Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023
Höfundar / Authors: Poorya Foroutan Pajoohian (1,2), Audur Anna Aradottir Pind (1,2), Jenny Lorena Molina Estupiñan (1,2), Dennis Christensen (3), Thorunn A. Olafsdottir (1), Ingileif Jonsdottir (1), Stefania P. Bjarnarson (1,2)
Starfsvettvangur / Affiliations: 1. Faculty of Medicine, School of Health Sciences, University of Iceland, 2. Department of Immunology, Landspitali, the National University Hospital of Iceland, 3. Statens Serum Institute, Copenhagen, Denmark
Kynnir / Presenter: Poorya Foroutan Pajoohian
Most pathogens enter the body through the mucosal surfaces. The study aims to assess if heterologous route prime-boost immunization can induce strong and persistent humoral immune responses. We immunized neonatal mice with a pneumococcal conjugate vaccine, Pn1-CRM197, and two adjuvants, by heterologous subcutaneous (s.c) priming with CAF01 followed by intranasal (i.n.) booster with mmCT, or two homologous immunizations, either s.c. or i.n.. Blood and saliva were collected at different time points and spleen, bone marrow (BM) and lungs two or five weeks post-booster to assess anti-Pn1 immune responses. Homologous s.c. immunization induced higher serum and lung IgG anti-Pn1. Homologous i.n.immunization induced higher serum IgA anti-Pn1 five weeks post-booster. Homologous s.c. immunization induced higher IgG anti-Pn1 antibody secreting cells (ASCs) in BM and spleen but lower IgA anti-Pn1 ASCs than other immunization strategies. By increasing dose of vaccine in booster of heterologous immunization, we observed increasing IgG and IgA anti-Pn1 levels in serum. Altogether, with the vaccine and adjuvants tested, IgG anti-Pn1 responses induced by heterologous s.c.-i.n. immunization was inferior to homologous s.c. immunization, it induced higher IgA anti-Pn1 response than homologous s.c. immunization. Interestingly, by increasing the vaccine dose in the booster (0.25 µg to 4 µg) in heterologous s.c./i.n. immunization, a stronger IgG anti-Pn1 response can be reached.