Establishment of a mouse leukemia model and the exploring the way to enhance the anti-leukemia immunity using this mouse leukemia model.

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K19550
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Hematology
• Research Institution: Osaka University
• Principal Investigator: Jun Nakata 大阪大学, 医学系研究科, 寄附講座助教 (90528952)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: マウス白血病モデル / 癌免疫 / 癌ワクチン / WT1 / 併用療法 / ヘルパーペプチド

Outline of Final Research Achievements

We analyzed the immunological features of patients in Phase 2 clinical study of WT1 peptide vaccination for AML patients after chemotherapy. We found that the frequencies of WT1 specific CTLs were higher in good responders than in poor responders. Also we clarified the clonality of these CTLs and reported the results. Next, we established a new mouse leukemia model by transducing the human lukememia gene 'MLL/AF9' into the c-kit+ BM cells of B6 mice. By using this mouse leukeia model, we found that the helper WT1 peptide could enhance and prolong the anti-leukemia effect of WT1 CTL peptide vaccination and that combination peptide vaccination therapy could lead the better clinical outcome than the CTL peptide vaccination alone. WT1 specific CTLs in combination peptide vaccination were not exhausted at least whithin 3 months, so checkpoint blockade therapy showed no clinical benefit when we used it combined with the combination peptide vaccination therapy.

Free Research Field

癌免疫