Mechanisms of immunoediting and immune evasion in MLL-AF9 AML.

Immunoediting describes the dynamic sculpting of cancer cells to evade cancer immune control, thereby enabling the development of tumors in an immunocompetent host resulting in the outgrowth of cancer cells with reduced immunogenicity. Our objective was to assess the effect of immunoediting on the transcriptional landscape. To that extend, we first generated AML from oncogene MLL-AF9 expressed from the retrovirus MSCV-IRES-GFP, by transducing it into lineage depleted bone marrow cells. Viable GFP+ expressing cells were transplanted into Rag2-/-γc-/- recipients and all recipients developed AML. We then extracted and transplanted GFP+ AML cells from spleen into either into C57BL/6J immunocompetent or Rag2-/-γc-/- immunodeficient secondary recipient. Finally after secondary recipients developed AML, GFP+ cells from spleens were isolated and RNA sequencing was performed.