Immune-microbiota interaction in Finnish and Russian Karelia young people with high and low allergy prevalence

• Published in: Clinical & Experimental Allergy
• Main Authors: Ruokolainen, Lasse, Fyhrquist, Nanna, Laatikainen, Tiina, Auvinen, Petri, Fortino, Vittorio, Scala, Giovanni, Jousilahti, Pekka, Karisola, Piia, Vendelin, Johanna, Karkman, Antti, Markelova, Olga, Mäkelä, Mika J., Lehtimäki, Sari, Ndika, Joseph, Ottman, Noora, Paalanen, Laura, Paulin, Lars, Vartiainen, Erkki, von Hertzen, Leena, Greco, Dario, Haahtela, Tari, Alenius, Harri
• Other Authors: Helsinki Institute of Sustainability Science (HELSUS), Biosciences, Veijo Kaitala / Principal Investigator, University of Helsinki, HUMI - Human Microbiome Research, Research Programs Unit, Institute of Biotechnology, DNA Sequencing and Genomics, Staff Services, Department of Microbiology, HUS Inflammation Center, Department of Dermatology, Allergology and Venereology, HUS Shared Group Services, HUSLAB, Faculties
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley Blackwell 2020
• Subjects: environment and hygiene hypothesis; epidemiology; omics- and systems biology; LONG NONCODING RNAS; ASTHMA RISK; HOUSE-DUST; DISEASES; EXPOSURE; General medicine; internal medicine and other clinical medicine; karelia*; karelian
• Online Access: http://hdl.handle.net/10138/320390

Background After the Second World War, the population living in the Karelian region was strictly divided by the "iron curtain" between Finland and Russia. This resulted in different lifestyle, standard of living, and exposure to the environment. Allergic manifestations and sensitization to common allergens have been much more common on the Finnish compared to the Russian side. Objective The remarkable allergy disparity in the Finnish and Russian Karelia calls for immunological explanations. Methods Young people, aged 15-20 years, in the Finnish (n = 69) and Russian (n = 75) Karelia were studied. The impact of genetic variation on the phenotype was studied by a genome-wide association analysis. Differences in gene expression (transcriptome) were explored from the blood mononuclear cells (PBMC) and related to skin and nasal epithelium microbiota and sensitization. Results The genotype differences between the Finnish and Russian populations did not explain the allergy gap. The network of gene expression and skin and nasal microbiota was richer and more diverse in the Russian subjects. When the function of 261 differentially expressed genes was explored, innate immunity pathways were suppressed among Russians compared to Finns. Differences in the gene expression paralleled the microbiota disparity. High Acinetobacter abundance in Russians correlated with suppression of innate immune response. High-total IgE was associated with enhanced anti-viral response in the Finnish but not in the Russian subjects. Conclusions and clinical relevance Young populations living in the Finnish and Russian Karelia show marked differences in genome-wide gene expression and host contrasting skin and nasal epithelium microbiota. The rich gene-microbe network in Russians seems to result in a better-balanced innate immunity and associates with low allergy prevalence. Peer reviewed