The role of MDSCs in the development of bone marrow fibrosis.

Abstract

e18532 Background: Myelofibrosis is a type of myeloproliferative disorder, and research indicates that the immunosuppressive tumor microenvironment plays a significant role in the pathogenesis of myelofibrosis, with myeloid-derived suppressor cells (MDSC) being the primary inhibitory cells involved in shaping the tumor immune microenvironment. In this study, we used flow cytometry to detect the number of MDSC in the bone marrow of myelofibrosis patients, and the concentration of CCL2 in the supernatant of bone marrow MDSC cells of patients with myelofibrosis was detected by Elisa technique. Methods: In this study, we utilized flow cytometry to identify the number of Lin-HLA-DR-CD33+ labeled MDSC in the bone marrow of 109 myelofibrosis patients and 20 healthy individuals. Subsequently, we detected the CCL2 concentration in the cell culture supernatant of bone marrow MDSC cells from 42 patients with bone marrow fibrosis after stable culture using ELISA technique. Results: The results of flow cytometry revealed a significant increase in the percentage of MDSC in the bone marrow of myelofibrosis patients (15.16±6.25%) compared to healthy individuals (1.72±0.88%) (p<0.0001). Among them, the MDSC counts were 20.86±6.17% in PMF patients, 18.10±4.77% in post-ET MF patients, and 15.58±3.65% in post-PV MF patients, with no significant statistical difference in MDSC counts among the three groups.And them, the CCL2 concentration in the supernatant was 13.67±1.68 pg/ml for patients with MDSC count <5% (n=6), 36.36±11.88 pg/ml for patients with MDSC count between 5% and 10% (n=16), 55.12±9.71 pg/ml for patients with MDSC count between 10% and 20% (n=14), and 83.19±14.01 pg/ml for patients with MDSC count >20% (n=6). Conclusions: Research has shown that the number of MDSCs is elevated in patients with myelofibrosis compared to healthy individuals. We also found that as the MDSC count increased, the CCL2 concentration in the cell culture supernatant increased accordingly, suggesting that CCL2 may be involved in the proliferation and activation of MDSCs.