The Evaluation of The Antitumoral Immune Responseby Using Mouse Pluripotent S tem Cell in Breas tCancer Mice Model

Objective: More than a century ago, it was illus trated that immunizationwith embryonic materials can lead to the rejectionof a transplantable tumor. On the other hand, s tudies over thepas t few decades have shown that embryonic s tem cells (ESCs)and their induced counterparts (induced pluripotent s tem cells;iPSCs) have similar cellular and molecular properties to cancercells and could s timulate the immune sys tem, trigger an antitumorresponse and reject tumor cells after transplantation.Materials and Methods: The mouse ESC line C۱۷ and breas tcancer cell line ۴T۱ were provided by Royan S tem Cell Bankand cultured in their appropriate medium. The C۱۷ cells wereprepared in two inactive and lysate forms before vaccination.For inactivation, the cells were irradiated with a ۱۵ Gy gamma-ray. Cell lysates were obtained after five cycles of freezethawing.BALB/C mice were divided for immunization intofour groups including C۱۷ in lysate and inactive forms, adjuvant,and PBS. Immunization was done three times one weekapart. Mice were challenged with ۴T۱ cells one week after thelas t immunization. Tumor growth was monitored every ۳ days.Finally, ۲۱ days after the tumor challenge, all mice were sacrificed.The his tological assay was performed in all groups.Results: The tumor size was significantly reduced in mice immunizedwith C۱۷ cell lysate compared to the PBS group (pvalue <۰.۰۱). Also, the frequency of CD۸+ T cells in the tumortissues significantly increased in the lysate vaccinated group.Conclusion: The results indicated that immunization withlysate of C۱۷ ESCs could s timulate the immune responseagains t a murine breas t carcinoma model.

Keywords:

Antitumor Responses , Breas t Cancer , Cell Lysate , Mouse Embryonic S tem Cell