Immunomodulatory Drugs (IMiDs) Increase the Production of IL-2 from Stimulated T Cells by Increasing PKC-θ Activation and Enhancing the DNA-Binding Activity of AP-1 but Not NF-κB, OCT-1, or NF-AT

Abstract

Immunomodulatory drugs (IMiDs) are orally available small molecules that potently inhibit tumor necrosis factor-alpha (TNF-alpha) production by lipopolysaccharide (LPS)-stimulated human peripheral blood mononuclear cells (HuPBMCs) but enhance secretion of such cytokines as interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) by stimulated T cells. The mechanism of cytokine regulation by IMiDs has not yet been determined. In the present study, we investigated the effects of one of the IMiDs, CC-4047 (Actimid, Celgene, Warren, NJ), on synthesis of IL-2 protein and mRNA and on the activity and expression of transcription factors. Treatment with CC-4047 enhances the secretion of IL-2 protein and the expression of IL-2 mRNA in a dose-dependent and time-dependent manner. In T cells stimulated with phorbol myristate acetate (PMA)/ionomycin, CC-4047 enhanced the DNA-binding activity of activated protein-1 (AP-1) but not NF-kappaB, Octomer-1 (OCT-1), or NFAT by 2-fold and 4-fold after an incubation time of 1 and 3 h, respectively. Luciferase reporter assays in Jurkat cells showed similar effects on transcription factor activity. Using in vitro kinase activity assays, we also showed that CC-4047 enhances the activity of protein kinase C-theta (PKC-theta) in stimulated T cells. The secreted IL-2 from HuPBMCs was shown to activate natural killer (NK) cells to lyse their target cell line K562. Taken together, our results demonstrate that the IMiDs exert their effects at least in part by activating PKC-theta and acting on AP-1 DNA-binding activity in T cells, resulting in augmented IL-2 synthesis and activation of IL- 2-dependent downstream effectors, such as NK cells.

RNA interference screening identifies lenalidomide sensitizers in multiple myeloma, including RSK2

“…on May 12, 2018. by guest www.bloodjournal.org From Consistent with previous studies, 5,17 we demonstrated that lenalidomide increases IL-2 production in PMA/ionomycin-stimulated Jurkat T cells simultaneously, with substantial downregulation of IKZF1. RSK2 inhibition did not downregulate IKZF1, but it was able to abolish lenalidomide-enhanced production of IL-2 in Jurkat T cells (Figure 5A-B).…”

Immunomodulatory drugs reorganize cytoskeleton by modulating Rho GTPases

“…2,14 Both lenalidomide and pomalidomide have been demonstrated to increase IL-2 and IFN-␥ production in activated T cells, to activate NK cells, and enhance antibody-dependent cellular cytotoxicity (ADCC). 15 Recently, Ramsay et al have shown that lenalidomide enhanced formation of the immunologic synapse between autologous T cells and CLL cells. 16 To study the molecular mechanism of action of this class of drugs, we have focused on the proximal and immediate molecular events that follow exposure of cells to IMiDs drugs in the absence of any costimulation.…”

“…25,26 IMiDs class of drugs have been shown to activate T cells and to stimulate T-cell cytotoxic activity through CD28 pathway and by inducing cytokines such as IL-2. 14,15,27,28 The induction of IL-2 by IMiDs drugs was demonstrated in T cells coactivated by either CD3 ligation or treatment with phorbol myristate acetate (PMA). 17,29 To test the involvement of Rho GTPases in IMiDs drugs-induced IL-2 expression in activated T cells, we treated primary CD4 ϩ T cells activated by anti-CD3 with pomalidomide or lenalidomide in the presence or absence of specific ROCK1 and Rac1 inhibitors and then followed IL-2 protein expression by ELISA.…”

Thalidomide and its analogues: A review of the potential for immunomodulation of fibrosis diseases and opthalmopathy (Review)

“…Furthermore, tyrosine phosphorylation of CD28 induced by lenalidomide was able to facilitate the recruitment and activation of upstream molecules in multiple intracellular signaling pathways, including phosphatidylinositol-3-kinase (PI3K) and NF-κB (33). As CD28 and IMiDs have no kinase activity, other signaling proteins such as protein kinase C (PKC) may be involved in the indirect mechanism underlying CD28 phosphorylation (34,35). Payvandi et al (35) demonstrated that IMiDs increased IL-2 production in stimulated T cells via enhancing PKC-θ activation and DNA-binding activity of activated protein-1 (AP-1).…”

“…As CD28 and IMiDs have no kinase activity, other signaling proteins such as protein kinase C (PKC) may be involved in the indirect mechanism underlying CD28 phosphorylation (34,35). Payvandi et al (35) demonstrated that IMiDs increased IL-2 production in stimulated T cells via enhancing PKC-θ activation and DNA-binding activity of activated protein-1 (AP-1). In addition to conventional T cells, regulatory T cells (Tregs) are a group of immunosuppressive T cells that function in self-tolerance and the immune response (36).…”