Frontiers in Immunology (Dec 2022)

The Yin-Yang of myeloid cells in the leukemic microenvironment: Immunological role and clinical implications

  • Fábio Magalhães-Gama,
  • Fábio Magalhães-Gama,
  • Fábio Magalhães-Gama,
  • Fabíola Silva Alves-Hanna,
  • Fabíola Silva Alves-Hanna,
  • Nilberto Dias Araújo,
  • Nilberto Dias Araújo,
  • Mateus Souza Barros,
  • Mateus Souza Barros,
  • Flavio Souza Silva,
  • Flavio Souza Silva,
  • Claudio Lucas Santos Catão,
  • Claudio Lucas Santos Catão,
  • Júlia Santos Moraes,
  • Izabela Cabral Freitas,
  • Andréa Monteiro Tarragô,
  • Andréa Monteiro Tarragô,
  • Andréa Monteiro Tarragô,
  • Adriana Malheiro,
  • Adriana Malheiro,
  • Adriana Malheiro,
  • Andréa Teixeira-Carvalho,
  • Andréa Teixeira-Carvalho,
  • Andréa Teixeira-Carvalho,
  • Allyson Guimarães Costa,
  • Allyson Guimarães Costa,
  • Allyson Guimarães Costa,
  • Allyson Guimarães Costa,
  • Allyson Guimarães Costa

DOI
https://doi.org/10.3389/fimmu.2022.1071188
Journal volume & issue
Vol. 13

Abstract

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The leukemic microenvironment has a high diversity of immune cells that are phenotypically and functionally distinct. However, our understanding of the biology, immunology, and clinical implications underlying these cells remains poorly investigated. Among the resident immune cells that can infiltrate the leukemic microenvironment are myeloid cells, which correspond to a heterogeneous cell group of the innate immune system. They encompass populations of neutrophils, macrophages, and myeloid-derived suppressor cells (MDSCs). These cells can be abundant in different tissues and, in the leukemic microenvironment, are associated with the clinical outcome of the patient, acting dichotomously to contribute to leukemic progression or stimulate antitumor immune responses. In this review, we detail the current evidence and the many mechanisms that indicate that the activation of different myeloid cell populations may contribute to immunosuppression, survival, or metastatic dissemination, as well as in immunosurveillance and stimulation of specific cytotoxic responses. Furthermore, we broadly discuss the interactions of tumor-associated neutrophils and macrophages (TANs and TAMs, respectively) and MDSCs in the leukemic microenvironment. Finally, we provide new perspectives on the potential of myeloid cell subpopulations as predictive biomarkers of therapeutical response, as well as potential targets in the chemoimmunotherapy of leukemias due to their dual Yin-Yang roles in leukemia.

Keywords