We now show that peptide formulation as a lipid A conjugate improves antigen uptake and presentation by DCs in vitro, resulting in higher CD8 and CD4 T cell activation and cytokine production, and that prophylactic and therapeutic vaccination with CRX-527 conjugates containing tumor-specific cytotoxic T lymphocytes (CTL) or T-helper epitopes strongly promote T cell activation, resulting in effective tumor control in vivo. Here, CD4 is linked to neoplasm.