Recombinant human PRAME immunization reducesPRAME-expressing tumor growth in mice

Intrоduction.Human antigen PRAME is preferentially expressed in a number of different tumor types and may be a potent target for anti-tumor immunotherapy.Purpose.To study anti-tumor action of immunogenic mix recombinant PRAME protein and adjuvant in mice with innate immunity.Materials and methods.C57BL/6 female mice were used for immunization with purified human recombinant protein PRAME. Human PRAME gene coding sequence was cloned in mammalian expressing vector pCEP4 and resulting plasmid was introduced in mouse melanoma B16F10 cells by transfection followed by RQ-PCR, Western blot and flow-cytometry analysis. Then stably PRAME-transfected melanoma cells were injected in mice.Results.The mouse melanoma B16F10 cells stably expressing human PRAME protein were obtained. We demonstrate the 10-fold decreased tumor volume in mice with melanoma B16F10 expressing human PRAME after preventive immunization series with recombinant PRAME protein. The tumor volume reducing was correlated with high titer (6.14 × 10 5) of anti-PRAME antibodies in mice sera.Conclusion.These data indicate that recombinant protein PRAME is immunogenic and may be a potent antigen for immunotherapuetics studies.