C-C motif chemokine receptor-like 2 promotes the interferon-γ signaling response in myeloid neoplasms with erythroid differentiation and mutated <i>TP53</i>

Patients with myeloid neoplasms with loss-of-function TP53 mutations and erythroid differentiation have poor outcomes, and a better understanding of disease biology is required. Upregulation of interferon-γ (IFN-γ) signaling has been associated with acute myeloid leukemia (AML) progression, selection of TP53 mutated clones and chemotherapy resistance, but its drivers remain unclear. In this study, we found that the surface receptor C-C motif chemokine receptor-like 2 (CCRL2) is over-expressed in AML with erythroid differentiation and TP53 mutations compared to other AML subtypes and healthy hematopoietic cells. CCRL2 knockout (KO) suppressed erythroleukemia growth in vitro and in vivo. Further proteomics and transcriptomics analysis revealed IFN-γ signaling response as the top CCRL2-regulated pathway in erythroleukemia. Our mechanistic studies support direct CCRL2-driven IFN-γ signaling upregulation without a clear effect of exogenous IFN-γ, through phosphorylation of STAT1, which is partially mediated by JAK2. CCRL2/IFN-γ signaling is up-regulated in erythroid leukemias, and TP53 mutated AML and appears to be directly induced by TP53 KO. Finally, CCRL2/IFN-γ signaling is associated with the transformation of pre-leukemic single-hit TP53 clones to multi-hit TP53 mutated AML, increased resistance to venetoclax and worse survival in AML. Overall, our findings support the view that CCRL2 is an essential driver of cell-autonomous IFN-γ signaling response in myeloid neoplasms with erythroid differentiation and TP53 mutations, and highlight CCRL2 as a relevant novel target for these neoplasms.