Cieniewicz, B.; Oliveira, E.; Saxton, M.; Torabi, D.; Bhatta, A.; Kukutla, P.; Arballo, A.; Yang, Z.; Yu, B.; Fate, M.; Ning, H.; Corey, L.; Maiti, A.; Corey, D.

Disruption of the lipid asymmetric bilayer is a common feature observed in cancer cells. We utilized the natural immune receptor TIM-4 to interrogate for loss of plasma membrane phospholipid polarity in primary acute myelogenous leukemia (AML) samples. We performed FACs analysis in 33 patients and correlated TIM-4-L expression frequency and intensity with molecular disease characteristics. In normal tissues, TIM-4-L is confined to the internal leaflet of the plasma membrane. By contrast, 86% of untreated AML blasts in our analysis displayed upregulation of cell surface TIM-4-L. These observations were agnostic to AML genetic classification, as samples with mutations in TP53, ASXL1, and RUNX1, also displayed TIM-4-L upregulation similar to that seen in favorable and intermediate subtypes. This TIM-4-L dysregulation was also stably present in both Kasumi-1 and MV-4-11 AML cell lines. To evaluate the potential of upregulated TIM-4-L to serve as a target for adoptive T cell therapy (ACT), we constructed TIM-4-L-directed engineered T cells, which demonstrated potent anti-leukemic effects, effectively eliminating AML cell lines both in vitro and in vivo. This approach led to the eradication of AML cells across a range of endogenous TIM-4-L expression levels. These results highlight TIM-4-L as a highly prevalent and novel target for T cell-based therapy in AML. Further investigations into the role of TIM-4-L in AML pathogenesis and its potential as an anti-leukemic target for clinical development are warranted.