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Epigenetic/Genetic variations in CG-rich elements of immune-related genes contribute to food allergy development during childhood
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  • Maria Kostara,
  • Vasiliki Chondrou,
  • Vassilis Fotopoulos,
  • Argyro Sgourou,
  • Sophia Tsabouri
Maria Kostara
University General Hospital of Ioannina

Corresponding Author:[email protected]

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Vasiliki Chondrou
Hellenic Open University
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Vassilis Fotopoulos
Hellenic Open University
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Argyro Sgourou
Hellenic Open University
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Sophia Tsabouri
University of Ioannina
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Abstract

Background: Genetic areas of FOXP3 TSDR, HLA-G upstream of CpG island 96, CpG41 and CpG73 islands of the HLA‐DRB1 and HLA-DQB1 genes respectively, previously documented to display immune modulatory properties, were subjected to epigenetic/genetic analysis to assess their influence in IgE-mediated food allergy (FA) development in children. Methods: 64 orally challenged and IgE- tested food allergic subjects together with 44 controls were recruited. Targeted pyrosequencing analysis, to detect DNA methylation status and genetic variations was utilized and experimental results obtained were analysed by statistical software platform and correlated to clinical data. Also, transcription factor (TF) binding sites at study areas were unmasked by the JASPAR prediction database. Results: Parents’ smoking was significantly correlated with aberrant methylation patterns, regardless food allergic or control status. HLA-G promoter region showed a trend for hypomethylation in food allergic subjects, with one of the CG sites displaying significantly decreased methylation values. Rs1233333, residing within HLA-G promoter region preserved a protective role towards DNA methylation. Variable methylation patterns were recorded for CpG41 of the HLA‐DRB1 gene and hypermethylation of the region was significantly correlated with the presence of (Single Nucleotide Polymorphisms) SNPs. TFs’ recognition sites, located at studied genetic areas and exerting pivotal regulatory biological roles, are potentially affected from divergent DNA methylation status. Conclusions: We propose that HLA-G expression is triggered by food derived allergens, providing a TregFoxP3-/HLA-G+ subpopulation generation and direct immune-tolerance. Furthermore, clear evidence is provided for the underlying co-operation of genetic polymorphisms with epigenetic events, mainly at CpG41 island of HLA-DRB1 gene, which need an extended investigation and elucidation.
31 Jan 2022Submitted to Pediatric Allergy and Immunology
09 Feb 2022Reviewer(s) Assigned
31 Mar 2022Review(s) Completed, Editorial Evaluation Pending
14 Apr 2022Editorial Decision: Revise Major
03 May 20221st Revision Received
03 May 2022Review(s) Completed, Editorial Evaluation Pending
10 May 2022Reviewer(s) Assigned
24 May 2022Editorial Decision: Accept
Jun 2022Published in Pediatric Allergy and Immunology volume 33 issue 6. 10.1111/pai.13812