Figure 1: Albumin-binding peptide conjugation enhances LN targeting and immunogenicity of peptide antigens.

A, Schematic of DSPE conjugated to EGP₂₀ via a PEG spacer. B, Schematic of cyclized albumin-binding peptide conjugated to EGP₂₀ peptide via a PEG spacer. C-D, C57BL6/J mice were injected s.c. at the tail base with 15 nmol TAMRA labeled EGP₂₀ peptide or ABP-PEG-EGP₂₀ and 25 µg c-di-GMP adjuvant. C, Axillary (ax) and inguinal (ing) LNs were resected 24 hours later and imaged using IVIS. Shown are resected nodes. D, Quantification of background-subtracted radiant efficiency of images shown in C ((photons*s⁻¹*cm⁻²*steradian⁻¹)/(µW*cm²)). n = 6/LN type; student’s t-test; representative of 2 independent experiments. E, C57BL6/J mice were primed on day 0 and boosted on day 14 with 5 nmol EGP₂₀ peptide or EGP₂₀-conjugate and 25 µg c-di-GMP. Tetramer staining was performed on day 21. Mean tetramer responses quantified as % tetramer⁺ of CD8⁺. n = 6–9/group; ANOVA with Bonferroni correction for shown preplanned comparisons; representative of 2 independent experiments. *P<0.05, **P<0.01, ***P<0.001.