CK2α-mediated dual signaling drives P-glycoprotein-dependent tuberculosis drug resistance in macrophages

Background P-glycoprotein (P-gp/MDR1) overexpression in macrophages contributes to tuberculosis (TB) treatment failure by reducing intracellular drug accumulation. The molecular mechanisms by which host macrophages upregulate P-gp remain poorly defined. The present study investigated whether CK2α functions as an upstream kinase regulating P-gp expression in macrophages and examined its therapeutic relevance in TB. Methods P-gp regulation was characterized in PMA-differentiated THP-1 macrophages by immunoblotting, RT-PCR, qRT-PCR, immunofluorescence, co-immunoprecipitation, and subcellular fractionation, and in U-937 macrophages by immunoblotting. Signaling pathways were dissected using pharmacological inhibitors, siRNA knockdown, and overexpression. P-gp efflux function was assessed by rhodamine-123 accumulation assay. Flow cytometry was used to evaluate CK2α-dependent P-gp regulation in PBMC-derived primary macrophages. P-gp expression and TB pathology were examined in Mycobacterium tuberculosis H37Rv-infected BALB/c mice. Results During monocyte-to-macrophage differentiation, CK2α activated AKT at Ser129, leading to NF-κB-dependent P-gp induction. In mature macrophages, rifampin induced P-gp through CK2α-mediated Hsp90β phosphorylation and subsequent PXR stabilization. CK2 inhibition or CSNK2A1 knockdown suppressed P-gp expression through both pathways and increased intracellular rhodamine-123 accumulation. In Mtb -infected mice, co-administration of the CK2 inhibitor DRB with rifampin suppressed lung P-gp expression, reduced pulmonary bacterial burden compared to rifampin monotherapy, and attenuated lung inflammation. PBMC-derived primary macrophages showed the same CK2α-dependent dual pathway regulation. Conclusions The present study identifies CK2α as a common upstream kinase for both NF-κB- and PXR-dependent P-gp induction in macrophages. CK2 inhibitors, for which clinical safety data are available from oncology trials, may warrant evaluation as adjunctive agents against P-gp-mediated drug resistance in TB treatment.