Protein Kinase C Inhibitor Generates Stable Human Tolerogenic Dendritic Cells

Abstract

Tolerogenic dendritic cells (DCs) are a promising tool for a specific form of cellular therapy whereby immunological tolerance can be induced in the context of transplantation and autoimmunity. From libraries of bioactive lipids, nuclear receptor ligands, and kinase inhibitors, we screened conventional protein kinase C inhibitors (PKCIs) bisindolylmaleimide I, Gö6983, and Ro32-0432 with strong tolerogenic potential. PKCI-treated human DCs were generated by subjecting them to a maturation process after differentiation of immature DCs. The PKCI-treated DCs had a semimature phenotype, showing high production of IL-10, and efficiently induced IL-10–producing T cells and functional Foxp3+ regulatory T cells from naive CD4+ T cells, thus eliciting a strong immunosuppressive function. They also showed CCR7 expression and sufficient capacity for migration toward CCR7 ligands. Additionally, PKCI-treated DCs were highly stable when exposed to inflammatory stimuli such as proinflammatory cytokines or LPS. Conventional PKCIs inhibited NF-κB activation of both the canonical and noncanonical pathways of DC maturation, thus suppressing the expression of costimulatory molecules and IL-12 production. High production of IL-10 in PKCI-treated DCs was due to not only an increase of intracellular cAMP, but also a synergistic effect of increased cAMP and NF-κB inhibition. Moreover, PKCI-treated mouse DCs that had properties similar to PKCI-treated human DCs prevented graft-versus-host disease in a murine model of acute graft-versus-host disease. Conventional PKCI-treated DCs may be useful for tolerance-inducing therapy, as they satisfy the required functional characteristics for clinical-grade tolerogenic DCs.

Tolerogenic Dendritic Cells Induced by BD750 Ameliorate Proinflammatory T cell Responses and Experimental Autoimmune Encephalitis in Mice

“…Induction of tolDC has been experimentally achieved by suppressive agents, including IL-10 and TGF-β; immunomodulatory drugs, such as dexamethasone and vitamin D; and genetic modification (14). Our previous study identified that a benzothiazole derivative, BD750 [2-(2-benzothiazoleyl)-4,5,6,7-tetrahydro-2H-indazol-3-ol, C 14 H 13 N 3 OS, MW: 271.3], is an inhibitor of JAK3/STAT5 signaling and can inhibit T cell proliferation (15).…”

Small-molecule screening identifies inhibition of salt-inducible kinases as a therapeutic strategy to enhance immunoregulatory functions of dendritic cells

“…For instance, disruption of signaling pathways linking microbial recognition receptors to NF-κB activation with small-molecule inhibitors of protein kinase C (PKC) or glycogen synthase kinase-3β (GSK-3β) up-regulates IL-10 production by lipopolysaccharide (LPS)-stimulated MΦs (17,18). Conversely, CREB activation by EP2/EP4 prostanoid receptor agonists like prostaglandin E 2 (PGE 2 ) promotes IL-10 production by myeloid cells (19).…”

Cholinergic Actions of Autoantibodies from Breast Cancer Patients on Dendritic Cells

“…It must be taken into account that it is usually accepted that iDC, after antigen-"danger signal" become into mDC. However, recently it has been reported that after the stimulation with, some drugs, microorganisms, or the tumor microenvironment, iDC differentiation and/or mDC formation could be altered [25][26][27]. The analysis of tumor infiltrating DC in murine melanoma revealed the presence of myeloid and plasmacytoid DC populations, most of these DC appeared immature, but about a third expressed a mature phenotype [28].…”