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Updated: Jul 15, 2026
A Strategy for the Study of IL-9-Producing Lymphoid Cells in the Nippostrongylus brasiliensis Infection Model
Published on: March 3, 2023
Initial support for the hypothesis that PAR2 is involved in the immune response to Nippostrongylus brasiliensis in
Mark G Devlin1, Robin B Gasser, Tom M Cocks
1Department of Pharmacology, The University of Melbourne, Parkville 3010, Melbourne, Victoria, Australia. markd@unimelb.edu.au
Abstract:
Protease-activated receptor 2 (PAR(2)) is a cell surface receptor that detects trypsin and trypsin-like enzymes. Although the precise pathophysiological roles of PAR(2) are yet to be determined, the receptor has been broadly implicated in inflammation and allergy. However, no studies have investigated the possible roles of PAR(2) in hosts infected by parasitic helminths. Therefore, in this preliminary investigation, we compared the infectivity of the nematode Nippostrongylus brasiliensis in mice lacking the PAR(2) gene (PAR2-/- ) and in their 'background-strain' controls (129SV). PAR2-/- mice displayed elevated fecal egg counts and decreased levels of total serum IgE, after a subcutaneous infection with 900 infective third-stage N. brasiliensis larvae compared with 129SV mice that were not susceptible to infection. In addition, in a separate study in BALB/c mice, two immunological hallmarks of parasite infection, IgE- and IL-10-expressing lymphocytes, were shown to be augmented after the coadministration of the classic antigen ovalbumin with the PAR(2)-activating peptide SLIGRL (single letter amino acid sequence) but not the inactive reverse peptide LRGILS. These findings provide initial support for the proposal that PAR(2) is a recognition receptor for nematode-derived proteases.
Insights
Protease-activated receptor 2 (PAR2) plays a role in parasitic helminth infections. Mice lacking PAR2 showed altered immune responses and parasite load, suggesting PAR2 recognizes nematode proteases.
Area of Science:
- Immunology
- Parasitology
- Molecular Biology
Background:
- Protease-activated receptor 2 (PAR2) is a cell surface receptor involved in inflammation and allergy.
- The role of PAR2 in parasitic helminth infections remains unexplored.
- PAR2 detects trypsin and trypsin-like enzymes.
Purpose of the Study:
- To investigate the role of PAR2 in hosts infected with the parasitic nematode Nippostrongylus brasiliensis.
- To determine if PAR2 recognizes nematode-derived proteases.
Main Methods:
- Comparison of Nippostrongylus brasiliensis infectivity in PAR2-deficient (PAR2-/-) mice and wild-type controls (129SV).
- Analysis of fecal egg counts and serum IgE levels.
- In a separate study, BALB/c mice were co-administered ovalbumin with a PAR2-activating peptide (SLIGRL) or an inactive control peptide (LRGILS).
- Assessment of IgE- and IL-10-expressing lymphocytes.
Main Results:
- PAR2-/- mice exhibited increased fecal egg counts compared to controls.
- PAR2-/- mice showed decreased total serum IgE levels.
- Coadministration of ovalbumin and SLIGRL augmented IgE- and IL-10-expressing lymphocytes, unlike the inactive peptide.
Conclusions:
- PAR2 appears to influence the host's immune response to Nippostrongylus brasiliensis infection.
- Findings suggest PAR2 may function as a recognition receptor for proteases derived from nematodes.
