The Btk inhibitor ibrutinib impairs the innate immune response against Mycobacterium tuberculosis mediated by macrophages and γδ T cells

COLADO A; GENOULA M; KVIATCOVSKY D; PODAZA E; RISNIK D; ELÍAS E; MARÍN FRANCO JL; COUGOULE C; MARIDONNEAU-PARINI I; JANCIC C; GIORNADO, M; SASIAIN MC; GAMBERALE R; BALBOA L; BORGE, M

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

The Bruton?s Tyrosine Kinase (Btk) inhibitor, ibrutinib, has been recently approved for the treatment of Chronic Lymphocytic Leukemia (CLL) patients. We have previously found that ibrutinib affected macrophage polarization and TNF-α secretion in response to M. tuberculosis (Mtb). Considering that ibrutinib is now being introduced in countries with high incidence rates of tuberculosis (TB), such as Argentina, we aimed to extend the study on the effect of ibrutinib on the immune response to Mtb mediated by macrophages and γδ T cells.Macrophages were differentiated by culturing monocytes with M-CSF for 7 days. TNFα, IL-8 and IL-10 secretion were measured by ELISA after macrophage stimulation with irradiated Mtb, Pam3CK or LPS for 24h. Phospho-p65 of NFkB was evaluated by Western blot. Phagocytosis of Mtb-FITC by macrophages was evaluated by flow cytometry. Bacillary loads were determined by colony-forming units assay. γδ T cells were purified by using MACS and after 24h of Mtb stimulation, IFN-γ was evaluated by ELISA and CD69 expression by flow cytometry. Statistical significance was determined using the non-parametric Friedman test followed by the Dunn?s post-test.We found that ibrutinib significantly reduced TNF-α, IL-10 and IL-8 secretion (n=10, p˂0.05) and diminished phospho-p65 (n=5, p˂0.05) in response to irradiated Mtb. Moreover, ibrutinib impaired TNF-α secretion by macrophages in response to LPS and Pam3CK (n=10, p˂0.05). Then, we found that ibrutinib significantly enhanced Mtb phagocytosis (n=14, p˂0.05) and preliminary results showed a slight increase in the bacillary loads obtained from ibrutinib-treated macrophages. CD69 upregulation and IFN-γ secretion was also impaired in γδ T cells in response to Mtb (n=8, p˂0.05).Our results suggest that the innate-immune response to Mtb might be compromised in ibrutinib-treated patients. Thus, increased awareness should be taken during ibrutinib treatment especially from countries with high incidence rates of TB.