Myeloid malignancies arise from an altered hematopoietic stem cell and mainly comprise
acute myeloid leukemia, myelodysplastic syndromes, myeloproliferative malignancies,
and chronic myelomonocytic leukemia. Myeloid neoplastic leukemic cells may influence
the growth and differentiation of other hematopoietic cell lineages in peripheral
blood and bone marrow. Myeloid-derived suppressor cells (MDSCs) and mesenchymal stromal
cells (MSCs) display immunoregulatory properties by controlling the innate and adaptive
immune systems that may induce a tolerant and supportive microenvironment for neoplasm
development. This review analyzes the main features of MDSCs and MSCs in myeloid malignancies.
The number of MDSCs is elevated in myeloid malignancies exhibiting high immunosuppressive
capacities, whereas MSCs, in addition to their immunosuppression contribution, regulate
myeloid leukemia cell proliferation, apoptosis, and chemotherapy resistance. Moreover,
MSCs may promote MDSC expansion, which may mutually contribute to the creation of
an immuno-tolerant neoplasm microenvironment. Understanding the implication of MDSCs
and MSCs in myeloid malignancies may favor their potential use in immunotherapeutic
strategies.
