Figure 1.

Albumin fusion enhances the bioavailability of antigen in the dLN. (a) Schematic of pharmacokinetic model describing absorbance rate (k_abs) and clearance rate (k_clear), which determine bioavailability in lymphoid organs. (b) Schematic of MSA-E7_38–57 protein design. (c) FITC labeled E7_38–57 or MSA-E7_38–57 was injected either subcutaneously or intravenously in mice (n = 3 mice per group). <10 μl blood draws were used to quantify antigen concentration in serum over the course of 24 hours following injection; data was used to determine pharmacokinetic model fits, shown with solid lines. (d) Calculated k_abs rates for E7_38–57 peptide and MSA-E7_38–57 (fit data ± SE). (e) Splenocytes from E7_38–57-vaccinated mice were restimulated in the presence of brefeldin A with indicated antigen, either fresh or treated with 10% mouse serum for 24 hours. Shown is the percentage IFNγ response from serum-treated antigen restimulation compared to response from fresh antigen as measured by intracellular cytokine staining (n = 2 replicates). (f) FITC-labeled E7_38–57 or MSA-E7_38–57 was injected subcutaneously in mice at the indicated doses. 8 hours after injection, inguinal lymph nodes were excised and imaged on IVIS (n = 6 lymph nodes per group). Data are representative of two independent experiments. Statistical significance calculated using two-tailed t tests (d,e) or one-way ANOVA with Dunnett’s multiple comparisons test against PBS (f).