Pischedda S, Rivero-Calle I, Gómez-Carballa A, Cebey-López M, Barral-Arca R, Gómez-Rial J, Pardo-Seco J, Curras-Tuala MJ, Viz-Lasheras S, Bello X, Crujeiras AB, Diaz-Lagares A, González-López MT, Martinón-Torres F, and Salas A
Background: Respiratory syncytial virus (RSV) infection has been associated with the subsequent development of recurrent wheezing and asthma, although the mechanisms involved are still unknown. We investigate the role of epigenetics in the respiratory morbidity after infection by comparing methylation patterns from children who develop recurrent wheezing (RW-RSV), subsequent asthma (AS-RVS), and those experiencing complete recovery (CR-RSV)., Methods: Prospective, observational study of infants aged < 2 years with RSV respiratory infection admitted to hospital and followed-up after discharge for at least three years. According to their clinical course, patients were categorized into subgroups: RW-RSV ( n = 36), AS-RSV ( n = 9), and CR-RSV ( n = 32). The DNA genome-wide methylation pattern was analyzed in whole blood samples, collected during the acute phase of the infection, using the Illumina Infinium Methylation EPIC BeadChip (850K CpG sites). Differences in methylation were determined through a linear regression model adjusted for age, gender and cell composition., Results: Patients who developed respiratory sequelae showed a statistically significant higher proportion of NK and CD8T cells (inferred through a deconvolution approach) than those with complete recovery. We identified 5,097 significant differentially methylated positions (DMPs) when comparing RW-RSV and AS-RVS together against CR-RSV. Methylation profiles affect several genes involved in airway inflammation processes. The most significant DMPs were found to be hypomethylated in cases and therefore generally leading to overexpression of affected genes. The lead CpG position (cg24509398) falls at the gene body of EYA3 ( P -value = 2.77×10 -10 ), a tyrosine phosphatase connected with pulmonary vascular remodeling, a key process in the asthma pathology. Logistic regression analysis resulted in a diagnostic epigenetic signature of 3-DMPs (involving genes ZNF2698 , LOC102723354 and RPL15 / NKIRAS1 ) that allows to efficiently differentiate sequelae cases from CR-RSV patients (AUC = 1.00). Enrichment pathway analysis reveals the role of the cell cycle checkpoint (FDR P -value = 4.71×10 -2 ), DNA damage (FD P -value = 2.53×10 -2 ), and DNA integrity checkpoint (FDR P -value = 2.56×10 -2 ) in differentiating sequelae from CR-RSV patients., Conclusions: Epigenetic mechanisms might play a fundamental role in the long-term sequelae after RSV infection, contributing to explain the different phenotypes observed., Competing Interests: IR-C has received honoraria from GSK, Pfizer, Sanofi Pasteur and MSD for taking part in advisory boards and expert meetings and for acting as a speaker in congresses outside the scope of the submitted work. IR-C has also acted as subinvestigator in randomized controlled trials of Ablynx, Abbot, Seqirus, Sanofi Pasteur MSD, Sanofi Pasteur, Cubist, Wyeth, Merck, Pfizer, Roche, Regeneron, Jansen, Medimmune, Novavax, Novartis and GSK. FM-T has received honoraria from GSK group of companies, Pfizer Inc, Sanofi Pasteur, MSD, Seqirus, Biofabri and Janssen for taking part in advisory boards and expert meetings and for acting as a speaker in congresses outside the scope of the submitted work. FM-T has also acted as principal investigator in randomized controlled trials of the above-mentioned companies as well as Ablynx, Gilead, Regeneron, Roche, Abbott, Novavax, and MedImmune, with honoraria paid to his institution. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Pischedda, Rivero-Calle, Gómez-Carballa, Cebey-López, Barral-Arca, Gómez-Rial, Pardo-Seco, Curras-Tuala, Viz-Lasheras, Bello, Crujeiras, Diaz-Lagares, González-López, Martinón-Torres, Salas and GENDRES consortium.)