Antigen accumulation in the B cell follicle is impaired in aged mice

Abstract Vaccine responses are impaired in aged mice and older people. An essential early step in mounting successful responses to vaccines is the delivery of antigens from the site of injection to the draining lymph node. This study tested the hypothesis that particle drainage to the lymph node is impaired in older mice after intramuscular injection. We observed fewer 20nm nanoparticles in the B cell follicle of the draining lymph node in aged mice after intramuscular injection. However, there was no significant difference in the abundance of larger 1000nm particles in the lymph nodes of aged mice, which are typically transported to the lymph node by antigen presenting cells. This data suggests that access of smaller antigens to the B cell follicle is impaired in ageing and may have implications for the initiation of T and B cell responses after vaccination. Competing Interest Statement Michelle Linterman reports funding from GSK outside this work. The remaining authors have no additional financial interests. Footnotes ↵* Co-senior authors