Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster E2
Höfundar / Authors: Poorya Foroutan Pajoohian1,2, Jenny Lorena Molina Estupiñan1,2, Auður Anna Aradóttir Pind1,2, Gabriel Kristian Pedersen3, Dennis Christensen3, Ingileif Jónsdóttir1, Stefanía P. Bjarnarson1,2
Starfsvettvangur / Affiliations: 1 Faculty of Medicine, School of Health Sciences, University of Iceland, Iceland 2 Department of Immunology, Landspitali, the National University Hospital of Iceland, Iceland 3 Statens Serum Institut, Copenhagen, Denmark
Kynnir / Presenter: Poorya Foroutan Pajoohian
Understanding how immunization schedules shape B-cell activation, GC formation and fate decisions of GC outputs is critical for an optimal vaccine design. We compared a heterologous regimen, s.c. priming with 0.25 µg Pn1-CRM197 + CAF01, followed by i.n. booster with 0.25, 2 or 4 µg formulated with mmCT, to a homologous s.c. CAF01/s.c. mmCT schedule. Spleens were analyzed 14 days post-boost by flow cytometry for GC B cells, memory subsets, plasmablasts/plasma cells and BAFF-R/BCMA expression. Germinal center induction was largely comparable across the different schedules. However, memory B cell profiles varied between schedules: the homologous schedule yielded more class-switched memory B cells, whereas heterologous schedules favored induction of unswitched IgM⁺ memory B cells that expressed higher BAFF-R, a receptor linked to longevity and recall. Heterologous schedule led to fewer plasmablasts/plasma cells differentation and lower BCMA expression than homologous immunization Interestingly, functionally splenic IgM⁺ memory B cells can traffic to mucosal compartments, undergo IgA class-switching and support mucosal immunity. These findings offer valuable insights for designing vaccine strategies that enhance long-lasting B cell mediated immunity with dual protective capacity againstboth systemic and mucosal infections.