Abstract :
[en] Background: AML is an aggressive cancer with low survival rates. While current therapies trigger resistance and relapse, immune checkpoint blockade (ICB) has limited effectiveness. Selecting AML patients for immunotherapies is challenging due to disease heterogeneity and absence of universal immune markers. Patient immune profiling will dissect AML-immune cell interactions to suggest combinatorial treatments.
Aim: We hypothesize that distinct AML subtypes follow specific paths to trigger T-cell dysfunction. AML blast-specific immune profiling will identify subgroups with distinct immune characteristics, further assessed by T-cell-AML co-cultures and FACS analysis.
Methods: Our integrative omics approach included bulk differential gene expression analysis, cell differentiation gene signature identification, tumor microenvironment (TME) immune cell type composition (xCell), and tumor immune dysfunction/exclusion (TIDE) prediction to publicly available patient cohorts. Celligner computational alignment identified cell lines resembling the AML patient subgroups profiled for in vitro/ex vivo investigations. Immune-related and major histocompatibility complex (MHC) gene expression levels were examined in the Cancer Cell Line Encyclopedia cohort. We combined T-cell activation assays in AML co-cultures (HEL, F36P, MUTZ3, MONO-MAC1, U937, TF1 cells) with multiparametric FACS analysis to monitor T-cell functionality.
Results: Three immunophenotypes emerged: (1) one subgroup is characterized by TME T-cell infiltration, T-cell dysfunction, low MHC, and high PD-L1 expression and correlates with megakaryoblastic/erythroleukemic differentiation, and patients with a history of myelodysplastic syndrome and early prevented T-cell activation/proliferation signaling (HEL, F36P); (2) a profile associated with myelomonocytic/monocytic AML differentiation (MUTZ3, MONO-MAC1), with a T-cell-depleted TME, M2 macrophage enrichment upregulated MHC subunit and immunosuppressive factor expression levels (VISTA, galectins, and TIM-3); (3) an immunostimulatory subgroup, characterized by low MHC and immune marker gene expression levels (U937, TF1).
Conclusion: Our study reveals distinct AML immunophenotypes linked to diverse immunomodulatory factors, maturation stages, and modulatory potential on T-cell activation/proliferation. These subtypes will be instrumental in predicting responders to potential combinatorial regimens including immunotherapies.
