Viral chemokine fusion proteins as vaccine carrier. (A) Ten C3H/HeN mice per group were immunized with DNA constructs pvMIP2sFv38 or pMC148sFv38. Control groups of mice received PBS or were immunized with pvMIP2M-sFv38. As positive control, mice were immunized intraperitoneally with tumor-specific immunoglobulin conjugated to KLH (Ig38-KLH, 50 μg).15,16 The log-rank P value is for comparison of pvMIP2sFv38 with control pvMIP2M-sFv38. (B-C) To test effects of preexisting anticarrier immunity, mice initially were immunized with pvMIP2-Muc1 to establish anti-vMIP2 antibody responses. Then the mice were immunized with pvMIP2sFv38 ([pvMIP2-Muc1[pvMIP2sFv38) or control pvMIP2-Muc1 ([pvMIP2-Muc1]pvMIP2-Muc1). The serum levels of anti-Id38 IgG (B, C) or anti-vMIP2 IgG (D) tested after 2 weeks after the last vaccination. (E) A survival plot of representative 4 independent experiments with 10 mice/group, challenged intraperitoneally with a lethal dose of 38C13 tumor cells. The log-rank P value is for comparison of pvMIP2sFv38 with PBS. (F) Chemokine coadministration reduced levels anti-Id38 IgG. Data from pooled sera from 5 mice per group vaccinated with pvMIP2sFv38 vaccine together with competing chemokine construct (pvMIP2-Muc1), or irrelevant chemokine plasmid (pMCP3-Muc1) or antigen (pMucS). The P value is a comparison between groups pMucS + pvMIP2sFv38 and pvMIP2-Muc1 + pvMIP2sFv38. Error bars depict the standard error of the mean of 5 mice per group.