The role of macrophage subtypes and exosomes in immunomodulation

Table 1 Macrophage subtypes and their characteristic markers and stimuli

Macrophage types	Suggested roles	Markers	Different stimulator factors	References
M1	Pro-inflammation, microbicidal effect, tumor resistance	IL-6, IL-10 (low), IL-12 (high), iNOS, CD80, CD86, CXCL9, CXCL10, CXCL11, CCL15, CCL20, CCL22, TLR2, TLR4, MHCII, TNF-α	IL-1, IL-6, IL-12, CXCL1-3, CXCL-5, CXCL8-10, CCL2, Type I IFN, IFN-γ, TNF-α, STAT1, iNOS, LPS, M-CSF, NF-κB, IRF5 miR-155, miR-125b, DNMT1, DNMT3b, HDAC3	[19, 28,29,30,31]
M2a	Allergy, profibrotic, anti-inflammatory, wound healing	IL-10, IL-1R, IL-27Rα, CCL1, CCL17, CCL18, CCL22, CD11b, CD45, CD206, YM1, RELMα, IGF1, DCIR, Stabilin 1, Factor XIII-A, Ly6C, TREM-2, DC-SIGN	IL-4, IL-10, IL-13, (PPAR-γ)	[19, 28, 32,33,34,35]
M2b	Th2 activation, immune regulation, promoting infection, tumor progression	IL-6, TNF-α, CD86, SPHK1	IL-1β, LPS	[28, 31, 36]
M2c	Immunosuppression, phagocytosis, tissue repair, matrix remodeling	IL-10, CXCL13, CD163, CD206, CXCR4, TGF-β, MerTK,	IL-10, glucocorticoids IL-6, IL-10, TNF-α, TLR,	[28, 36, 37]
M2d	Tumor progression, angiogenesis, clearance of apoptotic tissue	IL-10, VEGF, TGF-β,	LPS	[28, 36, 38]

CCL, C–C chemokine ligand; CXCL, C–X–C chemokine ligand; CXCR, C–X–C chemokine receptor; DCIR, dendritic cell immunoreceptor; IFN, interferon; IFNγ, interferon-γ; IL, interleukin; IL-1R, IL-1 receptor; IL-27Rα, IL-27 receptor α-chain; iNOS, inducible nitric-oxide synthase; RELMα, resistin-like molecule-α; SPHK1, sphingosine kinase 1; TLR, Toll-like receptor; CD, cluster of differentiation; TGF-β, transforming growth factor-β; STATs, signal transducer and activator of transcription; PPAR-γ, peroxisome proliferator-activated receptor gamma; TNF-α, tumor necrotic factor-α; YM1, chitinase-like protein 3; LPS, lipopolysaccharides; VEGF, vascular endothelial growth factor; ICAM, intercellular adhesion molecule; DC-SIGN, dendritic cell-specific ICAM-grabbing non integrin; IRF5, interferon regulatory factor 5; HDAC3, histone deacetylase 3; MerTK, myeloid epithelial reproductive tyrosine kinase; M-CSF, macrophage-colony-stimulating factor; DNMT, DNA methyl transferase; miRs, microRNAs; NF-κB, nuclear factor-κB; MHCII, major histocompatibility complex II; IGF, insulin-like growth factor; Ly6C, lymphocyte antigen 6 complex; TREM-2, triggering receptor expressed on myeloid cells 2

ISSN: 1689-1392