Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster V23
Höfundar / Authors: Auður Anna Aradóttir Pind (1, 2), Brynjar Halldórsson (1), Poorya Foroutan Pajoohian (1, 2), Sankar Rathinam (3), Már Másson (3), Stefanía P. Bjarnarson (1, 2), Ingileif Jónsdóttir (1, 2)
Starfsvettvangur / Affiliations: 1. Department of Immunology, Landspítali – the National University Hospital of Iceland, Reykjavík, Iceland 2. Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavík, Iceland 3. Faculty of Pharmaceutical Sciences, School of Health Sciences, University of Iceland, Reykjavík, Iceland
Kynnir / Presenter: Auður Anna Aradóttir Pind
Responses to neonatal vaccination are typically weak and short-lived, but can be improved with adjuvants. Chitosan, a linear polysaccharide derived from chitin has immunostimulatory potential, yet its effects in neonates remain unclear. Moreover, detailed descriptions of the structural properties of chitosan derivatives are often lacking, limiting reproducibility across studies. We evaluated the adjuvant activity of polycationic N,N,N-trimethylchitosan (TMC) and chitosan-HCl salt in a neonatal mouse model to identify structural features contributing to their activity. Neonatal mice received a single immunization with pneumococcal conjugate vaccine (Pn1-CRM197, 2 µg/mouse) alone or adjuvanted with TMC, chitosan-HCl, or native chitosan at two doses (50 or 200 µg/mouse). Pn1-specific serum IgG was measured bi-weekly by ELISA, and antibody-secreting cells (ASC) in bone marrow were enumerated by ELISPOT eight weeks post immunization. Mice given Pn1-CRM197 alone or with chitosan-HCl showed weak responses, while inclusion of chitosan or TMC significantly enhanced Pn1-specific IgG at all time points. Importantly, TMC also increased ASC in bone marrow. This study is the first in a series aimed at identifying structural features of chitosan that are critical for its adjuvant activity. Our findings indicate that TMC has immunostimulatory properties that enhance neonatal immune responses to pneumococcal vaccination, supporting further investigation of related chitosan derivatives.