Bruton's Tyrosine Kinase-Going Beyond the B Cell.

Area of Science:

• Immunology
• Cell Biology
• Pharmacology

Background:

• Bruton's Tyrosine Kinase (BTK) is crucial for B cell signaling and increasingly recognized for its role in myeloid cell regulation.
• BTK influences key pathways in monocytes, macrophages, microglia, and granulocytes, affecting phagocytosis, inflammation, and metabolism.
• While BTK inhibitors (BTKis) are approved for B cell cancers, their efficacy extends to autoimmune and neuroinflammatory disorders.

Purpose of the Study:

• To review and compare how BTK inhibition affects inflammatory phenotypes and functions across different myeloid-derived cell subsets.
• To provide cell-specific insights into BTK's role as a regulator of innate immunity.
• To explore the translational potential of BTKis in various inflammatory diseases.

Main Methods:

• Literature review and synthesis of existing research on BTK function in myeloid cells.
• Comparative analysis of BTK inhibition effects across distinct myeloid cell types.
• Examination of molecular pathways modulated by BTK in innate immune cells.

Main Results:

• BTK plays a significant role in regulating inflammatory responses and functions within diverse myeloid cell populations.
• BTK inhibition alters phenotypes related to phagocytosis, inflammatory signaling (NFκB, STAT3, NLRP3), and cell metabolism in myeloid cells.
• Evidence supports the therapeutic potential of BTKis in conditions like rheumatoid arthritis, IgA nephropathy, multiple sclerosis, and chronic spontaneous urticaria.

Conclusions:

• BTK is a central regulator of innate immunity and myeloid cell function, with cell-specific regulatory roles.
• Understanding cell-specific effects of BTK inhibition is key to expanding its therapeutic applications.
• BTK inhibitors hold significant translational promise for a wide range of immune-mediated and inflammatory diseases.