Gut Microbiota Abrogates Anti-α-Gal IgA Response in Lungs and Protects against Experimental Aspergillus Infection in Poultry

• Published in: Vaccines (Basel) Vol. 8; no. 2; pp. 285 - 21
• Main Authors: Mateos-Hernández, Lourdes, Risco-Castillo, Veronica, Torres-Maravilla, Edgar, Bermúdez-Humarán, Luis G., Alberdi, Pilar, Hodžić, Adnan, Hernández-Jarguin, Angelica, Rakotobe, Sabine, Galon, Clemence, Devillers, Elodie, de la Fuente, Jose, Guillot, Jacques, Cabezas-Cruz, Alejandro
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 07.06.2020; MDPI
• Subjects: alpha-Gal; Animal biology; Animals; Antibodies; Aspergillosis; Aspergillus fumigatus; B7 antigen; Bacteria; Coliforms; cross-protective immunity; Cytokines; E coli; Ecology, environment; Epitopes; Flow cytometry; Galactose; Glycan; granulomas; Human health and pathology; Immune response; Immune system; Immunization; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Infections; Infectious diseases; Intestinal microflora; Isotypes; Life Sciences; Lungs; Mammals; Microbiology and Parasitology; Microbiota; Monkeys & apes; Mortality; Mycology; Oral administration; Pathogenesis; Pathogens; Proteins; Reduction; Reptiles & amphibians; Symbiosis; Tropical diseases; Turkeys; Veterinary medicine and animal Health; Wildfowl; France; United States > US; Spain; microbiota; alpha-Gal; Aspergillus fumigatus; granulomas; cross-protective immunity; aspergillosis
• ISSN: 2076-393X; 2076-393X
• DOI: 10.3390/vaccines8020285

Naturally occurring human antibodies (Abs) of the isotypes IgM and IgG and reactive to the galactose-α-1,3-galactose (α-Gal) epitope are associated with protection against infectious diseases, caused by pathogens expressing the glycan. Gut microbiota bacteria expressing α-Gal regulate the immune response to this glycan in animals lacking endogenous α-Gal. Here, we asked whether the production of anti-α-Gal Abs in response to microbiota stimulation in birds, confers protection against infection by Aspergillus fumigatus, a major fungal pathogen that expresses α-Gal in its surface. We demonstrated that the oral administration of Escherichia coli O86:B7 strain, a bacterium with high α-Gal content, reduces the occurrence of granulomas in lungs and protects turkeys from developing acute aspergillosis. Surprisingly, the protective effect of E. coli O86:B7 was not associated with an increase in circulating anti-α-Gal IgY levels, but with a striking reduction of anti-α-Gal IgA in the lungs of infected turkeys. Subcutaneous immunization against α-Gal did not induce a significant reduction of lung anti-α-Gal IgA and failed to protect against an infectious challenge with A. fumigatus. Oral administration of E. coli O86:B7 was not associated with the upregulation of lung cytokines upon A. fumigatus infection. We concluded that the oral administration of bacteria expressing high levels of α-Gal decreases the levels of lung anti-α-Gal IgA, which are mediators of inflammation and lung damage during acute aspergillosis.