Macrophages are tissue-resident professional phagocytes and antigen-presenting cells, which differentiate from circulating peripheral blood monocytes. Macrophages can be characterized as being activated into two major phenotypes, classically activated M1 macrophages and alternatively activated M2 macrophages. M1 macrophages comprise immune effector cells with an acute inflammatory phenotype. These are highly aggressive against bacteria, including secretion of pro-inflammatory cytokines, engulfment of foreign entities, generation of reactive oxygen and nitrogen species, and assistance in T-helper type1 (Th1) cell responses to fight infection.

Creative Biolabs offers highly customized assays to induce M1 macrophages and characterize their polarization states.

M1 Macrophage Polarization

M1 macrophage polarization is the process by which macrophages differentiate into a pro-inflammatory phenotype in response to specific stimuli (e.g., lipopolysaccharide (LPS), tumor necrosis factor–α (TNF-α), interferon-gamma (IFN-γ), etc.).

Fig. 1 M1 macrophage polarization pathways.^1,3

Its core features include:

• Secretion of pro-inflammatory factors: e.g., IL-1β, IL-6, IL-12, IL-23, TNF-α, etc., which activate the Th1-type immune response and enhance inflammation.
• Generation of reactive oxygen/nitrogen species: Generates reactive oxygen intermediates (ROIs) and reactive nitrogen intermediates (RNIs) via inducible nitric oxide synthase (iNOS) to directly kill pathogens.
• Surface markers: High expression of CD80, CD86, TLR2/4, MHC-II and iNOS to enhance antigen presentations.
• Functional duality: Short-term activation clears pathogens and suppresses tumors, but long-term activation leads to tissue damage such as chronic inflammation and fibrosis.

Key factors that have been identified to trigger M1 polarization include:

• Pathogen-associated molecules: Bacterial LPS, viral RNA/DNA activate NF-κB via TLR.
• Th1-type cytokines: IFN-γ (core-inducing factor), TNF-α, GM-CSF.
• Metabolites: Succinate stabilizes HIF-1α and enhances glycolysis by inhibiting proline hydroxylase.
• Pathological microenvironment: A hypoxic, high-glycemic environment (e.g., diabetes mellitus) activates NF-κB via ROS and promotes M1 polarization.

M1 Macrophage Polarization Assay at Creative Biolabs

Based on surface markers and the distinctly produced cytokines, Creative Biolabs provides the validation of each polarized macrophage. Enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), and flow cytometry (FC) could be conducted to analyze surface markers and cytokine expression upon request. Our polarization protocols are designed to achieve a stable, optimal, and effective regimen for in vitro induction to drive antigen-specific immune responses. Our M1 macrophage polarization assay allows the assessment of cytokine profiles, cell surface receptor expression, scavenging functions, and the ability to activate or suppress T-cell proliferation.

Table 1 Service process of M1 macrophage polarization assay

This service provides full chain support from basic polarization detection to mechanism deep-dive through the combination strategy of standardized process + flexible customization. It is suitable for academic research, pharmaceutical R&D and biotech companies' novel immunotherapy development needs.

• Can be used to test the promotion of TAM repolarization to M1 by PD-1 inhibitors.
• Can be used as a drug screening platform.

Related Products

Through our M1 macrophage polarization assay service, researchers can obtain critical data on macrophage activation status, which is essential for developing novel therapeutic strategies and drug screening.

In addition to assay services, we have also launched a series of related products to further support scientific research. For example, our monocyte, macrophage and cytokine assay kits can effectively facilitate the culture and activation of M1 macrophages. These products not only enhance the convenience of experiments, but also provide researchers with more flexibility.

Below are some of our popular products. You can click to view the details.

Service Features

High Purity Polarization

We use high efficiency sorting technology to guarantee the rate of live cells and avoid the interference of dead cells and use a high efficiency induction kit to obtain >90% M1 cells.

Multimodal Detection Platform

We integrate flow cytometry, mass spectrometry, and live cell imaging to dynamically analyze the polarization process in space and time.

Disease Model Integration

We can perform tumor microenvironment simulations such as 3D co-culture, hypoxia treatment and construct metabolic perturbation models for disease-related M1 polarization studies.

Publications

Zhen-Shun Gan et al. investigated the cross-regulatory interactions between M1 macrophage polarization and iron metabolism. They evaluated the effect of iron on M1 macrophage polarization. They found that iron significantly reduced the mRNA levels of IL-6, IL-1β, TNF-α, and iNOS produced by IFN-γ-polarized M1 macrophages. Immunofluorescence analysis showed that iron also decreased iNOS production. However, iron did not impair the ability of M1-polarized macrophages to phagocytose FITC-dextran, but rather enhanced it.

Fig. 2 Effect of iron on STAT1 activation in M1 macrophages.^2,3

Overall, these findings suggest that iron decreases the polarization of M1 macrophages and inhibits the production of proinflammatory cytokines.

Scientific Resources

Learn More Macrophage Biology

Download Macrophage Polarization

Learn More Different Approaches to Regulating Polarization of Tumor-Associated Macrophages

Learn More Isolation and Identification of Macrophages

Q & A

Q: Can your M1 macrophage polarization assay service be used to evaluate potential therapeutic candidates?

A: Absolutely. Our M1 macrophage polarization assay is well suited for evaluating potential therapeutic candidates, especially compounds that are designed to modulate macrophage function. Through this integrated approach, our services can provide valuable insights for drug development, helping researchers screen and optimize therapeutic candidates that modulate macrophage function.

Q: Is there flexibility in the stimulation protocol for M1 polarization induction?

A: Yes. We offer a dual strategy of basic protocols and customized optimization.

Q: What is the typical reporting cycle for test results?

A: The reporting lead time for test results usually depends on several factors, including the number of samples, the complexity of the experiment, and the need for data analysis. Whenever you need us, feel free to contact us for progress updates. We are committed to providing you with timely service.

Q: What types of research projects is this service applicable to?

A: Our M1 macrophage polarization assay service is suitable for many types of research projects, including but not limited to:

• Explore the fundamental role of macrophage polarization in immune responses and inflammatory processes.
• Study the role and mechanism of M1 polarization in models of tumors, infections, autoimmune diseases and metabolic diseases.
• Evaluate the effects of new drugs or therapeutic regimens on macrophage polarization to identify potential immunotherapeutic targets.
• Investigate the role of vaccines in regulating macrophage polarization to inform vaccine design.
• Explore the role of different microorganisms in regulating macrophage polarization.

We welcome clients from all types of research backgrounds to speak with our team of experts to ensure the service meets your specific research needs.

References

1. Martins, Rubens Andrade, et al. "Regenerative Inflammation: The Mechanism Explained from the Perspective of Buffy-Coat Protagonism and Macrophage Polarization." International Journal of Molecular Sciences 25.20 (2024): 11329. https://doi.org/10.3390/ijms252011329
2. Gan, Zhen-Shun, et al. "Iron reduces M1 macrophage polarization in RAW264. 7 macrophages associated with inhibition of STAT1." Mediators of inflammation 2017.1 (2017): 8570818. https://doi.org/10.1155/2017/8570818
3. Under Open Access license CC BY 4.0, without modification.