Taxonomic group: protista / Euglenozoa
(Phylum: Euglenozoa)
Host organism: Homo sapiens
Organ / tissue: cell surface,
Life stage: epimastigoteAssociated disease: Chagas disease [ICD11:
1F53 
, ICD11:
XN56V 
];
infection due to Trypanosoma cruzi [ICD11:
XN56V 
]
The structure was elucidated in this paperNCBI PubMed ID: 31107901Publication DOI: 10.1371/journal.pntd.0007418Journal NLM ID: 101291488Publisher: San Francisco, CA: Public Library of Science
Correspondence: cbuscaglia89

iib.unsam.edu.ar
Institutions: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECh), Universidad Nacional de San Martín (UNSAM) and Consejo Nacional de investigaciones científicas y técnicas (CONICET), Buenos Aires, Argentina, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Pabellón 2, Ciudad Universitaria, C1428EGA Buenos Aires, Argentina, CONICET-UBA, Centro de Investigación en Hidratos de Carbono (CIHIDECAR), C1428EGA Buenos Aires, Argentina, Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires e Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), UBA-CONICET, C1428EGA Buenos Aires, Argentina
Background: Trypanosoma cruzi, the agent of Chagas disease, is a protozoan parasite transmitted to humans by blood-sucking triatomine vectors. However, and despite its utmost biological and epidemiological relevance, T. cruzi development inside the digestive tract of the insect remains a poorly understood process. Methods/principle findings: Here we showed that Gp35/50 kDa mucins, the major surface glycoproteins from T. cruzi insect-dwelling forms, are involved in parasite attachment to the internal cuticle of the triatomine rectal ampoule, a critical step leading to its differentiation into mammal-infective forms. Experimental evidence supporting this conclusion could be summarized as follows: i) native and recombinant Gp35/50 kDa mucins directly interacted with hindgut tissues from Triatoma infestans, as assessed by indirect immunofluorescence assays; ii) transgenic epimastigotes over-expressing Gp35/50 kDa mucins on their surface coat exhibited improved attachment rates (~2-3 fold) to such tissues as compared to appropriate transgenic controls and/or wild-type counterparts; and iii) certain chemically synthesized compounds derived from Gp35/50 kDa mucins were able to specifically interfere with epimastigote attachment to the inner lining of T. infestans rectal ampoules in ex vivo binding assays, most likely by competing with or directly blocking insect receptor(s). A solvent-exposed peptide (smugS peptide) from the Gp35/50 kDa mucins protein scaffolds and a branched, Galf-containing trisaccharide (Galfβ1-4[Galpβ1-6]GlcNAcα) from their O-linked glycans were identified as main adhesion determinants for these molecules. Interestingly, exogenous addition of a synthetic Galfβ1-4[Galpβ1-6]GlcNAcα derivative or of oligosaccharides containing this structure impaired the attachment of Dm28c but not of CL Brener epimastigotes to triatomine hindgut tissues; which correlates with the presence of Galf residues on the Gp35/50 kDa mucins' O-glycans on the former but not the latter parasite clone. Conclusion/significance: These results provide novel insights into the mechanisms underlying T. cruzi-triatomine interplay, and indicate that inter-strain variations in the O-glycosylation of Gp35/50 kDa mucins may lead to differences in parasite differentiation and hence, in parasite transmissibility to the mammalian host. Most importantly, our findings point to Gp35/50 kDa mucins and/or the Galf biosynthetic pathway, which is absent in mammals and insects, as appealing targets for the development of T. cruzi transmission-blocking strategies.
trisaccharide, glycoproteins, O-glycan, Trypanosoma cruzi, mucins, Parasite, Chagas disease
Structure type: structural motif or average structure
Location inside paper: abstract
Compound class: O-glycan
Contained glycoepitopes: IEDB_136044,IEDB_136095,IEDB_137472,IEDB_141794,IEDB_141807,IEDB_151531,IEDB_190606,SB_165,SB_166,SB_187,SB_195,SB_7,SB_88
Methods: Western blotting, binding assays, immunofluorescence analyses, flow cytometry analysis, FLAG-affinity chromatography
Comments, role: mucins adhesion determinant
NCBI Taxonomy refs (TaxIDs): 5693
Show glycosyltransferases
There is only one chemically distinct structure: