The spleen as a sanctuary site for residual leukemic cells following ABT-199 monotherapy in ETP-ALL

Two mice in which luciferase-positive LOUCY ETP-ALL cells were xenografted were treated with either vehicle or ABT-199 (50 mg/kg) for 11 days. Afterwards, single cells suspensions were made from bone marrow and spleen of both mice for 10x Genomics scRNA-seq. Following quality control, a total of 13,681 spleen cells and 11,442 bone marrow cells of the control mouse and 15,955 spleen cells and 9,443 bone marrow cells of the ABT 199 treated mouse were processed for further analysis. Our data show that ABT-199 triggers transcriptional changes in T-cell differentiation genes in leukemic cells obtained from the spleen microenvironment. These results are in line with our previous findings that mature typical T-ALL are resistant to ABT-199. 10x Genomics single cell RNA-sequencing of LOUCY cells isolated from the bone marrow and spleen of xenograft mice following 11 days of vehicle or ABT-199 treatment