Flow cytometry and targeted immune transcriptomics identify distinct profiles in patients with chronic myeloid leukemia receiving tyrosine kinase inhibitors with or without interferon-α

• Published in: Journal of translational medicine 2020-01, Vol.18 (1), p.2-2, Article 2
• Main Authors: Alves, Raquel, McArdle, Stephanie E B, Vadakekolathu, Jayakumar, Gonçalves, Ana Cristina, Freitas-Tavares, Paulo, Pereira, Amélia, Almeida, Antonio M, Sarmento-Ribeiro, Ana Bela, Rutella, Sergio
• Format: Article
• Language: English
• Subjects: Cancer; CD4 antigen; Chronic myeloid leukemia; Clinical trials; Data analysis; Flow Cytometry; Gene expression; Gene expression profiling; Humans; Imatinib; Immune monitoring; Immune response; Immune system; Immunology; Immunosurveillance; Immunotherapy; Inhibitors; Interferon; Interferon-alpha - therapeutic use; Interleukin 21; Kinases; Leukemia; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - drug therapy; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - genetics; Lymphocytes; Lymphocytes T; Myeloid leukemia; Natural killer cells; Patients; PD-1 protein; PD-L1 protein; Peripheral blood; Population studies; Protein Kinase Inhibitors - pharmacology; Protein Kinase Inhibitors - therapeutic use; Software; Suppressor cells; Transcriptome; Tumor cells; Tumor necrosis factor-TNF; Tyrosine kinase inhibitors; α-Interferon
• ISSN: 1479-5876; 1479-5876
• DOI: 10.1186/s12967-019-02194-x

Tumor cells have evolved complex strategies to escape immune surveillance, a process which involves NK cells and T lymphocytes, and various immunological factors. Indeed, tumor cells recruit immunosuppressive cells [including regulatory T-cells (Treg), myeloid-derived suppressor cells (MDSC)] and express factors such as PD-L1. Molecularly targeted therapies, such as imatinib, have off-target effects that may influence immune function. Imatinib has been shown to modulate multiple cell types involved in anti-cancer immune surveillance, with potentially detrimental or favorable outcomes. Imatinib and other tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML) have dramatically changed disease course. Our study aimed to characterize the different populations of the immune system in patients with CML affected by their treatment. Forty-one patients with CML [33 treated with TKIs and 8 with TKIs plus interferon (IFN)-α] and 20 controls were enrolled in the present study. Peripheral blood populations of the immune system [referred to as the overview of immune system (OVIS) panel, Treg cells and MDSCs] and PD-1 expression were evaluated by flow cytometry. The immunological profile was assessed using the mRNA Pan-Cancer Immune Profiling Panel and a NanoString nCounter FLEX platform. Patients receiving combination therapy (TKIs + IFN-α) had lower numbers of lymphocytes, particularly T cells [838/µL (95% CI 594-1182)] compared with healthy controls [1500/µL (95% CI 1207 - 1865), p = 0.017]. These patients also had a higher percentage of Treg (9.1%) and CD4 PD-1 cells (1.65%) compared with controls [Treg (6.1%) and CD4 /PD-1 (0.8%); p ≤ 0.05]. Moreover, patients treated with TKIs had more Mo-MDSCs (12.7%) whereas those treated with TKIs + IFN-α had more Gr-MDSC (21.3%) compared to controls [Mo-MDSC (11.4%) and Gr-MDSC (8.48%); p ≤ 0.05]. CD56 NK cells, a cell subset endowed with immune-regulatory properties, were increased in patients receiving TKIs plus IFN-α compared with those treated with TKIs alone. Interestingly, serum IL-21 was significantly lower in the TKIs plus IFN-α cohort. Within the group of patients treated with TKI monotherapy, we observed that individuals receiving 2nd generation TKIs had lower percentages of CD4 Treg (3.63%) and Gr-MDSC (4.2%) compared to patients under imatinib treatment (CD4 Treg 6.18% and Gr-MDSC 8.2%), but higher levels of PD-1-co-expressing CD4 cells (1.92%). Our results suggest that TKIs in combination with IFN-α ma