Table 1.

Phenotypes, inducers, hallmarks, and functions of activated and polarized macrophages.^[23,30]

Phenotypes	Inducers	Membrane receptors	Enzymes	Cytokines	Chemokines	Functions
M1	IFN-γ, TNF-α, LPS	CD86, MHC-II, IL-2Ra, IL-15Ra, IL-7R	iNOS (RNI/ROI), PTGS2	IL-1, IL-6, IL-10 (low), IL-12 (high), IL-15, IL-23, TNF-α	CCL8, CCL15, CCL19, CCL20, CXCL9, CXCL10, CXCL11, CXCL13	Th1 response; type I inflammation; phagocytosis; intracellular pathogen killing; tumor resistance; proinflammatory
M2a	IL-4, IL-13	MHC-II, MRC1, SR-A1, DCL-1, DCSIGN, MS4A4A, CLECSF6	Arg (Polyamine), PTGS1	IL-10, Decoy IL-1RII, IL-1ra, FN1, bIG-H3, IGF-1, PDFGC, F13A1, PGL2, TGF-β	CCL13, CCL14, CCL17, CCL18, CCL23, CCL26	Th2 response; type II inflammation; allergy reaction; parasite encapsulation, killing and immunity; antiinflammatory
M2b	LPS, IL-1β, antigen–antibody immune complexes (ICs), Toll-like receptor (TLR) agonists, IL-1R ligands	MHC-II, CD86	SPHK1	IL-1, IL-6, IL-10 (high), IL-12 (low), TNF-α	CCL1, CCL20, CXCL1, CXCL2, CXCL3	Th2 activation; immunomodulation; interacting with B lymphocytes and maintaining antibody production; proinflammatory or antiinflammatory
M2c	IL-10, TGF-β, glucocorticoids	CD163, TLR-8, TLR-1, IL-21R, SLAM, MR (CD206)	–	IL-10, TGF-β	CCL18; Matrix (PTX3, versican, α antitrypsin)	Prohealing; immunomodulation; matrix deposition; tissue remodeling; inflammation termination