BTK drives neutrophil activation for sterilizing antifungal immunity
Jigar V. Desai, … , Tobias M. Hohl, Michail S. Lionakis
Jigar V. Desai, … , Tobias M. Hohl, Michail S. Lionakis
Published May 2, 2024
Citation Information: J Clin Invest. 2024;134(12):e176142. https://doi.org/10.1172/JCI176142.
View: Text | PDF
Research Article Immunology Infectious disease

BTK drives neutrophil activation for sterilizing antifungal immunity

Abstract

We describe a previously unappreciated role for Bruton’s tyrosine kinase (BTK) in fungal immune surveillance against aspergillosis, an unforeseen complication of BTK inhibitors (BTKi) used for treating B cell lymphoid malignancies. We studied BTK-dependent fungal responses in neutrophils from diverse populations, including healthy donors, patients who were treated with BTKi, and X-linked agammaglobulinemia patients. Upon fungal exposure, BTK was activated in human neutrophils in a TLR2-, Dectin-1-, and FcγR-dependent manner, triggering the oxidative burst. BTK inhibition selectively impeded neutrophil-mediated damage to Aspergillus hyphae, primary granule release, and the fungus-induced oxidative burst by abrogating NADPH oxidase subunit p40phox and GTPase RAC2 activation. Moreover, neutrophil-specific Btk deletion in mice enhanced aspergillosis susceptibility by impairing neutrophil function, not recruitment or lifespan. Conversely, GM-CSF partially mitigated these deficits by enhancing p47phox activation. Our findings underline the crucial role of BTK signaling in neutrophils for antifungal immunity and provide a rationale for GM-CSF use to offset these deficits in patients who are susceptible.

Authors

Jigar V. Desai, Marissa A. Zarakas, Andrew L. Wishart, Mark Roschewski, Mariano A. Aufiero, Agnes Donkò, Gustaf Wigerblad, Neta Shlezinger, Markus Plate, Matthew R. James, Jean K. Lim, Gulbu Uzel, Jenna R.E. Bergerson, Ivan Fuss, Robert A. Cramer, Luis M. Franco, Emily S. Clark, Wasif N. Khan, Daisuke Yamanaka, Georgios Chamilos, Jamel El-Benna, Mariana J. Kaplan, Louis M. Staudt, Thomas L. Leto, Steven M. Holland, Wyndham H. Wilson, Tobias M. Hohl, Michail S. Lionakis

×

Figure 6

BTK acts downstream of TLR2, FcγR, and Dectin-1 engagement to promote the neutrophil oxidative burst.

Options: View larger image (or click on image) Download as PowerPoint
BTK acts downstream of TLR2, FcγR, and Dectin-1 engagement to promote th...
(A–C) Representative FACS histograms (upper panels) and mean fluorescence intensity (MFI) summary data (lower panels) for phosphorylated BTK (at Y223) in healthy donor neutrophils at baseline and at the indicated timepoints after stimulation with the TLR2 agonist Pam3CSK4 (A), FcγR-engaging immobilized immune complexes (iIC) (B) or Dectin-1-engaging β-glucan particles (OXCA) (C) (n = 5). (D and E) Luminol-based assay of reactive oxygen species (ROS) production in human neutrophils. Representative temporal traces of chemiluminescence (left panels) and AUC for luminol-amplified chemiluminescence relative light units (RLU) (right panels) when vehicle or ibrutinib-treated (D) or acalabrutinib-treated (E) healthy donor neutrophils were stimulated as indicated (n = 4–6). (F) AUC of luminol-amplified chemiluminescence RLU in neutrophils isolated from ibrutinib- or acalabrutinib- treated lymphoma patients, before and at day 3 after treatment initiation and stimulated as indicated (n = 12). Each dot represents an individual healthy donor or patient. Quantitative data are means ± SEM (A–C). Ibrutinib concentration, 250 nM. BTKi, BTK inhibitor; Pam3CSK4: Pam3CysSerLys4; iIC: immobilized immune complexes; OXCA: β-glucan particles (NaCLO-oxidized Candida albicans). *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001 using repeated measures 1-way ANOVA with Šidák’s multiple comparisons test (A–C), or 2-sided paired t test (D–F) or 2-sided Wilcoxon test (F).