AUTHOR=Yermanos Alexander , Kräutler Nike Julia , Pedrioli Alessandro , Menzel Ulrike , Greiff Victor , Stadler Tanja , Oxenius Annette , Reddy Sai T. TITLE=IgM Antibody Repertoire Fingerprints in Mice Are Personalized but Robust to Viral Infection Status JOURNAL=Frontiers in Cellular and Infection Microbiology VOLUME=Volume 10 - 2020 YEAR=2020 URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2020.00254 DOI=10.3389/fcimb.2020.00254 ISSN=2235-2988 ABSTRACT=Antibody repertoire sequencing provides a molecular fingerprint of current and past pathogens encountered by the immune system. Most repertoire studies in humans require measuring the B cell response in the blood, resulting in a large bias to the IgM isotype. The extent to which the circulating IgM antibody repertoire correlates to lymphoid tissue-resident B cells in the setting of viral infection remains largely uncharacterized. Therefore, we compared the IgM repertoires from both blood and bone marrow (BM) plasma cells (PCs) following acute or chronic lymphocytic choriomeningitis virus (LCMV) infection in mice. Despite previously reported serum alterations between acute and chronic infection, IgM repertoire signatures based on clonal diversity metrics, public clones, network and phylogenetic analysis were largely unable to distinguish infection cohorts. Our findings, however, revealed mouse-specific congruence between the blood and PC repertoires irrespective of infection status. Our study reveals that IgM repertoire analyses may be unsuitable for providing a fingerprint of current or previous immune challenges.