Offer of the technology which offers the human antibody cheaply making use of the iPS cell and the said iPS cell of the B cell origin by simple technique and the immunity type human conversion mouse etc which uses the cell which is differentiated from the said iPS cell. In the B cell, to clone which can obtain C/EBP and the Pax5 revelation deterrent the nuclear initialization factor which is not included, the nuclear acid which especially Oct3/4, Sox2, Klf4 and c-Myc the code is done, by making contact being the cell which is converted, the cell (B-iPS cell) where the immunoglobulin gene is reconstructed, at the same time differentiation multipurpose Characteristic and possesses self duplication talent. Differentiating the B-iPS cell cell of the B cell origin which immunity is done with the specified antigen, it features that you recover the antibody from the culture of the B cell which can, production manner of the monoclonal antibody for the said specified antigen. Differentiating the B-iPS cell, it features that it transplants the human hemotopoiesis immunity type cell which can, to the immunity incomplete mouse, production manner of the immunity type human conversion mouse.簡便な手法によるB細胞由来のiPS細胞、該iPS細胞を用いてヒト抗体を安価に提供する技術、該iPS細胞から分化させた細胞を用いた免疫系ヒト化マウス等の提供。B細胞に、C/EBPαおよびPax5発現阻害物質を含まない核初期化因子、特にOct3/4、Sox2、Klf4およびc-Mycをコードする核酸、を接触させることにより得られるクローン化された細胞であって、免疫グロブリン遺伝子が再構成されており、かつ分化多能性および自己複製能を有する細胞(B-iPS細胞)。所定の抗原で免疫したB細胞由来のB-iPS細胞細胞を分化させて得られるB細胞の培養物から抗体を回収することを特徴とする、該所定の抗原に対するモノクローナル抗体の製造方法。B-iPS細胞を分化させて得られるヒト造血・免疫系細胞を、免疫不全マウスに移植することを特徴とする、免疫系ヒト化マウスの作製方法。
