Characterization of polarization states of canine monocyte derived macrophages

Qingkang Lyu; Edwin J A Veldhuizen; Irene S Ludwig; Victor P M G Rutten; Willem van Eden; Alice J A M Sijts; Femke Broere

doi:10.1371/journal.pone.0292757

Characterization of polarization states of canine monocyte derived macrophages

PLoS One. 2023 Nov 8;18(11):e0292757. doi: 10.1371/journal.pone.0292757. eCollection 2023.

Authors

Qingkang Lyu^{1

2}, Edwin J A Veldhuizen¹, Irene S Ludwig¹, Victor P M G Rutten^{1

3}, Willem van Eden¹, Alice J A M Sijts¹, Femke Broere^{1

4}

Affiliations

¹ Department Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
² Immunology Center of Georgia, Augusta University, Augusta, GA, United States of America.
³ Department of Veterinary Tropical diseases, Faculty of Veterinary Science, Pretoria University, Pretoria, South Africa.
⁴ Department of Clinical Sciences of Companion Animals, Faculty Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.

Abstract

Macrophages can reversibly polarize into multiple functional subsets depending on their micro-environment. Identification and understanding the functionality of these subsets is relevant for the study of immune‑related diseases. However, knowledge about canine macrophage polarization is still in its infancy. In this study, we polarized canine monocytes using GM-CSF/IFN- γ and LPS towards M1 macrophages or M-CSF and IL-4 towards M2 macrophages and compared them to undifferentiated monocytes (M0). Polarized M1 and M2 macrophages were thoroughly characterized for morphology, surface marker features, gene profiles and functional properties. Our results showed that canine M1-polarized macrophages obtained a characteristic large, roundish, or amoeboid shape, while M2-polarized macrophages were smaller and adopted an elongated spindle-like morphology. Phenotypically, all macrophage subsets expressed the pan-macrophage markers CD14 and CD11b. M1-polarized macrophages expressed increased levels of CD40, CD80 CD86 and MHC II, while a significant increase in the expression levels of CD206, CD209, and CD163 was observed in M2-polarized macrophages. RNAseq of the three macrophage subsets showed distinct gene expression profiles, which are closely associated with immune responsiveness, cell differentiation and phagocytosis. However, the complexity of the gene expression patterns makes it difficult to assign clear new polarization markers. Functionally, undifferentiated -monocytes, and M1- and M2- like subsets of canine macrophages can all phagocytose latex beads. M2-polarized macrophages exhibited the strongest phagocytic capacity compared to undifferentiated monocytes- and M1-polarized cells. Taken together, this study showed that canine M1 and M2-like macrophages have distinct features largely in parallel to those of well-studied species, such as human, mouse and pig. These findings enable future use of monocyte derived polarized macrophages particularly in studies of immune related diseases in dogs.

Copyright: © 2023 Lyu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cell Differentiation
Dogs
Macrophages* / metabolism
Monocytes* / metabolism
Phagocytosis

Grants and funding

The China Scholarship Council (CSC) offered a scholarship with award number 201606170114 to Qingkang Lyu. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.