Infection with <em>Toxocara canis</em> Inhibits the Production of IgE Antibodies to α-Gal in Humans: Towards a Conceptual Framework of the Hygiene Hypothesis?
Adnan Hodžić,
Lourdes Mateos-Hernández,
Emilie Fréalle,
Patricia Román-Carrasco,
Pilar Alberdi,
Muriel Pichavant,
Veronica Risco-Castillo,
Delphine Le Roux,
Jérôme Vicogne,
Wolfgang Hemmer,
Herbert Auer,
Ines Swoboda,
Georg Gerhard Duscher,
José de la Fuente,
Alejandro Cabezas-Cruz
Affiliations
Adnan Hodžić
Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
Lourdes Mateos-Hernández
UMR BIPAR, INRAE, ANSES, Ecole Nationale Vétérinaire d’Alfort, Université Paris-Est, 94706 Maisons-Alfort, France
Emilie Fréalle
CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019–UMR 8204–CIIL–Center for Infection and Immunity of Lille, University of Lille, F-59000 Lille, France
Patricia Román-Carrasco
Molecular Biotechnology Section, FH Campus Wien, University of Applied Sciences, 1030 Vienna, Austria
Pilar Alberdi
SaBio, Instituto de Investigación en Recursos Cinegéticos (IREC-CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real, Spain
Muriel Pichavant
CHU Lille, Laboratory of Parasitology and Mycology, F-59000 Lille, France
Veronica Risco-Castillo
EA 7380 Dynamyc, UPEC, USC, ANSES, Ecole Nationale Vétérinaire d’Alfort, Université Paris-Est, 94706 Maisons-Alfort, France
Delphine Le Roux
UMR BIPAR, INRAE, ANSES, Ecole Nationale Vétérinaire d’Alfort, Université Paris-Est, 94706 Maisons-Alfort, France
Jérôme Vicogne
CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019–UMR9017–CIIL–Center for Infection and Immunity of Lille, University of Lille, F-59000 Lille, France
Wolfgang Hemmer
FAZ-Floridsdorf Allergy Center, 1210 Vienna, Austria
Herbert Auer
Department of Medical Parasitology, Institute of Specific Prophylaxis and Tropical Medicine, Center of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria
Ines Swoboda
Molecular Biotechnology Section, FH Campus Wien, University of Applied Sciences, 1030 Vienna, Austria
Georg Gerhard Duscher
AGES-Austrian Agency for Health and Food Safety, 1220 Vienna, Austria
José de la Fuente
SaBio, Instituto de Investigación en Recursos Cinegéticos (IREC-CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real, Spain
Alejandro Cabezas-Cruz
UMR BIPAR, INRAE, ANSES, Ecole Nationale Vétérinaire d’Alfort, Université Paris-Est, 94706 Maisons-Alfort, France
α-Gal syndrome (AGS) is a type of anaphylactic reaction to mammalian meat characterized by an immunoglobulin (Ig)E immune response to the oligosaccharide α-Gal (Galα1-3Galβ1-4GlcNAc-R). Tick bites seems to be a prerequisite for the onset of the allergic disease in humans, but the implication of non-tick parasites in α-Gal sensitization has also been deliberated. In the present study, we therefore evaluated the capacity of helminths (Toxocara canis, Ascaris suum, Schistosoma mansoni), protozoa (Toxoplasma gondii), and parasitic fungi (Aspergillus fumigatus) to induce an immune response to α-Gal. For this, different developmental stages of the infectious agents were tested for the presence of α-Gal. Next, the potential correlation between immune responses to α-Gal and the parasite infections was investigated by testing sera collected from patients with AGS and those infected with the parasites. Our results showed that S. mansoni and A. fumigatus produce the terminal α-Gal moieties, but they were not able to induce the production of specific antibodies. By contrast, T. canis, A. suum and T. gondii lack the α-Gal epitope. Furthermore, the patients with T. canis infection had significantly decreased anti-α-Gal IgE levels when compared to the healthy controls, suggesting the potential role of this nematode parasite in suppressing the allergic response to the glycan molecule. This rather intriguing observation is discussed in the context of the ‘hygiene hypothesis’. Taken together, our study provides new insights into the relationships between immune responses to α-Gal and parasitic infections. However, further investigations should be undertaken to identify T. canis components with potent immunomodulatory properties and to assess their potential to be used in immunotherapy and control of AGS.
