Effect of DNA immunizations alone encoding inflammatory chemokine and β-defensin fusions with gp120.

DNA immunizations alone encoding inflammatory chemokine and β-defensin fusions with gp120 elicit strong humoral responses. (A)Env-protein (HIV-1, isolate 89.6)–specific serum antibody responses in pooled sera from 5 mice immunized 5 times with DNA plasmids expressing the following proteins: secretable gp120 alone (pgp120), the fusion of gp120 with human MCP-3 (pMCP3gp120), human MDC (pMDCgp120), murine β-defensin 2 (pmDF2βgp120), and viral chemokine antagonist vMIP2 (pvMIP2gp120). The data are representative of 3 independent experiments, each involving 5 mice per group. (B) Anti-gp120 antibody responses of individual mice at 1:100 serum dilution. Each closed circle represents an individual mouse serum. No anti-gp120 binding is detected in sera from PBS-treated mice or mice immunized with a control construct expressing MCP-3 fusion with enhanced green fluorescent protein (EGFP) (pMCP3-EGFP). (C) Coadministration of DNA expressing chemokine and gp120 (pMCP3 plus pgp120) does not induce α-gp120 antibodies. Data are from pooled sera of 5 mice per group vaccinated 4 times with gene gun. ELISA was performed with titrated amounts of sera in 96-well plates coated with 2.5 μg/mL purified gp120 of HIV-1 (isolate 89.6, produced in vaccinia).