Ruxolitinib Modulates P-Glycoprotein Function, Delays T Cell Activation, and Impairs CCL19 Chemokine-Directed...

Area of Science:

• Immunology
• Pharmacology
• Cell Biology

Background:

• Cytotoxic T lymphocytes (CTLs) play a crucial role in immune responses.
• P-glycoprotein (Pgp/ABCB1) is implicated in CTL function, but its regulation is not fully understood.
• Ruxolitinib is a JAK1/2 inhibitor used for hematologic malignancies and inflammatory conditions.

Purpose of the Study:

• To investigate the effect of ruxolitinib on Pgp expression and function in human CD8+ T cells.
• To determine how ruxolitinib influences T cell activation, differentiation, and migration.

Main Methods:

• Assessed Pgp mRNA and protein levels in activated human CD8+ T cells.
• Measured calcein accumulation and ATPase activity in Pgp-expressing cells and CTLs.
• Analyzed surface marker expression (Pgp, CD8, PD-1) and T cell transmigration.
• Utilized varying concentrations of ruxolitinib, including therapeutic levels (1-3 μM).

Main Results:

• CD8+ T cells express Pgp dynamically during activation.
• Ruxolitinib modulated Pgp function and ATPase activity in a concentration-dependent manner.
• Therapeutic ruxolitinib concentrations inhibited Pgp, CD8, and PD-1 upregulation during T cell activation.
• Ruxolitinib impaired CTL transmigration, suggesting disruption of lymphoid homing.

Conclusions:

• Ruxolitinib modulates Pgp at both transcriptional and functional levels in CTLs.
• Clinically relevant ruxolitinib concentrations alter T cell activation and migration.
• JAK inhibitor-mediated immunomodulation requires careful consideration for various T cell-based therapies.