Figure 8.

Serum antibody titers to (A) LdNH36-dg2 and (B) LdNH36-E-WT (non-polyhistidine tagged) for subtypes IgG1, IgG2a, and IgG2b in response to vaccination with microparticle-formulated LdNH36-dg2 protein and CpG or control formulations. BALB/c mice were vaccinated subcutaneously at weeks 0 and 3 with 40 μg of LdNH36-dg2 protein plus varying amounts of CpG adjuvant (10, 20, 40, or 80 μg) encapsulated in separate PLGA microparticles (MP). Vaccine controls included microparticle-LdNH36-dg2 and soluble LdNH36-dg2 + CpG. Mice were vaccinated in 2 cohorts, separated by 2 d (cohort 1, filled triangles; cohort 2, open squares). Week 5 serum was analyzed by ELISA for LdNH36-dg2- and LdNH36-E-WT-specific IgG1, IgG2a, and IgG2b responses. Negative control groups (microparticle-CpG, empty microparticle, and PBS) had antibody titers less than 10³ and are not plotted. *p < 0.05, **p < 0.01, ***p < 0.001.