American Society of Hirudotherapy

Molecular cloning and functional characterization of a short peptidoglycan recognition protein from triangle-shell pearl mussel (Hyriopsis cumingii).

Research article published in Fish & shellfish immunology (2018)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Antimicrobial ResistanceDrug DevelopmentGenomics & ProteomicsHuang Y et al. · Fish & shellfish immunology, 2018

Abstract

Peptidoglycan (PGN) is an important target of recognition in invertebrate innate immunity. PGN recognition proteins (PGRPs) are responsible for PGN recognition. In this study, we cloned and functionally analyzed a short PGRP (HcPGRP2) from the triangle-shell pearl mussel Hyriopsis cumingii. The full-length cDNA sequence of HcPGRP2 gene was 1185 bp containing an open reading frame of 882 bp encoding a 293 amino acid protein. HcPGRP2 was predicted to have two SH3b domains and a conserved C-terminal PGRP domain. Quantitative real-time RT-PCR showed that HcPGRP2 was expressed in all examined tissues and its expression was induced most significantly by Staphylococcus aureus and Vibrio parahaemolyticus in the hepatopancreas and gills. RNA interference by siRNA results revealed that HcPGRP2 was involved in the regulation of whey acidic protein, theromacin, and defensin expression. As a pattern-recognition receptor, recombinant HcPGRP2 (rHcPGRP2) protein can bind and agglutinate (Ca2+ dependent) all tested bacteria. rHcPGRP2 exhibited specific binding to PGN but not to lipopolysaccharide. Moreover, rHcPGRP2 inhibited the growth activities of S. aureus and V. parahaemolyticus in vitro and accelerated the clearance of V. parahaemolyticus in vivo. Overall, our results indicated that HcPGRP2 may play an important role in the antibacterial immune mechanisms of H. cumingii.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal Article
Indexed MeSH termsAnimalsBivalviaCarrier ProteinsCloning, MolecularDNA, ComplementaryGene Expression RegulationGillsHepatopancreasImmunity, InnateLipopolysaccharidesPeptidoglycanPhylogeny

Summary

Peptidoglycan (PGN) is an important target of recognition in invertebrate innate immunity. PGN recognition proteins (PGRPs) are responsible for PGN recognition. In this study, we cloned and functionally analyzed a short PGRP (HcPGRP2) from the triangle-shell pearl mussel Hyriopsis cumingii.

Why This Matters for Hirudotherapy

This laboratory study cloned a short peptidoglycan recognition protein (HcPGRP2) from the triangle-shell pearl mussel Hyriopsis cumingii and characterized it functionally, showing the recombinant protein bound and agglutinated bacteria in a calcium-dependent manner, bound peptidoglycan specifically (but not lipopolysaccharide), inhibited Staphylococcus aureus and Vibrio parahaemolyticus growth in vitro, and accelerated bacterial clearance in vivo, indicating a role in the mollusc's innate antibacterial immunity. For ASH it is adjacent rather than central: it concerns an aquatic invertebrate (a mussel, not a leech) and informs the comparative biology of invertebrate innate immunity and antimicrobial host-defense molecules that surrounds the leech-secretome discovery story. This is preclinical molecular work in a non-leech species with no human or therapeutic data, so it carries no clinical implication for hirudotherapy and should be framed strictly as basic invertebrate-immunity research.

Citation

Molecular cloning and functional characterization of a short peptidoglycan recognition protein from triangle-shell pearl mussel (Hyriopsis cumingii).

Huang Y et al. · Fish & shellfish immunology, 2018

Added to ASH library: May 28, 2026 · Site last updated: June 18, 2026

This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.