The present invention provides immunostimulatory compositions. Generally, the immunostimulatory compositions include at least partially purified conjugates that include at least one IRM moiety covalently coupled to an antigenic peptide. In some embodiments, the immunostimulatory composition includes monomeric conjugates. In other embodiments, the immunostimulatory composition includes an aggregate of a conjugate and at least one other antigenic peptide (e.g., another conjugate and/or unconjugated peptide). The present invention also provides methods of using such immunostimulatory compositions. In some embodiments, the methods include inducing an immune response by contacting the immunostimulatory composition with an immune cell. In other embodiments, the method includes treating a condition by administering an immunostimulatory composition to a subject in an amount effective to ameliorate at least one symptom or clinical sign of the condition.
