Novel mouse model resistant to irreversible BTK inhibitors: a tool identifying new therapeutic targets and side...

Area of Science:

• Immunology
• Pharmacology
• Genetics

Background:

• Bruton tyrosine kinase (BTK) inhibitors have transformed B-lymphocyte malignancy and autoimmune disease treatments.
• Most BTK inhibitors bind irreversibly to cysteine 481 (C481) in the BTK catalytic domain.
• Acquired resistance to BTK inhibitors often arises from the C481S mutation.

Purpose of the Study:

• To generate and characterize a novel C481S knock-in mouse model.
• To investigate the impact of the C481S mutation on B-lymphocyte function and drug sensitivity.
• To explore BTK-independent effects of irreversible BTK inhibitors on T-lymphocytes.

Main Methods:

• Generation of a C481S knock-in mouse model.
• Phenotypic analysis of B lymphocytes.
• Assessment of sensitivity to reversible and irreversible BTK inhibitors.
• Evaluation of T-lymphocyte activation in response to irreversible inhibitors.

Main Results:

• The C481S knock-in mice exhibited no overt B-lymphocyte abnormalities.
• B lymphocytes from C481S mice were resistant to irreversible BTK inhibitors but sensitive to reversible ones.
• Irreversible BTK inhibitors impaired T-lymphocyte activation independently of BTK, mirroring effects in patients.

Conclusions:

• The C481S knock-in mouse is a valuable tool for studying BTK-independent effects of irreversible inhibitors.
• This model facilitates the identification of novel therapeutic targets and potential side effects associated with BTK inhibitors.
• T-lymphocyte impairment by irreversible inhibitors occurs through BTK-independent mechanisms.