Ibrutinib enhances IL-17 response by modulating the function of bone marrow derived dendritic cells

Abstract

Ibrutinib (PCI-32765) is an irreversible dual Btk/Itk inhibitor shown to be effective in treating several B cell malignancies. However, limited studies have been conducted to study the effect of this drug on myeloid cell function. Hence, we studied the effect of ibrutinib treatment on TLR-4 mediated activation of bone marrow derived dendritic cell culture (DCs). Upon ibrutinib treatment, LPS-treated DCs displayed lower synthesis of TNF-a and nitric oxide (NO) and higher induction of IL-6, TGF-b, IL-10 and IL-18. While ibrutinib dampened MHC-II and CD86 expression on DCs, CD80 expression was upregulated. Further, ibrutinib-treated DCs promoted T cell proliferation and enhanced IL-17 production upon co-culture with nylon wool enriched T cells. Taken together, our results indicate that ibrutinib modulates TLR-4 mediated DC activation to promote an IL-17 response. We describe a novel mode of action for ibrutinib on DCs which should be explored to treat other forms of cancer besides B cell malignancies.

Ibrutinib treatment improves T cell number and function in CLL patients

“…However, we found a moderate increase in the frequency of T cells capable of producing IL-17 (Th17 cells). Ibrutinib has also been recently found to enhance IL-17 responses indirectly by modulating the function of antigen-presenting cells such as dendritic cells (47). In vivo, Th17 cells have been found to undergo FAS-mediated AICD (48), a process that could also be blocked by ITK inhibition.…”

A Tec kinase BTK inhibitor ibrutinib promotes maturation and activation of dendritic cells

“…Bone marrow-derived DCs from C57BL/6 mice were cultivated as described previously with some modifications. 3 Briefly, bone marrow cells were isolated from femurs and tibias of mice, treated with ACK lysis buffer and plated in complete RPMI medium supplemented with 10% fetal bovine serum (Atlanta Biologicals), 1% penicillin (20 Units/mL)/streptomycin (20 μg/mL) (Life Technologies) and 20 ng/mL GM-CSF (Peprotech) for 7 d. At Day 1, 1 μM ibrutinib (Pharmacyclics Inc.) or PBS was added to the culture and remained in the supernatant until the end of the culture period to generate ibrutinib-treated and untreated DCs, respectively. At Day 7, ibrutinib-treated and untreated DCs were collected by gently harvesting the cells in the floating fraction of the culture medium to obtain > 60% purity of CD11c + DCs, which was then analyzed for expression of surface markers by flow cytometry.…”

“…T cell and B cell fractions were prepared from OT-II mice which was described previously. 3,5 Briefly, single cell suspensions prepared from the spleens from OT-II mice in complete RPMI medium were treated with ACK Lysis buffer and incubated in pre-equilibrated nylon wool columns for 1 h. After incubation, cells were eluted from the column to get the T cell enriched fraction with >90% CD3 + T cells. The column was plunged with media to recover the B cell enriched fraction with >65% cells B220 + B cells and approximately 25% CD3 + T cells.…”

“…In addition to its role in killing malignant B cells, ibrutinib modulates the recruitment and cytokine responses of myeloid cells in immune complex disease models. 2 Since ibrutinib has been shown to differentially regulate cytokine production and surface marker expression in murine DCs, 3 we were interested in further exploring how ibrutinib modulates DC function. A study on DCs from BTK −/− mice suggests that BTK participates in the in vitro development of DCs, modulates LPS-induced cytokine and surface marker expression in DCs and alters the ability of BTK −/− DCs to activate CD4 + T cell responses.…”

Emerging role of BCR signaling inhibitors in immunomodulation of chronic lymphocytic leukemia

“…Ibrutinib-treated DCs also promoted T-cell proliferation and enhanced IL-17 cytokine production in coculture via TLR4-modulated activation. 89 In addition, in a report from Stiff et al on the effects of ibrutinib treatment on MDSCs, which express BTK, ibrutinib inhibited BTK phosphorylation. 90 Together with reduced cell migration and inhibition of in vitro MDSC generation, ibrutinib treatment also reduced MDSCs in spleen and EMT6 murine mammary tumors.…”