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Updated: May 10, 2026
Studying Cryptosporidium Infection in 3D Tissue-derived Human Organoid Culture Systems by Microinjection
Published on: September 14, 2019
Identification and characterization of Cryptosporidium parvum Clec, a novel C-type lectin domain-containing
Seema Bhalchandra1, Jacob Ludington, Isabelle Coppens
1Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Boston, Massachusetts, USA.
Abstract:
Cryptosporidium species are waterborne apicomplexan parasites that cause diarrheal disease worldwide. Although the mechanisms underlying Cryptosporidium-host cell interactions are not well understood, mucin-like glycoproteins of the parasite are known to mediate attachment and invasion in vitro. We identified C. parvum Clec (CpClec), a novel mucin-like glycoprotein that contains a C-type lectin domain (CTLD) and has orthologs in C. hominis and C. muris. CTLD-containing proteins are ligand-binding proteins that function in adhesion and signaling and are present in a wide range of organisms, from humans to viruses. However, this is the first report of a CTLD-containing protein in protozoa and in Apicomplexa. CpClec is predicted to be a type 1 membrane protein, with a CTLD, an O-glycosylated mucin-like domain, a transmembrane domain, and a cytoplasmic tail containing a YXX sorting motif. The predicted structure of CpClec displays several characteristics of canonical CTLD-containing proteins, including a long loop region hydrophobic core associated with calcium-dependent glycan binding as well as predicted calcium- and glycan-binding sites. CpClec expression during C. parvum infection in vitro is maximal at 48 h postinfection, suggesting that it is developmentally regulated. The 120-kDa mass of native CpClec is greater than predicted, most likely due to O-glycosylation. CpClec is localized to the surface of the apical region and to dense granules of sporozoites and merozoites. Taken together, these findings, along with the known functions of C. parvum mucin-like glycoproteins and of CTLD-containing proteins, strongly implicate a significant role for CpClec in Cryptosporidium-host cell interactions.
Insights
Researchers discovered a novel protein, Cryptosporidium parvum Clec (CpClec), crucial for parasite-host interactions in Cryptosporidium infections. This mucin-like glycoprotein aids in attachment and invasion, offering new targets for controlling diarrheal diseases.
Area of Science:
- Parasitology
- Molecular Biology
- Infectious Diseases
Background:
- Cryptosporidium species are significant waterborne apicomplexan parasites causing global diarrheal disease.
- Mechanisms of Cryptosporidium-host cell interactions are poorly understood, though parasite mucin-like glycoproteins are implicated in attachment and invasion.
Purpose of the Study:
- To identify and characterize novel proteins involved in Cryptosporidium-host cell interactions.
- To investigate the structure, function, and localization of a newly identified mucin-like glycoprotein, CpClec.
Main Methods:
- Bioinformatic analysis to identify the C. parvum Clec (CpClec) gene and predict its protein structure.
- Analysis of CpClec's predicted features, including C-type lectin-like domain (CTLD), glycosylation, and membrane localization.
- Investigation of CpClec expression timing and localization in C. parvum during in vitro infection.
Main Results:
- Identification of CpClec, a novel mucin-like glycoprotein with a CTLD, in C. parvum, C. hominis, and C. muris.
- CpClec possesses characteristics of canonical CTLD proteins, including predicted calcium- and glycan-binding sites, and is O-glycosylated.
- CpClec expression peaks at 48 hours post-infection and is localized to the apical surface and dense granules of parasite stages.
Conclusions:
- CpClec is the first reported CTLD-containing protein in protozoa and Apicomplexa.
- Its structure, developmental regulation, and localization strongly suggest a critical role in Cryptosporidium attachment to and invasion of host cells.
- CpClec represents a potential therapeutic target for Cryptosporidium infections.
