Engineered CCR5 superagonist chemokine as adjuvant in anti-tumor DNA vaccination

Chemokine receptors are promising targets for enhancing T-cell immunity and anti-cancer therapy. CCL5 is a potential adjuvant for DNA vaccination. We postulated that CCR5 superagonists could be even more effective. A CCR5 superagonist derived from natural CCL5 by directed in vitro evolution, namely 1P7, is used as a DNA vaccine adjuvant and expressed as fused chemokine-Ig (1P7-Ig). We show that OVA + 1P7-Ig DNA co-inoculation induced higher frequencies of OVA-specific CD8 lymphocytes than OVA + CCL5-Ig or controls and gave an even better protection against tumor growth in a CCR5-dependant manner. Our results indicate that CCR5-superagonists may provide potent adjuvants for vaccines.