Zabalza, AnaVera, AndreaAlari-Pahissa, ElisendaMunteis Olivas, ElviraMoreira Villanueva, AntíaYélamos López, JoséLlop, MireiaLópez-Botet, M. (Miguel)Martínez Rodríguez, Jose E.2020-06-032020-06-032020Zabalza A, Vera A, Alari-Pahissa E, Munteis E, Moreira A, Yélamos J, Llop M, López-Botet M, Martínez-Rodríguez JE. Impact of cytomegalovirus infection on B cell differentiation and cytokine production in multiple sclerosis. J Neuroinflammation. 2020; 17(1):161. DOI: 10.1186/s12974-020-01840-21742-2094http://hdl.handle.net/10230/44884Background: Human cytomegalovirus (HCMV) infection has been recently associated with a low risk of multiple sclerosis (MS), yet the basis behind this observation remains uncertain. In this study, we aimed to determine in MS patients whether HCMV induces modifications in the peripheral B cell compartment. Methods: HCMV serostatus was determined in 73 MS patients (55 relapsing-remitting MS (RRMS); 18 progressive MS (PMS)) and 30 healthy controls, assessing their B cell immunophenotype and cytokine production (GM-CSF, IL-6, IL-10, and TNFα) by flow cytometry. Results: HCMV seropositivity in untreated MS patients (n = 45) was associated with reduced switched memory B cells, contrasting with an opposite effect in PMS. Expansions of transitional B cells were observed in HCMV(+) IFNβ-treated RRMS patients but not in HCMV(-) cases (p < 0.01), suggesting that HCMV may influence the distribution of B cell subsets modulating the effects of IFNβ. Considering the B cell functional profile, HCMV(-) PMS displayed an increased secretion of proinflammatory cytokines (IL-6, TNFα) as compared to HCMV(+) PMS and RRMS cases (p < 0.001). Conclusions: Our study reveals an influence of HCMV infection on the phenotype and function of B cells, promoting early differentiation stages in RRMS and reducing the proinflammatory cytokine profile in advanced MS forms, which might be related with the putative protective role of this virus in MS.application/pdfeng© The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data mainfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1186/s12974-020-01840-2B cellsHuman cytomegalovirusInterferon-betaMultiple sclerosisinfo:eu-repo/semantics/openAccess