Work

Elucidating the systemic humoral response and immune microenvironment at the implant interface of the Vaccine Platform for Extended Antigen Release (VPEAR) 9238

Year: 2025

Type: article

Abstract: Description The Vaccine Platform for Extended Antigen Release (VPEAR) is an implantable device with a polyanhydride depot that sustains the release of the model antigen ovalbumin (OVA) and the adjuvant CpG ODN 1826 for over 24 weeks. A PVDF membrane cap serves as an immune interface, which also prevents cellular infiltration into the depot. Compared to bolus vaccinated mice, VPEAR-implanted animals exhibit consistently higher serum levels of OVA-specific IgG. VPEAR implanted animals also show increased OVA-specific IgG-secreting cells (ISCs) in lymph nodes by week 12 post-vaccination. Histological analysis of the immune interface reveals a highly vascularized tissue layer, while ELISpot assays confirm enrichment of OVA-specific ISCs on the cap. B220+ GL7+ cells also persist on the cap for over 24 weeks, suggesting germinal center activity. Preliminary qPCR data show elevated CXCL13 expression, critical for B-cell zone formation, and CCL5, a recruiter of T cells and monocytes, but no upregulation of CCL21, which is associated with T-cell zones. These findings suggest VPEAR elicits a robust humoral response with sustained B-cell activity at the cap, which may be consistent with a B-cell-dominated tertiary lymphoid structure. Topic Categories Vaccines and Immunotherapy (VAC)

Source: The Journal of Immunology

DOI: 10.1093/jimmun/vkaf283.2664