-glycan Manα1-3(Manα1-6)Manβ1-4GlcNAcβ1-4GlcNAcβ1- Asn (TriMan). All but Lewis X were variously expressed by miracidia and sporocysts of S. mansoni. Most notably, α3-fucosylated LDN (F-LDN, F-LDN-F, LDN-F) was prominently expressed on the larval surface and amongst glycoproteins released during larval transformation and early sporocyst development, possibly implying a role for these glycotopes in snail–schistosome interactions. Interestingly, Fucα2Fucα3- subsituted LDN (LDN-DF, DF-LDN-DF) and LDN-F were heterogeneously surface-expressed on individuals of a given larval population, particularly amongst miracidia. In contrast, LDN and TriMan primarily localised in internal somatic tissues and exhibited only minor surface expression. Immunoblots indicate that glycotopes occur on overlapping but distinct protein sets in both larval stages, further demonstrating the underlying complexity of schistosome glycosylation. Additionally, sharing of specific larval glycotopes with Biomphalaria glabrata suggests an evolutionary convergence of carbohydrate expression between schistosomes and their snail host.

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Section: Discussionmentioning

confidence: 99%

Glycotope analysis in miracidia and primary sporocysts of Schistosoma mansoni: Differential expression during the miracidium-to-sporocyst transformation

Peterson

Hokke

Deelder

et al. 2009

International Journal for Parasitology

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“…Accordingly, glycan-binding proteins, commonly referred to as lectins, play a crucial role in innate (and adaptive) immunity. Binding of potential pathogens by lectins leads to phagocytosis, complement activation, and antigen processing but also regulation of adaptive immune functions (1). In addition to their role in pathogen recognition, some lectins act as direct defense effectors by intoxicating the antagonist upon binding.…”

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confidence: 99%

Methylated glycans as conserved targets of animal and fungal innate defense

Wohlschlager

Butschi

Grassi

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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Effector proteins of innate immune systems recognize specific nonself epitopes. Tectonins are a family of β-propeller lectins conserved from bacteria to mammals that have been shown to bind bacterial lipopolysaccharide (LPS). We present experimental evidence that two Tectonins of fungal and animal origin have a specificity for O-methylated glycans. We show that Tectonin 2 of the mushroom Laccaria bicolor (Lb-Tec2) agglutinates Gram-negative bacteria and exerts toxicity toward the model nematode Caenorhabditis elegans, suggesting a role in fungal defense against bacteria and nematodes. Biochemical and genetic analysis of these interactions revealed that both bacterial agglutination and nematotoxicity of Lb-Tec2 depend on the recognition of methylated glycans, namely O-methylated mannose and fucose residues, as part of bacterial LPS and nematode cell-surface glycans. In addition, a C. elegans gene, termed samt-1, coding for a candidate membrane transport protein for the presumptive donor substrate of glycan methylation, S-adenosyl-methionine, from the cytoplasm to the Golgi was identified. Intriguingly, limulus lectin L6, a structurally related antibacterial protein of the Japanese horseshoe crab Tachypleus tridentatus, showed properties identical to the mushroom lectin. These results suggest that O-methylated glycans constitute a conserved target of the fungal and animal innate immune system. The broad phylogenetic distribution of O-methylated glycans increases the spectrum of potential antagonists recognized by Tectonins, rendering this conserved protein family a universal defense armor.

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“…Pattern recognition proteins are ubiquitous in crustacean innate immune systems (Medzhitov and Janeway, 2000;Vasta et al, 2007;Vazquez et al, 2009;Wang and Wang, 2013) and often activate coagulation of proteinaceous material with antimicrobial consequences (Martin et al, 1991;Jiravanichpaisal et al, 2006;Schmidt et al, 2010;Loof et al, 2011). The origin of the fluids associated with cuticle expansion remains unanswered and requires further attention.…”

Section: Discussionmentioning

confidence: 99%

Barnacle biology before, during and after settlement and metamorphosis: a study of the interface

Essock‐Burns

Gohad

Orihuela

et al. 2016

Journal of Experimental Biology

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Mobile barnacle cypris larvae settle and metamorphose, transitioning to sessile juveniles with morphology and growth similar to that of adults. Because biofilms exist on immersed surfaces on which they attach, barnacles must interact with bacteria during initial attachment and subsequent growth. The objective of this study was to characterize the developing interface of the barnacle and substratum during this key developmental transition to inform potential mechanisms that promote attachment. The interface was characterized using confocal microscopy and fluorescent dyes to identify morphological and chemical changes to the interface and the status of bacteria present as a function of barnacle developmental stage. Staining revealed patchy material containing proteins and nucleic acids, reactive oxygen species amidst developing cuticle, and changes in bacteria viability at the developing interface. We found that as barnacles metamorphose from the cyprid to juvenile stage, proteinaceous materials with the appearance of coagulated liquid were released into and remained at the interface. It stained positive for proteins, including phosphoprotein, as well as nucleic acids. Regions of the developing cuticle and the patchy material itself stained for reactive oxygen species. Bacteria were absent until the cyprid was firmly attached, but populations died as barnacle development progressed. The oxidative environment may contribute to the cytotoxicity observed for bacteria and has the potential for oxidative crosslinking of cuticle and proteinaceous materials at the interface.

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Biological Roles of Lectins in Innate Immunity: Molecular and Structural Basis for Diversity in Self/Non-Self Recognition

Cited by 62 publications

References 73 publications

Glycotope analysis in miracidia and primary sporocysts of Schistosoma mansoni: Differential expression during the miracidium-to-sporocyst transformation

Glycotope analysis in miracidia and primary sporocysts of Schistosoma mansoni: Differential expression during the miracidium-to-sporocyst transformation

Methylated glycans as conserved targets of animal and fungal innate defense

Barnacle biology before, during and after settlement and metamorphosis: a study of the interface

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