The alternatively activated, anti-inflammatory M2-macrophages can be separated into at least three subgroups (M2a, M2b, and M2c), which have different functions, including regulation of immunity, maintenance of tolerance and wound healing. Creative Biolabs is well equipped and versed in M2a, M2b, and M2c macrophage polarization assay. Our assay is also designed to evaluate the cell surface receptor expression, cytokine profiles, scavenging functions, and ability to activate or suppress T-cell proliferation.

Introduction to M2 Macrophages

Macrophages are among the earliest arrivals to mediate the host foreign body response. They are plastic cells of the innate immune system that act a wide range of immune- and homeostasis-related functions. Due to their plasticity, macrophages can polarize into a spectrum of activated phenotypes (M1 and M2). M2 macrophages may act later in an anti-inflammatory response by producing cytokines such as interleukin (IL)-4, IL-10, and IL-13. Bacteria such as Yersinia spp., Borrelia burgdorferi, Ehrlichia muris, Chlamydia pneumoniae, Rickettsia conorii or Salmonella typhimurium favor the occurrence of M2 profiles in macrophages. The M2 profile consists of a range of lectin-like molecules, arginase-1 (Arg1), and a lot of immunoregulatory genes and proteins. It is worth noting that the number of bacteria inducing an M2 profile is less than those inducing an M1 profile. This may be related to the fact that antibacterial responses are of T helper type 1 (Th1)-type rather than Th2-type. In tumors, tumor-associated macrophages (TAMs), usually present an M2 state, exerting an inhibitory effect on the cytotoxic function of tumor-killing immune cells, thus impairing antitumor immunity.

Fig.1 Intracellular signaling and metabolic pathways activated into RA anti-inflammatory M2 macrophages.^1,2

M2 Macrophage Polarization Assay at Creative Biolabs

Based on our powerful Macrophage Therapeutics Development Platform, macrophages can be efficiently transformed into M2 and demonstrate effective phagocytosis. M2 macrophages can be generated with specific stimuli, such as lipopolysaccharide (LPS), L-1β, IL-4, IL-10, IL-13, IL-33, macrophage colony-stimulating factor (M-CSF), or transforming growth factor (TGF) beta. M2a, M2b, and M2c macrophages are activated by IL-4 and IL-13, immunes complexes associated with TLRs or glucocorticoids, IL-10 and TGF-β, respectively. According to the way of stimulation, macrophages express several different markers and secrete different mediators. For the validation of M2 macrophages, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), flow cytometry (FC) are usually carried out to analyze surface markers and cytokines expression upon request. Our assay also offers a wide range of valuable candidates to assess the potential of drugs to disrupt the M2 polarization-induced signaling.

Scientists at Creative Biolabs are experts in M2 macrophage polarization assay and are pleased to assist our clients based on their requirements. For more information on M2 macrophage polarization assay, please feel free to contact us and further discuss with our scientists.

References

1. Cutolo, Maurizio, et al. "The role of M1/M2 macrophage polarization in rheumatoid arthritis synovitis." Frontiers in Immunology 13 (2022): 867260.
2. Under Open Access license CC BY 4.0, without modification.