Pali-Schöll I, Bianchini R, Afify SM, Hofstetter G, Winkler S, Ahlers S, Altemeier T, Mayerhofer H, Hufnagl K, Korath ADJ, Pranger C, Widhalm R, Hann S, Wittek T, Kasper-Giebl A, Pacios LF, Roth-Walter F, Vercelli D, von Mutius E, and Jensen-Jarolim E
Background: Growing up on a cattle farm and consuming raw cow's milk protects against asthma and allergies. We expect a cattle-specific protein as active component in this farm effect., Methods: Dust was collected from cattle and poultry stables and from mattresses of households. Urine was obtained from cattle, and ambient aerosols were sampled. Samples were analysed for BLG by SDS PAGE/immunoblot and mass spectrometry, and for association with metals by SEC-ICP-MS. PBMC of healthy donors were incubated with BLG +/- zinc, and proliferation and cytokines determined. BALB/c mice were pre-treated intranasally with stable dust extract containing BLG or depleted of BLG, and subsequent allergy response after sensitization was evaluated on antibody and symptom level., Results: A major protein in dust from cattle farms and ambient air was identified as BLG. Urine from female and male cattle is a major source of BLG. In dust samples, BLG was associated with zinc. In vitro , zinc-BLG provoked significantly lower proliferation of CD4 + and CD8 + cells while inducing significantly higher levels of IFN-γ and IL-6 than the apo-BLG devoid of zinc. In vivo , pre-treatment of mice with dust extract containing BLG resulted in lower allergy symptom scores to BLG and unrelated Bet v 1 than pre-treatment with extract depleted of BLG. These in vitro and in vivo effects were independent of endotoxin., Conclusion: The lipocalin BLG is found in large amounts in cattle urine, accumulates in bovine dust samples and is aerosolized around farms. Its association with zinc favorably shapes the human cellular immune response towards Th1-cytokines in vitro . BLG together with zinc in stable dust protects mice from allergic sensitization. BLG with its associated ligands may in an innate manner contribute to the allergy-protective farm effect., Competing Interests: IPS and EJJ report personal fees from Bencard Allergie GmbH, Germany, outside the submitted work. EJJ, LFP and FRW are inventors of EP2894478; “LCN2 as a tool for allergy diagnostic and therapy”, EP 14150965.3, Year: 01/2014; US 14/204,570, owned by Biomedical International R+D GmbH, Vienna, Austria, the basis for the dietary lozenge immunoBON®. EJJ is shareholder in this company. Dr. von Mutius reports grants from German Centre for Lung Research (DZL), personal fees from Elsevier GmbH, personal fees from Georg Thieme Verlag, personal fees from Springer‐Verlag GmbH, personal fees from Elsevier Ltd., personal fees from Chinese University of Hongkong, personal fees from European Commission, personal fees from HIPP GmbH & Co. KG, personal fees from AstraZeneca, personal fees from Massachusetts Medical Society, personal fees from Böhringer Ingelheim International GmbH, from European Respiratory Society (ERS), personal fees from Universiteit Utrecht, Faculteit Diergeneeskunde, personal fees from Universität Salzburg, personal fees from Springer Medizin Verlag GmbH, personal fees from Japanese Society of Pediatric Allergy and Clinical Immunology (JSPACI), personal fees from Klinikum Rechts der Isar, Munich, personal fees from University of Colorado, personal fees from Paul‐Martini‐Stiftung, Berlin, personal fees from Imperial College London, personal fees from Verein zur Förderung der Pneumologie am Krankenhaus Großhansdorf e.V., personal fees from Pneumologie Development, personal fees from Mondial Congress & Events GmbH & Co. KG, personal fees from American Academy of Allergy, Asthma and Immunology , personal fees from Margaux Orange, personal fees from Volkswagen Stiftung, personal fees from Österreichische Gesellschaft für Allergologie und Immunologie, personal fees from OM Pharma S.A., personal fees from Hanson Wade Ltd., personal fees from iKOMM GmbH, personal fees from DSI Dansk Borneastma Cemter, personal fees from American Thoracic Society, personal fees from Universiteit Utrecht, Faculteit Betawetenschappen, outside the submitted work; In addition, Dr. von Mutius has a patent Patent LU101064 pending, a patent Patent EP2361632 with royalties paid to ProtectImmun, a patent Patent EP1411977 with royalties paid to ProtectImmun, a patent Patent EP1637147 with royalties paid to ProtectImmun, and a patent Patent EP1964570 licensed to ProtectImmun and Erika von Mutius is: Member of the EXPANSE (funded by European Commission) Scientific Advisory Board, Member of the BEAMS External Scientific Advisory Board (ESAB), Member of the Editorial Board of “The Journal of Allergy and Clinical Immunology: In Practice”, Member of the Scientific Advisory Board of the Children’s Respiratory and Environmental Workgroup (CREW), Member of the International Scientific & Societal Advisory Board (ISSAB) of Utrecht Life Sciences (ULS), University of Utrecht, Member of External Review Panel of the Faculty of Veterinary Science, University of Utrecht, Member of the Selection Committee for the Gottfried Wilhelm Leibniz Programme (DFG), Member of the International Advisory Board of Asthma UK Centre for Applied Research (AUKCAR), Member of the International Advisory Board of “The Lancet Respiratory Medicine”, Member of the Scientific Advisory Board of the CHILD (Canadian Healthy Infant Longitudinal Development) study, McMaster University, Hamilton, Canada. The other authors declare no relevant conflict of interest in relation to this publication., (© 2022 The Authors. Clinical and Translational Allergy published by John Wiley & Sons Ltd on behalf of European Academy of Allergy and Clinical Immunology.)