fa Original article Original article <strong>Introduction:</strong> Human papillomavirus (HPV) 16 E7 protein is expressed constitutively by HPV-infected tumor cells. Mutant versions of E7 are considered as safer candidates for immunotherapy of cervical cancer.&nbsp; Different strategies including formulation with adjuvants are used to induce a potent immune response against antigenic proteins. <strong>Methods: </strong>In this experimental study, we used <em>Escherichia coli </em>as a host to recombinantly express wild-type E7 and its mutant non-oncogenic form as E7GGG. We formulated both antigens with Montanide ISA 266 adjuvant and evaluated IFN-&gamma; and IL-4 cytokines and antibody levels and also tumor regression in tumor-harboring C57BL/6 mice. <strong>R</strong><strong>esults:</strong> It was demonstrated that formulation of E7 and E7GGG antigens with Montanide ISA 266 resulted in a Th2-biased immune response. In the therapeutic mouse model, these formulations resulted in significant tumor regression compared to the control group. <strong>Conclusion: </strong>The formulation of the wild-type E7 and mutant E7GGG with Montanide ISA 266 might not be an optimal approach to regress TC-1 induced tumor; however, such combinations might be considered as an additive approach for stimulating the immune responses. Human Papillomavirus 16, E7 Oncogene, Protein Vaccine. 29 33 http://vacres.pasteur.ac.ir/browse.php?a_code=A-10-1-38&slc_lang=fa&sid=1 M Mashhadi Abolghasem Shirazi No Department of Microbiology, Pharmaceutical Science Branch, Islamic Azad University, Tehran, Iran. F Roohvand No Department of Molecular Virology, Pasteur Institute of Iran, Tehran, Iran. A Arashkia Yes Department of Molecular Virology, Pasteur Institute of Iran, Tehran, Iran.